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Portner COS, Rong EG, Ramirez JA, Wolf YI, Bosse AP, Koonin EV, Rochman ND. Host age structure reshapes parasite symbiosis: collaboration begets pathogens, competition begets virulent mutualists. Biol Direct 2022; 17:30. [DOI: 10.1186/s13062-022-00343-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2022] [Accepted: 10/14/2022] [Indexed: 11/13/2022] Open
Abstract
Abstract
Background
Symbiotic relationships are ubiquitous in the biosphere. Inter-species symbiosis is impacted by intra-specific distinctions, in particular, those defined by the age structure of a population. Older individuals compete with younger individuals for resources despite being less likely to reproduce, diminishing the fitness of the population. Conversely, however, older individuals can support the reproduction of younger individuals, increasing the population fitness. Parasitic relationships are commonly age structured, typically, more adversely affecting older hosts.
Results
We employ mathematical modeling to explore the differential effects of collaborative or competitive host age structures on host-parasite relationships. A classical epidemiological compartment model is constructed with three disease states: susceptible, infected, and recovered. Each of these three states is partitioned into two compartments representing young, potentially reproductive, and old, post-reproductive, hosts, yielding 6 compartments in total. In order to describe competition and collaboration between old and young compartments, we model the reproductive success to depend on the fraction of young individuals in the population. Collaborative populations with relatively greater numbers of post-reproductive hosts enjoy greater reproductive success whereas in purely competitive populations, increasing the post-reproductive subpopulation reduces reproductive success.
Conclusions
We demonstrate that, in collaborative host populations, pathogens strictly impacting older, post-reproductive individuals can reduce population fitness even more than pathogens that directly impact younger, potentially reproductive individuals. In purely competitive populations, the reverse is observed, and we demonstrate that endemic, virulent pathogens can oxymoronically form a mutualistic relationship with the host, increasing the fitness of the host population. Applications to endangered species conservation and invasive species containment are discussed.
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Catalano S, La Morgia V, Molinar Min AR, Fanelli A, Meneguz PG, Tizzani P. Gastrointestinal Parasite Community and Phenotypic Plasticity in Native and Introduced Alien Lagomorpha. Animals (Basel) 2022; 12:ani12101287. [PMID: 35625133 PMCID: PMC9138120 DOI: 10.3390/ani12101287] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2022] [Revised: 05/07/2022] [Accepted: 05/12/2022] [Indexed: 02/01/2023] Open
Abstract
Simple Summary The introduction of alien species outside their native range represents one of the main threats to biodiversity conservation and it is mainly driven by human activities. In this work, we used the introduction of an alien lagomorph (Sylvilagus floridanus) outside its natural range as a case study to describe and evaluate the long-term effects on the native lagomorph community. In particular, S. floridanus was host to different exotic parasites, which adapted to new biotic and abiotic conditions and, as a consequence, invaded and largely altered the parasite community of native Lagomorpha species. This work represents the first exploratory study on the ecological macro-community formed by native and alien host species and their parasitofauna. Further efforts are needed to fully understand the strategies and factors conditioning the evolution of these specific parasite communities, and more in general the factors influencing the effect and evolution of alien pathogens in a new geographic area. Abstract The Convention on Biological Diversity classifies “Invasive Alien Species” as those whose introduction and spread represents a threat for biodiversity. Introduction of alien pathogens, including parasites, is one of the main consequences of the introduction of invasive alien species. The objective of this work was to assess the parasite community composition in native lagomorphs (Lepus europaeus and Lepus timidus varronis) in sympatric and non-sympatric conditions with an alien lagomorph (Sylvilagus floridanus), and to evaluate the phenotypic traits of exotic parasites in such conditions. We firstly describe the characteristics of the parasite community in the different host species (richness, prevalence, abundance and intensity), and, secondly, the phenotypic traits of the observed parasite species in each host. Nine helminths were reported on: eight nematodes (Obeliscoides cuniculi, Trichostrongylus calcaratus, Trichostrongylus retortaeformis, Trichostrongylus affinis, Trichuris leporis, Trichostrongylus colubriformis, Passalurus ambiguus, and Nematodirus sp.) and one unidentified cestode. In addition, exotic parasites showed significantly different phenotypic plasticity after spillover from S. floridanus to L. europaeus, whereas endemic parasite species were not isolated in the alien S. floridanus. Our results highlight that the community of autochthonous and allochthonous Lagomorpha in northwestern Italy represents an extremely interesting system for modelling ecological and evolutionary interactions between parasites and their hosts.
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Affiliation(s)
- Stefano Catalano
- Department of Veterinary Medicine and Animal Production, University of Naples Federico II, 80137 Naples, Italy;
- Moredun Research Institute, Pentlands Science Park, Penicuik EH26 0PZ, UK
| | - Valentina La Morgia
- Institute for Environmental Protection and Research (ISPRA), Via Ca’ Fornacetta 9, Ozzano Emilia, 40064 Bologna, Italy;
| | - Anna Rita Molinar Min
- Department of Veterinary Sciences, University of Turin, Largo Paolo Braccini 2, Grugliasco, 10095 Turin, Italy; (A.R.M.M.); (P.G.M.)
| | - Angela Fanelli
- Department of Veterinary Medicine, University of Bari, Valenzano, 70010 Bari, Italy;
| | - Pier Giuseppe Meneguz
- Department of Veterinary Sciences, University of Turin, Largo Paolo Braccini 2, Grugliasco, 10095 Turin, Italy; (A.R.M.M.); (P.G.M.)
| | - Paolo Tizzani
- Department of Veterinary Sciences, University of Turin, Largo Paolo Braccini 2, Grugliasco, 10095 Turin, Italy; (A.R.M.M.); (P.G.M.)
- Correspondence:
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Frogge H, Jones RA, Angedakin S, Busobozi R, Kabagambe P, Angwela FO, Thompson González N, Brown M. Constraints on population growth of blue monkeys (Cercopithecus mitis) in Kibale National Park, Uganda. BEHAVIOUR 2022. [DOI: 10.1163/1568539x-bja10160] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Abstract
Changes in population size are driven by environmental and social factors. In spite of repeated efforts to identify the constraints on an unusually low-density population of blue monkeys (Cercopithecus mitis), it remains unclear why this generalist species fails to thrive in Kibale National Park in Uganda. While an unidentified disease may occasionally obstruct conception, it does not seem to limit overall reproductive rates. Infanticide at this site is infrequent due to the long tenures of resident males. Our analyses indicate that the single biggest constraint on blue monkey densities may be feeding competition with grey-cheeked mangabeys (Lophocebus albigena): across Kibale, the densities of these two species are strongly and negatively correlated. Though further analysis is needed to understand the timing and strength of feeding competition between them, we conclude that blue monkeys at Ngogo experience competitive exclusion from grey-cheeked mangabeys, possibly resolving the 50-year mystery surrounding this population.
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Affiliation(s)
- Hannah Frogge
- Department of Anthropology, University of California, Santa Barbara, CA, USA
| | - Revee A. Jones
- Division of Solid Tumor Oncology, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Samuel Angedakin
- Department of Primatology, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany
| | | | - Prime Kabagambe
- Makerere University Biological Field Stations, Kampala, Uganda
| | - Felix O. Angwela
- Makerere University Biological Field Stations, Kampala, Uganda
- School of Agriculture and Environmental Science, Mountains of the Moon University, Fort Portal, Uganda
| | | | - Michelle Brown
- Department of Anthropology, University of California, Santa Barbara, CA, USA
- Department for the Ecology of Animal Societies, Max Planck Institute of Animal Behavior, Konstanz, Germany
- Department of Biology, University of Konstanz, Konstanz, Germany
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Bethge J, Razafimampiandra JC, Wulff A, Dausmann KH. Seasonal changes in the parasite prevalence of a small Malagasy lemur species (Lepilemur edwardsi). Integr Zool 2022; 18:427-439. [PMID: 35276032 DOI: 10.1111/1749-4877.12647] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
Parasitic infections can impact the fitness of individuals and can have influence on animals' population dynamics. An individuals' parasite prevalence often changes depending on external or seasonal changes, e.g., rainfall and ambient temperatures, but also on internal changes, e.g., changes in body condition. In this study we aimed to identify the environmental factors that may influence the intestinal parasite and ectoparasite prevalence of the folivorous Malagasy primate species, Lepilemur edwardsi, living in a seasonal dry deciduous forest. Species living in this habitat have to adapt to seasonal changes of ambient temperature, with almost no precipitation during the dry season and hence strong fluctuations of resource availability throughout the year. We sampled the feces and ectoparasites of L. edwardsi throughout the year. Intestinal parasite prevalence increased from the wet to the dry season and was highest in the late dry season, which might be due to the accompanying decrease in diet-quality. Conversely, ectoparasite prevalence decreased in the dry season, presumably due to the prevailing unfavorable environmental conditions for the development of ectoparasites (i.e., mites and ticks). Paired with the higher resting metabolism and stress level of L. edwardsi during the late dry season, it seems that this species may struggle when dry seasons intensify in its habitat. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Janina Bethge
- Institute of Zoology, Functional Ecology, Universität Hamburg, Martin-Luther-King-Platz 3, Hamburg, 20146, Germany
| | - Jean Claude Razafimampiandra
- Mention Zoologie et Biodiversité Animale, Faculté des Sciences, Université d'Antananarivo, B.P. 906, 101, Antananarivo, Madagascar
| | - Arne Wulff
- Institute of Zoology, Functional Ecology, Universität Hamburg, Martin-Luther-King-Platz 3, Hamburg, 20146, Germany
| | - Kathrin H Dausmann
- Institute of Zoology, Functional Ecology, Universität Hamburg, Martin-Luther-King-Platz 3, Hamburg, 20146, Germany
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Determinants of prevalence and co-infestation by ecto- and endoparasites in the Atlas day gecko, Quedenfeldtia trachyblepharus, an endemic species of Morocco. Parasitol Res 2021; 120:2543-2556. [PMID: 33748890 DOI: 10.1007/s00436-021-07120-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Accepted: 03/09/2021] [Indexed: 10/21/2022]
Abstract
The present work was undertaken to investigate the occurrence of ectoparasites (mites and ticks) and endoparasites (haemogregarines and helminths) in the Atlas day gecko, Quedenfeldtia trachyblepharus (Boettger, 1874), a high-altitude Moroccan endemic lizard. The study examinated also the effect of some host parameters (age, sex, size, body condition), in addition to the season and altitude on the prevalence and intensity of parasite infestations. The study was conducted in three localities from May to September 2019. The results indicated that 35% of juvenile geckos were found to be parasited by one type of parasite. Contrarily, up to three types of parasites were detected in the adults. The prevalence of mite infestations was 48.02%, with a mean intensity of 11.80 ± 15.69. The patterns of mite infestations was found to be mainly related to the altitude, while the prevalence and intensity of infestations were linked to the host size, and to the sex and season, respectively. Larvae and nymphs of Ixodes ricinus (Linnaeus, 1758) were the only life stages infesting geckos, with a prevalence and mean intensity of infestations of 4.41% and 2.2 ± 1.48, respectively. The tick infestations observed were mainly related to the season. The prevalence and intensity of haemogregarine infections were, respectively, 7.92% and 0.24 ± 0.15. The altitude was found to be the only factor associated with this infection. This study also revealed the presence of one helminth genus, Spauligodon sp., with a prevalence and mean intensity of 12.33% and 1.46 ± 0.88, respectively. Spauligodon infestations was significantly associated with age, host size and altitude. This finding represents the first citation of this parasite in Quedenfeldtia genus. Our study indicated that there was no significant relationship between parasite load and geckos body condition, which suggested a stable interaction between the gecko and its parasites. However, it showed a difference of infection between the localities, which could be in relation with habitat conditions.
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Patterns and processes of pathogen exposure in gray wolves across North America. Sci Rep 2021; 11:3722. [PMID: 33580121 PMCID: PMC7881161 DOI: 10.1038/s41598-021-81192-w] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Accepted: 12/29/2020] [Indexed: 01/30/2023] Open
Abstract
The presence of many pathogens varies in a predictable manner with latitude, with infections decreasing from the equator towards the poles. We investigated the geographic trends of pathogens infecting a widely distributed carnivore: the gray wolf (Canis lupus). Specifically, we investigated which variables best explain and predict geographic trends in seroprevalence across North American wolf populations and the implications of the underlying mechanisms. We compiled a large serological dataset of nearly 2000 wolves from 17 study areas, spanning 80° longitude and 50° latitude. Generalized linear mixed models were constructed to predict the probability of seropositivity of four important pathogens: canine adenovirus, herpesvirus, parvovirus, and distemper virus-and two parasites: Neospora caninum and Toxoplasma gondii. Canine adenovirus and herpesvirus were the most widely distributed pathogens, whereas N. caninum was relatively uncommon. Canine parvovirus and distemper had high annual variation, with western populations experiencing more frequent outbreaks than eastern populations. Seroprevalence of all infections increased as wolves aged, and denser wolf populations had a greater risk of exposure. Probability of exposure was positively correlated with human density, suggesting that dogs and synanthropic animals may be important pathogen reservoirs. Pathogen exposure did not appear to follow a latitudinal gradient, with the exception of N. caninum. Instead, clustered study areas were more similar: wolves from the Great Lakes region had lower odds of exposure to the viruses, but higher odds of exposure to N. caninum and T. gondii; the opposite was true for wolves from the central Rocky Mountains. Overall, mechanistic predictors were more informative of seroprevalence trends than latitude and longitude. Individual host characteristics as well as inherent features of ecosystems determined pathogen exposure risk on a large scale. This work emphasizes the importance of biogeographic wildlife surveillance, and we expound upon avenues of future research of cross-species transmission, spillover, and spatial variation in pathogen infection.
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Comas M. Body condition, sex and elevation in relation to mite parasitism in a high mountain gecko. J Zool (1987) 2019. [DOI: 10.1111/jzo.12751] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- M. Comas
- Estación Biológica de Doñana (EBD) Spanish National Research Council (CSIC) Sevilla Spain
- Department of Zoology Faculty of Science Universidad de Granada Granada Spain
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Herrera J, Nunn CL. Behavioural ecology and infectious disease: implications for conservation of biodiversity. Philos Trans R Soc Lond B Biol Sci 2019; 374:20180054. [PMID: 31352881 DOI: 10.1098/rstb.2018.0054] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Behaviour underpins interactions among conspecifics and between species, with consequences for the transmission of disease-causing parasites. Because many parasites lead to declines in population size and increased risk of extinction for threatened species, understanding the link between host behaviour and disease transmission is particularly important for conservation management. Here, we consider the intersection of behaviour, ecology and parasite transmission, broadly encompassing micro- and macroparasites. We focus on behaviours that have direct impacts on transmission, as well as the behaviours that result from infection. Given the important role of parasites in host survival and reproduction, the effects of behaviour on parasitism can scale up to population-level processes, thus affecting species conservation. Understanding how conservation and infectious disease control strategies actually affect transmission potential can therefore often only be understood through a behavioural lens. We highlight how behavioural perspectives of disease ecology apply to conservation by reviewing the different ways that behavioural ecology influences parasite transmission and conservation goals. This article is part of the theme issue 'Linking behaviour to dynamics of populations and communities: application of novel approaches in behavioural ecology to conservation'.
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Affiliation(s)
- James Herrera
- Department of Evolutionary Anthropology, Duke University, 103 Science Drive, Durham, NC 27705, USA
| | - Charles L Nunn
- Department of Evolutionary Anthropology, Duke University, 103 Science Drive, Durham, NC 27705, USA.,Duke Global Health Institute, Duke University, 103 Science Drive, Durham, NC 27705, USA
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Martínez-Padilla J, Redpath SM, Zeineddine M, Mougeot F. Insights into population ecology from long-term studies of red grouseLagopus lagopus scoticus. J Anim Ecol 2013; 83:85-98. [DOI: 10.1111/1365-2656.12098] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2013] [Accepted: 04/30/2013] [Indexed: 01/17/2023]
Affiliation(s)
- Jesus Martínez-Padilla
- Museo Nacional de Ciencias Naturales; Department of Evolutionary Biology; José Guitérrez Abascal 2 28006 Madrid Spain
| | - Steve M. Redpath
- ACES; Department of Biological Sciences; University of Aberdeen; Zoology Building Tillydrone Av. Aberdeen AB24 2TZ UK
| | - Mohammed Zeineddine
- ACES; Department of Biological Sciences; University of Aberdeen; Zoology Building Tillydrone Av. Aberdeen AB24 2TZ UK
| | - François Mougeot
- EEZA-CSIC; La Cañada de San Urbano; 04120 Almeria Spain
- IREC (CSIC-UCLM-JCCM); Ronda de Toledo s/n 13005 Ciuada Real Spain
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Chapman DS, Cornell SJ, Kunin WE. Interactions between harvesting, noise and territoriality in a model of red grouse population cycles. J Anim Ecol 2009; 78:476-84. [DOI: 10.1111/j.1365-2656.2008.01496.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
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Lefèvre T, Lebarbenchon C, Gauthier-Clerc M, Missé D, Poulin R, Thomas F. The ecological significance of manipulative parasites. Trends Ecol Evol 2008; 24:41-8. [PMID: 19026461 DOI: 10.1016/j.tree.2008.08.007] [Citation(s) in RCA: 173] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2008] [Revised: 08/25/2008] [Accepted: 08/28/2008] [Indexed: 11/30/2022]
Abstract
The diversity of ways in which host manipulation by parasites interferes with ecological and evolutionary processes governing biotic interactions has been recently documented, and indicates that manipulative parasites are full participants in the functioning of ecosystems. Phenotypic alterations in parasitised hosts modify host population ecology, apparent competition processes, food web structure and energy and nutrient flow between habitats, as well as favouring habitat creation. As is usually the case in ecology, these phenomena can be greatly amplified by a series of secondary consequences (cascade effects). Here we review the ecological relevance of manipulative parasites in ecosystems and propose directions for further research.
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Affiliation(s)
- Thierry Lefèvre
- GEMI/UMR CNRS-IRD 2724, 911 Avenue Agropolis, BP 64501, 34394 Montpellier Cedex 5, France
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Trzcinski MK, Walde SJ, Taylor PD. Spatial variation in population growth rate and community structure affects local and regional dynamics. J Anim Ecol 2008; 77:1153-61. [DOI: 10.1111/j.1365-2656.2008.01432.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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13
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Shirakashi S, Teruya K, Ogawa K. Altered behaviour and reduced survival of juvenile olive flounder, Paralichthys olivaceus, infected by an invasive monogenean, Neoheterobothrium hirame. Int J Parasitol 2008; 38:1513-22. [DOI: 10.1016/j.ijpara.2008.04.005] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2008] [Revised: 04/03/2008] [Accepted: 04/07/2008] [Indexed: 10/22/2022]
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PIERTNEY STUARTB, LAMBIN XAVIER, MACCOLL ANDREWDC, LOCK KERRY, BACON PHILIPJ, DALLAS JOHNF, LECKIE FIONA, MOUGEOT FRANCOIS, RACEY PAULA, REDPATH STEVE, MOSS ROBERT. Temporal changes in kin structure through a population cycle in a territorial bird, the red grouse Lagopus lagopus scoticus. Mol Ecol 2008; 17:2544-51. [DOI: 10.1111/j.1365-294x.2008.03778.x] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Joly P, Guesdon V, Fromont E, Plenet S, Grolet O, Guegan JF, Hurtrez-Bousses S, Thomas F, Renaud F. Heterozygosity and parasite intensity: lung parasites in the water frog hybridization complex. Parasitology 2007; 135:95-104. [PMID: 17908359 DOI: 10.1017/s0031182007003599] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
In hybridogenetic systems, hybrid individuals are fully heterozygous because one of the parental genomes is discarded from the germinal line before meiosis. Such systems offer the opportunity to investigate the influence of heterozygosity on susceptibility to parasites. We studied the intensity of lung parasites (the roundworm Rhabdias bufomis and the fluke Haplometra cylindracea) in 3 populations of water frogs of the Rana lessonae-esculenta complex in eastern France. In these mixed populations, hybrid frogs (R. esculenta) outnumbered parental ones (R. lessonae). Despite variation in parasite intensity and demographic variability among populations, the relationship between host age and intensity of parasitism suggests a higher susceptibility in parentals than in hybrids. Mortality is probably enhanced by lung parasites in parental frogs. On the other hand, while parental frogs harboured higher numbers of H. cylindracea than hybrid frogs, the latter had higher numbers of R. bufonis. Despite such discrepancies, these results support the hybrid resistance hypothesis, although other factors, such as differences in body size, age-related immunity, differential exposure risks and hemiclonal selection, could also contribute to the observed patterns of infection.
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Affiliation(s)
- P Joly
- UMR 5023 Ecology of Fluvial Hydrosystems, Université Claude Bernard Lyon1, F-69622 Villeurbanne, France.
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REYNOLDS-HOGLAND MELISSAJ, PACIFICI LARAB, MITCHELL MICHAELS. Linking resources with demography to understand resource limitation for bears. J Appl Ecol 2007. [DOI: 10.1111/j.1365-2664.2007.01317.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Hudson PJ, Cattadori IM, Boag B, Dobson AP. Climate disruption and parasite-host dynamics: patterns and processes associated with warming and the frequency of extreme climatic events. J Helminthol 2007; 80:175-82. [PMID: 16768860 DOI: 10.1079/joh2006357] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Levels of parasitism and the dynamics of helminth systems is subject to the impact of environmental conditions such that we may expect long term increases in temperature will increase the force of infection and the parasite's basic reproduction number, R0. We postulate that an increase in the force of infection will only lead to an increase in mean intensity of adults when adult parasite mortality is not determined by acquired immunity. Preliminary examination of long term trends of parasites of rabbits and grouse confirm these predictions. Parasite development rate increases with temperature and while laboratory studies indicate this is linear some recent studies indicate that this may be non-linear and would have an important impact on R0. Warming would also reduce the selective pressure for the development of arrestment and this would increase R0 so that in systems like the grouse and Trichostrongylus tenuis this would increase the instability and lead to larger disease outbreaks. Extreme climatic events that act across populations appear important in synchronizing transmission and disease outbreaks, so it is speculated that climate disruption will lead to increased frequency and intensity of disease outbreaks in parasite populations not regulated by acquired immunity.
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Affiliation(s)
- P J Hudson
- Center for Infectious Disease Dynamics, Penn State University, PA 16802, USA.
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Seivwright LJ, Redpath SM, Mougeot F, Leckie F, Hudson PJ. Interactions between intrinsic and extrinsic mechanisms in a cyclic species: testosterone increases parasite infection in red grouse. Proc Biol Sci 2006; 272:2299-304. [PMID: 16191643 PMCID: PMC1560195 DOI: 10.1098/rspb.2005.3233] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Field studies of mechanisms involved in population regulation have tended to focus on the roles of either intrinsic or extrinsic factors, but these are rarely mutually exclusive and their interactions can be crucial in determining dynamics. Experiments on red grouse Lagopus lagopus scoticus have shown that population instability can be caused both by the effects of a parasitic nematode, Trichostrongylus tenuis, on host production or by changes in testosterone influencing aggressive behaviour and recruitment. We experimentally tested for an interaction between testosterone and T. tenuis in free-living male grouse. A total of 123 grouse were caught in autumn, treated with an anthelmintic to remove parasites, and then given either testosterone or empty, control, implants. After one month grouse were re-infected with a standard dose of parasites. We show that males with increased testosterone levels had greater parasite intensities than controls after one year. We discuss possible physiological and behavioural mechanisms linking testosterone and increased parasite intensity, and the implications for our understanding of complex, unstable population dynamics.
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Affiliation(s)
- Linzi J Seivwright
- Centre for Ecology and Hydrology Hill of BrathensBanchory, Aberdeenshire AB31 4BW, UK
| | - Stephen M Redpath
- Centre for Ecology and Hydrology Hill of BrathensBanchory, Aberdeenshire AB31 4BW, UK
- IREC (CSIC-UCLM-JCCM) Ronda de Toledo13005 Ciudad Real, Spain
- Author for correspondence ()
| | - François Mougeot
- Centre for Ecology and Hydrology Hill of BrathensBanchory, Aberdeenshire AB31 4BW, UK
| | - Fiona Leckie
- Centre for Ecology and Hydrology Hill of BrathensBanchory, Aberdeenshire AB31 4BW, UK
| | - Peter J Hudson
- Center for Infectious Disease Dynamics, Biology Department, Mueller Lab Penn State UniversityUniversity Park, PA 16802, USA
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Holmstad PR, Hudson PJ, Skorping A. The influence of a parasite community on the dynamics of a host population: a longitudinal study on willow ptarmigan and their parasites. OIKOS 2005. [DOI: 10.1111/j.0030-1299.2005.13640.x] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Matthiopoulos J, Halley JM, Moss R. SOCIALLY INDUCED RED GROUSE POPULATION CYCLES NEED ABRUPT TRANSITIONS BETWEEN TOLERANCE AND AGGRESSION. Ecology 2005. [DOI: 10.1890/04-0253] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
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MOUGEOT FRANÇOIS, PIERTNEY STUARTB, LECKIE FIONA, EVANS SHARON, MOSS ROBERT, REDPATH STEVEM, HUDSON PETERJ. Experimentally increased aggressiveness reduces population kin structure and subsequent recruitment in red grouse Lagopus lagopus scoticus. J Anim Ecol 2005. [DOI: 10.1111/j.1365-2656.2005.00947.x] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
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Mougeot F, Evans SA, Redpath SM. Interactions between population processes in a cyclic species: parasites reduce autumn territorial behaviour of male red grouse. Oecologia 2005; 144:289-98. [PMID: 15891828 DOI: 10.1007/s00442-005-0080-x] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2004] [Accepted: 03/01/2005] [Indexed: 01/17/2023]
Abstract
The causes of population cycles fascinate and perplex ecologist. Most work have focused on single processes, whether extrinsic or intrinsic, more rarely on how different processes might interact to cause or mould the unstable population dynamics. In red grouse (Lagopus lagopus scoticus), two causal mechanisms have been supported: territorial behaviour (changes in autumn aggressiveness) and parasites (parasite induced reduction in fecundity). Here, we report on how these two regulatory processes might interact, by testing whether the parasite suspected to cause the grouse cycles, the nematode Trichostrongylus tenuis, reduces male autumn territorial behaviour. We either treated males with an anthelmintic, to remove parasites (dosed or D-males), or challenged them with infective T. tenuis larvae, to increase parasite intensity (challenged or C-males). We first show that dosing was effective in removing T. tenuis parasites, while parasite intensities increased in challenged birds during the autumn. Because old males initially had more parasites than young males, the treatments generated greater differences in parasite intensity in old than in young males. We also show that various aspects of territorial behaviour (increase in testosterone-dependent comb size in autumn, territorial call rate, likelihood of winning territorial interactions and over-winter survival) were significantly higher in dosed than in challenged males, but in old birds only. Our data thus supported the hypothesis that parasites reduce male aggressiveness during the autumn territorial contests, and could thereby influence recruitment. Our results also highlight that the territorial behaviour of young males, which have fewer parasites, is not as limited by parasites as that of old, previously territorial males. We discuss the implications of these findings for our understanding of the processes regulating red grouse populations and causing their complex, unstable population dynamics.
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Affiliation(s)
- Franccois Mougeot
- Centre for Ecology and Hydrology, Hill of Brathens, AB31 4BW, Banchory, Scotland, UK.
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Cattadori IM, Haydon DT, Hudson PJ. Parasites and climate synchronize red grouse populations. Nature 2005; 433:737-41. [PMID: 15716952 DOI: 10.1038/nature03276] [Citation(s) in RCA: 129] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2004] [Accepted: 12/15/2004] [Indexed: 01/17/2023]
Abstract
There is circumstantial evidence that correlated climatic conditions can drive animal populations into synchronous fluctuations in abundance. However, it is unclear whether climate directly affects the survival and fecundity of individuals, or indirectly, by influencing food and natural enemies. Here we propose that climate affects trophic interactions and could be an important mechanism for synchronizing spatially distributed populations. We show that in specific years the size of red grouse populations in northern England either increases or decreases in synchrony. In these years, widespread and correlated climatic conditions during May and July affect populations regionally and influence the density-dependent transmission of the gastrointestinal nematode Trichostrongylus tenuis, a parasite that reduces grouse fecundity. This in turn forces grouse populations into synchrony. We conclude that specific climatic events may lead to outbreaks of infectious diseases or pests that may cause dramatic, synchronized changes in the abundance of their hosts.
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Affiliation(s)
- Isabella M Cattadori
- Center for Infectious Diseases Dynamics, Mueller Laboratory, The Pennsylvania State University, University Park, Pennsylvania 16802, USA.
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Laurenson MK, Norman RA, Gilbert L, Reid HW, Hudson PJ. Mountain hares, louping-ill, red grouse and harvesting: complex interactions but few data. J Anim Ecol 2004. [DOI: 10.1111/j.0021-8790.2004.00851.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
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Cope DR, Iason GR, Gordon IJ. Disease reservoirs in complex systems: a comment on recent work by Laurenson et al. J Anim Ecol 2004. [DOI: 10.1111/j.0021-8790.2004.00850.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Mougeot F, Redpath SM, Moss R, Matthiopoulos J, Hudson PJ. Territorial behaviour and population dynamics in red grouse Lagopus lagopus scoticus. I. Population experiments. J Anim Ecol 2003. [DOI: 10.1046/j.1365-2656.2003.00781.x] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Affiliation(s)
- Peter J Hudson
- Department of Biology, Pennsylvania State University, University Park, PA 16802, USA.
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Mougeot F, Redpath SM, Leckie F, Hudson PJ. The effect of aggressiveness on the population dynamics of a territorial bird. Nature 2003; 421:737-9. [PMID: 12610624 DOI: 10.1038/nature01395] [Citation(s) in RCA: 89] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2002] [Accepted: 12/31/2002] [Indexed: 11/09/2022]
Abstract
A central issue in ecology lies in identifying the importance of resources, natural enemies and behaviour in the regulation of animal populations. Much of the debate on this subject has focused on animals that show cyclic fluctuations in abundance. However, there is still disagreement about the role of extrinsic (food, parasites or predators) and intrinsic (behaviour) factors in causing cycles. Recent studies have examined the impact of natural enemies, although spatial patterns resulting from restricted dispersal or recruitment are increasingly recognized as having the potential to influence unstable population dynamics. We tested the hypothesis that population cycles in a territorial bird, red grouse Lagopus lagopus scoticus, are caused by delayed density-dependent changes in the aggressiveness and spacing behaviour of males. Here we show that increasing aggressiveness experimentally for a short period in autumn reduced recruitment and subsequent breeding density by 50%, and changed population trajectories from increasing to declining. Intrinsic processes can therefore have fundamental effects on population dynamics.
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Affiliation(s)
- F Mougeot
- CEH Banchory, Hill of Brathens, Glassel, Banchory, Aberdeenshire AB31 4BW, UK.
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Sibly RM, Hone J, Clutton-Brock TH. Population growth rate: determining factors and role in population regulation. Introduction. Philos Trans R Soc Lond B Biol Sci 2002; 357:1149-51. [PMID: 12396507 PMCID: PMC1693023 DOI: 10.1098/rstb.2002.1130] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
- Richard M Sibly
- School of Animal and Microbial Sciences, University of Reading, PO Box 228, Reading RG6 6AJ, UK
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Godfray HCJ, Rees M. Population growth rates: issues and an application. Philos Trans R Soc Lond B Biol Sci 2002; 357:1307-19. [PMID: 12396521 PMCID: PMC1693033 DOI: 10.1098/rstb.2002.1131] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Current issues in population dynamics are discussed in the context of The Royal Society Discussion Meeting 'Population growth rate: determining factors and role in population regulation'. In particular, different views on the centrality of population growth rates to the study of population dynamics and the role of experiments and theory are explored. Major themes emerging include the role of modern statistical techniques in bringing together experimental and theoretical studies, the importance of long-term experimentation and the need for ecology to have model systems, and the value of population growth rate as a means of understanding and predicting population change. The last point is illustrated by the application of a recently introduced technique, integral projection modelling, to study the population growth rate of a monocarpic perennial plant, its elasticities to different life-history components and the evolution of an evolutionarily stable strategy size at flowering.
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Affiliation(s)
- H Charles J Godfray
- NERC Centre for Population Biology and Department of Biological Sciences, Imperial College at Silwood Park, Ascot, Berkshire SL5 7PY, UK.
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