Health Of Wildlife Populations Research Articles

Impact of Climate Change on Vector-Borne Diseases in Wildlife

Purpose: This study sought to investigate the impact of climate change on vector-borne diseases in wildlife.
 Methodology: The study adopted a desktop research methodology. Desk research refers to secondary data or that which can be collected without fieldwork. Desk research is basically involved in collecting data from existing resources hence it is often considered a low cost technique as compared to field research, as the main cost is involved in executive’s time, telephone charges and directories. Thus, the study relied on already published studies, reports and statistics. This secondary data was easily accessed through the online journals and library.
 Findings: The findings reveal that there exists a contextual and methodological gap relating to climate change on vector-borne diseases in wildlife. Preliminary empirical review revealed that that environmental shifts, driven by climate change, profoundly influenced the distribution and transmission dynamics of diseases among wildlife populations. Through a comprehensive review of empirical studies, it was found that warmer temperatures, altered precipitation patterns, and extreme weather events expanded vector habitats, increasing disease exposure for wildlife. The research emphasized the importance of interdisciplinary approaches and proactive measures, such as habitat restoration and disease surveillance, to mitigate disease risks and promote ecosystem resilience. Overall, the study highlighted the urgent need to address the interconnected challenges of climate change, vector-borne diseases, and wildlife health to safeguard environmental and human well-being.
 Unique Contribution to Theory, Practice and Policy: The Ecological Niche theory, Disease Ecology theory and One Health theory may be used to anchor future studies on climate change on vector-borne diseases in wildlife. The study provided recommendations that contributed to theory, practice, and policy. From a theoretical perspective, it emphasized the need for interdisciplinary research to understand the complex interactions between climate change, vector populations, and disease transmission. Practically, the study recommended adaptive management strategies, such as habitat restoration and disease surveillance, to mitigate disease risks in wildlife. Policy-wise, it called for integrating climate resilience and biodiversity conservation efforts, along with public education campaigns and international cooperation, to address the transboundary nature of vector-borne disease threats. Overall, these recommendations aimed to build resilience in ecosystems, protect biodiversity, and ensure the health of wildlife populations amidst climate change.

Role of the World Organisation for Animal Health in global wildlife disease surveillance.

This paper examines the role of the World Organisation for Animal Health (WOAH) in the global surveillance and management of pathogens. Since the creation of WOAH, one of its missions has been to ensure transparency of the global animal health situation. WOAH established a Working Group on Wildlife in 1994 to inform and advise WOAH Members, leadership, and technical teams on issues relating to wildlife health. In 2020 it conducted a consultation with its Members before developing a Wildlife Health Framework to improve global health and wildlife conservation. WOAH Members report diseases in wildlife, but detections are dependent on the surveillance systems in place. As an example of data collected in the most recent years (2019-2023), 154 countries have reported 68,862,973 cases, through alert messages and weekly updates, for 84 diseases. One-hundred and fifty countries have reported 68,672,115 cases in domestic animals and 95 countries have reported 190,858 cases in wild animals. These figures illustrate the performance of the organization in collecting data on wildlife, and provide an indication of the difference in completeness of data collected in domestic animals and wildlife. There are several challenges to wildlife disease surveillance and real figures remain unknown; they depend on the existence, quality and sensitivity of national surveillance. A WOAH-led One Health approach with cross-sectoral collaboration is needed to improve surveillance sensitivity, address the challenges and help safeguard wildlife population health and biodiversity conservation.

Bat cellular immunity varies by year and dietary habit amidst land conversion.

Monitoring the health of wildlife populations is essential in the face of increased agricultural expansion and forest fragmentation. Loss of habitat and habitat degradation can negatively affect an animal's physiological state, possibly resulting in immunosuppression and increased morbidity or mortality. We sought to determine how land conversion may differentially impact cellular immunity and infection risk in Neotropical bats species regularly infected with bloodborne pathogens, and to evaluate how effects may vary over time and by dietary habit. We studied common vampire bats (Desmodus rotundus), northern yellow-shouldered bats (Sturnira parvidens) and Mesoamerican mustached bats (Pteronotus mesoamericanus), representing the dietary habits of sanguivory, frugivory and insectivory respectively, in northern Belize. We compared estimated total white blood cell count, leukocyte differentials, neutrophil to lymphocyte ratio and infection status with two bloodborne bacterial pathogens (Bartonella spp. and hemoplasmas) of 118 bats captured in a broadleaf, secondary forest over three years (2017-2019). During this period, tree cover decreased by 14.5% while rangeland expanded by 14.3%, indicating increasing habitat loss and fragmentation. We found evidence for bat species-specific responses of cellular immunity between years, with neutrophil counts significantly decreasing in S. parvidens from 2017 to 2018, but marginally increasing in D. rotundus. However, the odds of infection with Bartonella spp. and hemoplasmas between 2017 and 2019 did not differ between bat species, contrary to our prediction that pathogen prevalence may increase with land conversion. We conclude that each bat species invested differently in cellular immunity in ways that changed over years of increasing habitat loss and fragmentation. We recommend further research on the interactions between land conversion, immunity and infection across dietary habits of Neotropical bats for informed management and conservation.

A new multiplexed magnetic capture-Droplet digital PCR tool for monitoring wildlife population health and pathogen surveillance.

Anthropogenic stressors are exacerbating the emergence and spread of pathogens worldwide. In regions like the Arctic, where ecosystems are particularly susceptible, marked changes are predicted in regional diversity, intensity, and patterns of infectious diseases. To understand such rapidly changing host-pathogen dynamics and mitigate the impacts of novel pathogens, we need sensitive disease surveillance tools. We developed and validated a novel multiplexed, magnetic capture, and ddPCR tool for the surveillance of multiple pathogens in polar bears, a sentinel species that is considered susceptible to climate change and other stressors with a pan-Arctic distribution. Through sequence-specific magnetic capture, we concentrated five target template sequences from three zoonotic bacteria (Erysipelothrix rhusiopathiae, Francisella tularensis, and Mycobacterium tuberculosis complex) and two parasitic (Toxoplasma gondii and Trichinella spp.) pathogens from large quantities (<100 g) of host tissue. We then designed and validated two multiplexed probe-based ddPCR assays for the amplification and detection of the low-concentration target DNA. Validations used 48 polar bear tissues (muscle and liver). We detected 14, 1, 3, 4, and 22 tissue positives for E. rhusiopathiae, F. tularensis, M. tuberculosis complex, T. gondii, and Trichinella spp., respectively. These multiplexed assays offer a rapid, specific tool for quantifying and monitoring the changing geographical and host distributions of pathogens relevant to human and animal health.

Areal roughness of the dorsal nail plate

Objective: Beau’s lines, onychorrhexis, and psoriatic lesions of the dorsal nail plate may be missed by photographic methods, indicating a need for surface texture measurement methods that are more quantitative, sensitive, and repeatable than visual inspection or imaging. We conducted this study to evaluate the utility of surface texture measurements of cadaveric nails that can be associated with histopathological studies in the future. Materials: The nail plates of four cadaveric right pollices and halluces were cleaned and molded, cast in clear epoxy, and scanned with a Sensofar S Neox optical profilometer. A one-way analysis of variance (ANOVA) was performed to determine statistical significance of findings. Results: Almost no differences were observed between the pollex and hallux scans, and between the distal and proximal regions. The greatest differences were found between individuals. Although lower magnification (5×) is less sensitive than higher magnification (20×), the lower magnification represented and characterized more of the dorsal nail plate. Conclusions: The dorsal nail plate areal roughness has a measurable range of values that may serve as a starting point for evaluating pathological findings, particularly Beau’s lines and psoriatic lesions. The sensitivity of these techniques may be especially valuable in the recognition of less severe states of these diseases that may enable the diagnosis of earlier stages of growth disruptions (Beau’s lines) or psoriasis. Such applications could be especially useful in investigations of the health of wildlife populations or vulnerable human populations with incomplete treatment records.

Persistent organic pollutants and trace elements detected in New Zealand fur seals (long-nosed fur seal; Arctocephalus forsteri) from New South Wales, Australia, between 1998 and 2019

Environmental pollution is a growing threat to wildlife health and biodiversity. The relationship between marine mammals and pollutants is, however, complex and as new chemicals are introduced to ecosystems alongside concomitant, interacting threats such as climate change and habitat degradation, the cumulative impact of these stressors to wildlife continues to expand. Understanding the health of wildlife populations requires a holistic approach to identify potential threatening processes. In the context of environmental pollution in little studied wildlife species, it is important to catalogue the current exposome to develop effective biomonitoring programs that can support diagnosis of health impacts and management and mitigation of pollution. In New South Wales, Australia, the New Zealand fur seal (Arctocephalus forsteri) is a resident species experiencing population growth following devastating historic hunting practices. This study presents a retrospective investigation into the exposure of New Zealand fur seals to a range of synthetic organic compounds and essential and non-essential trace elements. Liver tissue from 28 seals were broadly analyzed to assess concentrations of organochlorine and organophosphate pesticides, polychlorinated biphenyls, per- and polyfluoroalkyl substances, and essential and non-essential trace elements. In addition to contributing extensive pollution baseline data for the species, the work explores the influence of sex, age, and body condition on accumulation patterns. Further, based on these findings, it is recommended that a minimum of 11 juvenile male New Zealand fur seals are sampled and analyzed annually in order to maintain a holistic biomonitoring approach for this population.

Wildlife Population Health

Book reviews express the opinions of the individual authors regarding the value of the book's content for Journal of Wildlife Diseases readers. The reviews are subjective assessments and do not necessarily reflect the opinions of the editors, nor do they establish any official policy of the Wildlife Disease Association.

Gene expression and wildlife health: varied interpretations based on perspective

We evaluated wildlife population health from the perspective of statistical means vs. variances. We outlined the choices necessary to provide the framework for our study. These consisted of spatial and temporal boundaries (e.g., choice of sentinel species, populations, time frame), measurement techniques (molecular to population level), and appropriate statistical analyses. We chose to assess the health of 19 sea otter populations, located in the north Pacific from the Aleutian Islands, AK, to Santa Barbara, CA, and varying in population growth rates and length of occupancy. Our focal metric was gene expression (i.e., mRNA transcripts) data that we had previously generated across sea otter populations as a measure of population health. We used statistical methods with different approaches (i.e., means vs. variances) and examined the subsequent interpretive outcomes and how these influence our assessment of “health.” Interpretations based on analyses using variances versus means overlapped to some degree. In general, sea otter populations with low variation in gene expression were limited by food resources and at or near carrying capacity. In populations where the variation in gene expression was moderate or high, four out of five populations were increasing in abundance, or had been recently increasing. Where we had additional information on sources of stressors at the level of the population, we were able to draw inferences from those stressors to specific gene expression results. For example, gene expression patterns of sea otters from Western Prince William Sound were consistent with long term exposure to petroleum hydrocarbons, whereas in Kachemak Bay, patterns were consistent with exposure to algal toxins. Ultimately, determination of population or ecosystem health will be most informative when multiple metrics are examined across disciplines in the context of specific scenarios and goals.

Tissue-specific assessment of oxidative status: Wild boar as a case study.

In recent decades, there has been a fast-growing interest in using biomarkers of oxidative stress (BOS) in conservation programs of many vertebrate species. Biomarkers of oxidative stress can be measured in different biological samples (e.g., body fluids and tissues). However, since comparisons of the same battery of BOS among tissues of the same individual are scarce in the literature, the chosen target tissues regularly rely on arbitrary decisions. Our research aimed to determine if the oxidative status of free-ranging wild boar (Sus scrofa) naturally infected with Mycobacterium spp (etiological agent of tuberculosis, TB), varies depending on the sample where it was quantified. We compared antioxidant p-nitrophenyl esterase activity (EA), glutathione peroxidase (GPX) concentrations, and total oxidative status (TOS) in serum, lung, spleen, kidney, and muscle of 63 wild boar hunter-harvested in central Spain. Biomarkers of oxidative stress in serum had higher concentrations than in other tissues. The poor agreement between serum and other tissues highlights the importance of running complete BOS assessments in the same fluid or tissue. Further, low concentrations of BOS in tissues of TB-affected individuals were observed, and significant differences between healthy and sick boar were only detected in the serum of individuals developing mild TB and in the muscle of individuals with mild or severe disease status. However, all organs from wild boars affected with mild TB were not in oxidative imbalance compared to healthy control animals, suggesting that wild boars may cope well with TB. Our data indicate that serum and other tissues can be used as BOS in field conservation programs to monitor wildlife population health. Still, context-specific validations are needed to determine the most appropriate samples to use.

Socioeconomic factors predict population changes of large carnivores better than climate change or habitat loss

Land-use and climate change have been linked to changes in wildlife populations, but the role of socioeconomic factors in driving declines, and promoting population recoveries, remains relatively unexplored. Here, we evaluate potential drivers of population changes observed in 50 species of some of the world’s most charismatic and functionally important fauna—large mammalian carnivores. Our results reveal that human socioeconomic development is more associated with carnivore population declines than habitat loss or climate change. Rapid increases in socioeconomic development are linked to sharp population declines, but, importantly, once development slows, carnivore populations have the potential to recover. The context- and threshold-dependent links between human development and wildlife population health are challenges to the achievement of the UN Sustainable development goals.

WILDLIFE HEALTH AND THE NORTH AMERICAN MODEL OF WILDLIFE CONSERVATION.

The management of wildlife in the United States and Canada, including the monitoring and maintenance of the health of wildlife populations and the ecosystems on which they depend, are conducted under a set of principles that aim for sustainable use. This set of principles is known as the North American Model of Wildlife Conservation (the Model), and it guides wildlife management and conservation decisions in both countries. The purpose of this perspective is to highlight how wildlife health is an important part of the Model and is vital to its future. It is proposed that wildlife health and the Model support one another. First, the history and fundamental ideas of a public trust that shaped the Model are reviewed. Next, wildlife health is defined and examples are offered that highlight how the Model supports wildlife health and how health affects the Model, as well as the limitations or threats if one moves away from the Model's defining principles. Finally, controversies surrounding the Model are reviewed and a perspective on the future is offered, based in large part on the work of Aldo Leopold. Leopold's thinking about health of the land and its organisms was well ahead of its time, and the scientific underpinnings of his writings in making the case for wildlife health and the Model are recounted. As a simple addendum to Leopold's land ethic, a plea for a health ethic is called for, whereby healthy wildlife and healthy landscapes are an obligation of the Model and modern society because health "tends to preserve the integrity, stability and beauty of the biotic community."41.

A multifaceted index of population health to detect risk-prone populations and underlying stressors in wildlife

Local declines of wild populations represent the most visible part of biodiversity loss, and their detection often relies on long-term surveys. An alternative to identify risk-prone populations is to use indicators informing on their general health (i.e., their general fitness and ability to cope with changing environment) based on simple and complementary parameters estimated from snapshot sampling. However, most studies on wildlife population health focus on one or only a few parameters, yielding potentially biased conclusions for conservation. Here, we developed a multifaceted index of population health by combining 3 complementary indicators, namely pathological, ecological, and genetic indicators, based on an integrative approach traditionally used to assess ecosystem multifunctionality. We investigated their complementarity and relevance for detecting brown trout (Salmo trutta) risk-prone populations at a large spatial scale, and the underlying environmental stressors. The multifaceted health index properly represented the individual indicators' complementary information. It identified a cluster of moderately risk-prone populations and raised the alarm for one population. Each indicator was individually associated with distinct environmental stressors relevant for brown trout requirements. The multifaceted health index highlighted surrounding agricultural land and oxygen concentration as the most impacting environmental factors for the general health and sustainability of brown trout populations. The implementation of such integrative index can be transferred to a wide range of species and contexts. This index therefore provides to environmental managers and conservationists a snapshot and easily operated tool to identify risk-prone populations and areas to restore or conserve.

Cooperation and Cattle Herding in Eighteenth Century Acadia: Implications for Archaeological Studies of Agropastoralism

Anthropological studies of cattle management have frequently used nomadic open-range African pastoralists as models even when examining more sedentary agro-pastoralists relying upon combinations of crops and livestock that prevent or inhibit mobility. The relatively limited number of datasets on more sedentary agro-pastoralists makes it difficult to assess the suitability of this analogy when modeling and understanding herd dynamics in sedentary or semi-sedentary societies like those in the European Neolithic or pre-industrial colonies in North America. Census data on seventeenth- and eighteenth-century French colonists in eastern Canada and the northeastern U.S. reveal that household herds average fewer than eight individuals. Herds this small would have been dangerously close to collapse if animals were slaughtered and would not have had sufficient numbers to grow quickly. Using effective population size, a measure from wildlife biology, to assess the demographic and genetic health of wildlife populations, we demonstrate that Acadian herders were able to overcome the challenges of their small herds by participating in village or inter-village herd networks. Furthermore, we demonstrate that differences in herd management existed across the Acadian colonies and correspond, in part, to local involvement in cod fishing. We suggest this case study may provide a useful model for understanding prehistoric sedentary agropastoralism and the role of cooperation in prehistoric animal management decisions.

Missing Release Data in Capture-Mark-Recovery Analyses: Consequences for Inference

Abstract Demographic probabilities, such as annual survival and harvest probability, are key metrics used in research and for monitoring the health of wildlife populations and sustainability of harvest. For waterfowl populations, annual estimates of these probabilities come from mark-recovery analysis of data from coordinated banding operations. The Brownie model is the most commonly used parameterization for analyzing mark-recovery data from harvested species. However, if banded waterfowl are not released during a year of a multiyear banding operation, then estimating annual survival and recovery probabilities from a dead recovery model is a challenge. Due to coronavirus disease 2019, many wildlife monitoring efforts, including annual waterfowl banding programs, were canceled or reduced during 2020 and 2021, highlighting the need for wildlife managers to better understand the consequences of missing data on analyses and regulatory decisions. We summarized methods of model parameterization and use of alternative methods to explore the behavior of demographic parameter estimates when a year of release data was missing. Comparing constrained fixed-effect models (we set parameters during the missing year of data equal to parameters for years with release data) with random-effect models, we found that 1) bias of estimates during a year of missing release data was smaller when using a random-effect model, 2) the direction of the bias was unpredictable, but the expected range in bias could be generally known commensurate to the underlying variability in survival and recovery probabilities, and 3) potential bias was greatest if the missing year of releases occurred during the final year of a time series. We conclude that in some circumstances, various modeling approaches can provide reasonable estimates during a year of missing release data, particularly when underlying demographic parameters, or the parameter constrained in a model, vary little over time (e.g., adult survival in long-lived species), which would result in relatively little bias in the other estimated parameter (e.g., annual recovery probability). We also suggest that using alternative analytical techniques, such as random-effect models, may improve estimates for the demographic parameters of interest when release data are missing. Random-effect models also allowed us to estimate parameters, such as juvenile recovery probabilities, during the year of missing release data, which are not identifiable using standard modeling techniques. Where accurate and precise parameter estimation is important for making harvest management decisions and regardless of the model type or the data used, there is no analytical replacement for missing release data. We suggest that practitioners determine the potential consequences for missing data through simulation by using empirical data and simulated data with known demographic probabilities to determine the best actions to take for analyzing their capture-recovery data when release data are missing.

Quantitative photogrammetric methodology for measuring mammalian belly score in the painted dog.

The use of “belly scoring” can offer a novel, non-invasive objective management tool to gauge food intake between individuals, groups, and populations, and thus, population fitness. As food availability is increasingly affected by predation, ecological competition, climate change, habitat modification, and other human activities, an accurate belly scoring tool can facilitate comparisons among wildlife populations, serving as an early warning indicator of threats to wildlife population health and potential population collapse. In social species, belly scores can also be a tool to understand social behavior and ranking. We developed and applied the first rigorous quantitative photogrammetric methodology to measure belly scores of wild painted dogs (Lycaon pictus). Our methodology involves: (1) Rigorous selection of photographs of the dorso/lateral profile of individuals at a right angle to the camera, (2) photogrammetrically measuring belly chord length and “belly drop” in pixels, (3) adjusting belly chord length as a departure from a standardized leg angle, and (4) converting pixel measurements to ratios to eliminate the need to introduce distance from the camera. To highlight a practical application, this belly score method was applied to 631 suitable photographs of 15 painted dog packs that included 186 individuals, all collected between 2004–2015 from allopatric painted dog populations in and around Hwange (n = 462) and Mana Pools National Parks (n = 169) in Zimbabwe. Variation in mean belly scores exhibited a cyclical pattern throughout the year, corresponding to biologically significant patterns to include denning demand and prey availability. Our results show significant differences between belly scores of the two different populations we assessed, thus highlighting food stress in the Hwange population. In the face of growing direct and indirect anthropogenic disturbances, this standardised methodology can provide a rapid, species-specific non-invasive management tool that can be applied across studies to rapidly detect emergent threats.

The Dividing Line Between Wildlife Research and Management-Implications for Animal Welfare.

Wild animals are used for research and management purposes in Sweden and throughout the world. Animals are often subjected to similar procedures and risks of compromised welfare from capture, anesthesia, handling, sampling, marking, and sometimes selective removal. The interpretation of the protection of animals used for scientific purposes in Sweden is based on the EU Directive 2010/63/EU. The purpose of animal use, irrespective if the animal is suffering or not, decides the classification as a research animal, according to Swedish legislation. In Sweden, like in several other European countries, the legislation differs between research and management. Whereas, animal research is generally well-defined and covered in the legislation, wildlife management is not. The protection of wild animals differs depending on the procedure they are subjected to, and how they are classified. In contrast to wildlife management activities, research projects have to implement the 3Rs and must undergo ethical reviews and official animal welfare controls. It is often difficult to define the dividing line between the two categories, e.g., when marking for identification purposes. This gray area creates uncertainty and problems beyond animal welfare, e.g., in Sweden, information that has been collected during management without ethical approval should not be published. The legislation therefore needs to be harmonized. To ensure consistent ethical and welfare assessments for wild animals at the hands of humans, and for the benefit of science and management, we suggest that both research and management procedures are assessed by one single Animal Ethics Committee with expertise in the 3Rs, animal welfare, wildlife population health and One Health. We emphasize the need for increased and improved official animal welfare control, facilitated by compatible legislation and a similar ethical authorization process for all wild animal procedures.

Characteristics of animal-related motor vehicle crashes in select National Park Service units—United States, 1990–2013

Objectives: Nationally, animal–motor vehicle crashes (AVCs) account for 4.4% of all types of motor vehicle crashes (MVCs). AVCs are a safety risk for drivers and animals and many National Park Service (NPS) units (e.g., national park, national monument, or national parkway) have known AVC risk factors, including rural locations and substantial animal densities. We sought to describe conditions and circumstances involving AVCs to guide traffic and wildlife management for prevention of AVCs in select NPS units.Methods: We conducted an analysis using NPS law enforcement MVC data. An MVC is a collision involving an in-transit motor vehicle that occurred or began on a public roadway. An AVC is characterized as a collision between a motor vehicle and an animal. A non-AVC is a crash between a motor vehicle and any object other than an animal or noncollision event (e.g., rollover crash). The final data for analysis included 54,068 records from 51 NPS units during 1990–2013. Counts and proportions were calculated for categorical variables and medians and ranges were calculated for continuous variables. We used Pearson’s chi-square to compare circumstances of AVCs and non-AVCs. Data were compiled at the park regional level; NPS parks are assigned to 1 of 7 regions based on the park’s location.Results: AVCs accounted for 10.4% (5,643 of 54,068) of all MVCs from 51 NPS units. The Northeast (2,021 of 5,643; 35.8%) and Intermountain (1,180 of 5,643; 20.9%) regions had the largest percentage of the total AVC burden. November was the peak month for AVCs across all regions (881 of 5,643; 15.6%); however, seasonality varied by park geographic regions. The highest counts of AVCs were reported during fall for the National Capital, Northeast/Southeast, and Northeast regions; winter for the Southeast region; and summer for Intermountain and Pacific West regions.Conclusions: AVCs represent a public health and wildlife safety concern for NPS units. AVCs in select NPS units were approximately 2-fold higher than the national percentage for AVCs. The peak season for AVCs varied by NPS region. Knowledge of region-specific seasonality patterns for AVCs can help NPS staff develop mitigation strategies for use primarily during peak AVC months. Improving AVC data collection might provide NPS with a more complete understanding of risk factors and seasonal trends for specific NPS units. By collecting information concerning the animal species hit, park managers can better understand the impacts of AVC to wildlife population health.

Biochemical and physiological parameters associated withTrypanosomaevansiprevalence in wild capybaras (Hydrochoerushydrochaeris)

Parasites can be detrimental to the health of wildlife populations and may negatively affect several aspects of the life history of their hosts. Investigating host health, therefore, is key to understanding important mechanisms of the host–parasite interaction at the individual and population levels. Recently, we reported a prevalence of 10% of Trypanosoma evansi Steel, 1884 in a population of capybaras (Hydrochoerus hydrochaeris (L., 1766)) from Esteros del Iberá, Argentina; however, the impact of T. evansi infection on capybaras is unknown. The aim of this study was to explore associations between T. evansi infection and biochemical and physiological parameters in wild capybaras using blood samples (n = 60) from a managed population of free-ranging capybaras from Esteros del Iberá. Infection by T. evansi was negatively associated with body condition, albumin, alpha-2 globulin concentrations, albumin/globulin ratio, and eosinophil counts, and it was positively associated with spleen index and gamma-globulin concentrations. These results suggest that T. evansi infection may pose a significant impact on the health of wild capybaras.

Local knowledge to enhance wildlife population health surveillance: Conserving muskoxen and caribou in the Canadian Arctic

Monitoring and surveillance of wildlife populations, including demographics and health, is often challenging, particularly in resource-constrained and remote settings. However, in areas characterized by subsistence oriented societies, the users of renewable resources hold a vast and holistic ecological knowledge about the natural environment. This knowledge can be instrumental for understanding and early detection of changes in wildlife populations. Using qualitative research methods and participatory epidemiology techniques we documented the local knowledge from resource users of the community of Iqaluktutiaq (Nunavut, Canada) to assess the health and population status and trends for muskoxen and caribou in the area. Semi-structured individual interviews, followed by group interviews, were implemented with 38 participants, and research findings were summarized and then verified with 31 interviewees. Local knowledge identified major declines in the number of muskoxen and caribou in the study area that were corroborated by subsequent aerial population estimates for both species. Observations made by participants allowed inference of possible mechanisms for the recent population declines, including poor recruitment, poor body condition, and increased morbidity and mortality (including endemic and emerging diseases). Engaging resource users in the process of knowledge generation was useful to identify further research priorities and fostered trust among parties that facilitated the subsequent collaborative development of management plans for these species. We use our experience to illustrate that local knowledge contributes to a holistic understanding of wildlife health and can serve as an early warning system to detect changes in wildlife populations. These participatory approaches are portable to other species and settings and can enhance conservation and co-management efforts for wildlife species worldwide.

Variation in ungulate body fat: Individual versus temporal effects

ABSTRACTThe use of ultrasonograhic measurements of muscle and body fat represent a relatively new data stream that can be used to address questions regarding ungulate condition. We have learned that measurements of body fat and presumably overall body condition among individual animals, even those taken from the same herd at that same time, are highly variable. Relatively little consideration has been given to the sources of variation in body fat and other physiological parameters in wildlife populations. We evaluated the components of variation in late‐winter mule deer (Odocoileus hemionus) body fat estimates: sampling variation (i.e., variation induced by the particular set of individuals that were sampled) and process variation (i.e., variation stemming from biological processes) with a long‐term data set (2002–2015) from Colorado, USA. We collected our data from across Colorado as part of historical research, ongoing research, and periodic population monitoring programs. Mean percent ingesta‐free body fat (%IFBF) for sampled mule deer was 7.20 ± 1.20% (SD). Covariates related to individual deer explained approximately 4% of the total variation in %IFBF and annual effects explained an additional 13% of the variation. Substantial residual variation in %IFBF (83%) remained unexplained. The source of the 83% of unexplained variation is partially linked to fine‐scale spatial dynamics but also additional individual metrics we were unable to capture, primarily the presence or absence of dependent young. We speculate that the primary factors influencing late‐winter mule deer body fat and overall condition are individual in nature. These results present a cautionary check on herd‐level inference that can be made from individual late‐winter body fat estimates and we postulate that for mule deer, alternative and additional body condition metrics may offer added utility in management scenarios. However, an important next step to better understand wildlife population health is to evaluate the sources and magnitude of variation within other body condition metrics, with the goal of further refining data that can better allow biologists to incorporate herd health into population management recommendations. © 2017 The Wildlife Society.