200 research outputs found
Modeling raccoon (Procyon lotor) habitat connectivity to identify potential corridors for rabies spread
The United States Department of Agriculture (USDA), Animal and Plant Health Inspection Service (APHIS), Wildlife Services National Rabies Management Program has conducted cooperative oral rabies vaccination (ORV) programs since 1997. Understanding the eco-epidemiology of raccoon (Procyon lotor) variant rabies (raccoon rabies) is critical to successful management. Pine (Pinus spp.)-dominated landscapes generally support low relative raccoon densities that may inhibit rabies spread. However, confounding landscape features, such as wetlands and human development, represent potentially elevated risk corridors for rabies spread, possibly imperiling enhanced rabies surveillance and ORV planning. Raccoon habitat suitability in pine-dominated landscapes in Massachusetts, Florida, and Alabama was modeled by the maximum entropy (Maxent) procedure using raccoon presence, and landscape and environmental data. Replicated (n = 100/state) bootstrapped Maxent models based on raccoon sampling locations from 2012â2014 indicated that soil type was the most influential variable in Alabama (permutation importance PI = 38.3), which, based on its relation to landcover type and resource distribution and abundance, was unsurprising. Precipitation (PI = 46.9) and temperature (PI = 52.1) were the most important variables in Massachusetts and Florida, but these possibly spurious results require further investigation. The Alabama Maxent probability surface map was ingested into Circuitscape for conductance visualizations of potential areas of habitat connectivity. Incorporating these and future results into raccoon rabies containment and elimination strategies could result in significant cost-savings for rabies management here and elsewhere
Development of On-Shore Behavior Among Polar Bears (\u3ci\u3eUrsus maritimus\u3c/i\u3e) in the Southern Beaufort Sea: Inherited or Learned?
Polar bears (Ursus maritimus) are experiencing rapid and substantial changes to their environment due to global climate change. Polar bears of the southern Beaufort Sea (SB) have historically spent most of the year on the sea ice. However, recent reports from Alaska indicate that the proportion of the SB subpopulation observed onâshore during late summer and early fall has increased. Our objective was to investigate whether this onâshore behavior has developed through genetic inheritance, asocial learning, or through social learning. From 2010 to 2013, genetic data were collected from SB polar bears in the fall via hair snags and remote biopsy darting onâshore and in the spring from captures and remote biopsy darting on the sea ice. Bears were categorized as either onâshore or offâshore individuals based on their presence onâshore during the fall. Levels of genetic relatedness, firstâorder relatives, motherâoffspring pairs, and fatherâoffspring pairs were determined and compared within and between the two categories: onâshore versus offâshore. Results suggested transmission of onâshore behavior through either genetic inheritance or social learning as there was a higher than expected number of firstâorder relatives exhibiting onâshore behavior. Genetic relatedness and parentage data analyses were in concurrence with this finding, but further revealed motherâoffspring social learning as the primary mechanism responsible for the development of onâshore behavior. Recognizing that onâshore behavior among polar bears was predominantly transmitted via social learning from mothers to their offspring has implications for future management and conservation as sea ice continues to decline
Use of Subsistence-Harvested Whale Carcasses by Polar Bears in the Southern Beaufort Sea
The availability of a food subsidy has the potential to influence the condition, behavior, fitness, and population dynamics of a species. Since the early 2000s, monitoring efforts along the coast of northern Alaska have indicated a higher proportion of polar bears (Ursus maritimus) of the southern Beaufort Sea (SB) subpopulation coming onshore to feed on subsistence-harvested bowhead whale (Balaena mysticetus) carcasses during the fall and early winter seasons. Concurrently, Indigenous communities annually hunt bowhead whale and deposit the unused remains at localized âbone piles,â creating the potential for human-bear interactions. Our objective was to determine the annual number of polar bears feeding at the bone pile near Kaktovik, Alaska. Using a hair snag surrounding the bone pile, we collected hair samples to identify individual bears via microsatellite genotypes during 2011 â 14. We used capture-mark-recapture data in the POPAN open-population model to estimate the number of bears visiting the bone pile. We estimated that as many as 72 (SE = 9) and 76 (SE = 10) male and female polar bears, respectively, used the bone pile located at Kaktovik, Alaska, in 2012, which represents approximately 16% of the SB polar bear subpopulation. It will be important to monitor the number of bears using the bone pile and subsequent human-bear interactions and conflicts along the northern coast of Alaska, if sea ice continues to recede.Lâexistence de subventions alimentaires a la possibilitĂ© dâinfluencer lâĂ©tat, le comportement, la condition physique et la dynamique de la population dâune espĂšce. Depuis le dĂ©but des annĂ©es 2000, les efforts de surveillance dĂ©ployĂ©s sur la cĂŽte nord de lâAlaska ont laissĂ© entrevoir une plus grande proportion dâours polaires (Ursus maritimus) de la sous-population du sud de la mer de Beaufort venant sur le littoral pour manger les carcasses des baleines borĂ©ales (Balaena mysticetus) pĂȘchĂ©es Ă des fins de subsistance pendant les saisons de lâautomne et du dĂ©but de lâhiver. En mĂȘme temps, les collectivitĂ©s autochtones chassent les baleines borĂ©ales tous les ans et dĂ©posent leurs restes dans des « tas dâossements », ce qui crĂ©e la possibilitĂ© dâinteractions entre les humains et les ours. Notre objectif consistait Ă dĂ©terminer le nombre annuel dâours polaires qui sâalimentent au tas dâossements situĂ© prĂšs de Kaktovik, en Alaska. De 2011 Ă 2014, Ă lâaide dâun piĂšge Ă poils placĂ© prĂšs du tas dâossements, nous avons recueilli des Ă©chantillons de poils afin dâidentifier les ours individuels au moyen de gĂ©notypes microsatellites. Nous avons employĂ© les donnĂ©es de capture-marquage-recapture du modĂšle de population ouverte POPAN pour estimer le nombre dâours se rendant au tas dâossements. Nous avons estimĂ© que jusquâĂ 72 (ET = 9) et 76 (ET = 10) ours polaires mĂąles et femelles, respectivement, ont utilisĂ© le tas dâossements de Kaktovik, en Alaska, en 2012, ce qui reprĂ©sente environ 16 % de la sous-population dâours polaires du sud de la mer de Beaufort. Il sera important de surveiller le nombre dâours qui utilisent le tas dâossements de mĂȘme que les interactions et les conflits entre les humains et les ours qui sâensuivront sur la cĂŽte nord de lâAlaska si la glace de mer continue de reculer
Regional Estimation of Soil Carbon and Other Environmental Indicators Using EPIC and i_EPIC
Computer models are important tools for assessing regional carbon sequestration and other environmental impacts of agricultural management practices. The Environmental Policy Integrated Climate (EPIC) model is a very flexible model that has been used to make a wide range of field- and regional-scale environmental assessments. Large regional-scale applications of EPIC and similar models can require thousands of runs, resulting in a huge data management task. To address this problem, the Center for Agricultural and Rural Development (CARD) has developed an interactive EPIC (i_EPIC) software package that provides an automated approach to executing large sets of EPIC simulations. Overviews of both the latest EPIC version and the i_EPIC software package are presented. We also present examples of regional applications using both EPIC and i_EPIC conducted by the Resource and Environmental Policy Division of CARD, by the Joint Global Change Research Institute of the University of Maryland and the Pacific Northwest National Laboratory, and by the Resource Assessment Division of the Natural Resources Conservation Service, U.S. Department of Agriculture
High winds and melting sea ice trigger landward movement in a polar bear population of concern
Some animal species are responding to climate change by altering the timing of events like mating and migration. Such behavioral plasticity can be adaptive, but it is not always. Polar bears (Ursus maritimus) from the southern Beaufort Sea subpopulation have mostly remained on ice year-round, but as the climate warms and summer sea ice declines, a growing proportion of the subpopulation is summering ashore. The triggers of this novel behavior are not well understood. Our study uses a parametric time-to-event model to test whether biological and/or time-varying environmental variables thought to influence polar bear movement and habitat selection also drive decisions to swim ashore. We quantified the time polar bears spent occupying offshore sea ice of varying ice concentrations. We evaluated variations in the ordinal date bears moved to land with respect to local environmental conditions such as sea ice concentration and wind across 10 years (2005â2015). Results from our study suggest that storm events (i.e., sustained high wind speeds) may force polar bears from severely degraded ice habitat and catalyze seasonal movements to land. Unlike polar bears long adapted to complete summer ice melt, southern Beaufort Sea bears that summer ashore appear more tolerant of poor-quality sea ice habitat and are less willing to abandon it. Our findings provide a window into emergent, climatically mediated behavior in an Arctic marine mammal vulnerable to rapid habitat decline
Importance of resource selection and social behavior to partitioning of hostile space by sympatric canids
Investigations into mechanisms of resource partitioning are particularly suited to systems where nascent interactive behaviors are observable. Wolf (Canis lupus) recolonization of the Greater Yellowstone Ecosystem provided such a system, and we were able to identify behaviors influencing the partitioning of resources by coyotes (Canis latrans) and wolves. We observed coyoteâwolf interactions immediately after wolf recolonization, when reemergent behaviors mediating the outcome of competitive interactions were detectable and mechanisms of spatial avoidance were identifiable. Although coyotes used the same space as wolves, they likely minimized risk of encounter by making adaptive changes in resource selection based on perception of wolf activity and potential scavenging opportunities. When exploiting carrion subsidies (i.e., wolf-killed ungulates), coyotes relied on social behaviors (i.e., numerical advantage in concert with heightened aggression) to mitigate escalating risk from wolves and increase resource-holding potential. By adapting behaviors to fluctuating risk, coyotes might reduce the amplitude of competitive asymmetries. We concluded coyotes do not perceive wolves as a threat requiring generalized spatial avoidance. Rather, the threat of aggressive interactions with wolves is spatially discrete and primarily contained to areas adjacent to carrion resources
Contaminants in polar bears from the circumpolar Arctic: state of knowledge and further recommendations for monitoring and research - Action #42 of the Circumpolar action plan for polar bear conservation
Sentinel-based Surveillance of Coyotes to Detect Bovine Tuberculosis, Michigan
Coyotes could be used as sentinels to detect Mycobacterium bovis in the wild
Diet-driven mercury contamination is associated with polar bear gut microbiota
7openInternationalInternational coauthor/editorThe gut microbiota may modulate the disposition and toxicity of environmental contaminants within a host but, conversely, contaminants may also impact gut bacteria. Such contaminant-gut microbial connections, which could lead to alteration of host health, remain poorly known and are rarely studied in free-ranging wildlife. The polar bear (Ursus maritimus) is a long-lived, wide-ranging apex predator that feeds on a variety of high trophic position seal and cetacean species and, as such, is exposed to among the highest levels of biomagnifying contaminants of all Arctic species. Here, we investigate associations between mercury (THg; a key Arctic contaminant), diet, and the diversity and composition of the gut microbiota of polar bears inhabiting the southern Beaufort Sea, while accounting for host sex, age class and body condition. Bacterial diversity was negatively associated with seal consumption and mercury, a pattern seen for both Shannon and Inverse Simpson alpha diversity indices (adjusted R2â=â0.35, F1,18â=â8.00, Pâ=â0.013 and adjusted R2â=â0.26, F1,18â=â6.04, Pâ=â0.027, respectively). No association was found with sex, age class or body condition of polar bears. Bacteria known to either be involved in THg methylation or considered to be highly contaminant resistant, including Lactobacillales, Bacillales and Aeromonadales, were significantly more abundant in individuals that had higher THg concentrations. Conversely, individuals with higher THg concentrations showed a significantly lower abundance of Bacteroidales, a bacterial order that typically plays an important role in supporting host immune function by stimulating intraepithelial lymphocytes within the epithelial barrier. These associations between diet-acquired mercury and microbiota illustrate a potentially overlooked outcome of mercury accumulation in polar bears.openWatson, S.; McKinney, M.A.; Pindo, M.; Bull, M.; Atwood, T.C.; Hauffe, H.C.; Perkins, S.E.Watson, S.; Mckinney, M.A.; Pindo, M.; Bull, M.; Atwood, T.C.; Hauffe, H.C.; Perkins, S.E
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