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Ragonese IG, Sarkar MR, Hall RJ, Altizer S. Extreme heat reduces host and parasite performance in a butterfly-parasite interaction. Proc Biol Sci 2024; 291:20232305. [PMID: 38228180 DOI: 10.1098/rspb.2023.2305] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2023] [Accepted: 12/12/2023] [Indexed: 01/18/2024] Open
Abstract
Environmental temperature fundamentally shapes insect physiology, fitness and interactions with parasites. Differential climate warming effects on host versus parasite biology could exacerbate or inhibit parasite transmission, with far-reaching implications for pollination services, biocontrol and human health. Here, we experimentally test how controlled temperatures influence multiple components of host and parasite fitness in monarch butterflies (Danaus plexippus) and their protozoan parasites Ophryocystis elektroscirrha. Using five constant-temperature treatments spanning 18-34°C, we measured monarch development, survival, size, immune function and parasite infection status and intensity. Monarch size and survival declined sharply at the hottest temperature (34°C), as did infection probability, suggesting that extreme heat decreases both host and parasite performance. The lack of infection at 34°C was not due to greater host immunity or faster host development but could instead reflect the thermal limits of parasite invasion and within-host replication. In the context of ongoing climate change, temperature increases above current thermal maxima could reduce the fitness of both monarchs and their parasites, with lower infection rates potentially balancing negative impacts of extreme heat on future monarch abundance and distribution.
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Affiliation(s)
- Isabella G Ragonese
- Odum School of Ecology, College of Veterinary Medicine, University of Georgia, Athens, GA 30602, USA
- Center for the Ecology of Infectious Diseases, College of Veterinary Medicine, University of Georgia, Athens, GA 30602, USA
| | - Maya R Sarkar
- College of Biological Sciences, University of Minnesota, St Paul, MN 5455, USA
| | - Richard J Hall
- Odum School of Ecology, College of Veterinary Medicine, University of Georgia, Athens, GA 30602, USA
- Center for the Ecology of Infectious Diseases, College of Veterinary Medicine, University of Georgia, Athens, GA 30602, USA
- Department of Infectious Diseases, College of Veterinary Medicine, University of Georgia, Athens, GA 30602, USA
| | - Sonia Altizer
- Odum School of Ecology, College of Veterinary Medicine, University of Georgia, Athens, GA 30602, USA
- Center for the Ecology of Infectious Diseases, College of Veterinary Medicine, University of Georgia, Athens, GA 30602, USA
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2
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Sánchez CA, Penrose MT, Kessler MK, Becker DJ, McKeown A, Hannappel M, Boyd V, Camus MS, Padgett-Stewart T, Hunt BE, Graves AF, Peel AJ, Westcott DA, Rainwater TR, Chumchal MM, Cobb GP, Altizer S, Plowright RK, Boardman WSJ. Land use, season, and parasitism predict metal concentrations in Australian flying fox fur. Sci Total Environ 2022; 841:156699. [PMID: 35710009 DOI: 10.1016/j.scitotenv.2022.156699] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2022] [Revised: 05/19/2022] [Accepted: 06/10/2022] [Indexed: 06/15/2023]
Abstract
Urban-living wildlife can be exposed to metal contaminants dispersed into the environment through industrial, residential, and agricultural applications. Metal exposure carries lethal and sublethal consequences for animals; in particular, heavy metals (e.g. arsenic, lead, mercury) can damage organs and act as carcinogens. Many bat species reside and forage in human-modified habitats and could be exposed to contaminants in air, water, and food. We quantified metal concentrations in fur samples from three flying fox species (Pteropus fruit bats) captured at eight sites in eastern Australia. For subsets of bats, we assessed ectoparasite burden, haemoparasite infection, and viral infection, and performed white blood cell differential counts. We examined relationships among metal concentrations, environmental predictors (season, land use surrounding capture site), and individual predictors (species, sex, age, body condition, parasitism, neutrophil:lymphocyte ratio). As expected, bats captured at sites with greater human impact had higher metal loads. At one site with seasonal sampling, bats had higher metal concentrations in winter than in summer, possibly owing to changes in food availability and foraging. Relationships between ectoparasites and metal concentrations were mixed, suggesting multiple causal mechanisms. There was no association between overall metal load and neutrophil:lymphocyte ratio, but mercury concentrations were positively correlated with this ratio, which is associated with stress in other vertebrate taxa. Comparison of our findings to those of previous flying fox studies revealed potentially harmful levels of several metals; in particular, endangered spectacled flying foxes (P. conspicillatus) exhibited high concentrations of cadmium and lead. Because some bats harbor pathogens transmissible to humans and animals, future research should explore interactions between metal exposure, immunity, and infection to assess consequences for bat and human health.
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Affiliation(s)
- Cecilia A Sánchez
- Odum School of Ecology, University of Georgia, Athens, GA, USA; Center for the Ecology of Infectious Diseases, University of Georgia, Athens, GA, USA.
| | - Michael T Penrose
- Department of Environmental Science, Baylor University, Waco, TX, USA
| | | | - Daniel J Becker
- Department of Biology, University of Oklahoma, Norman, OK, USA
| | | | | | - Victoria Boyd
- Commonwealth Scientific and Industrial Research Organisation (CSIRO), Health and Biosecurity Business Unit, The Australian Centre for Disease Preparedness (ACDP), Geelong, VIC, Australia
| | - Melinda S Camus
- Department of Pathology, College of Veterinary Medicine, University of Georgia, Athens, GA, USA
| | - Ticha Padgett-Stewart
- Department of Microbiology and Cell Biology, Montana State University, Bozeman, MT, USA
| | - Brooklin E Hunt
- Department of Microbiology and Cell Biology, Montana State University, Bozeman, MT, USA
| | - Amelia F Graves
- Department of Microbiology and Cell Biology, Montana State University, Bozeman, MT, USA
| | - Alison J Peel
- Centre for Planetary Health and Food Security, Griffith University, Nathan, QLD, Australia
| | | | - Thomas R Rainwater
- Tom Yawkey Wildlife Center and Belle W. Baruch Institute of Coastal Ecology and Forest Science, Clemson University, Georgetown, SC, USA
| | | | - George P Cobb
- Department of Environmental Science, Baylor University, Waco, TX, USA
| | - Sonia Altizer
- Odum School of Ecology, University of Georgia, Athens, GA, USA; Center for the Ecology of Infectious Diseases, University of Georgia, Athens, GA, USA
| | - Raina K Plowright
- Department of Microbiology and Cell Biology, Montana State University, Bozeman, MT, USA
| | - Wayne S J Boardman
- School of Animal and Veterinary Sciences, University of Adelaide, SA, Australia
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3
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Majewska AA, Davis AK, Altizer S, de Roode JC. Parasite dynamics in North American monarchs predicted by host density and seasonal migratory culling. J Anim Ecol 2022; 91:780-793. [PMID: 35174493 DOI: 10.1111/1365-2656.13678] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2021] [Accepted: 01/31/2022] [Indexed: 11/30/2022]
Abstract
Insect-pathogen dynamics can show seasonal and inter-annual variation that covaries with fluctuations in insect abundance and climate. Long-term analyses are especially needed to track parasite dynamics in migratory insects, in part because their vast habitat ranges and high mobility might dampen local effects of density and climate on infection prevalence. Monarch butterflies (Danaus plexippus) are commonly infected with the protozoan Ophryocystis elektroscirrha (OE). Because this parasite lowers monarch survival and flight performance, and because migratory monarchs have experienced declines in recent decades, it is important to understand patterns and drivers of infection. 3. Here we compiled data on OE infection spanning 50 years, from wild monarchs sampled in the USA, Canada, and Mexico during summer breeding, fall migrating, and overwintering periods. We examined eastern versus western North American monarchs separately, to ask how abundance estimates, resource availability, climate, and breeding season length impact infection trends. We further assessed the intensity of migratory culling, which occurs when infected individuals are removed from the population during migration. 4. Average infection prevalence was four times higher in western compared to eastern subpopulations. In eastern North America, the proportion of infected monarchs increased three-fold since the mid-2000s. In the western region, the proportion of infected monarchs declined sharply from 2000-2015, and increased thereafter. For both eastern and western subpopulations, years with greater summer adult abundance predicted greater infection prevalence, indicating that transmission increases with host breeding density. Environmental variables (temperature and NDVI) were not associated with changes in infected adults. We found evidence for migratory culling of infected butterflies, based on declines in parasitism during fall migration. We estimated that tens of millions fewer monarchs reach overwintering sites in Mexico as a result of OE, highlighting the need to consider the parasite as a potential threat to the monarch population. 5. Increases in infection among eastern North American monarchs post-2002 suggest that changes to the host's ecology or environment have intensified parasite transmission. Further work is needed to examine the degree to which human practices, such as mass caterpillar rearing and the widespread planting of exotic milkweed, have contributed to this trend.
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Affiliation(s)
| | - Andrew K Davis
- Odum School of Ecology, University of Georgia, Athens, GA, USA
| | - Sonia Altizer
- Odum School of Ecology, University of Georgia, Athens, GA, USA
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Teitelbaum CS, Altizer S, Hall RJ. Habitat Specialization by Wildlife Reduces Pathogen Spread in Urbanizing Landscapes. Am Nat 2021; 199:238-251. [DOI: 10.1086/717655] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Affiliation(s)
- Claire S. Teitelbaum
- Odum School of Ecology and Center for the Ecology of Infectious Diseases, University of Georgia, Athens, Georgia 30602
| | - Sonia Altizer
- Odum School of Ecology and Center for the Ecology of Infectious Diseases, University of Georgia, Athens, Georgia 30602
| | - Richard J. Hall
- Odum School of Ecology and Center for the Ecology of Infectious Diseases, University of Georgia, Athens, Georgia 30602
- Department of Infectious Diseases, College of Veterinary Medicine, University of Georgia, Athens, Georgia 30602
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5
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Prouty C, Barriga P, Davis AK, Krischik V, Altizer S. Host Plant Species Mediates Impact of Neonicotinoid Exposure to Monarch Butterflies. Insects 2021; 12:insects12110999. [PMID: 34821799 PMCID: PMC8623494 DOI: 10.3390/insects12110999] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/12/2021] [Revised: 10/27/2021] [Accepted: 11/02/2021] [Indexed: 11/16/2022]
Abstract
Simple Summary Neonicotinoids are the most widely used insecticides in North America and many studies document the negative effects of neonicotinoids on bees. Monarch butterflies are famous for their long-distance migrations, and for their ability to sequester toxins from their milkweed host plants. The neonicotinoids imidacloprid and clothianidin were suggested to correlate with declines in North American monarchs. We examined how monarch development, survival, and flight were affected by exposure to neonicotinoids, and how these effects depend on milkweed host plant species that differ in their cardenolide toxins. Monarch survival and flight were unaffected by low and intermediate neonicotinoid doses. At the highest dose, neonicotinoids negatively affected monarch pupation and survival, for caterpillars that fed on the least toxic milkweed. Monarchs fed milkweed of intermediate toxicity experienced moderate negative effects of high insecticide doses. Monarchs fed the most toxic milkweed species had no negative consequences associated with neonicotinoid treatment. Our work shows that monarchs tolerate low neonicotinoid doses, but experience detrimental effects at higher doses, depending on milkweed species. To our knowledge, this is the first study to show that host plant species potentially reduce the residue of neonicotinoid insecticides on the leaf surface, and this phenomenon warrants further investigation. Abstract Neonicotinoids are the most widely used insecticides in North America. Numerous studies document the negative effects of neonicotinoids on bees, and it remains crucial to demonstrate if neonicotinoids affect other non-target insects, such as butterflies. Here we examine how two neonicotinoids (imidacloprid and clothianidin) affect the development, survival, and flight of monarch butterflies, and how these chemicals interact with the monarch’s milkweed host plant. We first fed caterpillars field-relevant low doses (0.075 and 0.225 ng/g) of neonicotinoids applied to milkweed leaves (Asclepias incarnata), and found no significant reductions in larval development rate, pre-adult survival, or adult flight performance. We next fed larvae higher neonicotinoid doses (4–70 ng/g) and reared them on milkweed species known to produce low, moderate, or high levels of secondary toxins (cardenolides). Monarchs exposed to the highest dose of clothianidin (51–70 ng/g) experienced pupal deformity, low survival to eclosion, smaller body size, and weaker adult grip strength. This effect was most evident for monarchs reared on the lowest cardenolide milkweed (A. incarnata), whereas monarchs reared on the high-cardenolide A. curassavica showed no significant reductions in any variable measured. Our results indicate that monarchs are tolerant to low doses of neonicotinoid, and that negative impacts of neonicotinoids depend on host plant type. Plant toxins may confer protective effects or leaf physical properties may affect chemical retention. Although neonicotinoid residues are ubiquitous on milkweeds in agricultural and ornamental settings, commonly encountered doses below 50 ng/g are unlikely to cause substantial declines in monarch survival or migratory performance.
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Affiliation(s)
- Cody Prouty
- Odum School of Ecology, University of Georgia, Athens, GA 30602, USA; (P.B.); (A.K.D.); (S.A.)
- Correspondence:
| | - Paola Barriga
- Odum School of Ecology, University of Georgia, Athens, GA 30602, USA; (P.B.); (A.K.D.); (S.A.)
| | - Andrew K. Davis
- Odum School of Ecology, University of Georgia, Athens, GA 30602, USA; (P.B.); (A.K.D.); (S.A.)
| | - Vera Krischik
- Department of Entomology, University of Minnesota, St. Paul, MN 55108, USA;
| | - Sonia Altizer
- Odum School of Ecology, University of Georgia, Athens, GA 30602, USA; (P.B.); (A.K.D.); (S.A.)
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Sánchez CA, Ragonese IG, de Roode JC, Altizer S. Thermal tolerance and environmental persistence of a protozoan parasite in monarch butterflies. J Invertebr Pathol 2021; 183:107544. [PMID: 33582107 DOI: 10.1016/j.jip.2021.107544] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2020] [Revised: 01/25/2021] [Accepted: 01/28/2021] [Indexed: 11/29/2022]
Abstract
Many parasites have external transmission stages that persist in the environment prior to infecting a new host. Understanding how long these stages can persist, and how abiotic conditions such as temperature affect parasite persistence, is important for predicting infection dynamics and parasite responses to future environmental change. In this study, we explored environmental persistence and thermal tolerance of a debilitating protozoan parasite that infects monarch butterflies. Parasite transmission occurs when dormant spores, shed by adult butterflies onto host plants and other surfaces, are later consumed by caterpillars. We exposed parasite spores to a gradient of ecologically-relevant temperatures for 2, 35, or 93 weeks. We tested spore viability by feeding controlled spore doses to susceptible monarch larvae, and examined relationships between temperature, time, and resulting infection metrics. We also examined whether distinct parasite genotypes derived from replicate migratory and resident monarch populations differed in their thermal tolerance. Finally, we examined evidence for a trade-off between short-term within-host replication and long-term persistence ability. Parasite viability decreased in response to warmer temperatures over moderate-to-long time scales. Individual parasite genotypes showed high heterogeneity in viability, but differences did not cluster by migratory vs. resident monarch populations. We found no support for a negative relationship between environmental persistence and within-host replication, as might be expected if parasites invest in short-term reproduction at the cost of longer-term survival. Findings here indicate that dormant spores can survive for many months under cooler conditions, and that heat dramatically shortens the window of transmission for this widespread and virulent butterfly parasite.
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Affiliation(s)
- Cecilia A Sánchez
- Odum School of Ecology, University of Georgia, Athens, GA, USA; Center for the Ecology of Infectious Diseases, University of Georgia, Athens, GA, USA.
| | - Isabella G Ragonese
- Odum School of Ecology, University of Georgia, Athens, GA, USA; Center for the Ecology of Infectious Diseases, University of Georgia, Athens, GA, USA.
| | | | - Sonia Altizer
- Odum School of Ecology, University of Georgia, Athens, GA, USA; Center for the Ecology of Infectious Diseases, University of Georgia, Athens, GA, USA.
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Teitelbaum CS, Hepinstall-Cymerman J, Kidd-Weaver A, Hernandez SM, Altizer S, Hall RJ. Urban specialization reduces habitat connectivity by a highly mobile wading bird. Mov Ecol 2020; 8:49. [PMID: 33372623 PMCID: PMC7720518 DOI: 10.1186/s40462-020-00233-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Accepted: 11/17/2020] [Indexed: 06/12/2023]
Abstract
BACKGROUND Mobile animals transport nutrients and propagules across habitats, and are crucial for the functioning of food webs and for ecosystem services. Human activities such as urbanization can alter animal movement behavior, including site fidelity and resource use. Because many urban areas are adjacent to natural sites, mobile animals might connect natural and urban habitats. More generally, understanding animal movement patterns in urban areas can help predict how urban expansion will affect the roles of highly mobile animals in ecological processes. METHODS Here, we examined movements by a seasonally nomadic wading bird, the American white ibis (Eudocimus albus), in South Florida, USA. White ibis are colonial wading birds that forage on aquatic prey; in recent years, some ibis have shifted their behavior to forage in urban parks, where they are fed by people. We used a spatial network approach to investigate how individual movement patterns influence connectivity between urban and non-urban sites. We built a network of habitat connectivity using GPS tracking data from ibis during their non-breeding season and compared this network to simulated networks that assumed individuals moved indiscriminately with respect to habitat type. RESULTS We found that the observed network was less connected than the simulated networks, that urban-urban and natural-natural connections were strong, and that individuals using urban sites had the least-variable habitat use. Importantly, the few ibis that used both urban and natural habitats contributed the most to connectivity. CONCLUSIONS Habitat specialization in urban-acclimated wildlife could reduce the exchange of propagules and nutrients between urban and natural areas, which has consequences both for beneficial effects of connectivity such as gene flow and for detrimental effects such as the spread of contaminants or pathogens.
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Affiliation(s)
| | | | - Anjelika Kidd-Weaver
- Warnell School of Forestry and Natural Resources, University of Georgia, Athens, GA, USA
- Present address: College of Agriculture, Forestry and Life Sciences, Clemson University, Clemson, SC, USA
| | - Sonia M Hernandez
- Warnell School of Forestry and Natural Resources, University of Georgia, Athens, GA, USA
- Southeastern Cooperative Wildlife Disease Study, College of Veterinary Medicine, University of Georgia, Athens, GA, USA
| | - Sonia Altizer
- Odum School of Ecology, University of Georgia, Athens, GA, USA
| | - Richard J Hall
- Odum School of Ecology, University of Georgia, Athens, GA, USA
- Department of Infectious Diseases, College of Veterinary Medicine, University of Georgia, Athens, GA, USA
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Abstract
Anthropogenic landscape modification such as urbanization can expose wildlife to toxicants, with profound behavioural and health effects. Toxicant exposure can alter the local transmission of wildlife diseases by reducing survival or altering immune defence. However, predicting the impacts of pathogens on wildlife across their ranges is complicated by heterogeneity in toxicant exposure across the landscape, especially if toxicants alter wildlife movement from toxicant-contaminated to uncontaminated habitats. We developed a mechanistic model to explore how toxicant effects on host health and movement propensity influence range-wide pathogen transmission, and zoonotic exposure risk, as an increasing fraction of the landscape is toxicant-contaminated. When toxicant-contaminated habitat is scarce on the landscape, costs to movement and survival from toxicant exposure can trap infected animals in contaminated habitat and reduce landscape-level transmission. Increasing the proportion of contaminated habitat causes host population declines from combined effects of toxicants and infection. The onset of host declines precedes an increase in the density of infected hosts in contaminated habitat and thus may serve as an early warning of increasing potential for zoonotic spillover in urbanizing landscapes. These results highlight how sublethal effects of toxicants can determine pathogen impacts on wildlife populations that may not manifest until landscape contamination is widespread.
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Affiliation(s)
- Cecilia A Sánchez
- Odum School of Ecology, College of Veterinary Medicine; University of Georgia, Athens, GA, USA.,Center for the Ecology of Infectious Diseases, College of Veterinary Medicine; University of Georgia, Athens, GA, USA
| | - Sonia Altizer
- Odum School of Ecology, College of Veterinary Medicine; University of Georgia, Athens, GA, USA.,Center for the Ecology of Infectious Diseases, College of Veterinary Medicine; University of Georgia, Athens, GA, USA
| | - Richard J Hall
- Odum School of Ecology, College of Veterinary Medicine; University of Georgia, Athens, GA, USA.,Center for the Ecology of Infectious Diseases, College of Veterinary Medicine; University of Georgia, Athens, GA, USA.,Department of Infectious Diseases, College of Veterinary Medicine; University of Georgia, Athens, GA, USA
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9
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Teitelbaum CS, Altizer S, Hall RJ. Movement rules determine nomadic species' responses to resource supplementation and degradation. J Anim Ecol 2020; 89:2644-2656. [PMID: 32783225 DOI: 10.1111/1365-2656.13318] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Accepted: 07/27/2020] [Indexed: 11/29/2022]
Abstract
In environments that vary unpredictably, many animals are nomadic, moving in an irregular pattern that differs from year to year. Exploring the mechanisms of nomadic movement is needed to understand how animals survive in highly variable environments, and to predict behavioural and population responses to environmental change. We developed a network model to identify plausible mechanisms of nomadic animal movement by comparing the performance of multiple movement rules along a continuum from nomadism to residency. Using simulations and analytical results, we explored how different types of habitat modifications (that augment or decrease resource availability) might affect the abundance and movement rates of animals following each of these rules. Movement rules for which departure from patches depended on resource availability and/or competition performed almost equally well and better than residency or uninformed movement under most conditions, even though animals using each rule moved at substantially different rates. Habitat modifications that stabilized resources, either by resource supplementation or degradation, eroded the benefits of informed nomadic movements, particularly for movements based on resource availability alone. These results suggest that simple movement rules can explain nomadic animal movements and determine species' responses to environmental change. In particular, landscape stabilization and supplementation might be useful strategies for promoting populations of resident animals, but would be less beneficial for managing highly mobile species, many of which are threatened by habitat disruption and changes in climate.
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Affiliation(s)
| | - Sonia Altizer
- Odum School of Ecology, University of Georgia, Athens, GA, USA
| | - Richard J Hall
- Odum School of Ecology, University of Georgia, Athens, GA, USA.,Department of Infectious Diseases, College of Veterinary Medicine, University of Georgia, Athens, GA, USA
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10
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Becker DJ, Broos A, Bergner LM, Meza DK, Simmons NB, Fenton MB, Altizer S, Streicker DG. Temporal patterns of vampire bat rabies and host connectivity in Belize. Transbound Emerg Dis 2020. [PMCID: PMC8246562 DOI: 10.1111/tbed.13754] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Affiliation(s)
- Daniel J. Becker
- Odum School of Ecology University of Georgia Athens GA USA
- Center for the Ecology of Infectious Disease University of Georgia Athens GA USA
- Department of Biology Indiana University Bloomington IN USA
| | - Alice Broos
- MRC–University of Glasgow Centre for Virus Research Glasgow UK
| | - Laura M. Bergner
- MRC–University of Glasgow Centre for Virus Research Glasgow UK
- Institute of Biodiversity, Animal Health and Comparative Medicine University of Glasgow Glasgow UK
| | - Diana K. Meza
- MRC–University of Glasgow Centre for Virus Research Glasgow UK
- Institute of Biodiversity, Animal Health and Comparative Medicine University of Glasgow Glasgow UK
| | - Nancy B. Simmons
- Department of Mammalogy Division of Vertebrate Zoology American Museum of Natural History New York NY USA
| | | | - Sonia Altizer
- Odum School of Ecology University of Georgia Athens GA USA
- Center for the Ecology of Infectious Disease University of Georgia Athens GA USA
| | - Daniel G. Streicker
- Odum School of Ecology University of Georgia Athens GA USA
- MRC–University of Glasgow Centre for Virus Research Glasgow UK
- Institute of Biodiversity, Animal Health and Comparative Medicine University of Glasgow Glasgow UK
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Becker DJ, Speer KA, Brown AM, Fenton MB, Washburne AD, Altizer S, Streicker DG, Plowright RK, Chizhikov VE, Simmons NB, Volokhov DV. Ecological and evolutionary drivers of haemoplasma infection and bacterial genotype sharing in a Neotropical bat community. Mol Ecol 2020; 29:1534-1549. [PMID: 32243630 PMCID: PMC8299350 DOI: 10.1111/mec.15422] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2019] [Revised: 03/16/2020] [Accepted: 03/23/2020] [Indexed: 12/21/2022]
Abstract
Most emerging pathogens can infect multiple species, underlining the importance of understanding the ecological and evolutionary factors that allow some hosts to harbour greater infection prevalence and share pathogens with other species. However, our understanding of pathogen jumps is based primarily around viruses, despite bacteria accounting for the greatest proportion of zoonoses. Because bacterial pathogens in bats (order Chiroptera) can have conservation and human health consequences, studies that examine the ecological and evolutionary drivers of bacterial prevalence and barriers to pathogen sharing are crucially needed. Here were studied haemotropic Mycoplasma spp. (i.e., haemoplasmas) across a species-rich bat community in Belize over two years. Across 469 bats spanning 33 species, half of individuals and two-thirds of species were haemoplasma positive. Infection prevalence was higher for males and for species with larger body mass and colony sizes. Haemoplasmas displayed high genetic diversity (21 novel genotypes) and strong host specificity. Evolutionary patterns supported codivergence of bats and bacterial genotypes alongside phylogenetically constrained host shifts. Bat species centrality to the network of shared haemoplasma genotypes was phylogenetically clustered and unrelated to prevalence, further suggesting rare-but detectable-bacterial sharing between species. Our study highlights the importance of using fine phylogenetic scales when assessing host specificity and suggests phylogenetic similarity may play a key role in host shifts not only for viruses but also for bacteria. Such work more broadly contributes to increasing efforts to understand cross-species transmission and the epidemiological consequences of bacterial pathogens.
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Affiliation(s)
- Daniel J. Becker
- Department of BiologyIndiana UniversityBloomingtonINUSA
- Center for the Ecology of Infectious DiseaseUniversity of GeorgiaAthensGAUSA
| | - Kelly A. Speer
- Richard Gilder Graduate SchoolAmerican Museum of Natural HistoryNew YorkNYUSA
- Department of Invertebrate ZoologyNational Museum of Natural HistorySmithsonian InstitutionWashingtonDCUSA
- Center for Conservation GenomicsSmithsonian Conservation Biology InstituteNational Zoological ParkWashingtonDCUSA
| | - Alexis M. Brown
- Department of Ecology and EvolutionStony Brook UniversityStony BrookNYUSA
| | | | - Alex D. Washburne
- Department of Microbiology and ImmunologyMontana State UniversityBozemanMTUSA
| | - Sonia Altizer
- Center for the Ecology of Infectious DiseaseUniversity of GeorgiaAthensGAUSA
- Odum School of EcologyUniversity of GeorgiaAthensGAUSA
| | - Daniel G. Streicker
- Odum School of EcologyUniversity of GeorgiaAthensGAUSA
- MRC–University of Glasgow Centre for Virus ResearchGlasgowUK
- Institute of Biodiversity, Animal Health and Comparative MedicineUniversity of GlasgowGlasgowUK
| | - Raina K. Plowright
- Department of Microbiology and ImmunologyMontana State UniversityBozemanMTUSA
| | - Vladimir E. Chizhikov
- Center for Biologics Evaluation and Research, Food and Drug AdministrationSilver SpringMDUSA
| | - Nancy B. Simmons
- Richard Gilder Graduate SchoolAmerican Museum of Natural HistoryNew YorkNYUSA
- Department of MammalogyDivision of Vertebrate ZoologyAmerican Museum of Natural HistoryNew YorkNYUSA
| | - Dmitriy V. Volokhov
- Center for Biologics Evaluation and Research, Food and Drug AdministrationSilver SpringMDUSA
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12
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Becker DJ, Nachtmann C, Argibay HD, Botto G, Escalera-Zamudio M, Carrera JE, Tello C, Winiarski E, Greenwood AD, Méndez-Ojeda ML, Loza-Rubio E, Lavergne A, de Thoisy B, Czirják GÁ, Plowright RK, Altizer S, Streicker DG. Leukocyte Profiles Reflect Geographic Range Limits in a Widespread Neotropical Bat. Integr Comp Biol 2020; 59:1176-1189. [PMID: 30873523 PMCID: PMC6907035 DOI: 10.1093/icb/icz007] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Quantifying how the environment shapes host immune defense is important for understanding which wild populations may be more susceptible or resistant to pathogens. Spatial variation in parasite risk, food and predator abundance, and abiotic conditions can each affect immunity, and these factors can also manifest at both local and biogeographic scales. Yet identifying predictors and the spatial scale of their effects is limited by the rarity of studies that measure immunity across many populations of broadly distributed species. We analyzed leukocyte profiles from 39 wild populations of the common vampire bat (Desmodus rotundus) across its wide geographic range throughout the Neotropics. White blood cell differentials varied spatially, with proportions of neutrophils and lymphocytes varying up to six-fold across sites. Leukocyte profiles were spatially autocorrelated at small and very large distances, suggesting that local environment and large-scale biogeographic factors influence cellular immunity. Generalized additive models showed that bat populations closer to the northern and southern limits of the species range had more neutrophils, monocytes, and basophils, but fewer lymphocytes and eosinophils, than bats sampled at the core of their distribution. Habitats with access to more livestock also showed similar patterns in leukocyte profiles, but large-scale patterns were partly confounded by time between capture and sampling across sites. Our findings suggest that populations at the edge of their range experience physiologically limiting conditions that predict higher chronic stress and greater investment in cellular innate immunity. High food abundance in livestock-dense habitats may exacerbate such conditions by increasing bat density or diet homogenization, although future spatially and temporally coordinated field studies with common protocols are needed to limit sampling artifacts. Systematically assessing immune function and response over space will elucidate how environmental conditions influence traits relevant to epidemiology and help predict disease risks with anthropogenic disturbance, land conversion, and climate change.
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Affiliation(s)
- Daniel J Becker
- Odum School of Ecology, University of Georgia, Athens, GA 30602, USA.,Center for the Ecology of Infectious Disease, University of Georgia, Athens, GA 30602, USA.,Department of Biology, Indiana University, Bloomington, IN 47405, USA
| | - Cecilia Nachtmann
- Odum School of Ecology, University of Georgia, Athens, GA 30602, USA
| | - Hernan D Argibay
- Departamento de Ecología, Genética y Evolución, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires C1428EGA, Argentina
| | - Germán Botto
- Department of Microbiology and Immunology, Montana State University, Bozeman, MT 59715, USA.,Departamento de Metodos Cuantitativos, Facultad de Medicina, Universidad de la República, Montevideo 11800, Uruguay
| | - Marina Escalera-Zamudio
- Department of Wildlife Diseases, Leibniz Institute for Zoo and Wildlife Research, Berlin 10315, Germany.,Department of Zoology, University of Oxford, Oxford OX1 3SY, UK
| | - Jorge E Carrera
- Facultad de Ciencias, Universidad Nacional de Piura, Piura 20009, Peru.,Programa de Conservación de Murciélagos de Perú, Piura Lima-1, Peru
| | - Carlos Tello
- Association for the Conservation and Development of Natural Resources, Lima 15037, Peru.,Yunkawasi, Lima 15049, Peru
| | - Erik Winiarski
- Departamento de Histología, Facultad de Medicina, Universidad de la República, Montevideo 11800, Uruguay
| | - Alex D Greenwood
- Department of Wildlife Diseases, Leibniz Institute for Zoo and Wildlife Research, Berlin 10315, Germany.,Department of Veterinary Medicine, Freie Universität Berlin, Berlin 14163, Germany
| | - Maria L Méndez-Ojeda
- Facultad de Medicina Veterinaria y Zootecnia, Universidad Veracruzana, Veracruz 91710, Mexico
| | - Elizabeth Loza-Rubio
- Centro Nacional de Investigación Disciplinaria en Microbiología Animal, Instituto Nacional de Investigaciones Forestales, Agrícolas y Pecuarias, Mexico City 05110, Mexico
| | - Anne Lavergne
- Laboratoire des Interactions Virus-Hôtes, Institut Pasteur de la Guyane, Cayenne, French Guiana F-97300, France
| | - Benoit de Thoisy
- Laboratoire des Interactions Virus-Hôtes, Institut Pasteur de la Guyane, Cayenne, French Guiana F-97300, France
| | - Gábor Á Czirják
- Department of Wildlife Diseases, Leibniz Institute for Zoo and Wildlife Research, Berlin 10315, Germany
| | - Raina K Plowright
- Department of Microbiology and Immunology, Montana State University, Bozeman, MT 59715, USA
| | - Sonia Altizer
- Odum School of Ecology, University of Georgia, Athens, GA 30602, USA.,Center for the Ecology of Infectious Disease, University of Georgia, Athens, GA 30602, USA
| | - Daniel G Streicker
- Odum School of Ecology, University of Georgia, Athens, GA 30602, USA.,Institute of Biodiversity, Animal Health and Comparative Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, UK.,MRC-University of Glasgow Centre for Virus Research, Glasgow G61 1QH, UK
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13
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Majewska AA, Altizer S. Planting gardens to support insect pollinators. Conserv Biol 2020; 34:15-25. [PMID: 30593718 DOI: 10.1111/cobi.13271] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2018] [Revised: 11/06/2018] [Accepted: 12/18/2018] [Indexed: 05/23/2023]
Abstract
Global insect pollinator declines have prompted habitat restoration efforts, including pollinator-friendly gardening. Gardens can provide nectar and pollen for adult insects and offer reproductive resources, such as nesting sites and caterpillar host plants. We conducted a review and meta-analysis to examine how decisions made by gardeners on plant selection and garden maintenance influence pollinator survival, abundance, and diversity. We also considered characteristics of surrounding landscapes and the impacts of pollinator natural enemies. Our results indicated that pollinators responded positively to high plant species diversity, woody vegetation, garden size, and sun exposure and negatively to the separation of garden habitats from natural sites. Within-garden features more strongly influenced pollinators than surrounding landscape factors. Growing interest in gardening for pollinators highlights the need to better understand how gardens contribute to pollinator conservation and how some garden characteristics can enhance the attractiveness and usefulness of gardens to pollinators. Further studies examining pollinator reproduction, resource acquisition, and natural enemies in gardens and comparing gardens with other restoration efforts and to natural habitats are needed to increase the value of human-made habitats for pollinators.
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Affiliation(s)
- Ania A Majewska
- Odum School of Ecology, University of Georgia, 140 E. Green Street, Athens, GA, 30602, U.S.A
- Center for the Ecology of Infectious Disease, University of Georgia, Athens, GA, 30602, U.S.A
| | - Sonia Altizer
- Odum School of Ecology, University of Georgia, 140 E. Green Street, Athens, GA, 30602, U.S.A
- Center for the Ecology of Infectious Disease, University of Georgia, Athens, GA, 30602, U.S.A
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14
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Majewska AA, Sims S, Schneider A, Altizer S, Hall RJ. Multiple transmission routes sustain high prevalence of a virulent parasite in a butterfly host. Proc Biol Sci 2019; 286:20191630. [PMID: 31480975 PMCID: PMC6742984 DOI: 10.1098/rspb.2019.1630] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Understanding factors that allow highly virulent parasites to reach high infection prevalence in host populations is important for managing infection risks to human and wildlife health. Multiple transmission routes have been proposed as one mechanism by which virulent pathogens can achieve high prevalence, underscoring the need to investigate this hypothesis through an integrated modelling-empirical framework. Here, we examine a harmful specialist protozoan infecting monarch butterflies that commonly reaches high prevalence (50–100%) in resident populations. We integrate field and modelling work to show that a combination of three empirically-supported transmission routes (vertical, adult transfer and environmental transmission) can produce and sustain high infection prevalence in this system. Although horizontal transmission is necessary for parasite invasion, most new infections post-establishment arise from vertical transmission. Our study predicts that multiple transmission routes, coupled with high parasite virulence, can reduce resident host abundance by up to 50%, suggesting that the protozoan could contribute to declines of North American monarchs.
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Affiliation(s)
- Ania A Majewska
- Odum School of Ecology, College of Veterinary Medicine, University of Georgia, Athens, GA, USA.,Center for the Ecology of Infectious Disease, College of Veterinary Medicine, University of Georgia, Athens, GA, USA.,Department of Biology, Emory University, Atlanta, GA, USA
| | - Stuart Sims
- Odum School of Ecology, College of Veterinary Medicine, University of Georgia, Athens, GA, USA
| | - Anna Schneider
- Wisconsin Department of Natural Resources, Madison, WI, USA
| | - Sonia Altizer
- Odum School of Ecology, College of Veterinary Medicine, University of Georgia, Athens, GA, USA.,Center for the Ecology of Infectious Disease, College of Veterinary Medicine, University of Georgia, Athens, GA, USA
| | - Richard J Hall
- Odum School of Ecology, College of Veterinary Medicine, University of Georgia, Athens, GA, USA.,Center for the Ecology of Infectious Disease, College of Veterinary Medicine, University of Georgia, Athens, GA, USA.,Department of Infectious Diseases, College of Veterinary Medicine, University of Georgia, Athens, GA, USA
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15
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Herrera JP, Chakraborty D, Rushmore J, Altizer S, Nunn C. The changing ecology of primate parasites: Insights from wild-captive comparisons. Am J Primatol 2019; 81:e22991. [PMID: 31265141 DOI: 10.1002/ajp.22991] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2019] [Revised: 04/10/2019] [Accepted: 04/21/2019] [Indexed: 12/23/2022]
Abstract
Host movements, including migrations or range expansions, are known to influence parasite communities. Transitions to captivity-a rarely studied yet widespread human-driven host movement-can also change parasite communities, in some cases leading to pathogen spillover among wildlife species, or between wildlife and human hosts. We compared parasite species richness between wild and captive populations of 22 primate species, including macro- (helminths and arthropods) and micro-parasites (viruses, protozoa, bacteria, and fungi). We predicted that captive primates would have only a subset of their native parasite community, and would possess fewer parasites with complex life cycles requiring intermediate hosts or vectors. We further predicted that captive primates would have parasites transmitted by close contact and environmentally-including those shared with humans and other animals, such as commensals and pests. We found that the composition of primate parasite communities shifted in captive populations, especially because of turnover (parasites detected in captivity but not reported in the wild), but with some evidence of nestedness (holdovers from the wild). Because of the high degree of turnover, we found no significant difference in overall parasite richness between captive and wild primates. Vector-borne parasites were less likely to be found in captivity, whereas parasites transmitted through either close or non-close contact, including through fecal-oral transmission, were more likely to be newly detected in captivity. These findings identify parasites that require monitoring in captivity and raise concerns about the introduction of novel parasites to potentially susceptible wildlife populations during reintroduction programs.
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Affiliation(s)
- James P Herrera
- Department of Evolutionary Anthropology, Duke University, Durham, North Carolina
| | - Debapriyo Chakraborty
- Department of Evolutionary Anthropology, Duke University, Durham, North Carolina.,EcoHealth Alliance, New York, New York
| | - Julie Rushmore
- Epicenter for Disease Dynamics, One Health Institute, School of Veterinary Medicine, University of California, Davis, California.,Odum School of Ecology, University of Georgia, Athens
| | - Sonia Altizer
- Odum School of Ecology, University of Georgia, Athens
| | - Charles Nunn
- Department of Evolutionary Anthropology, Duke University, Durham, North Carolina.,Duke Global Health Institute, Duke University, Durham, North Carolina
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16
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Teitelbaum CS, Huang S, Hall RJ, Altizer S. Migratory behaviour predicts greater parasite diversity in ungulates. Proc Biol Sci 2019; 285:rspb.2018.0089. [PMID: 29563269 DOI: 10.1098/rspb.2018.0089] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2018] [Accepted: 02/26/2018] [Indexed: 02/03/2023] Open
Abstract
Long-distance animal movements can increase exposure to diverse parasites, but can also reduce infection risk through escape from contaminated habitats or culling of infected individuals. These mechanisms have been demonstrated within and between populations in single-host/single-parasite interactions, but how long-distance movement behaviours shape parasite diversity and prevalence across host taxa is largely unknown. Using a comparative approach, we analyse the parasite communities of 93 migratory, nomadic and resident ungulate species. We find that migrants have higher parasite species richness than residents or nomads, even after considering other factors known to influence parasite diversity, such as body size and host geographical range area. Further analyses support a novel 'environmental tracking' hypothesis, whereby migration allows parasites to experience environments favourable to transmission year-round. In addition, the social aggregation and large group sizes that facilitate migration might increase infection risk for migrants. By contrast, we find little support for previously proposed hypotheses, including migratory escape and culling, in explaining the relationship between host movement and parasitism in mammals at this cross-species scale. Our findings, which support mechanistic links between long-distance movement and increased parasite richness at the species level, could help predict the effects of future environmental change on parasitism in migratory animals.
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Affiliation(s)
- Claire S Teitelbaum
- Odum School of Ecology, University of Georgia, Athens GA, USA .,Center for the Ecology of Infectious Diseases, University of Georgia, Athens GA, USA
| | - Shan Huang
- Senckenberg Biodiversity and Climate Research Centre, Frankfurt, Germany
| | - Richard J Hall
- Odum School of Ecology, University of Georgia, Athens GA, USA.,Center for the Ecology of Infectious Diseases, University of Georgia, Athens GA, USA.,Department of Infectious Diseases, College of Veterinary Medicine, University of Georgia, Athens GA, USA
| | - Sonia Altizer
- Odum School of Ecology, University of Georgia, Athens GA, USA.,Center for the Ecology of Infectious Diseases, University of Georgia, Athens GA, USA
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17
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Stephens PR, Altizer S, Ezenwa VO, Gittleman JL, Moan E, Han B, Huang S, Pappalardo P. Parasite sharing in wild ungulates and their predators: Effects of phylogeny, range overlap, and trophic links. J Anim Ecol 2019; 88:1017-1028. [PMID: 30921468 DOI: 10.1111/1365-2656.12987] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2018] [Accepted: 01/26/2019] [Indexed: 12/12/2022]
Abstract
Understanding factors that facilitate interspecific pathogen transmission is a central issue for conservation, agriculture, and human health. Past work showed that host phylogenetic relatedness and geographical proximity can increase cross-species transmission, but further work is needed to examine the importance of host traits, and species interactions such as predation, in determining the degree to which parasites are shared between hosts. Here we consider the factors that predict patterns of parasite sharing across a diverse assemblage of 116 wild ungulates (i.e., hoofed mammals in the Artiodactyla and Perissodactyla) and nearly 900 species of micro- and macroparasites, controlling for differences in total parasite richness and host sampling effort. We also consider the effects of trophic links on parasite sharing between ungulates and carnivores. We tested for the relative influence of range overlap, phylogenetic distance, body mass, and ecological dissimilarity (i.e., the distance separating species in a Euclidean distance matrix based on standardized traits) on parasite sharing. We also tested for the effects of variation in study effort as a potential source of bias in our data, and tested whether carnivores reported to feed on ungulates have more ungulate parasites than those that use other resources. As in other groups, geographical range overlap and phylogenetic similarity predicted greater parasite community similarity in ungulates. Ecological dissimilarity showed a weak negative relationship with parasite sharing. Counter to our expectations, differences, not similarity, in host body mass predicted greater parasite sharing between pairs of ungulate hosts. Pairs of well-studied host species showed higher overlap than poorly studied species, although including sampling effort did not reduce the importance of biological traits in our models. Finally, carnivores that feed on ungulates harboured a greater richness of ungulate helminths. Overall, we show that the factors that predict parasite sharing in wild ungulates are similar to those known for other mammal groups, and demonstrate the importance of controlling for heterogeneity in host sampling effort in future analyses of parasite sharing. We also show that ecological interactions, in this case trophic links via predation, can allow sharing of some parasite species among distantly related host species.
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Affiliation(s)
| | - Sonia Altizer
- Odum School of Ecology, University of Georgia, Athens, Georgia
| | - Vanessa O Ezenwa
- Odum School of Ecology, University of Georgia, Athens, Georgia.,Department of Infectious Diseases, College of Veterinary Medicine, University of Georgia, Athens, Georgia
| | | | - Emili Moan
- Department of Statistics, North Carolina State University, Raleigh, North Carolina
| | - Barbara Han
- Cary Institute of Ecosystem Studies, Millbrook, New York
| | - Shan Huang
- Senckenberg Biodiversity and Climate Research Centre (BiK-F), Frankfurt (Main), Germany
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18
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Abstract
Migratory animals undergo seasonal and often spectacular movements and perform crucial ecosystem services. In response to anthropogenic changes, including food subsidies, some migratory animals are now migrating shorter distances or halting migration altogether and forming resident populations. Recent studies suggest that shifts in migratory behaviour can alter the risk of infection for wildlife. Although migration is commonly assumed to enhance pathogen spread, for many species, migration has the opposite effect of lowering infection risk, if animals escape from habitats where pathogen stages have accumulated or if strenuous journeys cull infected hosts. Here, we summarize responses of migratory species to supplemental feeding and review modelling and empirical work that provides support for mechanisms through which resource-induced changes in migration can alter pathogen transmission. In particular, we focus on the well-studied example of monarch butterflies and their protozoan parasites in North America. We also identify areas for future research, including combining new technologies for tracking animal movements with pathogen surveillance and exploring potential evolutionary responses of hosts and pathogens to changing movement patterns. Given that many migratory animals harbour pathogens of conservation concern and zoonotic potential, studies that document ongoing shifts in migratory behaviour and infection risk are vitally needed.This article is part of the theme issue 'Anthropogenic resource subsidies and host-parasite dynamics in wildlife'.
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Affiliation(s)
- Dara A Satterfield
- Migratory Bird Center, Smithsonian Conservation Biology Institute, National Zoological Park, Washington, DC, USA
| | - Peter P Marra
- Migratory Bird Center, Smithsonian Conservation Biology Institute, National Zoological Park, Washington, DC, USA
| | - T Scott Sillett
- Migratory Bird Center, Smithsonian Conservation Biology Institute, National Zoological Park, Washington, DC, USA
| | - Sonia Altizer
- Odum School of Ecology, University of Georgia, Athens, GA, USA
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19
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Altizer S, Becker DJ, Epstein JH, Forbes KM, Gillespie TR, Hall RJ, Hawley DM, Hernandez SM, Martin LB, Plowright RK, Satterfield DA, Streicker DG. Food for contagion: synthesis and future directions for studying host-parasite responses to resource shifts in anthropogenic environments. Philos Trans R Soc Lond B Biol Sci 2019. [PMID: 29531154 DOI: 10.1098/rstb.2017.0102] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Human-provided resource subsidies for wildlife are diverse, common and have profound consequences for wildlife-pathogen interactions, as demonstrated by papers in this themed issue spanning empirical, theoretical and management perspectives from a range of study systems. Contributions cut across scales of organization, from the within-host dynamics of immune function, to population-level impacts on parasite transmission, to landscape- and regional-scale patterns of infection. In this concluding paper, we identify common threads and key findings from author contributions, including the consequences of resource subsidies for (i) host immunity; (ii) animal aggregation and contact rates; (iii) host movement and landscape-level infection patterns; and (iv) interspecific contacts and cross-species transmission. Exciting avenues for future work include studies that integrate mechanistic modelling and empirical approaches to better explore cross-scale processes, and experimental manipulations of food resources to quantify host and pathogen responses. Work is also needed to examine evolutionary responses to provisioning, and ask how diet-altered changes to the host microbiome influence infection processes. Given the massive public health and conservation implications of anthropogenic resource shifts, we end by underscoring the need for practical recommendations to manage supplemental feeding practices, limit human-wildlife conflicts over shared food resources and reduce cross-species transmission risks, including to humans.This article is part of the theme issue 'Anthropogenic resource subsidies and host-parasite dynamics in wildlife'.
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Affiliation(s)
- Sonia Altizer
- Odum School of Ecology, College of Veterinary Medicine, University of Georgia, Athens, GA, USA .,Center for the Ecology of Infectious Disease, College of Veterinary Medicine, University of Georgia, Athens, GA, USA
| | - Daniel J Becker
- Odum School of Ecology, College of Veterinary Medicine, University of Georgia, Athens, GA, USA.,Center for the Ecology of Infectious Disease, College of Veterinary Medicine, University of Georgia, Athens, GA, USA.,Department of Microbiology and Immunology, Montana State University, Bozeman, MT, USA
| | | | - Kristian M Forbes
- Department of Virology, University of Helsinki, Helsinki, Finland.,Department of Biology, The Pennsylvania State University, University Park, PA, USA.,Center for Infectious Disease Dynamics, The Pennsylvania State University, University Park, PA, USA
| | - Thomas R Gillespie
- Department of Environmental Sciences and Program in Population Biology, Ecology and Evolution, Rollins School of Public Health, Emory University, Atlanta, GA, USA.,Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, GA, USA
| | - Richard J Hall
- Odum School of Ecology, College of Veterinary Medicine, University of Georgia, Athens, GA, USA.,Center for the Ecology of Infectious Disease, College of Veterinary Medicine, University of Georgia, Athens, GA, USA.,Department of Infectious Disease, College of Veterinary Medicine, College of Veterinary Medicine, University of Georgia, Athens, GA, USA
| | - Dana M Hawley
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA, USA
| | - Sonia M Hernandez
- Warnell School of Forestry and Natural Resources, College of Veterinary Medicine, University of Georgia, Athens, GA, USA.,Southeastern Cooperative Wildlife Disease Study, College of Veterinary Medicine, University of Georgia, Athens, GA, USA
| | - Lynn B Martin
- Department of Integrative Biology, University of South Florida, Tampa, FL, USA
| | - Raina K Plowright
- Department of Microbiology and Immunology, Montana State University, Bozeman, MT, USA
| | - Dara A Satterfield
- Migratory Bird Center, Smithsonian Conservation Biology Institute, National Zoological Park, Washington, DC 20008, USA
| | - Daniel G Streicker
- Odum School of Ecology, College of Veterinary Medicine, University of Georgia, Athens, GA, USA.,Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow G12 8QQ, UK.,MRC-University of Glasgow Centre for Virus Research, Glasgow G61 1QH, UK
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20
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Becker DJ, Hall RJ, Forbes KM, Plowright RK, Altizer S. Anthropogenic resource subsidies and host-parasite dynamics in wildlife. Philos Trans R Soc Lond B Biol Sci 2019. [PMID: 29531141 DOI: 10.1098/rstb.2017.0086] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Affiliation(s)
- Daniel J Becker
- Odum School of Ecology, College of Veterinary Medicine, University of Georgia, Athens, GA, USA .,Center for the Ecology of Infectious Disease, College of Veterinary Medicine, University of Georgia, Athens, GA, USA.,Department of Microbiology and Immunology, Montana State University, Bozeman, MT, USA
| | - Richard J Hall
- Odum School of Ecology, College of Veterinary Medicine, University of Georgia, Athens, GA, USA.,Center for the Ecology of Infectious Disease, College of Veterinary Medicine, University of Georgia, Athens, GA, USA.,Department of Infectious Disease, College of Veterinary Medicine, University of Georgia, Athens, GA, USA
| | - Kristian M Forbes
- Department of Virology, University of Helsinki, Helsinki, Finland.,Center for Infectious Disease Dynamics, Pennsylvania State University, University Park, PA, USA.,Department of Biology, Pennsylvania State University, University Park, PA, USA
| | - Raina K Plowright
- Department of Microbiology and Immunology, Montana State University, Bozeman, MT, USA
| | - Sonia Altizer
- Odum School of Ecology, College of Veterinary Medicine, University of Georgia, Athens, GA, USA.,Center for the Ecology of Infectious Disease, College of Veterinary Medicine, University of Georgia, Athens, GA, USA
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21
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Becker DJ, Teitelbaum CS, Murray MH, Curry SE, Welch CN, Ellison T, Adams HC, Rozier RS, Lipp EK, Hernandez SM, Altizer S, Hall RJ. Assessing the contributions of intraspecific and environmental sources of infection in urban wildlife: Salmonella enterica and white ibis as a case study. J R Soc Interface 2018; 15:20180654. [PMID: 30958239 PMCID: PMC6303792 DOI: 10.1098/rsif.2018.0654] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2018] [Accepted: 11/15/2018] [Indexed: 01/11/2023] Open
Abstract
Conversion of natural habitats into urban landscapes can expose wildlife to novel pathogens and alter pathogen transmission pathways. Because transmission is difficult to quantify for many wildlife pathogens, mathematical models paired with field observations can help select among competing transmission pathways that might operate in urban landscapes. Here we develop a mathematical model for the enteric bacteria Salmonella enterica in urban-foraging white ibis ( Eudocimus albus) in south Florida as a case study to determine (i) the relative importance of contact-based versus environmental transmission among ibis and (ii) whether transmission can be supported by ibis alone or requires external sources of infection. We use biannual field prevalence data to restrict model outputs generated from a Latin hypercube sample of parameter space and select among competing transmission scenarios. We find the most support for transmission from environmental uptake rather than between-host contact and that ibis-ibis transmission alone could maintain low infection prevalence. Our analysis provides the first parameter estimates for Salmonella shedding and uptake in a wild bird and provides a key starting point for predicting how ibis response to urbanization alters their exposure to a multi-host zoonotic enteric pathogen. More broadly, our study provides an analytical roadmap to assess transmission pathways of multi-host wildlife pathogens in the face of scarce infection data.
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Affiliation(s)
- Daniel J. Becker
- Odum School of Ecology, University of Georgia, Athens, GA, USA
- Center for the Ecology of Infectious Disease, University of Georgia, Athens, GA, USA
- Department of Biology, Indiana University, Bloomington, IN, USA
| | - Claire S. Teitelbaum
- Odum School of Ecology, University of Georgia, Athens, GA, USA
- Center for the Ecology of Infectious Disease, University of Georgia, Athens, GA, USA
| | - Maureen H. Murray
- Warnell School of Forestry and Natural Resources, University of Georgia, Athens, GA, USA
- Southeastern Cooperative Wildlife Disease Study, University of Georgia, Athens, GA, USA
| | - Shannon E. Curry
- Warnell School of Forestry and Natural Resources, University of Georgia, Athens, GA, USA
- Southeastern Cooperative Wildlife Disease Study, University of Georgia, Athens, GA, USA
| | - Catharine N. Welch
- Warnell School of Forestry and Natural Resources, University of Georgia, Athens, GA, USA
- Southeastern Cooperative Wildlife Disease Study, University of Georgia, Athens, GA, USA
| | - Taylor Ellison
- Warnell School of Forestry and Natural Resources, University of Georgia, Athens, GA, USA
- Southeastern Cooperative Wildlife Disease Study, University of Georgia, Athens, GA, USA
| | - Henry C. Adams
- Warnell School of Forestry and Natural Resources, University of Georgia, Athens, GA, USA
- Southeastern Cooperative Wildlife Disease Study, University of Georgia, Athens, GA, USA
| | - R. Scott Rozier
- Department of Environmental Health Science, College of Public Health, University of Georgia, Athens, GA, USA
| | - Erin K. Lipp
- Department of Environmental Health Science, College of Public Health, University of Georgia, Athens, GA, USA
| | - Sonia M. Hernandez
- Warnell School of Forestry and Natural Resources, University of Georgia, Athens, GA, USA
- Southeastern Cooperative Wildlife Disease Study, University of Georgia, Athens, GA, USA
| | - Sonia Altizer
- Odum School of Ecology, University of Georgia, Athens, GA, USA
- Center for the Ecology of Infectious Disease, University of Georgia, Athens, GA, USA
| | - Richard J. Hall
- Odum School of Ecology, University of Georgia, Athens, GA, USA
- Center for the Ecology of Infectious Disease, University of Georgia, Athens, GA, USA
- Department of Infectious Disease, College of Veterinary Medicine, University of Georgia, Athens, GA, USA
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22
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Sánchez CA, Becker DJ, Teitelbaum CS, Barriga P, Brown LM, Majewska AA, Hall RJ, Altizer S. On the relationship between body condition and parasite infection in wildlife: a review and meta-analysis. Ecol Lett 2018; 21:1869-1884. [PMID: 30369000 DOI: 10.1111/ele.13160] [Citation(s) in RCA: 85] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2018] [Revised: 02/18/2018] [Accepted: 07/25/2018] [Indexed: 12/28/2022]
Abstract
Body condition metrics are widely used to infer animal health and to assess costs of parasite infection. Since parasites harm their hosts, ecologists might expect negative relationships between infection and condition in wildlife, but this assumption is challenged by studies showing positive or null condition-infection relationships. Here, we outline common condition metrics used by ecologists in studies of parasitism, and consider mechanisms that cause negative, positive, and null condition-infection relationships in wildlife systems. We then perform a meta-analysis of 553 condition-infection relationships from 187 peer-reviewed studies of animal hosts, analysing observational and experimental records separately, and noting whether authors measured binary infection status or intensity. Our analysis finds substantial heterogeneity in the strength and direction of condition-infection relationships, a small, negative average effect size that is stronger in experimental studies, and evidence for publication bias towards negative relationships. The strongest predictors of variation in study outcomes are host thermoregulation and the methods used to evaluate body condition. We recommend that studies aiming to assess parasite impacts on body condition should consider host-parasite biology, choose condition measures that can change during the course of infection, and employ longitudinal surveys or manipulate infection status when feasible.
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Affiliation(s)
- Cecilia A Sánchez
- Odum School of Ecology, University of Georgia, Athens, GA, USA.,Center for the Ecology of Infectious Disease, University of Georgia, Athens, GA, USA
| | - Daniel J Becker
- Odum School of Ecology, University of Georgia, Athens, GA, USA.,Center for the Ecology of Infectious Disease, University of Georgia, Athens, GA, USA.,Department of Microbiology and Immunology, Montana State University, Bozeman, MT, USA
| | - Claire S Teitelbaum
- Odum School of Ecology, University of Georgia, Athens, GA, USA.,Center for the Ecology of Infectious Disease, University of Georgia, Athens, GA, USA
| | - Paola Barriga
- Odum School of Ecology, University of Georgia, Athens, GA, USA.,Center for the Ecology of Infectious Disease, University of Georgia, Athens, GA, USA
| | - Leone M Brown
- Odum School of Ecology, University of Georgia, Athens, GA, USA.,Department of Biology, Tufts University, Medford, MA, USA
| | - Ania A Majewska
- Odum School of Ecology, University of Georgia, Athens, GA, USA.,Center for the Ecology of Infectious Disease, University of Georgia, Athens, GA, USA
| | - Richard J Hall
- Odum School of Ecology, University of Georgia, Athens, GA, USA.,Center for the Ecology of Infectious Disease, University of Georgia, Athens, GA, USA.,Department of Infectious Diseases, College of Veterinary Medicine, University of Georgia, Athens, GA, USA
| | - Sonia Altizer
- Odum School of Ecology, University of Georgia, Athens, GA, USA.,Center for the Ecology of Infectious Disease, University of Georgia, Athens, GA, USA
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23
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Becker DJ, Bergner LM, Bentz AB, Orton RJ, Altizer S, Streicker DG. Genetic diversity, infection prevalence, and possible transmission routes of Bartonella spp. in vampire bats. PLoS Negl Trop Dis 2018; 12:e0006786. [PMID: 30260954 PMCID: PMC6159870 DOI: 10.1371/journal.pntd.0006786] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2018] [Accepted: 08/27/2018] [Indexed: 12/20/2022] Open
Abstract
Bartonella spp. are globally distributed bacteria that cause endocarditis in humans and domestic animals. Recent work has suggested bats as zoonotic reservoirs of some human Bartonella infections; however, the ecological and spatiotemporal patterns of infection in bats remain largely unknown. Here we studied the genetic diversity, prevalence of infection across seasons and years, individual risk factors, and possible transmission routes of Bartonella in populations of common vampire bats (Desmodus rotundus) in Peru and Belize, for which high infection prevalence has previously been reported. Phylogenetic analysis of the gltA gene for a subset of PCR-positive blood samples revealed sequences that were related to Bartonella described from vampire bats from Mexico, other Neotropical bat species, and streblid bat flies. Sequences associated with vampire bats clustered significantly by country but commonly spanned Central and South America, implying limited spatial structure. Stable and nonzero Bartonella prevalence between years supported endemic transmission in all sites. The odds of Bartonella infection for individual bats was unrelated to the intensity of bat flies ectoparasitism, but nearly all infected bats were infested, which precluded conclusive assessment of support for vector-borne transmission. While metagenomic sequencing found no strong evidence of Bartonella DNA in pooled bat saliva and fecal samples, we detected PCR positivity in individual saliva and feces, suggesting the potential for bacterial transmission through both direct contact (i.e., biting) and environmental (i.e., fecal) exposures. Further investigating the relative contributions of direct contact, environmental, and vector-borne transmission for bat Bartonella is an important next step to predict infection dynamics within bats and the risks of human and livestock exposures.
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Affiliation(s)
- Daniel J. Becker
- Odum School of Ecology, University of Georgia, Athens, Georgia, United States of America
- Center for the Ecology of Infectious Disease, University of Georgia, Athens, Georgia, United States of Ameirca
- Department of Microbiology and Immunology, Montana State University, Bozeman, Montana, United States of America
| | - Laura M. Bergner
- Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow, United Kingdom
| | - Alexandra B. Bentz
- Department of Poultry Science, University of Georgia, Athens, Georgia, United States of America
- Department of Biology, Indiana University, Bloomington, Indiana, United States of America
| | - Richard J. Orton
- Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow, United Kingdom
- MRC–University of Glasgow Centre for Virus Research, Glasgow, United Kingdom
| | - Sonia Altizer
- Odum School of Ecology, University of Georgia, Athens, Georgia, United States of America
- Center for the Ecology of Infectious Disease, University of Georgia, Athens, Georgia, United States of Ameirca
| | - Daniel G. Streicker
- Odum School of Ecology, University of Georgia, Athens, Georgia, United States of America
- Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow, United Kingdom
- MRC–University of Glasgow Centre for Virus Research, Glasgow, United Kingdom
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24
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Oudemans PV, Alexander HM, Antonovics J, Altizer S, Thrall PH, Rose L. The distribution of mating-type bias in natural populations of the anther-smutUstilago violaceaonSilene albain Virginia. Mycologia 2018. [DOI: 10.1080/00275514.1998.12026921] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Affiliation(s)
- P. V. Oudemans
- Departments of Botany, and Systematics and Ecology, University of Kansas, Lawrence, Kansas 66045
| | - H. M. Alexander
- Departments of Botany, and Systematics and Ecology, University of Kansas, Lawrence, Kansas 66045
| | - J. Antonovics
- Department of Botany, Duke University, Durham, North Carolina 27708
| | - S. Altizer
- Department of Botany, Duke University, Durham, North Carolina 27708
| | - P. H. Thrall
- Department of Botany, Duke University, Durham, North Carolina 27708
| | - L. Rose
- Department of Botany, Duke University, Durham, North Carolina 27708
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25
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Satterfield DA, Maerz JC, Hunter MD, Flockhart DTT, Hobson KA, Norris DR, Streit H, de Roode JC, Altizer S. Migratory monarchs that encounter resident monarchs show life-history differences and higher rates of parasite infection. Ecol Lett 2018; 21:1670-1680. [PMID: 30152196 DOI: 10.1111/ele.13144] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2018] [Accepted: 07/27/2018] [Indexed: 01/24/2023]
Abstract
Environmental change induces some wildlife populations to shift from migratory to resident behaviours. Newly formed resident populations could influence the health and behaviour of remaining migrants. We investigated migrant-resident interactions among monarch butterflies and consequences for life history and parasitism. Eastern North American monarchs migrate annually to Mexico, but some now breed year-round on exotic milkweed in the southern US and experience high infection prevalence of protozoan parasites. Using stable isotopes (δ2 H, δ13 C) and cardenolide profiles to estimate natal origins, we show that migrant and resident monarchs overlap during fall and spring migration. Migrants at sites with residents were 13 times more likely to have infections and three times more likely to be reproductive (outside normal breeding season) compared to other migrants. Exotic milkweed might either attract migrants that are already infected or reproductive, or alternatively, induce these states. Increased migrant-resident interactions could affect monarch parasitism, migratory success and long-term conservation.
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Affiliation(s)
| | - John C Maerz
- Warnell School of Forestry and Natural Resources, University of Georgia, Athens, GA, 30602, USA
| | - Mark D Hunter
- Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI, 48109, USA
| | - D T Tyler Flockhart
- Departmment of Integrative Biology, University of Guelph, Guelph, ON, N1G2W1, Canada
| | - Keith A Hobson
- Department of Biology, Western University, London, ON, N6A5B7, Canada
| | - D Ryan Norris
- Departmment of Integrative Biology, University of Guelph, Guelph, ON, N1G2W1, Canada
| | - Hillary Streit
- Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI, 48109, USA
| | | | - Sonia Altizer
- Odum School of Ecology, University of Georgia, Athens, GA, 30602, USA
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26
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Becker DJ, Snedden CE, Altizer S, Hall RJ. Host Dispersal Responses to Resource Supplementation Determine Pathogen Spread in Wildlife Metapopulations. Am Nat 2018; 192:503-517. [PMID: 30205031 DOI: 10.1086/699477] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Many wildlife species occupy landscapes that vary in the distribution, abundance, and quality of food resources. Increasingly, urbanized and agricultural habitats provide supplemental food resources that can have profound consequences for host distributions, movement patterns, and pathogen exposure. Understanding how host and pathogen dispersal across landscapes is affected by the spatial extent of food-supplemented habitats is therefore important for predicting the consequences for pathogen spread and impacts on host occupancy. Here we develop a generalizable metapopulation model to understand how the relative abundance of provisioned habitats across the landscape and how the host dispersal responses to provisioning and infection influence patch occupancy by hosts and their pathogens. We find that pathogen invasion and landscape-level infection prevalence are greatest when provisioning increases patch attractiveness and disperser production and when infection has minimal costs on dispersal success. Alternatively, if provisioning promotes site fidelity or reduces disperser production, increasing the fraction of food-supplemented habitats can reduce landscape-scale infection prevalence and minimize disease-induced declines in host occupancy. This work highlights the importance of considering how resources and infection jointly influence host dispersal for predicting how changing resource distributions influence the spread of infectious diseases.
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27
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Becker DJ, Czirják GÁ, Volokhov DV, Bentz AB, Carrera JE, Camus MS, Navara KJ, Chizhikov VE, Fenton MB, Simmons NB, Recuenco SE, Gilbert AT, Altizer S, Streicker DG. Livestock abundance predicts vampire bat demography, immune profiles and bacterial infection risk. Philos Trans R Soc Lond B Biol Sci 2018; 373:20170089. [PMID: 29531144 PMCID: PMC5882995 DOI: 10.1098/rstb.2017.0089] [Citation(s) in RCA: 53] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/26/2017] [Indexed: 12/14/2022] Open
Abstract
Human activities create novel food resources that can alter wildlife-pathogen interactions. If resources amplify or dampen, pathogen transmission probably depends on both host ecology and pathogen biology, but studies that measure responses to provisioning across both scales are rare. We tested these relationships with a 4-year study of 369 common vampire bats across 10 sites in Peru and Belize that differ in the abundance of livestock, an important anthropogenic food source. We quantified innate and adaptive immunity from bats and assessed infection with two common bacteria. We predicted that abundant livestock could reduce starvation and foraging effort, allowing for greater investments in immunity. Bats from high-livestock sites had higher microbicidal activity and proportions of neutrophils but lower immunoglobulin G and proportions of lymphocytes, suggesting more investment in innate relative to adaptive immunity and either greater chronic stress or pathogen exposure. This relationship was most pronounced in reproductive bats, which were also more common in high-livestock sites, suggesting feedbacks between demographic correlates of provisioning and immunity. Infection with both Bartonella and haemoplasmas were correlated with similar immune profiles, and both pathogens tended to be less prevalent in high-livestock sites, although effects were weaker for haemoplasmas. These differing responses to provisioning might therefore reflect distinct transmission processes. Predicting how provisioning alters host-pathogen interactions requires considering how both within-host processes and transmission modes respond to resource shifts.This article is part of the theme issue 'Anthropogenic resource subsidies and host-parasite dynamics in wildlife'.
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Affiliation(s)
- Daniel J Becker
- Odum School of Ecology, University of Georgia, Athens, GA 30602, USA
- Center for the Ecology of Infectious Disease, University of Georgia, Athens, GA 30602, USA
- Department of Microbiology and Immunology, Montana State University, Bozeman, MT, USA
| | - Gábor Á Czirják
- Department of Wildlife Diseases, Leibniz Institute for Zoo and Wildlife Research, Berlin, Germany
| | - Dmitriy V Volokhov
- Center for Biologics Evaluation & Research, U.S. Food & Drug Administration, Rockville, MD, USA
| | - Alexandra B Bentz
- Department of Poultry Science, University of Georgia, Athens, GA, USA
- Department of Biology, Indiana University, Bloomington, IN, USA
| | - Jorge E Carrera
- Facultad de Ciencias, Universidad Nacional de Piura, Piura, Perú
- Programa de Conservación de Murciélagos de Perú, Piura, Perú
| | - Melinda S Camus
- Department of Pathology, College of Veterinary Medicine, University of Georgia, Athens, GA, USA
| | - Kristen J Navara
- Department of Poultry Science, University of Georgia, Athens, GA, USA
| | - Vladimir E Chizhikov
- Center for Biologics Evaluation & Research, U.S. Food & Drug Administration, Rockville, MD, USA
| | - M Brock Fenton
- Department of Biology, Western University, London, Ontario, Canada
| | - Nancy B Simmons
- Department of Mammalogy, Division of Vertebrate Zoology, American Museum of Natural History, New York, NY, USA
| | - Sergio E Recuenco
- Department of Preventive Medicine and Public Health, Faculty of Medicine, Universidad Nacional Mayor de San Marcos, Lima, Perú
| | - Amy T Gilbert
- National Wildlife Research Center, United States Department of Agriculture, Fort Collins, CO, USA
| | - Sonia Altizer
- Odum School of Ecology, University of Georgia, Athens, GA 30602, USA
- Center for the Ecology of Infectious Disease, University of Georgia, Athens, GA 30602, USA
| | - Daniel G Streicker
- Odum School of Ecology, University of Georgia, Athens, GA 30602, USA
- Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow, UK
- MRC-University of Glasgow Centre for Virus Research, Glasgow, UK
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28
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Becker DJ, Streicker DG, Altizer S, Derryberry E. Using host species traits to understand the consequences of resource provisioning for host-parasite interactions. J Anim Ecol 2018; 87:511-525. [PMID: 29023699 PMCID: PMC5836909 DOI: 10.1111/1365-2656.12765] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2016] [Accepted: 08/31/2017] [Indexed: 12/17/2022]
Abstract
Supplemental food provided to wildlife by human activities can be more abundant and predictable than natural resources, and subsequent changes in wildlife ecology can have profound impacts on host-parasite interactions. Identifying traits of species associated with increases or decreases in infection outcomes with resource provisioning could improve assessments of wildlife most prone to disease risks in changing environments. We conducted a phylogenetic meta-analysis of 342 host-parasite interactions across 56 wildlife species and three broad taxonomic groups of parasites to identify host-level traits that influence whether provisioning is associated with increases or decreases in infection. We predicted dietary generalists that capitalize on novel food would show greater infection in provisioned habitats owing to population growth and food-borne exposure to contaminants and parasite infectious stages. Similarly, species with fast life histories could experience stronger demographic and immunological benefits from provisioning that affect parasite transmission. We also predicted that wide-ranging and migratory behaviours could increase infection risks with provisioning if concentrated and non-seasonal foods promote dense aggregations that increase exposure to parasites. We found that provisioning increased infection with bacteria, viruses, fungi and protozoa (i.e. microparasites) most for wide-ranging, dietary generalist host species. Effect sizes for ectoparasites were also highest for host species with large home ranges but were instead lowest for dietary generalists. In contrast, the type of provisioning was a stronger correlate of infection outcomes for helminths than host species traits. Our analysis highlights host traits related to movement and feeding behaviour as important determinants of whether species experience greater infection with supplemental feeding. These results could help prioritize monitoring wildlife with particular trait profiles in anthropogenic habitats to reduce infectious disease risks in provisioned populations.
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Affiliation(s)
- Daniel J. Becker
- Odum School of EcologyUniversity of GeorgiaAthensGAUSA
- Center for the Ecology of Infectious DiseaseUniversity of GeorgiaAthensGAUSA
| | - Daniel G. Streicker
- Odum School of EcologyUniversity of GeorgiaAthensGAUSA
- Institute of Biodiversity, Animal Health and Comparative MedicineUniversity of GlasgowGlasgowUK
- MRC‐University of Glasgow Centre for Virus ResearchGlasgowUK
| | - Sonia Altizer
- Odum School of EcologyUniversity of GeorgiaAthensGAUSA
- Center for the Ecology of Infectious DiseaseUniversity of GeorgiaAthensGAUSA
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29
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Thogmartin WE, Wiederholt R, Oberhauser K, Drum RG, Diffendorfer JE, Altizer S, Taylor OR, Pleasants J, Semmens D, Semmens B, Erickson R, Libby K, Lopez-Hoffman L. Monarch butterfly population decline in North America: identifying the threatening processes. R Soc Open Sci 2017; 4:170760. [PMID: 28989778 PMCID: PMC5627118 DOI: 10.1098/rsos.170760] [Citation(s) in RCA: 100] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/22/2017] [Accepted: 08/24/2017] [Indexed: 05/24/2023]
Abstract
The monarch butterfly (Danaus plexippus) population in North America has sharply declined over the last two decades. Despite rising concern over the monarch butterfly's status, no comprehensive study of the factors driving this decline has been conducted. Using partial least-squares regressions and time-series analysis, we investigated climatic and habitat-related factors influencing monarch population size from 1993 to 2014. Potential threats included climatic factors, habitat loss (milkweed and overwinter forest), disease and agricultural insecticide use (neonicotinoids). While climatic factors, principally breeding season temperature, were important determinants of annual variation in abundance, our results indicated strong negative relationships between population size and habitat loss variables, principally glyphosate use, but also weaker negative effects from the loss of overwinter forest and breeding season use of neonicotinoids. Further declines in population size because of glyphosate application are not expected. Thus, if remaining threats to habitat are mitigated we expect climate-induced stochastic variation of the eastern migratory population of monarch butterfly around a relatively stationary population size.
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Affiliation(s)
- Wayne E. Thogmartin
- US Geological Survey, Upper Midwest Environmental Sciences Center, La Crosse, WI 54603, USA
| | - Ruscena Wiederholt
- Everglades Foundation, 18001 Old Cutler Road, Suite 625, Palmetto Bay, FL 33157, USA
| | - Karen Oberhauser
- Department of Fisheries, Wildlife and Conservation Biology, University of Minnesota, St Paul, MN 55455, USA
| | - Ryan G. Drum
- US Fish and Wildlife Service, Bloomington, MN 55437, USA
| | - Jay E. Diffendorfer
- US Geological Survey, Geosciences and Environmental Change Science Center, Denver, CO 80225, USA
| | - Sonia Altizer
- Odum School of Ecology, University of Georgia, Athens, GA 30602, USA
| | - Orley R. Taylor
- Department of Ecology and Evolutionary Biology, University of Kansas, Lawrence, KS 66045, USA
| | - John Pleasants
- Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames, IA 50011, USA
| | - Darius Semmens
- US Geological Survey, Geosciences and Environmental Change Science Center, Denver, CO 80225, USA
| | - Brice Semmens
- Scripps Institution of Oceanography, University of California, San Diego, La Jolla, CA 92093, USA
| | - Richard Erickson
- US Geological Survey, Upper Midwest Environmental Sciences Center, La Crosse, WI 54603, USA
| | - Kaitlin Libby
- School of Natural Resources & the Environment, The University of Arizona, Tucson, AZ 85721, USA
| | - Laura Lopez-Hoffman
- School of Natural Resources & the Environment, The University of Arizona, Tucson, AZ 85721, USA
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30
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Flockhart DTT, Brower LP, Ramirez MI, Hobson KA, Wassenaar LI, Altizer S, Norris DR. Regional climate on the breeding grounds predicts variation in the natal origin of monarch butterflies overwintering in Mexico over 38 years. Glob Chang Biol 2017; 23:2565-2576. [PMID: 28045226 DOI: 10.1111/gcb.13589] [Citation(s) in RCA: 53] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2016] [Accepted: 11/23/2016] [Indexed: 06/06/2023]
Abstract
Addressing population declines of migratory insects requires linking populations across different portions of the annual cycle and understanding the effects of variation in weather and climate on productivity, recruitment, and patterns of long-distance movement. We used stable H and C isotopes and geospatial modeling to estimate the natal origin of monarch butterflies (Danaus plexippus) in eastern North America using over 1000 monarchs collected over almost four decades at Mexican overwintering colonies. Multinomial regression was used to ascertain which climate-related factors best-predicted temporal variation in natal origin across six breeding regions. The region producing the largest proportion of overwintering monarchs was the US Midwest (mean annual proportion = 0.38; 95% CI: 0.36-0.41) followed by the north-central (0.17; 0.14-0.18), northeast (0.15; 0.11-0.16), northwest (0.12; 0.12-0.16), southwest (0.11; 0.08-0.12), and southeast (0.08; 0.07-0.11) regions. There was no evidence of directional shifts in the relative contributions of different natal regions over time, which suggests these regions are comprising the same relative proportion of the overwintering population in recent years as in the mid-1970s. Instead, interannual variation in the proportion of monarchs from each region covaried with climate, as measured by the Southern Oscillation Index and regional-specific daily maximum temperature and precipitation, which together likely dictate larval development rates and food plant condition. Our results provide the first robust long-term analysis of predictors of the natal origins of monarchs overwintering in Mexico. Conservation efforts on the breeding grounds focused on the Midwest region will likely have the greatest benefit to eastern North American migratory monarchs, but the population will likely remain sensitive to regional and stochastic weather patterns.
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Affiliation(s)
- D T Tyler Flockhart
- Department of Integrative Biology, University of Guelph, Guelph, ON, N1G 2W1, Canada
| | - Lincoln P Brower
- Department of Biology, Sweet Briar College, Sweet Briar, VA, 24595, USA
| | - M Isabel Ramirez
- Centro de Investigaciones en Geografía Ambiental, Universidad Nacional Autónoma de México, Antigua Carretera a Pátzcuaro No. 8701, C.P. 58190, Morelia, Michoacán, Mexico
| | - Keith A Hobson
- Environment Canada, Saskatoon, Saskatchewan, S7N 3H5, Canada
- Department of Biology, University of Western Ontario, London, Ontario, N6A 5B7, Canada
| | - Leonard I Wassenaar
- International Atomic Energy Agency, Department of Nuclear Sciences and Applications, A-1400, Vienna, Austria
| | - Sonia Altizer
- Odum School of Ecology, University of Georgia, Athens, GA, 30602, USA
| | - D Ryan Norris
- Department of Integrative Biology, University of Guelph, Guelph, ON, N1G 2W1, Canada
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31
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Stephens PR, Pappalardo P, Huang S, Byers JE, Farrell MJ, Gehman A, Ghai RR, Haas SE, Han B, Park AW, Schmidt JP, Altizer S, Ezenwa VO, Nunn CL. Global Mammal Parasite Database version 2.0. Ecology 2017; 98:1476. [DOI: 10.1002/ecy.1799] [Citation(s) in RCA: 79] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/02/2016] [Revised: 02/14/2017] [Accepted: 02/24/2017] [Indexed: 11/10/2022]
Affiliation(s)
- Patrick R. Stephens
- Odum School of Ecology; 140 E Green St., University of Georgia; Athens Georgia 30602 USA
| | - Paula Pappalardo
- Odum School of Ecology; 140 E Green St., University of Georgia; Athens Georgia 30602 USA
| | - Shan Huang
- Senckenberg Biodiversity and Climate Research Center (BiK-F); Senckenberganlage 25 D-60325 Frankfurt (Main) Germany
| | - James E. Byers
- Odum School of Ecology; 140 E Green St., University of Georgia; Athens Georgia 30602 USA
| | | | - Alyssa Gehman
- Department of Zoology; University of British Columbia; Vancouver British Columbia V6T1Z4 Canada
| | - Ria R. Ghai
- Department of Environmental Sciences; Emory University; Atlanta Georgia 30322 USA
| | - Sarah E. Haas
- Inland Fisheries Division; Texas Parks and Wildlife Department; Austin Texas 78744 USA
| | - Barbara Han
- Cary Institute of Ecosystem Ecology; Millbrook New York 12545 USA
| | - Andrew W. Park
- Odum School of Ecology; 140 E Green St., University of Georgia; Athens Georgia 30602 USA
| | - John P. Schmidt
- Odum School of Ecology; 140 E Green St., University of Georgia; Athens Georgia 30602 USA
| | - Sonia Altizer
- Odum School of Ecology; 140 E Green St., University of Georgia; Athens Georgia 30602 USA
| | - Vanessa O. Ezenwa
- Odum School of Ecology; 140 E Green St., University of Georgia; Athens Georgia 30602 USA
| | - Charles L. Nunn
- Biological Sciences; Duke University; Durham North Carolina 27708 USA
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32
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Flockhart DTT, Fitz-gerald B, Brower LP, Derbyshire R, Altizer S, Hobson KA, Wassenaar LI, Norris DR. Migration distance as a selective episode for wing morphology in a migratory insect. Mov Ecol 2017; 5:7. [PMID: 28417003 PMCID: PMC5381079 DOI: 10.1186/s40462-017-0098-9] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/14/2016] [Accepted: 03/06/2017] [Indexed: 06/07/2023]
Abstract
BACKGROUND Selective pressures that occur during long-distance migration can influence morphological traits across a range of taxa. In flying insects, selection should favour individuals that have wing morphologies that increase energy efficiency and survival. In monarch butterflies, differences in wing morphology between migratory and resident populations suggest that migratory populations have undergone selection for larger (as measured by length and area) and more elongated (as measured by roundness and aspect ratio) forewings. However, selection on wing morphology may also occur within migratory populations, particularly if individuals or populations consistently migrate different distances. RESULTS Using 613 monarch butterflies that were collected on the Mexican wintering grounds between 1976 - 2014, we tested whether monarch wing traits were associated with migratory distance from their natal areas in eastern North America (migration range: 774-4430 km), as inferred by stable-hydrogen (δ2H) and -carbon (δ13C) isotopic measurements. Monarchs that migrated farther distances to reach their overwintering sites tended to have longer and larger wings, suggesting positive selective pressure during migration on wing length and area. There was no relationship between migration distances and either roundness or aspect ratio. CONCLUSIONS Our results provide correlative evidence that the migratory period may act as a selective episode on monarch butterfly wing morphology, although selection during other portions of the annual cycle, as well as extensive mixing of individuals from various natal locations on the breeding grounds, likely counteracts directional selection of migration on morphology.
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Affiliation(s)
| | - Blair Fitz-gerald
- Department of Integrative Biology, University of Guelph, Guelph, ON N1G 2W1 Canada
| | - Lincoln P. Brower
- Department of Biology, Sweet Briar College, Sweet Briar, VA 24595 USA
| | - Rachael Derbyshire
- Department of Integrative Biology, University of Guelph, Guelph, ON N1G 2W1 Canada
| | - Sonia Altizer
- Odum School of Ecology, University of Georgia, Athens, GA 30602 USA
| | - Keith A. Hobson
- Environment Canada, Saskatoon, SK S7N 3H5 Canada
- Department of Biology, University of Western Ontario, London, ON N6A 5B7 Canada
| | - Leonard I. Wassenaar
- International Atomic Energy Agency, Department of Nuclear Sciences and Applications, Vienna, A-1400 Austria
| | - D. Ryan Norris
- Department of Integrative Biology, University of Guelph, Guelph, ON N1G 2W1 Canada
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Becker DJ, Chumchal MM, Bentz AB, Platt SG, Czirják GÁ, Rainwater TR, Altizer S, Streicker DG. Predictors and immunological correlates of sublethal mercury exposure in vampire bats. R Soc Open Sci 2017; 4:170073. [PMID: 28484633 PMCID: PMC5414270 DOI: 10.1098/rsos.170073] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/27/2017] [Accepted: 03/21/2017] [Indexed: 05/21/2023]
Abstract
Mercury (Hg) is a pervasive heavy metal that often enters the environment from anthropogenic sources such as gold mining and agriculture. Chronic exposure to Hg can impair immune function, reducing the ability of animals to resist or recover from infections. How Hg influences immunity and susceptibility remains unknown for bats, which appear immunologically distinct from other mammals and are reservoir hosts of many pathogens of importance to human and animal health. We here quantify total Hg (THg) in hair collected from common vampire bats (Desmodus rotundus), which feed on blood and are the main reservoir hosts of rabies virus in Latin America. We examine how diet, sampling site and year, and bat demography influence THg and test the consequences of this variation for eight immune measures. In two populations from Belize, THg concentrations in bats were best explained by an interaction between long-term diet inferred from stable isotopes and year. Bats that foraged more consistently on domestic animals exhibited higher THg. However, relationships between diet and THg were evident only in 2015 but not in 2014, which could reflect recent environmental perturbations associated with agriculture. THg concentrations were low relative to values previously observed in other bat species but still correlated with bat immunity. Bats with higher THg had more neutrophils, weaker bacterial killing ability and impaired innate immunity. These patterns suggest that temporal variation in Hg exposure may impair bat innate immunity and increase susceptibility to pathogens such as bacteria. Unexpected associations between low-level Hg exposure and immune function underscore the need to better understand the environmental sources of Hg exposure in bats and the consequences for bat immunity and susceptibility.
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Affiliation(s)
- Daniel J. Becker
- Odum School of Ecology, University of Georgia, Athens, GA, USA
- Center for the Ecology of Infectious Disease, University of Georgia, Athens, GA, USA
- e-mail:
| | | | | | - Steven G. Platt
- Wildlife Conservation Society, Myanmar Program, Yangon, Myanmar
| | - Gábor Á. Czirják
- Department of Wildlife Diseases, Leibniz Institute for Zoo and Wildlife Research, Berlin, Germany
| | - Thomas R. Rainwater
- Tom Yawkey Wildlife Center and Belle W. Baruch Institute of Coastal Ecology and Forest Science, Clemson University, Georgetown, SC, USA
| | - Sonia Altizer
- Odum School of Ecology, University of Georgia, Athens, GA, USA
- Center for the Ecology of Infectious Disease, University of Georgia, Athens, GA, USA
| | - Daniel G. Streicker
- Odum School of Ecology, University of Georgia, Athens, GA, USA
- Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow G12 8QQ, UK
- MRC-University of Glasgow Centre for Virus Research, Glasgow G61 1QH, UK
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Rushmore J, Allison AB, Edwards EE, Bagal U, Altizer S, Cranfield MR, Glenn TC, Liu H, Mudakikwa A, Mugisha L, Muller MN, Stumpf RM, Thompson ME, Wrangham R, Yabsley MJ. Screening wild and semi-free ranging great apes for putative sexually transmitted diseases: Evidence of Trichomonadidae infections. Am J Primatol 2017; 79:1-2. [DOI: 10.1002/ajp.22645] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Satterfield DA, Altizer S, Williams MK, Hall RJ. Environmental Persistence Influences Infection Dynamics for a Butterfly Pathogen. PLoS One 2017; 12:e0169982. [PMID: 28099501 PMCID: PMC5242512 DOI: 10.1371/journal.pone.0169982] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2016] [Accepted: 12/27/2016] [Indexed: 11/19/2022] Open
Abstract
Many pathogens, including those infecting insects, are transmitted via dormant stages shed into the environment, where they must persist until encountering a susceptible host. Understanding how abiotic conditions influence environmental persistence and how these factors influence pathogen spread are crucial for predicting patterns of infection risk. Here, we explored the consequences of environmental transmission for infection dynamics of a debilitating protozoan parasite (Ophryocystis elektroscirrha) that infects monarch butterflies (Danaus plexippus). We first conducted an experiment to observe the persistence of protozoan spores exposed to natural conditions. Experimental results showed that, contrary to our expectations, pathogen doses maintained high infectivity even after 16 days in the environment, although pathogens did yield infections with lower parasite loads after environmental exposure. Because pathogen longevity exceeded the time span of our experiment, we developed a mechanistic model to better explore environmental persistence for this host-pathogen system. Model analysis showed that, in general, longer spore persistence led to higher infection prevalence and slightly smaller monarch population sizes. The model indicated that typical parasite doses shed onto milkweed plants must remain viable for a minimum of 3 weeks for prevalence to increase during the summer-breeding season, and for 11 weeks or longer to match levels of infection commonly reported from the wild, assuming moderate values for parasite shedding rate. Our findings showed that transmission stages of this butterfly pathogen are long-lived and indicated that this is a necessary condition for the protozoan to persist in local monarch populations. This study provides a modeling framework for future work examining the dynamics of an ecologically important pathogen in an iconic insect.
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Affiliation(s)
- Dara A. Satterfield
- Odum School of Ecology, University of Georgia, Athens, Georgia, United States of America
- * E-mail:
| | - Sonia Altizer
- Odum School of Ecology, University of Georgia, Athens, Georgia, United States of America
| | - Mary-Kate Williams
- Biological Sciences, University of Arkansas at Little Rock, Little Rock, Arkansas, United States of America
| | - Richard J. Hall
- Odum School of Ecology, University of Georgia, Athens, Georgia, United States of America
- Department of Infectious Diseases, College of Veterinary Medicine, University of Georgia, Athens, Georgia, United States of America
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Barriga PA, Sternberg ED, Lefèvre T, de Roode JC, Altizer S. Occurrence and host specificity of a neogregarine protozoan in four milkweed butterfly hosts (Danaus spp.). J Invertebr Pathol 2016; 140:75-82. [DOI: 10.1016/j.jip.2016.09.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2016] [Revised: 09/08/2016] [Accepted: 09/13/2016] [Indexed: 10/21/2022]
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37
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McKay AF, Ezenwa VO, Altizer S. Consequences of Food Restriction for Immune Defense, Parasite Infection, and Fitness in Monarch Butterflies. Physiol Biochem Zool 2016; 89:389-401. [DOI: 10.1086/687989] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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Stephens PR, Altizer S, Smith KF, Alonso Aguirre A, Brown JH, Budischak SA, Byers JE, Dallas TA, Jonathan Davies T, Drake JM, Ezenwa VO, Farrell MJ, Gittleman JL, Han BA, Huang S, Hutchinson RA, Johnson P, Nunn CL, Onstad D, Park A, Vazquez-Prokopec GM, Schmidt JP, Poulin R. The macroecology of infectious diseases: a new perspective on global-scale drivers of pathogen distributions and impacts. Ecol Lett 2016; 19:1159-71. [PMID: 27353433 DOI: 10.1111/ele.12644] [Citation(s) in RCA: 110] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2016] [Revised: 04/12/2016] [Accepted: 05/31/2016] [Indexed: 01/26/2023]
Abstract
Identifying drivers of infectious disease patterns and impacts at the broadest scales of organisation is one of the most crucial challenges for modern science, yet answers to many fundamental questions remain elusive. These include what factors commonly facilitate transmission of pathogens to novel host species, what drives variation in immune investment among host species, and more generally what drives global patterns of parasite diversity and distribution? Here we consider how the perspectives and tools of macroecology, a field that investigates patterns and processes at broad spatial, temporal and taxonomic scales, are expanding scientific understanding of global infectious disease ecology. In particular, emerging approaches are providing new insights about scaling properties across all living taxa, and new strategies for mapping pathogen biodiversity and infection risk. Ultimately, macroecology is establishing a framework to more accurately predict global patterns of infectious disease distribution and emergence.
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Affiliation(s)
| | - Sonia Altizer
- Odum School of Ecology, University of Georgia, Athens, GA, 30602, USA
| | - Katherine F Smith
- Department of Ecology and Evolutionary Biology, Brown University, Providence, RI, 0291, USA
| | - A Alonso Aguirre
- Department of Environmental Science and Policy, George Mason University, Fairfax, VA, 22030, USA
| | - James H Brown
- Department of Biology, University of New Mexico, Albuquerque, NM, 87131, USA
| | - Sarah A Budischak
- Odum School of Ecology, University of Georgia, Athens, GA, 30602, USA
| | - James E Byers
- Odum School of Ecology, University of Georgia, Athens, GA, 30602, USA
| | - Tad A Dallas
- Odum School of Ecology, University of Georgia, Athens, GA, 30602, USA
| | - T Jonathan Davies
- Department of Biology, McGill University, Montreal, Quebec, H3A 0G4, Canada
| | - John M Drake
- Odum School of Ecology, University of Georgia, Athens, GA, 30602, USA
| | - Vanessa O Ezenwa
- Odum School of Ecology, University of Georgia, Athens, GA, 30602, USA
| | - Maxwell J Farrell
- Department of Biology, McGill University, Montreal, Quebec, H3A 0G4, Canada
| | - John L Gittleman
- Odum School of Ecology, University of Georgia, Athens, GA, 30602, USA
| | - Barbara A Han
- Cary Institute of Ecosystem Studies, Millbrook, New York, 12545, USA
| | - Shan Huang
- Senckenberg Biodiversity and Climate Research Centre (BiK-F), Senckenberg Gesellschaft für Naturforschung, Senckenberganlage 25, 60325, Frankfurt, Germany
| | - Rebecca A Hutchinson
- School of Electrical Engineering and Computer Science, Oregon State University, Corvallis, OR, 97331, USA
| | - Pieter Johnson
- Department of Ecology and Evolutionary Biology, University of Colorado, Boulder, CO, 80309, USA
| | - Charles L Nunn
- Biological Sciences, Duke University, Durham, NC, 27708, USA
| | - David Onstad
- ITD Data Analysis and Modelling, DuPont Agricultural Biotechnology, Experimental Station E353/317, Wilmington, DE, 19803, USA
| | - Andrew Park
- Odum School of Ecology, University of Georgia, Athens, GA, 30602, USA
| | | | - John P Schmidt
- Odum School of Ecology, University of Georgia, Athens, GA, 30602, USA
| | - Robert Poulin
- Department of Zoology, University of Otago, Dunedin, 9054, New Zealand
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Fritzsche McKay A, Ezenwa VO, Altizer S. Unravelling the Costs of Flight for Immune Defenses in the Migratory Monarch Butterfly. Integr Comp Biol 2016; 56:278-89. [PMID: 27260859 DOI: 10.1093/icb/icw056] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Migratory animals undergo extreme physiological changes to prepare for and sustain energetically costly movements; one potential change is reduced investment in immune defenses. However, because some migrants have evolved to minimize the energetic demands of movement (for example, through the temporary atrophy of non-essential organs such as those involved in reproduction), migratory animals could potentially avoid immunosuppression during long-distance journeys. In this study, we used a tethered flight mill to examine immune consequences of experimentally induced powered flight in eastern North American monarch butterflies. These butterflies undergo an annual two-way long-distance migration each year from as far north as Canada to wintering sites in Central Mexico. We quantified immune measures as a function of categorical flight treatment (flown versus control groups) and continuous measures of flight effort (e.g., flight distance, duration, and measures of efficiency). We also examined whether relationships between flight and immune measures depended on reproductive investment by experimentally controlling whether monarchs were reproductive or in state of reproductive diapause (having atrophied reproductive organs) prior to flight. Of the three immune responses we measured, hemocyte concentration (the number of immune cells) was lower in flown monarchs relative to controls but increased with flight distance among flown monarchs; the other two immune measures showed no relationship to monarch flight. We also found that monarchs that were reproductively active were less efficient fliers, as they exerted more power during flight than monarchs in reproductive diapause. However, reproductive status did not modify relationships between flight and immune measures. Results of this study add to a growing body of work suggesting that migratory monarchs-like some other animals that travel vast distances-can complete their journeys with efficient use of resources and minimal costs.
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Affiliation(s)
| | - Vanessa O Ezenwa
- *Odum School of Ecology, University of Georgia, Athens, GA 30602, USA Department of Infectious Diseases, College of Veterinary Medicine, University of Georgia, Athens, GA 30602, USA
| | - Sonia Altizer
- *Odum School of Ecology, University of Georgia, Athens, GA 30602, USA
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Satterfield DA, Villablanca FX, Maerz JC, Altizer S. Migratory monarchs wintering in California experience low infection risk compared to monarchs breeding year-round on non-native milkweed. Integr Comp Biol 2016; 56:343-52. [PMID: 27252207 DOI: 10.1093/icb/icw030] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Long-distance migration can lower infection risk for animal populations by removing infected individuals during strenuous journeys, spatially separating susceptible age classes, or allowing migrants to periodically escape from contaminated habitats. Many seasonal migrations are changing due to human activities including climate change and habitat alteration. Moreover, for some migratory populations, sedentary behaviors are becoming more common as migrants abandon or shorten their journeys in response to supplemental feeding or warming temperatures. Exploring the consequences of reduced movement for host-parasite interactions is needed to predict future responses of animal pathogens to anthropogenic change. Monarch butterflies (Danaus plexippus) and their specialist protozoan parasite Ophryocystis elektroscirrha (OE) provide a model system for examining how long-distance migration affects infectious disease processes in a rapidly changing world. Annual monarch migration from eastern North America to Mexico is known to reduce protozoan infection prevalence, and more recent work suggests that monarchs that forego migration to breed year-round on non-native milkweeds in the southeastern and south central Unites States face extremely high risk of infection. Here, we examined the prevalence of OE infection from 2013 to 2016 in western North America, and compared monarchs exhibiting migratory behavior (overwintering annually along the California coast) with those that exhibit year-round breeding. Data from field collections and a joint citizen science program of Monarch Health and Monarch Alert showed that infection frequency was over nine times higher for monarchs sampled in gardens with year-round milkweed as compared to migratory monarchs sampled at overwintering sites. Results here underscore the importance of animal migrations for lowering infection risk and motivate future studies of pathogen transmission in migratory species affected by environmental change.
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Affiliation(s)
| | - Francis X Villablanca
- Biological Sciences Department, California Polytechnic State University, San Luis Obispo, CA 93407, USA
| | - John C Maerz
- Warnell School of Forestry and Natural Resources, University of Georgia, Athens, GA 30602, USA
| | - Sonia Altizer
- *Odum School of Ecology, University of Georgia, Athens, GA 30602, USA
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Abstract
Recent theory suggests that animals that migrate to breed at higher latitudes may benefit from reduced pressure from natural enemies, including pathogens ("migratory escape"), and that migration itself weeds out infected individuals and lowers infection prevalence ("migratory culling"). The distribution and activity period of arthropod disease vectors in temperate regions is expected to respond rapidly to climate change, which could reduce the potential for migratory escape. However, climate change could have the opposite effect of reducing transmission if differential responses in the phenology and distribution of migrants and disease vectors reduce their overlap in space and time. Here we outline a simple modeling framework for exploring the influence of climate change on vector-borne disease dynamics in a migratory host. We investigate two scenarios under which pathogen transmission dynamics might be mediated by climate change: (1) vectors respond more rapidly than migrants to advancing phenology at temperate breeding sites, causing peak susceptible host density and vector emergence to diverge ("migratory mismatch") and (2) reduced migratory propensity allows increased nonbreeding survival of infected hosts and larger breeding-site epidemics (loss of migratory culling, here referred to as "sedentary amplification"). Our results highlight the need for continued surveillance of climate-induced changes to migratory behavior and vector activity to predict pathogen prevalence and its impacts on migratory animals.
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Affiliation(s)
- Richard J Hall
- Odum School of Ecology and Department of Infectious Diseases, College of Veterinary Medicine (both University of Georgia, Athens, GA, 30602 USA). The Odum School of Ecology affiliation is correct for co-authors Brown and Altizer
| | - Leone M Brown
- Odum School of Ecology and Department of Infectious Diseases, College of Veterinary Medicine (both University of Georgia, Athens, GA, 30602 USA). The Odum School of Ecology affiliation is correct for co-authors Brown and Altizer
| | - Sonia Altizer
- Odum School of Ecology and Department of Infectious Diseases, College of Veterinary Medicine (both University of Georgia, Athens, GA, 30602 USA). The Odum School of Ecology affiliation is correct for co-authors Brown and Altizer
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Altizer S, Hobson KA, Davis AK, De Roode JC, Wassenaar LI. Do Healthy Monarchs Migrate Farther? Tracking Natal Origins of Parasitized vs. Uninfected Monarch Butterflies Overwintering in Mexico. PLoS One 2015; 10:e0141371. [PMID: 26606389 PMCID: PMC4659535 DOI: 10.1371/journal.pone.0141371] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2015] [Accepted: 10/06/2015] [Indexed: 11/19/2022] Open
Abstract
Long-distance migration can lower parasite prevalence if strenuous journeys remove infected animals from wild populations. We examined wild monarch butterflies (Danaus plexippus) to investigate the potential costs of the protozoan Ophryocystis elektroscirrha on migratory success. We collected monarchs from two wintering sites in central Mexico to compare infection status with hydrogen isotope (δ2H) measurements as an indicator of latitude of origin at the start of fall migration. On average, uninfected monarchs had lower δ2H values than parasitized butterflies, indicating that uninfected butterflies originated from more northerly latitudes and travelled farther distances to reach Mexico. Within the infected class, monarchs with higher quantitative spore loads originated from more southerly latitudes, indicating that heavily infected monarchs originating from farther north are less likely to reach Mexico. We ruled out the alternative explanation that lower latitudes give rise to more infected monarchs prior to the onset of migration using citizen science data to examine regional differences in parasite prevalence during the summer breeding season. We also found a positive association between monarch wing area and estimated distance flown. Collectively, these results emphasize that seasonal migrations can help lower infection levels in wild animal populations. Our findings, combined with recent declines in the numbers of migratory monarchs wintering in Mexico and observations of sedentary (winter breeding) monarch populations in the southern U.S., suggest that shifts from migratory to sedentary behavior will likely lead to greater infection prevalence for North American monarchs.
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Affiliation(s)
- Sonia Altizer
- Odum School of Ecology, University of Georgia, Athens, Georgia, United States of America
- * E-mail:
| | - Keith A. Hobson
- Environment Canada, 11 Innovation Blvd., Saskatoon, Saskatchewan, Canada
- Department of Biology, University of Western Ontario, London, Ontario, Canada
| | - Andrew K. Davis
- Odum School of Ecology, University of Georgia, Athens, Georgia, United States of America
| | - Jacobus C. De Roode
- Department of Biology, Emory University, Atlanta, Georgia, United States of America
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Abstract
Long-distance animal migrations have important consequences for infectious disease dynamics. In some cases, migration lowers pathogen transmission by removing infected individuals during strenuous journeys and allowing animals to periodically escape contaminated habitats. Human activities are now causing some migratory animals to travel shorter distances or form sedentary (non-migratory) populations. We focused on North American monarch butterflies and a specialist protozoan parasite to investigate how the loss of migratory behaviours affects pathogen spread and evolution. Each autumn, monarchs migrate from breeding grounds in the eastern US and Canada to wintering sites in central Mexico. However, some monarchs have become non-migratory and breed year-round on exotic milkweed in the southern US. We used field sampling, citizen science data and experimental inoculations to quantify infection prevalence and parasite virulence among migratory and sedentary populations. Infection prevalence was markedly higher among sedentary monarchs compared with migratory monarchs, indicating that diminished migration increases infection risk. Virulence differed among parasite strains but was similar between migratory and sedentary populations, potentially owing to high gene flow or insufficient time for evolutionary divergence. More broadly, our findings suggest that human activities that alter animal migrations can influence pathogen dynamics, with implications for wildlife conservation and future disease risks.
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Affiliation(s)
| | - John C Maerz
- Warnell School of Forestry and Natural Resources, University of Georgia, Athens, GA 30602, USA
| | - Sonia Altizer
- Odum School of Ecology, University of Georgia, Athens, GA 30602, USA
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Pierce AA, Zalucki MP, Bangura M, Udawatta M, Kronforst MR, Altizer S, Haeger JF, de Roode JC. Serial founder effects and genetic differentiation during worldwide range expansion of monarch butterflies. Proc Biol Sci 2015; 281:rspb.2014.2230. [PMID: 25377462 DOI: 10.1098/rspb.2014.2230] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Range expansions can result in founder effects, increasing genetic differentiation between expanding populations and reducing genetic diversity along the expansion front. However, few studies have addressed these effects in long-distance migratory species, for which high dispersal ability might counter the effects of genetic drift. Monarchs (Danaus plexippus) are best known for undertaking a long-distance annual migration in North America, but have also dispersed around the world to form populations that do not migrate or travel only short distances. Here, we used microsatellite markers to assess genetic differentiation among 18 monarch populations and to determine worldwide colonization routes. Our results indicate that North American monarch populations connected by land show limited differentiation, probably because of the monarch's ability to migrate long distances. Conversely, we found high genetic differentiation between populations separated by large bodies of water. Moreover, we show evidence for serial founder effects across the Pacific, suggesting stepwise dispersal from a North American origin. These findings demonstrate that genetic drift played a major role in shaping allele frequencies and created genetic differentiation among newly formed populations. Thus, range expansion can give rise to genetic differentiation and declines in genetic diversity, even in highly mobile species.
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Affiliation(s)
- Amanda A Pierce
- Department of Biology, Emory University, Atlanta, GA 30322, USA
| | - Myron P Zalucki
- School of Biological Sciences, The University of Queensland, Brisbane 4072, Australia
| | - Marie Bangura
- Department of Biology, Emory University, Atlanta, GA 30322, USA
| | - Milan Udawatta
- Department of Biology, Emory University, Atlanta, GA 30322, USA
| | - Marcus R Kronforst
- Department of Ecology and Evolution, University of Chicago, Chicago, IL 60637, USA
| | - Sonia Altizer
- Odum School of Ecology, University of Georgia, Athens, GA 30602, USA
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Rushmore J, Allison AB, Edwards EE, Bagal U, Altizer S, Cranfield MR, Glenn TC, Liu H, Mudakikwa A, Mugisha L, Muller MN, Stumpf RM, Thompson ME, Wrangham R, Yabsley MJ. Screening wild and semi-free ranging great apes for putative sexually transmitted diseases: Evidence of Trichomonadidae infections. Am J Primatol 2015; 77:1075-85. [PMID: 26119266 DOI: 10.1002/ajp.22442] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2015] [Accepted: 06/02/2015] [Indexed: 11/07/2022]
Abstract
Sexually transmitted diseases (STDs) can persist endemically, are known to cause sterility and infant mortality in humans, and could have similar impacts in wildlife populations. African apes (i.e., chimpanzees, bonobos, and to a lesser extent gorillas) show multi-male mating behavior that could offer opportunities for STD transmission, yet little is known about the prevalence and impact of STDs in this endangered primate group. We used serology and PCR-based detection methods to screen biological samples from wild and orphaned eastern chimpanzees and gorillas (N = 172 individuals, including adults, and juveniles) for four classes of pathogens that either commonly cause human STDs or were previously detected in captive apes: trichomonads, Chlamydia spp., Treponema pallidum (syphilis and yaws), and papillomaviruses. Based on results from prior modeling and comparative research, we expected STD prevalence to be highest in females versus males and in sexually mature versus immature individuals. All samples were negative for Chlamydia, Treponema pallidum, and papillomaviruses; however, a high percentage of wild chimpanzee urine and fecal samples showed evidence of trichomonads (protozoa). Analysis revealed that females were more likely than males to have positive urine-but not fecal-samples; however, there was no evidence of age (sexual maturity) differences in infection status. Sequence analysis of chimpanzee trichomonad samples revealed a close relationship to previously described trichomonads within the genus Tetratrichomonas. Phylogenetic comparisons to archived sequences from multiple vertebrate hosts suggests that many of the chimpanzee parasites from our study are likely transmitted via fecal-oral contact, but the transmission of some Tetratrichomonas sequence-types remains unknown and could include sexual contact. Our work emphasizes that only a fraction of infectious agents affecting wild apes are presently known to science, and that further work on great ape STDs could offer insights for the management of endangered great apes and for understanding human STD origins.
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Affiliation(s)
- Julie Rushmore
- Odum School of Ecology, The University of Georgia, Athens, Georgia
- College of Veterinary Medicine, The University of Georgia, Athens, Georgia
| | - Andrew B Allison
- Baker Institute for Animal Health, Department of Microbiology and Immunology, College of Veterinary Medicine, Cornell University, Ithaca, New York
| | - Erin E Edwards
- College of Veterinary Medicine, The University of Georgia, Athens, Georgia
| | - Ujwal Bagal
- Institute of Bioinformatics, The University of Georgia, Athens, Georgia
| | - Sonia Altizer
- Odum School of Ecology, The University of Georgia, Athens, Georgia
| | - Mike R Cranfield
- Gorilla Doctors, Wildlife Health Center, University of California Davis, Davis, California
- The Department of Molecular and Pathobiology, Johns Hopkins School of Medicine, Baltimore, Maryland
| | - Travis C Glenn
- Department of Environmental Health Science, The University of Georgia, Athens, Georgia
| | - Hsi Liu
- National Center for HIV/AIDS, Viral Hepatitis, STD, and TB Prevention, Centers for Disease Control, Athens, Georgia
| | - Antoine Mudakikwa
- Rwanda Development Board, Department of Tourism and Conservation, Kigali, Rwanda
| | - Lawrence Mugisha
- Conservation and Ecosystem Health Alliance (CEHA), Kampala, Uganda
- College of Veterinary Medicine, Animal Resources and Biosecurity, Makerere University, Kampala, Uganda
| | - Martin N Muller
- Department of Anthropology, University of New Mexico, Albuquerque, New Mexico
| | - Rebecca M Stumpf
- Department of Anthropology, University of Illinois at Urbana-Champaign, Urbana, Illinois
| | | | - Richard Wrangham
- Department of Human Evolutionary Biology, Harvard University, Cambridge, Massachusetts
| | - Michael J Yabsley
- Warnell School of Forestry and Natural Resources, The University of Georgia and the Southeastern Cooperative Wildlife Disease Study, Department of Population Health, College of Veterinary Medicine, The University of Georgia, Athens, Georgia
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Becker DJ, Streicker DG, Altizer S. Linking anthropogenic resources to wildlife-pathogen dynamics: a review and meta-analysis. Ecol Lett 2015; 18:483-95. [PMID: 25808224 PMCID: PMC4403965 DOI: 10.1111/ele.12428] [Citation(s) in RCA: 211] [Impact Index Per Article: 23.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2014] [Revised: 08/19/2014] [Accepted: 02/12/2015] [Indexed: 11/30/2022]
Abstract
Urbanisation and agriculture cause declines for many wildlife, but some species benefit from novel resources, especially food, provided in human-dominated habitats. Resulting shifts in wildlife ecology can alter infectious disease dynamics and create opportunities for cross-species transmission, yet predicting host-pathogen responses to resource provisioning is challenging. Factors enhancing transmission, such as increased aggregation, could be offset by better host immunity due to improved nutrition. Here, we conduct a review and meta-analysis to show that food provisioning results in highly heterogeneous infection outcomes that depend on pathogen type and anthropogenic food source. We also find empirical support for behavioural and immune mechanisms through which human-provided resources alter host exposure and tolerance to pathogens. A review of recent theoretical models of resource provisioning and infection dynamics shows that changes in host contact rates and immunity produce strong non-linear responses in pathogen invasion and prevalence. By integrating results of our meta-analysis back into a theoretical framework, we find provisioning amplifies pathogen invasion under increased host aggregation and tolerance, but reduces transmission if provisioned food decreases dietary exposure to parasites. These results carry implications for wildlife disease management and highlight areas for future work, such as how resource shifts might affect virulence evolution.
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Affiliation(s)
- Daniel J Becker
- Odum School of Ecology, University of Georgia, Athens, GA, USA
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Huang S, Drake JM, Gittleman JL, Altizer S. Parasite diversity declines with host evolutionary distinctiveness: a global analysis of carnivores. Evolution 2015; 69:621-30. [PMID: 25639279 DOI: 10.1111/evo.12611] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2014] [Accepted: 01/16/2015] [Indexed: 01/03/2023]
Abstract
Evolutionarily distinctive host lineages might harbor fewer parasite species because they have fewer opportunities for parasite sharing than hosts having extant close relatives, or because diverse parasite assemblages promote host diversification. We evaluate these hypotheses using data from 930 species of parasites reported to infect free-living carnivores. We applied nonparametric richness estimators to estimate parasite diversity among well-sampled carnivore species and assessed how well host evolutionary distinctiveness, relative to other biological and environmental factors, explained variation in estimated parasite diversity. Species richness estimates indicate that the current published literature captures less than 50% of the true parasite diversity for most carnivores. Parasite species richness declined with evolutionary distinctiveness of carnivore hosts (i.e., length of terminal ranches of the phylogeny) and increased with host species body mass and geographic range area. We found no support for the hypothesis that hosts from more diverse lineages support a higher number of generalist parasites, but we did find evidence that parasite assemblages might have driven host lineage diversification through mechanisms linked to sexual selection. Collectively, this work provides strong support for host evolutionary history being an essential predictor of parasite diversity, and offers a simple model for predicting parasite diversity in understudied carnivore species.
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Affiliation(s)
- Shan Huang
- Odum School of Ecology, University of Georgia, Athens, Georgia, 30602; Department of Geophysical Sciences, University of Chicago, Chicago, Illinois, 60637.
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48
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Han BA, Park AW, Jolles AE, Altizer S. Infectious disease transmission and behavioural allometry in wild mammals. J Anim Ecol 2015; 84:637-646. [PMID: 25631200 DOI: 10.1111/1365-2656.12336] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2014] [Accepted: 11/26/2014] [Indexed: 01/15/2023]
Abstract
Animals' social and movement behaviours can impact the transmission dynamics of infectious diseases, especially for pathogens transmitted through close contact between hosts or through contact with infectious stages in the environment. Estimating pathogen transmission rates and R0 from natural systems can be challenging. Because host behavioural traits that underlie the transmission process vary predictably with body size, one of the best-studied traits among animals, body size might therefore also predict variation in parasite transmission dynamics. Here, we examine how two host behaviours, social group living and the intensity of habitat use, scale allometrically using comparative data from wild primate, carnivore and ungulate species. We use these empirical relationships to parameterize classical compartment models for infectious micro- and macroparasitic diseases, and examine how the risk of pathogen invasion changes as a function of host behaviour and body size. We then test model predictions using comparative data on parasite prevalence and richness from wild mammals. We report a general pattern suggesting that smaller-bodied mammal species utilizing home ranges more intensively experience greater risk for invasion by environmentally transmitted macroparasites. Conversely, larger-bodied hosts exhibiting a high degree of social group living could be more readily invaded by directly transmitted microparasites. These trends were supported through comparison of micro- and macroparasite species richness across a large number of carnivore, primate and ungulate species, but empirical data on carnivore macroparasite prevalence showed mixed results. Collectively, our study demonstrates that combining host behavioural traits with dynamical models of infectious disease scaled against host body size can generate testable predictions for variation in parasite risk across species; a similar approach might be useful in future work focused on predicting parasite distributions in local host communities.
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Affiliation(s)
- Barbara A Han
- Cary Institute for Ecosystem Studies, Box AB Millbrook, NY 12545, USA.,University of Georgia, Odum School of Ecology, 140 E, Green Street Athens, GA 30602, USA
| | - Andrew W Park
- University of Georgia, Odum School of Ecology, 140 E, Green Street Athens, GA 30602, USA.,University of Georgia, Department of Infectious Diseases, College of Veterinary Medicine, 501 D, W. Brooks Dr. Athens, GA 30602, USA
| | - Anna E Jolles
- Oregon State University, College of Veterinary Medicine and Department of Zoology, 105 Magruder Hall Corvallis, OR 97331-4801, USA
| | - Sonia Altizer
- University of Georgia, Odum School of Ecology, 140 E, Green Street Athens, GA 30602, USA
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Rushmore J, Caillaud D, Hall RJ, Stumpf RM, Meyers LA, Altizer S. Network-based vaccination improves prospects for disease control in wild chimpanzees. J R Soc Interface 2015; 11:20140349. [PMID: 24872503 DOI: 10.1098/rsif.2014.0349] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Many endangered wildlife populations are vulnerable to infectious diseases for which vaccines exist; yet, pragmatic considerations often preclude large-scale vaccination efforts. These barriers could be reduced by focusing on individuals with the highest contact rates. However, the question then becomes whether targeted vaccination is sufficient to prevent large outbreaks. To evaluate the efficacy of targeted wildlife vaccinations, we simulate pathogen transmission and control on monthly association networks informed by behavioural data from a wild chimpanzee community (Kanyawara N = 37, Kibale National Park, Uganda). Despite considerable variation across monthly networks, our simulations indicate that targeting the most connected individuals can prevent large outbreaks with up to 35% fewer vaccines than random vaccination. Transmission heterogeneities might be attributed to biological differences among individuals (e.g. sex, age, dominance and family size). Thus, we also evaluate the effectiveness of a trait-based vaccination strategy, as trait data are often easier to collect than interaction data. Our simulations indicate that a trait-based strategy can prevent large outbreaks with up to 18% fewer vaccines than random vaccination, demonstrating that individual traits can serve as effective estimates of connectivity. Overall, these results suggest that fine-scale behavioural data can help optimize pathogen control efforts for endangered wildlife.
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Affiliation(s)
- Julie Rushmore
- Odum School of Ecology, University of Georgia, Athens, GA 30602, USA College of Veterinary Medicine, University of Georgia, Athens, GA 30602, USA
| | - Damien Caillaud
- The Dian Fossey Gorilla Fund International, Atlanta, GA 30315, USA Section of Integrative Biology, The University of Texas at Austin, Austin, TX 78712, USA
| | - Richard J Hall
- Odum School of Ecology, University of Georgia, Athens, GA 30602, USA
| | - Rebecca M Stumpf
- Department of Anthropology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Lauren Ancel Meyers
- Section of Integrative Biology, The University of Texas at Austin, Austin, TX 78712, USA
| | - Sonia Altizer
- Odum School of Ecology, University of Georgia, Athens, GA 30602, USA
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Pierce AA, de Roode JC, Altizer S, Bartel RA. Extreme heterogeneity in parasitism despite low population genetic structure among monarch butterflies inhabiting the Hawaiian Islands. PLoS One 2014; 9:e100061. [PMID: 24926796 PMCID: PMC4057267 DOI: 10.1371/journal.pone.0100061] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2013] [Accepted: 05/22/2014] [Indexed: 11/18/2022] Open
Abstract
Host movement and spatial structure can strongly influence the ecology and evolution of infectious diseases, with limited host movement potentially leading to high spatial heterogeneity in infection. Monarch butterflies (Danaus plexippus) are best known for undertaking a spectacular long-distance migration in eastern North America; however, they also form non-migratory populations that breed year-round in milder climates such as Hawaii and other tropical locations. Prior work showed an inverse relationship between monarch migratory propensity and the prevalence of the protozoan parasite, Ophryocystis elektroscirrha. Here, we sampled monarchs from replicate sites within each of four Hawaiian Islands to ask whether these populations show consistently high prevalence of the protozoan parasite as seen for monarchs from several other non-migratory populations. Counter to our predictions, we observed striking spatial heterogeneity in parasite prevalence, with infection rates per site ranging from 4-85%. We next used microsatellite markers to ask whether the observed variation in infection might be explained by limited host movement and spatial sub-structuring among sites. Our results showed that monarchs across the Hawaiian Islands form one admixed population, supporting high gene flow among sites. Moreover, measures of individual-level genetic diversity did not predict host infection status, as might be expected if more inbred hosts harbored higher parasite loads. These results suggest that other factors such as landscape-level environmental variation or colonization-extinction processes might instead cause the extreme heterogeneity in monarch butterfly infection observed here.
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Affiliation(s)
- Amanda A. Pierce
- Biology Department, Emory University, Atlanta, Georgia, United States of America
- * E-mail:
| | - Jacobus C. de Roode
- Biology Department, Emory University, Atlanta, Georgia, United States of America
| | - Sonia Altizer
- Odum School of Ecology, University of Georgia, Athens, Georgia, United States of America
| | - Rebecca A. Bartel
- Odum School of Ecology, University of Georgia, Athens, Georgia, United States of America
- Red Wolf Recovery Program, United States Fish and Wildlife Service, Manteo, North Carolina, United States of America
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