1
|
Boggiatto PM, Buckley A, Cassmann ED, Seger H, Olsen SC, Palmer MV. Persistence of viral RNA in North American elk experimentally infected with an ancestral strain of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Sci Rep 2024; 14:11171. [PMID: 38750049 PMCID: PMC11096316 DOI: 10.1038/s41598-024-61414-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2024] [Accepted: 05/06/2024] [Indexed: 05/18/2024] Open
Abstract
White-tailed deer (Odocoileus virginianus) have emerged as a reservoir host for SARS-CoV-2 given their susceptibility to infection and demonstrated high rates of seroprevalence and infection across the United States. As SARS-CoV-2 circulates within free-ranging white-tailed deer populations, there is the risk of transmission to other wildlife species and even back to the human population. The goal of this study was to determine the susceptibility, shedding, and immune response of North American elk (Cervus elaphus canadensis) to experimental infection with SARS-CoV-2, to determine if another wide-ranging cervid species could potentially serve as a reservoir host for the virus. Here we demonstrate that while North American elk do not develop clinical signs of disease, they do develop a neutralizing antibody response to infection, suggesting the virus is capable of replicating in this mammalian host. Additionally, we demonstrate SARS-CoV-2 RNA presence in the medial retropharyngeal lymph nodes of infected elk three weeks after experimental infection. Consistent with previous observations in humans, these data may highlight a mechanism of viral persistence for SARS-CoV-2 in elk.
Collapse
Affiliation(s)
- Paola M Boggiatto
- Infectious Bacterial Diseases Research Unit, National Animal Disease Center, USDA, Agricultural Research Service, Ames, IA, USA.
| | - Alexandra Buckley
- Virus and Prion Research Unit, National Animal Disease Center, USDA, Agricultural Research, Ames, IA, USA
| | - Eric D Cassmann
- Virus and Prion Research Unit, National Animal Disease Center, USDA, Agricultural Research, Ames, IA, USA
| | - Hannah Seger
- Virus and Prion Research Unit, National Animal Disease Center, USDA, Agricultural Research, Ames, IA, USA
- Oak Ridge Institute for Science and Education, 1299 Bethel Valley Rd., Oak Ridge, TN, 37830, USA
| | - Steven C Olsen
- Infectious Bacterial Diseases Research Unit, National Animal Disease Center, USDA, Agricultural Research Service, Ames, IA, USA
| | - Mitchell V Palmer
- Infectious Bacterial Diseases Research Unit, National Animal Disease Center, USDA, Agricultural Research Service, Ames, IA, USA
| |
Collapse
|
2
|
Tibbs-Cortes BW, Rahic-Seggerman FM, Schmitz-Esser S, Boggiatto PM, Olsen S, Putz EJ. Fecal and vaginal microbiota of vaccinated and non-vaccinated pregnant elk challenged with Brucella abortus. Front Vet Sci 2024; 11:1334858. [PMID: 38352039 PMCID: PMC10861794 DOI: 10.3389/fvets.2024.1334858] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2023] [Accepted: 01/02/2024] [Indexed: 02/16/2024] Open
Abstract
Introduction Brucella abortus is the causative agent of brucellosis in cattle and in humans, resulting in economic losses in the agricultural sector and representing a major threat to public health. Elk populations in the American Northwest are reservoirs for this bacterium and transmit the agent to domestic cattle herds. One potential strategy to mitigate the transmission of brucellosis by elk is vaccination of elk populations against B. abortus; however, elk appear to be immunologically distinct from cattle in their responses to current vaccination strategies. The differences in host response to B. abortus between cattle and elk could be attributed to differences between the cattle and elk innate and adaptive immune responses. Because species-specific interactions between the host microbiome and the immune system are also known to affect immunity, we sought to investigate interactions between the elk microbiome and B. abortus infection and vaccination. Methods We analyzed the fecal and vaginal microbial communities of B. abortus-vaccinated and unvaccinated elk which were challenged with B. abortus during the periparturient period. Results We observed that the elk fecal and vaginal microbiota are similar to those of other ruminants, and these microbial communities were affected both by time of sampling and by vaccination status. Notably, we observed that taxa representing ruminant reproductive tract pathogens tended to increase in abundance in the elk vaginal microbiome following parturition. Furthermore, many of these taxa differed significantly in abundance depending on vaccination status, indicating that vaccination against B. abortus affects the elk vaginal microbiota with potential implications for animal reproductive health. Discussion This study is the first to analyze the vaginal microbiota of any species of the genus Cervus and is also the first to assess the effects of B. abortus vaccination and challenge on the vaginal microbiome.
Collapse
Affiliation(s)
- Bienvenido W. Tibbs-Cortes
- Infectious Bacterial Diseases Research Unit, United States Department of Agriculture, Ames, IA, United States
| | - Faith M. Rahic-Seggerman
- Interdepartmental Microbiology Graduate Program, Iowa State University, Ames, IA, United States
- Department of Animal Science, Iowa State University, Ames, IA, United States
| | - Stephan Schmitz-Esser
- Interdepartmental Microbiology Graduate Program, Iowa State University, Ames, IA, United States
- Department of Animal Science, Iowa State University, Ames, IA, United States
| | - Paola M. Boggiatto
- Infectious Bacterial Diseases Research Unit, United States Department of Agriculture, Ames, IA, United States
| | - Steven Olsen
- Infectious Bacterial Diseases Research Unit, United States Department of Agriculture, Ames, IA, United States
| | - Ellie J. Putz
- Infectious Bacterial Diseases Research Unit, United States Department of Agriculture, Ames, IA, United States
| |
Collapse
|
3
|
Jones JD, Proffitt KM, Ramsey JM, Almberg ES, Anderson NJ. Reproductive Fate of Brucellosis-Seropositive Elk (Cervus canadensis): Implications for Disease Transmission Risk. J Wildl Dis 2024; 60:52-63. [PMID: 37889938 DOI: 10.7589/jwd-d-22-00123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Accepted: 07/25/2023] [Indexed: 10/29/2023]
Abstract
Brucellosis is a disease caused by the bacterium Brucella abortus that infects elk (Cervus canadensis) and cattle (Bos taurus). There is the potential for transmission from wildlife to livestock through contact with infected material shed during abortions or live births. To understand the impact of exposure on pregnancy rates we captured 30-100 elk per year from 2011 through 2020, testing their blood for serologic exposure to B. abortus. Predicted pregnancy rates for seropositive animals were 9.6% lower in prime-age (2.5-15.5 yr; 85%, 95% confidence interval [CI]: 74-91%) and 37.7% lower in old (>15.5 yr; 43%, 95% CI: 19-71%) elk as compared with seronegative animals. To understand the risk of seropositive elk shedding B. abortus bacteria and the effects of exposure on elk reproductive performance, we conducted a 5-yr longitudinal study monitoring 30 seropositive elk. We estimated the annual probability of a seropositive elk having an abortion as 0.06 (95% CI: 0.02-0.15). We detected B. abortus at three abortions and two live births, using a combination of culture and PCR testing. The predicted probability of a pregnant seropositive elk shedding B. abortus during an abortion or live birth was 0.08 (95% CI: 0.04-0.19). To understand what proportion of seropositive elk harbored live B. abortus bacteria in their tissues, we euthanized seropositive elk at the end of 5 yr of monitoring and sampled tissues for B. abortus. Assuming perfect detection, the predicted probability of a seropositive elk having B. abortus in at least one tissue was 0.18 (95% CI: 0.06-0.43). The transmission risk seropositive elk pose is mitigated by decreased pregnancy rates, low probability of abortion events, low probability of shedding at live birth events, and reasonably low probability of B. abortus in tissues.
Collapse
Affiliation(s)
- Jennifer D Jones
- Montana Department of Fish, Wildlife & Parks, 1400 South 19th Avenue, Bozeman, Montana 59718, USA
| | - Kelly M Proffitt
- Montana Department of Fish, Wildlife & Parks, 1400 South 19th Avenue, Bozeman, Montana 59718, USA
| | - Jennifer M Ramsey
- Montana Department of Fish, Wildlife & Parks, 1400 South 19th Avenue, Bozeman, Montana 59718, USA
| | - Emily S Almberg
- Montana Department of Fish, Wildlife & Parks, 1400 South 19th Avenue, Bozeman, Montana 59718, USA
| | - Neil J Anderson
- Montana Department of Fish, Wildlife & Parks, 490 North Meridian Road, Kalispell, Montana 59901, USA
| |
Collapse
|
4
|
Barker KJ, Cole E, Courtemanch A, Dewey S, Gustine D, Mills K, Stephenson J, Wise B, Middleton AD. Large carnivores avoid humans while prioritizing prey acquisition in anthropogenic areas. J Anim Ecol 2023; 92:889-900. [PMID: 36757108 DOI: 10.1111/1365-2656.13900] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2022] [Accepted: 01/30/2023] [Indexed: 02/10/2023]
Abstract
Large carnivores are recovering in many landscapes where the human footprint is simultaneously growing. When carnivores encounter humans, the way they behave often changes, which may subsequently influence how they affect their prey. However, little research investigates the behavioural mechanisms underpinning carnivore response to humans. As a result, it is not clear how predator-prey interactions and their associated ecosystem processes will play out in the human-dominated areas into which carnivore populations are increasingly expanding. We hypothesized that humans would reduce predation risk for prey by disturbing carnivores or threatening their survival. Alternatively, or additionally, we hypothesized that humans would increase predation risk by providing forage resources that congregate herbivorous prey in predictable places and times. Using grey wolves Canis lupus in Jackson Hole, Wyoming, USA as a study species, we investigated 170 kill sites across a spectrum of human influences ranging from heavily restricted human activities on protected federal lands to largely unregulated activities on private lands. Then, we used conditional logistic regression to quantify how the probability of predation changed across varied types and amounts of human influences, while controlling for environmental characteristics and prey availability. Wolves primarily made kills in environmental terrain traps and where prey availability was high, but predation risk was significantly better explained with the inclusion of human influences than by environmental characteristics alone. Different human influences had different, and even converse, effects on the risk of wolf predation. For example, where prey were readily available, wolves preferentially killed animals far from motorized roads but close to unpaved trails. However, wolves responded less strongly to humans, if at all, where prey were scarce, suggesting they prioritized acquiring prey over avoiding human interactions. Overall, our work reveals that the effects of large carnivores on prey populations can vary considerably among different types of human influences, yet carnivores may not appreciably alter predatory behaviour in response to humans if prey are difficult to obtain. These results shed new light on the drivers of large carnivore behaviour in anthropogenic areas while improving understanding of predator-prey dynamics in and around the wildland-urban interface.
Collapse
Affiliation(s)
- Kristin J Barker
- Department of Environmental Science, Policy, and Management, University of California - Berkeley, Berkeley, California, USA
| | - Eric Cole
- National Elk Refuge, United States Fish and Wildlife Service, Jackson, Wyoming, USA
| | | | - Sarah Dewey
- National Park Service, Grand Teton National Park, Moose, Wyoming, USA
| | - David Gustine
- National Park Service, Grand Teton National Park, Moose, Wyoming, USA
| | - Kenneth Mills
- Wyoming Game and Fish Department, Pinedale, Wyoming, USA
| | - John Stephenson
- National Park Service, Grand Teton National Park, Moose, Wyoming, USA
| | - Benjamin Wise
- Wyoming Game and Fish Department, Jackson, Wyoming, USA
| | - Arthur D Middleton
- Department of Environmental Science, Policy, and Management, University of California - Berkeley, Berkeley, California, USA
| |
Collapse
|
5
|
Pascual DW, Goodwin ZI, Bhagyaraj E, Hoffman C, Yang X. Activation of mucosal immunity as a novel therapeutic strategy for combating brucellosis. Front Microbiol 2022; 13:1018165. [PMID: 36620020 PMCID: PMC9814167 DOI: 10.3389/fmicb.2022.1018165] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2022] [Accepted: 11/29/2022] [Indexed: 12/24/2022] Open
Abstract
Brucellosis is a disease of livestock that is commonly asymptomatic until an abortion occurs. Disease in humans results from contact of infected livestock or consumption of contaminated milk or meat. Brucella zoonosis is primarily caused by one of three species that infect livestock, Bacillus abortus in cattle, B. melitensis in goats and sheep, and B. suis in pigs. To aid in disease prophylaxis, livestock vaccines are available, but are only 70% effective; hence, improved vaccines are needed to mitigate disease, particularly in countries where disease remains pervasive. The absence of knowing which proteins confer complete protection limits development of subunit vaccines. Instead, efforts are focused on developing new and improved live, attenuated Brucella vaccines, since these mimic attributes of wild-type Brucella, and stimulate host immune, particularly T helper 1-type responses, required for protection. In considering their development, the new mutants must address Brucella's defense mechanisms normally active to circumvent host immune detection. Vaccination approaches should also consider mode and route of delivery since disease transmission among livestock and humans is believed to occur via the naso-oropharyngeal tissues. By arming the host's mucosal immune defenses with resident memory T cells (TRMs) and by expanding the sources of IFN-γ, brucellae dissemination from the site of infection to systemic tissues can be prevented. In this review, points of discussion focus on understanding the various immune mechanisms involved in disease progression and which immune players are important in fighting disease.
Collapse
|
6
|
Clifford Astbury C, Lee KM, Aguiar R, Atique A, Balolong M, Clarke J, Labonte R, Ruckert A, Togño KC, Viens AM, Wiktorowicz M, Yau A, Penney TL. Policies to prevent zoonotic spillover: protocol for a systematic scoping review of evaluative evidence. BMJ Open 2022; 12:e058437. [PMID: 36379648 PMCID: PMC9668000 DOI: 10.1136/bmjopen-2021-058437] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Accepted: 10/26/2022] [Indexed: 11/16/2022] Open
Abstract
INTRODUCTION The increasing incidence of pathogen transmission from animals to humans (zoonotic spillover events) has been attributed to behavioural practices and ecological and socioeconomic change. As these events sometimes involve pathogens with epidemic or pandemic potential, they pose a serious threat to population health. Public policies may play a key role in preventing these events. The aim of this review is to identify evaluations of public policies that target the determinants of zoonotic spillover, examining approaches taken to evaluation, choice of outcomes measures and evidence of effectiveness. Our approach to identifying and analysing this literature will be informed by a One Health lens, acknowledging the interconnectedness of human, animal and environmental health. METHODS AND ANALYSIS A systematic scoping review methodology will be used. To identify articles, we will search Medline, SCOPUS, Web of Science and Global Health in May 2021 using search terms combining animal health and the animal-human interface, public policy, prevention and zoonoses. We will screen titles and abstracts and extract data according to published guidelines for scoping reviews. All evaluations of public policies aiming to prevent zoonotic spillover events will be eligible for inclusion. We will summarise key data from each study, mapping policies along the spillover pathway and outlining the range of policies, approaches to evaluation and outcome measures. Review findings will provide a useful reference for researchers and practitioners, outlining the state of the evaluative evidence around policies to prevent zoonotic spillover. ETHICS AND DISSEMINATION Formal ethical approval is not required, because the study does not involve primary data collection. The findings of this study will be disseminated through a peer-reviewed publication, presentations and summaries for key stakeholders.
Collapse
Affiliation(s)
- Chloe Clifford Astbury
- School of Global Health, York University, Toronto, Ontario, Canada
- Dahdaleh Institute for Global Health Research, York University, Toronto, Ontario, Canada
| | - Kirsten M Lee
- School of Global Health, York University, Toronto, Ontario, Canada
- Dahdaleh Institute for Global Health Research, York University, Toronto, Ontario, Canada
| | - Raphael Aguiar
- Dahdaleh Institute for Global Health Research, York University, Toronto, Ontario, Canada
| | - Asma Atique
- School of Global Health, York University, Toronto, Ontario, Canada
| | | | - Janielle Clarke
- School of Global Health, York University, Toronto, Ontario, Canada
| | | | | | | | - A M Viens
- School of Global Health, York University, Toronto, Ontario, Canada
| | - M Wiktorowicz
- School of Global Health, York University, Toronto, Ontario, Canada
- Dahdaleh Institute for Global Health Research, York University, Toronto, Ontario, Canada
| | - Amy Yau
- London School of Hygiene & Tropical Medicine, London, UK
| | - Tarra L Penney
- School of Global Health, York University, Toronto, Ontario, Canada
- Dahdaleh Institute for Global Health Research, York University, Toronto, Ontario, Canada
| |
Collapse
|
7
|
Paterson JT, Proffitt KM, Rotella JJ. Incorporating vital rates and harvest into stochastic population models to forecast elk population dynamics. J Wildl Manage 2022. [DOI: 10.1002/jwmg.22189] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
| | - Kelly M. Proffitt
- Montana Department of Fish, Wildlife, and Parks Bozeman 59718 MT USA
| | - Jay J. Rotella
- Montana State University 310 Lewis Hall Bozeman MT 59718 USA
| |
Collapse
|
8
|
Towards an ecosystem model of infectious disease. Nat Ecol Evol 2021; 5:907-918. [PMID: 34002048 DOI: 10.1038/s41559-021-01454-8] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2020] [Accepted: 03/25/2021] [Indexed: 02/03/2023]
Abstract
Increasingly intimate associations between human society and the natural environment are driving the emergence of novel pathogens, with devastating consequences for humans and animals alike. Prior to emergence, these pathogens exist within complex ecological systems that are characterized by trophic interactions between parasites, their hosts and the environment. Predicting how disturbance to these ecological systems places people and animals at risk from emerging pathogens-and the best ways to manage this-remains a significant challenge. Predictive systems ecology models are powerful tools for the reconstruction of ecosystem function but have yet to be considered for modelling infectious disease. Part of this stems from a mistaken tendency to forget about the role that pathogens play in structuring the abundance and interactions of the free-living species favoured by systems ecologists. Here, we explore how developing and applying these more complete systems ecology models at a landscape scale would greatly enhance our understanding of the reciprocal interactions between parasites, pathogens and the environment, placing zoonoses in an ecological context, while identifying key variables and simplifying assumptions that underly pathogen host switching and animal-to-human spillover risk. As well as transforming our understanding of disease ecology, this would also allow us to better direct resources in preparation for future pandemics.
Collapse
|
9
|
Spatial Clustering by Red Deer and Its Relevance for Management of Chronic Wasting Disease. Animals (Basel) 2021; 11:ani11051272. [PMID: 33925184 PMCID: PMC8146590 DOI: 10.3390/ani11051272] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Revised: 04/23/2021] [Accepted: 04/26/2021] [Indexed: 11/17/2022] Open
Abstract
Herbivores like cervids usually graze on widely scattered forage, but anthropogenic food sources may cause spatial revisitation and aggregation, posing a risk for transmission of infectious diseases. In 2016, chronic wasting disease (CWD) was first detected in Norway. A legal regulation to ban supplemental feeding of cervids and to fence stored hay bales was implemented to lower aggregation of cervids. Knowledge of further patterns and causes of spatial revisitation can inform disease management. We used a recently developed revisitation analysis on GPS-positions from 13 red deer (Cervus elaphus) to identify the pattern of spatial clustering, and we visited 185 spatial clusters during winter to identify the causes of clustering. Anthropogenic food sources were found in 11.9% of spatial clusters, which represented 31.0% of the clusters in agricultural fields. Dumping of silage and hay bales were the main anthropogenic food sources (apart from agricultural fields), and unfenced hay bales were available despite the regulation. The probability of the clusters being in agricultural fields was high during winter. It may be necessary to find other ways of disposing of silage and enforcing the requirement of fencing around hay bales to ensure compliance, in particular during winters with deep snow.
Collapse
|
10
|
Couch CE, Wise BL, Scurlock BM, Rogerson JD, Fuda RK, Cole EK, Szcodronski KE, Sepulveda AJ, Hutchins PR, Cross PC. Effects of supplemental feeding on the fecal bacterial communities of Rocky Mountain elk in the Greater Yellowstone Ecosystem. PLoS One 2021; 16:e0249521. [PMID: 33831062 PMCID: PMC8031386 DOI: 10.1371/journal.pone.0249521] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2020] [Accepted: 03/19/2021] [Indexed: 12/27/2022] Open
Abstract
Supplemental feeding of wildlife is a common practice often undertaken for recreational or management purposes, but it may have unintended consequences for animal health. Understanding cryptic effects of diet supplementation on the gut microbiomes of wild mammals is important to inform conservation and management strategies. Multiple laboratory studies have demonstrated the importance of the gut microbiome for extracting and synthesizing nutrients, modulating host immunity, and many other vital host functions, but these relationships can be disrupted by dietary perturbation. The well-described interplay between diet, the microbiome, and host health in laboratory and human systems highlights the need to understand the consequences of supplemental feeding on the microbiomes of free-ranging animal populations. This study describes changes to the gut microbiomes of wild elk under different supplemental feeding regimes. We demonstrated significant cross-sectional variation between elk at different feeding locations and identified several relatively low-abundance bacterial genera that differed between fed versus unfed groups. In addition, we followed four of these populations through mid-season changes in supplemental feeding regimes and demonstrated a significant shift in microbiome composition in a single population that changed from natural forage to supplementation with alfalfa pellets. Some of the taxonomic shifts in this population mirrored changes associated with ruminal acidosis in domestic livestock. We discerned no significant changes in the population that shifted from natural forage to hay supplementation, or in the populations that changed from one type of hay to another. Our results suggest that supplementation with alfalfa pellets alters the native gut microbiome of elk, with potential implications for population health.
Collapse
Affiliation(s)
- Claire E. Couch
- Department of Fisheries & Wildlife, Oregon State University, Corvallis, Oregon, United States of America
| | - Benjamin L. Wise
- Wyoming Game & Fish Department, Jackson, Wyoming, United States of America
| | | | - Jared D. Rogerson
- Wyoming Game & Fish Department, Pinedale, Wyoming, United States of America
| | - Rebecca K. Fuda
- Oregon Department of Fish & Wildlife, Prineville, Oregon, United States of America
| | - Eric K. Cole
- U.S. Fish & Wildlife Service, National Elk Refuge, Jackson, Wyoming, United States of America
| | - Kimberly E. Szcodronski
- U.S. Geological Survey, Northern Rocky Mountain Science Center, Bozeman, Montana, United States of America
| | - Adam J. Sepulveda
- U.S. Geological Survey, Northern Rocky Mountain Science Center, Bozeman, Montana, United States of America
| | - Patrick R. Hutchins
- U.S. Geological Survey, Northern Rocky Mountain Science Center, Bozeman, Montana, United States of America
| | - Paul C. Cross
- U.S. Geological Survey, Northern Rocky Mountain Science Center, Bozeman, Montana, United States of America
| |
Collapse
|
11
|
Janousek WM, Graves TA, Berman EE, Chong GW, Cole EK, Dewey SR, Johnston AN, Cross PC. Human activities and weather drive contact rates of wintering elk. J Appl Ecol 2021. [DOI: 10.1111/1365-2664.13818] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- William M. Janousek
- United States Geological Survey Northern Rocky Mountain Science Center West Glacier MT USA
| | - Tabitha A. Graves
- United States Geological Survey Northern Rocky Mountain Science Center West Glacier MT USA
| | - Ethan E. Berman
- United States Geological Survey Northern Rocky Mountain Science Center West Glacier MT USA
| | - Geneva W. Chong
- United States Geological Survey Northern Rocky Mountain Science Center Bozeman MT USA
| | - Eric K. Cole
- United States Fish and Wildlife Service Jackson WY USA
| | - Sarah R. Dewey
- National Park Service Grand Teton National Park Moose WY USA
| | - Aaron N. Johnston
- United States Geological Survey Northern Rocky Mountain Science Center Bozeman MT USA
| | - Paul C. Cross
- United States Geological Survey Northern Rocky Mountain Science Center Bozeman MT USA
| |
Collapse
|
12
|
Ossi F, Ranc N, Moorcroft P, Bonanni P, Cagnacci F. Ecological and Behavioral Drivers of Supplemental Feeding Use by Roe Deer Capreolus capreolus in a Peri-Urban Context. Animals (Basel) 2020; 10:E2088. [PMID: 33182794 PMCID: PMC7698021 DOI: 10.3390/ani10112088] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Revised: 11/05/2020] [Accepted: 11/06/2020] [Indexed: 12/19/2022] Open
Abstract
Winter supplemental feeding of ungulates potentially alters their use of resources and ecological interactions, yet relatively little is known about the patterns of feeding sites use by target populations. We used camera traps to continuously monitor winter and spring feeding site use in a roe deer population living in a peri-urban area in Northern Italy. We combined circular statistics with generalized additive and linear mixed models to analyze the diel and seasonal pattern of roe deer visits to feeding sites, and the behavioral drivers influencing visit duration. Roe deer visits peaked at dawn and dusk, and decreased from winter to spring when vegetation regrows and temperature increases. Roe deer mostly visited feeding sites solitarily; when this was not the case, they stayed longer at the site, especially when conspecifics were eating, but maintained a bimodal diel pattern of visits. These results support an opportunistic use of feeding sites, following seasonal cycles and the roe deer circadian clock. Yet, the attractiveness of these artificial resources has the potential to alter intra-specific relationships, as competition for their use induces gatherings and may extend the contact time between individuals, with potential behavioral and epidemiological consequences.
Collapse
Affiliation(s)
- Federico Ossi
- Centro Agricoltura Alimenti Ambiente, Università degli Studi di Trento, Via Edmund Mach 1, 38010 San Michele all’Adige, Italy
- Department of Biodiversity and Molecular Ecology, Research and Innovation Centre, Fondazione Edmund Mach, Via E. Mach 1, 38010 San Michele all’Adige, Italy; (N.R.); (P.B.); (F.C.)
| | - Nathan Ranc
- Department of Biodiversity and Molecular Ecology, Research and Innovation Centre, Fondazione Edmund Mach, Via E. Mach 1, 38010 San Michele all’Adige, Italy; (N.R.); (P.B.); (F.C.)
- Department of Organismic and Evolutionary Biology, Harvard University, 26 Oxford Street, Cambridge, MA 02138, USA;
| | - Paul Moorcroft
- Department of Organismic and Evolutionary Biology, Harvard University, 26 Oxford Street, Cambridge, MA 02138, USA;
| | - Priscilla Bonanni
- Department of Biodiversity and Molecular Ecology, Research and Innovation Centre, Fondazione Edmund Mach, Via E. Mach 1, 38010 San Michele all’Adige, Italy; (N.R.); (P.B.); (F.C.)
- Department of Animal and Human Biology, University of Rome “La Sapienza”, Viale dell’Università 32, 00185 Rome, Italy
| | - Francesca Cagnacci
- Department of Biodiversity and Molecular Ecology, Research and Innovation Centre, Fondazione Edmund Mach, Via E. Mach 1, 38010 San Michele all’Adige, Italy; (N.R.); (P.B.); (F.C.)
- Department of Organismic and Evolutionary Biology, Harvard University, 26 Oxford Street, Cambridge, MA 02138, USA;
| |
Collapse
|
13
|
Yang Z, Pang M, Zhou Q, Song S, Liang W, Chen J, Guo T, Shao Z, Liu K. Spatiotemporal expansion of human brucellosis in Shaanxi Province, Northwestern China and model for risk prediction. PeerJ 2020; 8:e10113. [PMID: 33133781 PMCID: PMC7580622 DOI: 10.7717/peerj.10113] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2020] [Accepted: 09/16/2020] [Indexed: 12/21/2022] Open
Abstract
Background Human brucellosis imposes a heavy burden on the health and economy of endemic regions. Since 2011, China has reported at least 35,000 human brucellosis cases annually, with more than 90% of these cases reported in the northern. Given the alarmingly high incidence and variation in the geographical distribution of human brucellosis cases, there is an urgent need to decipher the causes of such variation in geographical distribution. Method We conducted a retrospective epidemiological study in Shaanxi Province from January 1, 2005 to December 31, 2018 to investigate the association between meteorological factors and transmission of human brucellosis according to differences in geographical distribution and seasonal fluctuation in northwestern China for the first time. Results Human brucellosis cases were mainly distributed in the Shaanbei upland plateau before 2008 and then slowly extended towards the southern region with significant seasonal fluctuation. The results of quasi-Poisson generalized additive mixed model (GAMM) indicated that air temperature, sunshine duration, rainfall, relative humidity, and evaporation with maximum lag time within 7 months played crucial roles in the transmission of human brucellosis with seasonal fluctuation. Compared with the Shaanbei upland plateau, Guanzhong basin had more obvious fluctuations in the occurrence of human brucellosis due to changes in meteorological factors. Additionally, the established GAMM model showed high accuracy in predicting the occurrence of human brucellosis based on the meteorological factors. Conclusion These findings may be used to predict the seasonal fluctuations of human brucellosis and to develop reliable and cost-effective prevention strategies in Shaanxi Province and other areas with similar environmental conditions.
Collapse
Affiliation(s)
- Zurong Yang
- Department of Epidemiology, Ministry of Education Key Lab of Hazard Assessment and Control in Special Operational Environment, School of Public Health, Air Force Medical University, Xi'an, Shaanxi, People's Republic of China.,Centre for Disease Prevention and Control in Northern Theater Command, Shenyang, People's Republic of China
| | - Miaomiao Pang
- Shaanxi Provincial Corps Hospital of Chinese People's Armed Police Force, Xi'an, Shaanxi, People's Republic of China
| | - Qingyang Zhou
- Centre for Disease Prevention and Control in Northern Theater Command, Shenyang, People's Republic of China
| | - Shuxuan Song
- Department of Epidemiology, Ministry of Education Key Lab of Hazard Assessment and Control in Special Operational Environment, School of Public Health, Air Force Medical University, Xi'an, Shaanxi, People's Republic of China
| | - Weifeng Liang
- Health Commission of Shaanxi Province, Xi'an, Shaanxi, People's Republic of China
| | - Junjiang Chen
- Department of Epidemiology, Ministry of Education Key Lab of Hazard Assessment and Control in Special Operational Environment, School of Public Health, Air Force Medical University, Xi'an, Shaanxi, People's Republic of China
| | - Tianci Guo
- Department of Epidemiology, Ministry of Education Key Lab of Hazard Assessment and Control in Special Operational Environment, School of Public Health, Air Force Medical University, Xi'an, Shaanxi, People's Republic of China
| | - Zhongjun Shao
- Department of Epidemiology, Ministry of Education Key Lab of Hazard Assessment and Control in Special Operational Environment, School of Public Health, Air Force Medical University, Xi'an, Shaanxi, People's Republic of China
| | - Kun Liu
- Department of Epidemiology, Ministry of Education Key Lab of Hazard Assessment and Control in Special Operational Environment, School of Public Health, Air Force Medical University, Xi'an, Shaanxi, People's Republic of China
| |
Collapse
|
14
|
Russell RE, DiRenzo GV, Szymanski JA, Alger KE, Grant EHC. Principles and Mechanisms of Wildlife Population Persistence in the Face of Disease. Front Ecol Evol 2020. [DOI: 10.3389/fevo.2020.569016] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
|
15
|
Sokolow SH, Nova N, Pepin KM, Peel AJ, Pulliam JRC, Manlove K, Cross PC, Becker DJ, Plowright RK, McCallum H, De Leo GA. Ecological interventions to prevent and manage zoonotic pathogen spillover. Philos Trans R Soc Lond B Biol Sci 2019; 374:20180342. [PMID: 31401951 PMCID: PMC6711299 DOI: 10.1098/rstb.2018.0342] [Citation(s) in RCA: 72] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Spillover of a pathogen from a wildlife reservoir into a human or livestock host requires the pathogen to overcome a hierarchical series of barriers. Interventions aimed at one or more of these barriers may be able to prevent the occurrence of spillover. Here, we demonstrate how interventions that target the ecological context in which spillover occurs (i.e. ecological interventions) can complement conventional approaches like vaccination, treatment, disinfection and chemical control. Accelerating spillover owing to environmental change requires effective, affordable, durable and scalable solutions that fully harness the complex processes involved in cross-species pathogen spillover. This article is part of the theme issue ‘Dynamic and integrative approaches to understanding pathogen spillover’.
Collapse
Affiliation(s)
- Susanne H Sokolow
- Hopkins Marine Station, Stanford University, Pacific Grove, CA 93950, USA.,Woods Institute for the Environment, Stanford University, Stanford, CA 94305, USA.,Marine Science Institute, University of California, Santa Barbara, CA 93106, USA
| | - Nicole Nova
- Department of Biology, Stanford University, Stanford, CA 94305, USA
| | - Kim M Pepin
- National Wildlife Research Center, USDA-APHIS, Fort Collins, CO 80521, USA
| | - Alison J Peel
- Environmental Futures Research Institute, Griffith University, Nathan, Queensland 4111, Australia
| | - Juliet R C Pulliam
- South African DST-NRF Centre of Excellence in Epidemiological Modelling and Analysis (SACEMA), Stellenbosch University, Stellenbosch 7600, South Africa
| | - Kezia Manlove
- Department of Wildland Resources and Ecology Center, Utah State University, Logan, UT 84321, USA
| | - Paul C Cross
- US Geological Survey, Northern Rocky Mountain Science Center, Bozeman, MT 59715, USA
| | - Daniel J Becker
- Department of Microbiology and Immunology, Montana State University, Bozeman, MT 59717, USA.,Department of Biology, Indiana University, Bloomington, IN 47403, USA
| | - Raina K Plowright
- Department of Microbiology and Immunology, Montana State University, Bozeman, MT 59717, USA
| | - Hamish McCallum
- Environmental Futures Research Institute, Griffith University, Nathan, Queensland 4111, Australia
| | - Giulio A De Leo
- Hopkins Marine Station, Stanford University, Pacific Grove, CA 93950, USA.,Woods Institute for the Environment, Stanford University, Stanford, CA 94305, USA.,Department of Biology, Stanford University, Stanford, CA 94305, USA
| |
Collapse
|
16
|
Woodruff SP, Jimenez MD. Winter predation patterns of wolves in Northwestern Wyoming. J Wildl Manage 2019. [DOI: 10.1002/jwmg.21710] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
|
17
|
Menke S, Heurich M, Henrich M, Wilhelm K, Sommer S. Impact of winter enclosures on the gut bacterial microbiota of red deer in the Bavarian Forest National Park. WILDLIFE BIOLOGY 2019. [DOI: 10.2981/wlb.00503] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Affiliation(s)
- Sebastian Menke
- S. Menke, K. Wilhelm and S. Sommer , Inst. of Ecology and Conservation Genomics, Univ. of Ulm, Albert-Einstein Allee 11, DE-89081 Ulm, Germany
| | - Marco Heurich
- M. Heurich and M. Henrich, Dept of Conservation and Research, Bavarian Forest National Park, Zoology, Grafenau, Germany
| | - Maik Henrich
- M. Heurich and M. Henrich, Dept of Conservation and Research, Bavarian Forest National Park, Zoology, Grafenau, Germany
| | - Kerstin Wilhelm
- S. Menke, K. Wilhelm and S. Sommer , Inst. of Ecology and Conservation Genomics, Univ. of Ulm, Albert-Einstein Allee 11, DE-89081 Ulm, Germany
| | - Simone Sommer
- S. Menke, K. Wilhelm and S. Sommer , Inst. of Ecology and Conservation Genomics, Univ. of Ulm, Albert-Einstein Allee 11, DE-89081 Ulm, Germany
| |
Collapse
|
18
|
Satterfield DA, Marra PP, Sillett TS, Altizer S. Responses of migratory species and their pathogens to supplemental feeding. Philos Trans R Soc Lond B Biol Sci 2019. [PMID: 29531149 DOI: 10.1098/rstb.2017.0094] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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'.
Collapse
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
| |
Collapse
|
19
|
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] [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'.
Collapse
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
| |
Collapse
|
20
|
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] [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
| |
Collapse
|
21
|
Cotterill GG, Cross PC, Middleton AD, Rogerson JD, Scurlock BM, du Toit JT. Hidden cost of disease in a free-ranging ungulate: brucellosis reduces mid-winter pregnancy in elk. Ecol Evol 2018; 8:10733-10742. [PMID: 30519402 PMCID: PMC6262735 DOI: 10.1002/ece3.4521] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2018] [Revised: 08/06/2018] [Accepted: 08/19/2018] [Indexed: 11/08/2022] Open
Abstract
Demonstrating disease impacts on the vital rates of free-ranging mammalian hosts typically requires intensive, long-term study. Evidence for chronic pathogens affecting reproduction but not survival is rare, but has the potential for wide-ranging effects. Accurately quantifying disease-associated reductions in fecundity is important for advancing theory, generating accurate predictive models, and achieving effective management. We investigated the impacts of brucellosis (Brucella abortus) on elk (Cervus canadensis) productivity using serological data from over 6,000 captures since 1990 in the Greater Yellowstone Ecosystem, USA. Over 1,000 of these records included known age and pregnancy status. Using Bayesian multilevel models, we estimated the age-specific pregnancy probabilities of exposed and naïve elk. We then used repeat-capture data to investigate the full effects of the disease on life history. Brucellosis exposure reduced pregnancy rates of elk captured in mid- and late-winter. In an average year, we found 60% of exposed 2-year-old elk were pregnant compared to 91% of their naïve counterparts (a 31 percentage point reduction, 89% HPDI = 20%-42%), whereas exposed 3- to 9-year-olds were 7 percentage points less likely to be pregnant than naïve elk of their same age (89% HPDI = 2%-11%). We found these reduced rates of pregnancy to be independent from disease-induced abortions, which afflict a portion of exposed elk. We estimate that the combination of reduced pregnancy by mid-winter and the abortions following mid-winter reduces the reproductive output of exposed female elk by 24%, which affects population dynamics to a similar extent as severe winters or droughts. Exposing hidden reproductive costs of disease is essential to avoid conflating them with the effects of climate and predation. Such reproductive costs cause complex population dynamics, and the magnitude of the effect we found should drive a strong selection gradient if there is heritable resistance.
Collapse
Affiliation(s)
| | - Paul C. Cross
- U.S. Geological SurveyNorthern Rocky Mountain Science CenterBozemanMontana
| | - Arthur D. Middleton
- Department of Environmental Science, Policy and ManagementUniversity of CaliforniaBerkeleyCalifornia
| | | | | | | |
Collapse
|
22
|
EFFECTS OF BRUCELLOSIS SEROLOGIC STATUS ON PHYSIOLOGY AND BEHAVIOR OF ROCKY MOUNTAIN ELK ( CERVUS CANADENSIS NELSONI) IN SOUTHWESTERN MONTANA, USA. J Wildl Dis 2018; 55:304-315. [PMID: 30277828 DOI: 10.7589/2018-01-011] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Brucellosis, caused by bacteria in the genus Brucella, is an infectious zoonosis affecting animals and humans worldwide. Free-ranging Rocky Mountain elk ( Cervus canadensis nelsoni) and bison ( Bison bison) in the Greater Yellowstone Ecosystem (areas of southwestern Montana, eastern Idaho, and northwestern Wyoming, US) are the self-sustaining reservoirs of bovine brucellosis ( Brucella abortus) and elk are considered the primary source of livestock infections. It has been hypothesized that Brucella-exposed elk might have different physiologic status (pregnancy rates and body condition) and migration behaviors than would healthy elk. Here we tested the effects of brucellosis serologic status on pregnancy rates and winter ingesta free body fat of 100 female elk in southwestern Montana. We also evaluated the effects of serologic status on two characteristics of spring migration behavior, migration types (migrant, mixed migrant, resident, disperser, nomad, and undetermined type) and timing (start and end dates and duration). The migration behaviors were quantified using a model-driven approach based on the relative net squared displacement. We detected a significant difference (P=0.003) in pregnancy rates between seropositive and seronegative elk, with about a 30% drop in seropositive individuals. However, we did not detect differences in body fat between seropositive and seronegative elk or differences in either migration type or timing of spring migration. These results confirmed that the major effect of brucellosis in free-ranging elk is associated with reproduction.
Collapse
|