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Leptospirosis, a neglected bacterial zoonosis, is a global public health issue disproportionately affecting impoverished communities such as urban slums in the developing world. A variety of animal species, including peridomestic rodents and dogs, can be infected with different strains of leptospirosis. Humans contract leptospirosis via exposure to water or soil contaminated with the urine of infected animals. Due to the unavailability of safe and effective vaccines, preventive strategies mainly focus on minimizing human exposure to contaminated environment. In marginalized communities, this approach is ineffective due to infrastructure deficiencies and the difficulties in implementing sanitation and hygiene practices. Moreover, continuing the expansion of urban slums worldwide will likely contribute to the increase in outbreaks of leptospirosis. Effective prevention of leptospirosis outbreaks will therefore require a thorough understanding of Leptospira transmission dynamics in impoverished, high‐density settings. We developed the agent‐based model MHMSLeptoDy to investigate Leptospira dynamics in a realistic, in silico high‐density community of rodents, dogs and human hosts, and two host‐adapted Leptospira strains. Virtual explorations using MHMSLeptoDy were undertaken to evaluate alternate interventions and to assess the zoonotic transmission risk of leptospirosis. A key finding from model explorations is that rodents are the main contributors of rodent‐adapted as well as dog‐adapted strains in the environment, whereas dogs play an important role in distributing the rodent‐adapted strain. Alternate leptospirosis control strategies can be evaluated using the open‐source, customizable agent‐based model, MHMSLeptoDy. This modelling approach provides a sophisticated mechanism to quantitatively evaluate nuanced intervention strategies and inform the design of rational, locally relevant leptospirosis control programmes. [ABSTRACT FROM AUTHOR]

The interactions of dogs and wildlife are receiving increasing attention across the globe. Evidence suggests that dogs can negatively affect wildlife in a variety of ways, including through the risk of predation, by hybridizing with other Canis species, by acting as a reservoir or vector of pathogens, and by competing with wildlife for resources. A multitude of observations and case studies for each of these interactions has led to calls to prioritize increased management of dogs, for instance, through population reduction, vaccination, movement restrictions, and enhanced care of the dogs themselves. Here, I argue that while the risks that dogs present to wildlife are real, they vary in their importance across the globe. Furthermore, often the approaches used to address these risks are championed without a full understanding of the likelihood of success given the necessary spatial scale of management, the availability of alternative management approaches, and the role dogs play in societies. For instance, culling, vaccination, and animal husbandry approaches in reducing the impacts of dogs on wildlife sometimes fail to recognize that local human populations actively recruit replacement dogs, that vaccination often fails to reach levels necessary for herd immunity, and that enhanced dog husbandry may have indirect impacts on wildlife by requiring environmentally impactful activities. I suggest there is a need for attention not only to identify the impacts of dogs but also to determine where and when such interactions with wildlife are problematic and the likelihood of success for any proposed management approach. The impacts of dogs should be mediated in a context-specific manner that accounts for factors such as the local density of dogs, the susceptibility of local wildlife populations to the risks that dog populations may represent, and the local societal norms that underpin how dogs might be managed. [ABSTRACT FROM AUTHOR]

Spilogale putorius interrupta (Plains Spotted Skunk) experienced range-wide declines beginning in the 1940s, and knowledge of population persistence and basic habitat requirements of the taxon remains limited. We surveyed for a population of the subspecies in the forested Ozark region of Arkansas. We deployed a dense camera-trap grid (>8000 trap-nights across a 24,611-ha study area) and recorded individuals on 6 occasions at 4 sites; their detection rate was amongst the lowest of all detected species. There were no observed differences between occupied and unoccupied sites. We captured and deployed radio-collars on 2 individuals that were tracked to 12 rest sites. Groundcover was sparse at rest sites, perhaps due to use of rocky outcrops by both individuals. [ABSTRACT FROM AUTHOR]

Differential habitat use and intraguild competition are both thought to be important drivers of animal population sizes and distributions. Habitat associations for individual species are well-established, and interactions between particular pairs of species have been highlighted in many focal studies. However, community-wide assessments of the relative strengths of these two factors have not been conducted. We built multi-scale habitat occupancy models for five carnivore taxa of New York’s Adirondack landscape and assessed the relative performance of these models against ones in which co-occurrences of potentially competing carnivore species were also incorporated. Distribution models based on habitat performed well for all species. Black bear (Ursus americanus) and fisher (Martes pennanti) distribution was similar in that occupancy of both species was negatively associated with paved roads. However, black bears were also associated with larger forest fragments and fishers with smaller forest fragments. No models with habitat features were more supported than the null habitat model for raccoons (Procyon lotor). Martens (Martes americana) were most associated with increased terrain ruggedness and elevation. Weasel (Mustela spp.) occupancy increased with the cover of deciduous forest. For most species dyads habitat-only models were more supported than those models with potential competitors incorporated. The exception to this finding was for the smallest carnivore taxa (marten and weasel) where habitat plus coyote abundance models typically performed better than habitat-only models. Assessing this carnivore community as whole, we conclude that differential habitat use is more important than species interactions in maintaining the distribution and structure of this carnivore guild. [ABSTRACT FROM AUTHOR]

Multi-host pathogens can pose a serious conservation threat when free-ranging domestic animal populations occur alongside susceptible populations of wild species. An example is canine distemper virus (CDV), which can occur at high prevalence in domestic dog (Canis familiaris) populations from which it may be transmitted (spillover) into wild carnivore populations. Effective management of such disease threats is hindered by our limited understanding of the the dynamics of interspecific CDV transmission in natural settings. We used a modeling approach to better understand CDV spillover threats to wild Indian foxes (Vulpes bengalensis) occurring in a protected grassland habitat in central India. An agent-based stochastic simulation model was built, and parameterized with data from ecological and epidemiological studies. Based on the sensitivity analyses of the model, the CDV incidence rate in dogs was most influenced by the proportion of roamer dogs in the dog population. The CDV incidence rate in dogs was also sensitive to the CDV introduction frequency in the dog population. The proportion of roamer dogs in the dog population also influenced the number of CDV spillover events. The basic reproductive number (R0) for CDV in the model fox population was 0.85, indicating that CDV could not be independently sustained in the fox population. We used the model to explore potential management strategies to mitigate the risk of CDV spillover. Vaccination of local dog populations was an ineffective disease control strategy, while fox vaccination was highly effective. Interventions potentially resulting in lower contact rates between dogs and foxes, like reduction in village dog density and restricting dog movements in fox habitat, implemented in a sustained and integrated manner would be most effective in mitigating disease threats to foxes. Such modeling approaches can be used to better understand disease threats for other species of management concern, and to contrast potential management interventions. [ABSTRACT FROM AUTHOR]

Abstract: Mass vaccination of dogs is a mainstay for efforts to control rabies and other viral pathogens. The success of such programs is a function of the ability to vaccinate sufficient proportions of animals to develop herd immunity. However, fully assessing success in reaching target vaccination-levels and in understanding the outcome of mass vaccination efforts is hindered if insufficient information is available on the demographics of dog populations and the prevalence of the targeted pathogens. While such information can sometimes be gained from questionnaire surveys, greater precision requires direct assessment of the dog populations. Here we show how such information can be gained from surveys of dogs conducted in association with mass-vaccination programs. We conducted surveys of dogs in six villages in rural Maharashtra, India, between February and July 2011 as part of an effort to reduce the risk of human rabies and virus transmission from dogs to wildlife. Mass vaccination efforts were conducted in each village, and paired with blood sample collection and photographic mark-recapture approaches to gain epidemiologic and demographic data. This data in turn facilitated estimates of dog abundance, population density and structure, vaccination coverage, and seroprevalence of antibodies against canine adenovirus (CAV), canine parvovirus (CPV), and canine distemper virus (CDV). The median dog population size for the six villages was 134 (range 90–188), the median dog population density was 719dogs per km2 (range 526–969), and the median human:dog ratio for these six villages was 34 (range 30–47). The median household:dog ratio for the six villages was 6 (range 5–8). Following vaccination efforts, the median vaccination coverage achieved was 34% (range 24–42%). The dog populations consisted mostly of adult dogs (67–86%) and the median sex ratio for the study area was male biased (1.55 males per female; range 0.9–2.5). The seroprevalence of antibodies against CAV, CPV and CDV was 68, 88 and 73%, respectively. Mass vaccination campaigns provide an opportunity to obtain vital epidemiological and demographic data, and develop a clearer understanding of the threats and impacts of diseases and disease control measures. [Copyright &y& Elsevier]

Across much of North America, river otter (Lontra canadensis) populations were extirpated or greatly reduced by the early 20th century. More recently, reintroductions have resulted in restored populations and the recommencement of managed trapping. Perhaps the best example of these river otter reintroductions occurred in Missouri, regarded as one of the most successful carnivore recovery programs in history. However, abundance estimates for river otter populations are difficult to obtain and often contentious when used to underpin management activities. We assessed the value of latrine site monitoring as a mechanism for quantifying river otter abundance. Analyses of fecal DNA to identify individual animals may result in an improved population estimate and have been used for a variety of mammal species. We optimized laboratory protocols, redesigned existing microsatellite primers, and calculated genotyping error rates to enhance genotyping success for a large quantity of river otter scat samples. We also developed a method for molecular sexing. We then extracted DNA from 1,421 scat samples and anal sac secretions (anal jelly) collected during latrine site counts along 22-34-km stretches representing 8-77% of 8 rivers in southern Missouri in 2009. Error rates were low for the redesigned microsatellites. We obtained genotypes at 7-10 microsatellite loci for 24% of samples, observing highest success for anal jelly samples (71%) and lowest for fresh samples (collected within 1 day of defecation). We identified 63 otters (41 M, 22 F) in the 8 rivers, ranging from 2 to 14 otters per river. Analyses using program CAPWIRE resulted in population estimates similar to the minimum genotyping estimate. Density estimates averaged 0.24?otters/km. We used linear regression to develop and contrast models predicting population size based on latrine site and scat count indices, which are easily collected in the field. Population size was best predicted by a combination of scats per latrine and latrines per kilometer. Our results provide methodological approaches to guide wildlife managers seeking to initiate similar river otter fecal genotyping studies, as well as to estimate and monitor river otter population sizes. [ABSTRACT FROM AUTHOR]

Within populations the contact rate of hosts and infectious parasites is mediated by the interactions of resource availability, host density, and host behavior. Fluctuations in host density can result in the loss or extinction of a parasite population as contact rates between parasites and susceptible individuals drop below thresholds of parasite population persistence. Less understood is how changes in resources and the behavioral ecology of host populations affect parasites. We used food provisioning to experimentally assess the effects of resource availability and of inducing host aggregation on the endoparasite community of free-ranging raccoons. Twelve independent raccoon populations were subjected to differential resource provisioning for two years: a clumped food distribution to aggregate hosts (n = 5 populations), a dispersed food distribution to add food without aggregating hosts (n = 3), and a no food treatment (n = 4). Remote cameras indicated that aggregation sizes were three to four times greater in aggregated versus non-aggregated populations. We considered endoparasites with direct and indirect life cycles separately and determined the best-fit models of parasite species richness in relation to host aggregation, food supplements, and host age and sex. Social aggregation had a negligible impact on the species richness of directly or indirectly transmitted parasites. However, food additions decreased the number of indirectly transmitted parasite species by 35% in the oldest age classes. These results suggest that while resource availability can influence the transmission of indirectly transmitted parasites, an examination of additional factors will be necessary to understand the role of host contact and factors that shape the community structure of endoparasites in natural environments. [ABSTRACT FROM AUTHOR]

Some species of carnivores fluctuate between a primarily solitary lifestyle and a group-living lifestyle, depending on resource availability. Understanding the ontogeny of this transition requires analyzing changes in space use. We analyzed radio-telemetry data from 41 adult raccoons Procyon lotor to assess the influence of an experimentally maintained clumped food source on spatial structure. We compared home-range size, two-dimensional overlap and volume of intersection (VI) values between 22 raccoons with access to the clumped food resource and 19 raccoons on an adjacent control site that received similar food quantities, but for which food was distributed in a non-clumped and spatially-temporally unpredictable pattern. No between-sex differences in home-range size occurred within either food site, nor did differences in home-range size occur between the two sites. However, the experimental-site animals had two-dimensional home-range overlap values and volume of intersection (VI) scores that were nearly twice those of raccoons inhabiting the control site. These differences appear to be driven by increased overlap among females from the experimental site, as males from the two treatment sites had similar home-range overlap and VI scores. Collectively, these results indicate that the distribution of resources can significantly change the extent of spatial overlap among individuals, even when the mean home-range size of the population does not change. This further suggests that while a site's overall resource availability influences population size, the spatial clumping of resources facilitates the formation of local aggregations. [ABSTRACT FROM AUTHOR]

Inverse correlations between genetic variability and parasitism are important concerns for conservation biologists. We examined correlations between neutral genetic variability and the presence of antibodies to canine distemper virus (CDV) and feline parvovirus (FPV) in a free-ranging population of raccoons. Over 3 years there was a strong relationship between age and seroprevalence rates. Most young animals were seronegative to CDV and FPV, but the oldest age class was greater than 80 per cent seropositive to both viruses. CDV-seropositive animals had greater heterozygosity and lower measures of inbreeding compared with CDV-seronegative animals. This relationship was strongest among the youngest animals and did not occur during a 1 year CDVepidemic. In contrast, FPV-seropositive animals only had significantly lower measures of inbreeding in 1 year, perhaps because FPV-associated mortality is relatively low or primarily occurs among very young individuals that were under-represented in our sampling. These results suggest that even in large outcrossing populations, animals with lower heterozygosity and higher measures of inbreeding are less likely to successfully mount an immune response when challenged by highly pathogenic parasites. [ABSTRACT FROM AUTHOR]

Free-ranging domestic dogs are the world's most common carnivore and can negatively interact with native wildlife at multiple levels. Yet the intraguild competitive effects of dogs on the distribution and habitat use of native carnivores are poorly known, especially in areas of conservation concern. We examined the spatial distribution of sympatric populations of radiocollared Indian foxes and free-ranging dogs to determine if Indian foxes alter their habitat use in the presence of dogs. We tested the effects of landcover type, primary prey abundance (rodents) and the presence of dogs as predictors of Indian fox spatial distribution in a threatened grassland habitat in central India. By counting rodent burrows, we determined that the relative abundance of rodents was higher in fallow land and agricultural land compared to natural grasslands. From radiotelemetry data, we determined that the presence of dogs was closely linked to human-modified habitats, such as agricultural land and human settlements. Top ranked models, based on Akaike's Information Criterion corrected for small sample size, indicated that the negative effects of the presence of dogs and agricultural land, and the positive effects of the presence of grassland and fallow land habitats were the strongest predictors of Indian fox spatial distribution. Thus, the use of the landscape by Indian foxes was determined not only by habitat type, but also by the presence of a mid-sized carnivore, the dog. Synthesis and applications. Our results show that the presence of domestic dogs on the periphery of natural habitats can interfere with the spatial distribution of a sympatric carnivore. Vaccination and sterilization programmes, aimed at reducing population sizes and pathogen prevalence, do not restrict the free-ranging behaviour of dogs. Therefore, in areas of conservation value, control of free-ranging dogs would be required to fully mitigate the deleterious effects of dogs on native carnivores and other wildlife. [ABSTRACT FROM AUTHOR]

1. Parasite transmission depends on the rate at which hosts come into contact with one another or the infectious stages of parasites. However, host contact rates and their influence on parasite transmission are difficult to quantify in natural settings and can fluctuate with host behaviour and the ecological constraints of parasites. 2. We investigated how experimental increases in rates of contact and social aggregation affected ectoparasite prevalence and intensity of free-ranging raccoons ( Procyon lotor). Twelve independent raccoon populations were subjected to differential resource provisions for 2 years: a clumped food distribution to aggregate hosts ( n = 5 aggregated populations), a dispersed food distribution to control for the effects of food without aggregating hosts ( n = 3) and a no food treatment ( n = 4). 3. Remote cameras indicated that aggregation sizes and rates of contact were three to four times greater in aggregated compared with that in non-aggregated populations. The number of ticks (adult Dermacentor variabilis) on raccoons in aggregated populations was 1·5–2·5 times greater from May to July, the primary time of tick seasonal occurrence. Conversely, louse ( Trichodectes octomaculatus) populations were c. 40% sparser on male raccoons in aggregated (compared with that in non-aggregated) populations because of greater overdispersion of lice and a larger number of male hosts harbouring fewer parasites. No treatment-related differences were found among fleas ( Orchopeas howardi). 4. These results were not consistent with our current understanding of parasite transmission; greater rates of host sociality led to increases in a parasite that does not rely on host contact for transmission (ticks) and declines in a parasite that depends on host contact for transmission (lice). We concluded that D. variabilis increased in aggregated sites because they can detect and seek out hosts and were more likely to drop off after obtaining a blood meal and re-attach to raccoons in these locations. Several factors may have contributed to sparser louse populations on male hosts, including a dilution effect that lowered per capita infestation levels. 5. These results indicate that ectoparasites can interact in unique ways with their hosts that are not consistent with other types of parasite species or models of their transmission. [ABSTRACT FROM AUTHOR]

The competitive dynamics between domestic and native carnivores are poorly studied. We examined competition for food between sympatric populations of free-ranging dogs (Canis familiaris) and Indian foxes (Vulpes bengalensis) through dietary analysis in a protected, dry grassland habitat in central India. We expected significant dietary overlap between dogs and foxes because of clear evidence of interference competition between dogs and foxes in this area. However, dogs subsisted largely on human-derived foods (HDFs) from direct feeding, and scavenging on garbage, crop residue, and livestock carcasses (83% relative occurrence [RO]). Wild-caught foods constituted only 11% RO of the diet of dogs. The majority of the diet of Indian foxes consisted of invertebrates (33% RO), rodents (20% RO), and fruits of Zizyphus (18.5% RO). Indian foxes did not consume HDF, nor did they scavenge from large-mammal carcasses, and included only a small portion of agricultural produce in their diet. The low contribution of HDF and agricultural food sources to the diet of Indian foxes was surprising because this species is a generalist omnivore. Dogs may be preventing foxes from accessing agricultural lands and human-associated foods by interference competition. [ABSTRACT FROM AUTHOR]

1. Dogs Canis familiaris are the world's most common carnivore and are known to interact with wildlife as predators, prey, competitors, and disease reservoirs or vectors. 2. Despite these varied roles in the community, the interaction of dogs with sympatric wild carnivore species is poorly understood. We review how dogs have been classified in the literature, and illustrate how the location and ranging behaviour of dogs are important factors in predicting their interactions with wild prey and carnivores. 3. We detail evidence of dogs as intraguild competitors with sympatric carnivores in the context of exploitative, interference and apparent competition. 4. Dogs can have localized impacts on prey populations, but in general they are not exploitative competitors with carnivores. Rather, most dog populations are highly dependent on human-derived food and gain a relatively small proportion of their diet from wild prey. However, because of human-derived food subsidies, dogs can occur at high population densities and thus could potentially outcompete native carnivores, especially when prey is limited. 5. Dogs can be effective interference competitors, especially with medium-sized and small carnivores. Dogs may fill the role of an interactive medium-sized canid within the carnivore community, especially in areas where the native large carnivore community is depauperate. 6. Dogs can also be reservoirs of pathogens, because most populations around the world are free-ranging and unvaccinated. Diseases such as rabies and canine distemper have resulted in severe population declines in several endangered carnivores coexisting with high-density dog populations. Dogs can therefore be viewed as pathogen-mediated apparent competitors, capable of facilitating large-scale population declines in carnivores. 7. Based on this information, we propose conceptual models that use dog population size and ranging patterns to predict the potential for dogs to be intraguild competitors. We discuss how interactions between dogs and carnivores might influence native carnivore communities. [ABSTRACT FROM AUTHOR]

Large mammalian carnivores are ecologically important because relatively few individuals can cause strong predation-driven direct effects or fear-driven indirect effects that can ripple through communities and, ultimately, influence ecosystem structure and function. Most mammalian carnivores are not large, however, but are small to midsized species collectively termed "mesocarnivores." Mesocarnivores are more numerous and more diverse than larger carnivores, and often reside in closer proximity to humans, yet we know little about how they influence communities and ecosystems. In this article we review the ecological role of the mesocarnivore and present examples where mesocarnivores drive community structure and function in roles similar to, or altogether different from, their larger brethren. Together, these examples substantiate the need for an assessment of the ecological role of mammalian carnivores beyond an examination of only the largest species. In particular, we emphasize the need to study the trophic penetrance of mesocarnivores and examine how ecological context modulates their functional role. [ABSTRACT FROM AUTHOR]

Since the 1940s, eastern spotted skunks (Spilogale putorius) have declined dramatically throughout the Midwest. One hypothesis for the decline is the loss of suitable habitat, although little is known about the ecological requirements of this species. To elucidate seasonal home range and habitat selection by eastern spotted skunks, we conducted telemetry-based field work in the Ouachita Mountains of western Arkansas, USA. During 2 years of field work, we collected day- and nighttime radiolocations for 33 eastern spotted skunks. We used kernel-based utilization distributions, volume of intersection indices, and weighted compositional analysis to evaluate seasonal home range dynamics and habitat selection. Although we found moderate adult male site fidelity, there were large seasonal differences in home range size, with ranges of between 76 ha and 175 ha (± 22-62 SE) during summer, fall, and winter, and home ranges of 866 ha (± 235 SE) during spring. Male home range increases in the spring were likely caused by questing behavior in search of reproductive females. Females maintained home ranges of 54 ha to 135 ha (± 7-30 SE) and moderate site fidelity during all seasons. During each season, we observed selection of young shortleaf pine (Pinus echinata) and hardwood stands over other available cover types, likely due to a preference for a dense, complex understory and a closed canopy overstory to reduce predation risk. Most habitats in the study region were managed for an herbaceous understory and an older, more open canopy, in part to benefit red-cockaded woodpecker (Picoides borealis) populations. Thus, if simultaneous management for these 2 vertebrates is a goal, a balance of early and late successional habitat should be reached. [ABSTRACT FROM AUTHOR]

Denning and resting site use by radiocollared eastern spotted skunks (Spilogale putorius) in the Ouachita Mountains of western Arkansas was investigated from May through August 2005 and 2006. We identified and characterized microhabitat and landscape characteristics of 127 resting and den sites. Sites were located in burrows excavated by other mammal species (48%), in decayed or burned root systems (22%), in rocky outcrops (14%), in eastern woodrat (Neotoma floridana) nests (9%), or in ground-level tree or log cavities (7%). Reuse of sites by the same individual was common (32.3%), but use of the same site by different individuals was rare, as was communal use of sites (<1.0% each). Contrasting used and putatively available dens and resting sites, we found that sites were selected based primarily on increased vegetative cover, which supports hypotheses that thermal regulation and predator avoidance may underlie den and resting site selection. Higher rock and vine densities, younger pine forest stands, older hardwood stands, steeper slope, and smaller site entrance also positively influenced resting and den site selection. These findings suggest that eastern spotted skunks select structurally complex sites, likely to enhance protection from predators. Eastern spotted skunks may thus be vulnerable to habitat alterations that reduce this structural complexity. [ABSTRACT FROM AUTHOR]

Abstract: The Procyonidae (Mammalia: Carnivora) have played a central role in resolving the controversial systematics of the giant and red pandas, but phylogenetic relationships of species within the family itself have received much less attention. Cladistic analyses of morphological characters conducted during the last two decades have resulted in topologies that group ecologically and morphologically similar taxa together. Specifically, the highly arboreal and frugivorous kinkajou (Potos flavus) and olingos (Bassaricyon) define one clade, whereas the more terrestrial and omnivorous coatis (Nasua), raccoons (Procyon), and ringtails (Bassariscus) define another clade, with the similar-sized Nasua and Procyon joined as sister taxa in this latter group. These relationships, however, have not been tested with molecular sequence data. We examined procyonid phylogenetics based on combined data from nine nuclear and two mitochondrial gene segments totaling 6534bp. We were able to fully resolve relationships within the family with strongly supported and congruent results from maximum parsimony, maximum likelihood, minimum evolution, and Bayesian analyses. We identified three distinct lineages within the family: a (Nasua, Bassaricyon) clade, a (Bassariscus, Procyon) clade, and a Potos lineage, the last of which is sister to the other two clades. These findings, which are in strong disagreement with prior fossil and morphology-based assessments of procyonid relationships, reemphasize the morphological and ecological flexibility of these taxa. In particular, morphological similarities between unrelated genera possibly reflect convergence associated with similar lifestyles and diets rather than ancestry. Furthermore, incongruence between the molecular supermatrix and a morphological character matrix comprised mostly of dental characters [Baskin, J.A., 2004. Bassariscus and Probassariscus (Mammalia, Carnivora, Procyonidae) from the early Barstovian (Middle Miocene). J. Vert. Paleo. 24, 709–720] may be due to non-independence among atomized dental characters that does not take into account the high developmental genetic correlation of these characters. Finally, molecular divergence dating analyses using a relaxed molecular clock approach suggest that intergeneric and intrageneric splits in the Procyonidae mostly occurred in the Miocene. The inferred divergence times for intrageneric splits for several genera whose ranges are bisected by the Panamanian Isthmus is significant because they suggest diversification well precedes the Great American Interchange, which has long been considered a primary underlying mechanism for procyonid evolution. [Copyright &y& Elsevier]

Carnivores are difficult to survey due, in large pert, to their relative rarity across the landscape and wariness toward humans. Several noninvasive methods may aid in overcoming these difficulties, but there has been little discussion of the relative merits and biases of these techniques. We assess the value of 5 noninvasive techniques based on results from 2 multiyear studies of carnivores (including members of Carnivora and Didelphidae) in New York forests. Two metrics were particularly valuable in assessing the species-specific value of any particular survey technique: latency to initial detection (LTD) and probability of detection (POD). We found differences in the value of techniques in detecting different species. For midsized species (raccoon [Procyon lotor], fisher [Martes pennanti], opossum [Didelphis virginiana], and domestic cat [Felis catus]), camera traps and track-plates were approximately equivalent in detection efficiency, but the potential for wariness toward the survey apparatus resulted in higher LTD for track-plates than for cameras. On the other hand, track-plates detected small carnivores (marten [M. americana] and weasels [Mustela spp.]) more often than cameras and had higher PODs for small and midsized species than did cameras. Cameras were efficient mechanisms for surveying bears (Ursus americanus; low LTD, high POD) but functioned poorly for discerning presence of coyotes (Canis latrans; high LTD, low POD). Scat surveys and snowtracking were the best methods for coyotes, which avoided camera traps and artificial tracking surfaces. Our analysis of fecal DNA revealed that trail-based fecal surveys were inefficient at detecting species other than coyotes, with the possible exception of red foxes (Vulpes vulpes). Genetic analyses of feces and snowtracking revealed the presence of foxes at sites where other techniques failed to discern these species, suggesting that cameras and track-plates are inefficient for surveying small canids in this region. The LTD of coyotes by camera traps was not correlated with their abundance as indexed by scat counts, but for other species this metric may offer an opportunity to assess relative abundance across sites. Snowtracking surveys were particularly robust (high POD) for detecting species active in winter and may be more effective than both cameras and track-plates where conditions are suitable. We recommend that survey efforts targeting multiple members of the carnivore community use multiple independent techniques and incorporate mechanisms to truth their relative value. [ABSTRACT FROM AUTHOR]

The role that host aggregation plays in structuring parasite assemblages was examined by experimentally increasing the contact rates of raccoons, Procyon lotor. Two populations of raccoons in southern New York were monitored for 2 years to determine baseline levels of host interaction and to identify the parasite assemblage. In the third year of the study, one population was provisioned with the addition of clumped food resources, while the other was provisioned with equal quantities of dispersed food resources. Remote photography showed that raccoons aggregated at clumped resources but not at dispersed resources, and therefore contact rates between individuals were higher in the site with clumped resources. There were no differences in parasitism between the sites prior to resource augmentation. Among ectoparasites, there were no significant changes in the prevalence or abundance of any species in response to the perturbation. In contrast, across the endoparasite assemblage within and across hosts, the prevalence of infection increased as a result of increased host contact. Strong increases in the prevalence of a few directly transmitted species and slight increases among most species lead to increased evenness in parasite prevalence, suggesting that parasites in this system are transmission limited. In addition, the number of parasite species per host (the parasite infracommunity) was higher in the clumped-resource population. These endoparasite results suggest that intraspecific variation in the species richness of parasite communities of individual hosts, and the prevalence of parasitic species in host populations as assessed across entire parasitic assemblages, is robustly influenced by intraspecific variation in the degree of host contact. Further, these results suggest that anthropogenic changes which alter resource availability may have important consequences for disease transmission in wildlife. [ABSTRACT FROM AUTHOR]

The eastern spotted skunk (Spilogale putorius) was once common throughout the midwestern and southeastern United States, with consistent annual range-wide harvests of »100 000 animals. In the 1940s, however, populations seemingly crashed and the species is currently listed by various state agencies as endangered, threatened, or 'of concern' across much of its range. We examined long-term harvest records from 10 states to better understand the 20th century population dynamics of eastern spotted skunks, to discern whether the putative decline was biologically real or an artifact of altered harvest pressures and to identify the timing of the decline. Analyses reveal unequivocally that the species was indeed once common in the Great Plains. Beginning in about 1940, harvests dramatically declined, although the onset of declines differed between states. By the early 1950s total harvests in all states were < 10% of pre-crash harvest. Thereafter, rates of decline slowed, but nevertheless continued, such that by the 1980s harvests were <1% of those during pre-decline years. Analyses show that these declines are real and not an artifact of harvest effort. Although the causes of the decline remain unclear, the analyses suggest a need for immediate attention to address the long-term persistence of this species. [ABSTRACT FROM AUTHOR]

Comments on how the expansion of the geographical range of the coyote in North America may influence community structure. The way that rising coyote densities in the suburbs may alter how the general public views wildlife; Ecological relevance of coyotes; Interactions between coyotes and humans, which may increase; View that people should change their behavior to avoid problematic encounters with coyotes; Outlook for the reintroduction and recovery of other top predators.

Focuses on a study which analyzed the variation in sex ratios in ungulates. Abundance of males and females in wild mammals; Methods of the study; Phylogeny and sex ratios without predation; Differential mortality of sexes due to predation.

Assesses the genetic relatedness, coalitions and social behavior of white-nosed coatis, Nasua narica. Complex cooperative behaviors; Estimated genetic relationship by measuring the similarity of multilocus deoxyribonucleic acid; Comparison between unrelated individuals and close relatives in the band.

• Traditional sample size calculations overestimate disease detection probabilities. • Incorporating real-world biases in the model improves sample size calculations. • Low prevalence scenarios are critical for sample size calculations. • Agent-based approach can inform harvest-based disease surveillance. Epidemiological surveillance for important wildlife diseases often relies on samples obtained from hunter-harvested animals. A problem, however, is that although convenient and cost-effective, hunter-harvest samples are not representative of the population due to heterogeneities in disease distribution and biased sampling. We developed an agent-based modeling framework that i) simulates a deer population in a user-generated landscape, and ii) uses a snapshot of the in silico deer population to simulate disease prevalence and distribution, harvest effort and sampling as per user-specified parameters. This framework can incorporate real-world heterogeneities in disease distribution, hunter harvest and harvest-based sampling, and therefore can be useful in informing wildlife disease surveillance strategies, specifically to determine population-specific sample sizes necessary for prompt detection of disease. Application of this framework is illustrated using the example of chronic wasting disease (CWD) surveillance in Missouri's white-tailed deer (Odocoileus virginianus) population. We show how confidence in detecting CWD is grossly overestimated under the unrealistic, but standard, assumptions that sampling effort and disease are randomly and independently distributed. We then provide adjusted sample size recommendations based on more realistic assumptions. Wildlife agencies can use these open-access models to design their CWD surveillance. Furthermore, these models can be readily adapted to other regions and other wildlife disease systems. [ABSTRACT FROM AUTHOR]

Discusses efforts to save the endangered black-footed ferret, Mustela nigripes and obligate parasites of the species. Eimeria; Neotrichodectes; Reasons for conserving parasitic species; Dependence of ferrets on prairie dog communities.

Spilogale putorius interrupta (Plains Spotted Skunk) has been documented to host a variety of macroparasites, but the impacts of these infections are largely unknown. We emphasize the importance of incorporating disease-ecology components into ongoing field-research studies by revisiting previously collected data on infection by the metastrongylid nematode Skrjabingylus chitwoodorum (Skunk Cranial Worm) in an Arkansas population of Plains Spotted Skunks that was monitored as part of a large-scale field study. Our reevaluation of the infection data suggests estimates of prevalence based on fecal flotations may underestimate true prevalence and that positive infection status may be correlated with smaller home-range size in female Plains Spotted Skunks. We encourage further research to better understand effects of this and other parasites on Spotted Skunk population vital rates and distribution. [ABSTRACT FROM AUTHOR]

The rich history and global abundance of domestic dogs (Canis familiaris) present a unique opportunity and an ideal model for interdisciplinary research. Canine evolutionary history demonstrates unprecedented changes across all levels of biological organization. These include diversification from highly social, pack-dwelling wild carnivores (extant gray wolves, C. lupus), to increased dependence on humans (domestication), to modern in-home colonization featuring close physical proximity to humans (interspecies bonding). The young, emerging field of "canine science" comprises numerous biological disciplines including evolution, genetics, cognition, behavior, physiology, comparative medicine, and ecology, drawing on studies of both natural and experimental systems and scaling across all levels of biological organization, from genomes to ecosystems. However, limited connections bridge the diverse fields associated with canine science, although in every branch it is recognized that this species is one of the most phenotypically variable mammals. However, there has been growing interest in integrating the insights from genomic evolution with those from ecophysiology and ecology, thus facilitating a more biologically comprehensive perspective of dogs. In particular, integrative, mechanistic, and/or ecological studies have been generally underrepresented. To address these emerging interests, we have collected the most compelling questions in the field of canine biology and present avenues of current and future research. This article serves to both orient the reader to this special issue, as well as offer a forward-looking perspective from diverse biological sub-disciplines to highlight current and future goals in canine research. [ABSTRACT FROM AUTHOR]

A letter to the editor is presented in response to the article “Recovery of Large Carnivores in Europe’s Modern Human-Dominated Landscapes” by G. Chapron et al. in the December 19, 2014 issue.

Robust tick surveillance enhances diagnosis and prevention of tick-borne pathogens, yet surveillance efforts in the United States are highly uneven, resulting in large surveillance vacuums, one of which spans the state of New Mexico. As part of a larger effort to fill this vacuum, we conducted both active and passive tick sampling in New Mexico, focusing on the southern portion of the state. We conducted active tick sampling using dragging and CO₂ trapping at 45 sites across Hidalgo, Doña Ana, Otero, and Eddy counties between June 2021 to May 2022. Sampling occurred intermittently, with at least one sampling event each month from June to October 2021, pausing in winter and resuming in March through May 2022. We also conducted opportunistic, passive tick sampling in 2021 and 2022 from animals harvested by hunters or captured or collected by researchers and animals housed in animal hospitals, shelters, and farms. All pools of ticks were screened for Rickettsia rickettsii, Rickettsia parkeri, Rickettsia amblyommatis, Ehrlichia ewingii, and Ehrlichia chaffeensis. Active sampling yielded no ticks. Passive sampling yielded 497 ticks comprising Carios kelleyi from pallid bats, Rhipicephalus sanguineus from dogs, mule deer, and Rocky Mountain elk, Otobius megnini from dogs, cats, horses, and Coues deer, Dermacentor parumapertus from dogs and black-tailed jackrabbits, Dermacentor albipictus from domesticated cats, mule deer and Rocky Mountain elk, and Dermacentor spp. from American black bear, Rocky Mountain elk, and mule deer. One pool of D. parumapterus from a black-tailed jackrabbit in Luna County tested positive for R. parkeri, an agent of spotted fever rickettsiosis. Additionally, a spotted fever group Rickettsia was detected in 6 of 7 C. kelleyi pools. Two ticks showed morphological abnormalities; however, these samples did not test positive for any of the target pathogens, and the cause of the abnormalities is unknown. Passive surveillance yielded five identified species of ticks from three domestic and six wild mammal species. Our findings update tick distributions and inform the public, medical, and veterinary communities of the potential tick-borne pathogens present in southern New Mexico. [ABSTRACT FROM AUTHOR]

We investigated the home range size, habitat selection, as well as the spatial and activity overlap, of four mid-sized carnivore species in the Central Pantanal, Mato Grosso do Sul, Brazil. From December 2005 to September 2008, seven crab-eating foxes Cerdocyon thous, seven brown-nosed coatis Nasua nasua, and six ocelots Leopardus pardalis were radio-collared and monitored. Camera trap data on these species were also collected for the crab-eating raccoon Procyon cancrivorus. We hypothesized that there would be large niche differentiation in preferred habitat-type or active period between generalist species with similar diet, and higher similarity in habitat-type or activity time between the generalist species (crab-eating foxes and coatis) and the more specialized ocelot. Individual home ranges were estimated using the utilization distribution index (UD– 95% fixed Kernel). With data obtained from radio-collared individuals, we evaluated habitat selection using compositional analysis. Median home range size of ocelots was 8 km2. The proportion of habitats within the home ranges of ocelots did not differ from the overall habitat proportion in the study area, but ocelots preferentially used forest within their home range. The median home range size of crab-eating foxes was 1.4 km2. Foxes showed second-order habitat selection and selected savanna over shrub-savanna vegetation. The median home range size for coati was 1.5 km2. Coati home ranges were located randomly in the study area. However, within their home range, coatis occurred more frequently in savanna than in other vegetation types. Among the four species, the overlap in activity period was the highest (87%) between ocelots and raccoons, with the least overlap occurring between the ocelot and coati (25%). We suggest that temporal segregation of carnivores was more important than spatial segregation, notably between the generalist coati, crab-eating fox and crab-eating raccoon. [ABSTRACT FROM AUTHOR]

Free-ranging domestic dogs Canis familiaris threaten wildlife species through predation, hybridization, competition for resources, and by contributing to the transmission of pathogens. The impacts of predation may be problematic, but in many regions the interactions of free-ranging dogs and wildlife are poorly studied. To determine the extent of the impacts of attacks by free-ranging dogs on Iranian mammals, we reviewed nearly 2 decades of social and traditional media reports and the scientific literature to gather data from across the country. We identified 160 free-ranging dog attacks (79 from academic articles, 14 from social media, and 67 from a variety of news websites) from 22 of the country's 31 provinces. Attacks by dogs were reported on 17 species, including nine Carnivora, six Artiodactyla, one Rodentia, and one Lagomorpha species. Most of the reported attacks on carnivores were on felids, including the Asiatic cheetah Acinonyx jubatus (n = 19), Eurasian lynx Lynx lynx (n = 18), caracal Caracal caracal (n = 10) and Pallas's cat Otocolobus manul (n = 8). Attacks on Artiodactyla were primarily reported for goitered gazelle Gazella subgutturosa (n = 47). Most of these attacks occurred within or adjacent to protected areas (n = 116, 73%), suggesting that free-ranging dogs are one of the most important human-associated threats to wildlife species even in protected landscapes. The impact of free-ranging dogs may be hampering conservation, and therefore we suggest some practical policy guidance for managing the impacts of free-ranging dogs on threatened species. [ABSTRACT FROM AUTHOR]

The plains spotted skunk (Spilogale interrupta) is of conservation concern because of widespread population declines and is being considered for listing under the United States Endangered Species Act. Although the taxon is relatively rare and difficult to study, recent research and reports provided some information about spotted skunks in Arkansas and Missouri, USA. Using this information, we employed full and simplified multivariate species distribution models to evaluate cover type associations and identify regions of high predicted presence for plains spotted skunks. The simple model contained percent forest and percent development within 5 km, land cover category, and distance to water. Percent forest within 5 km was the most important variable based on permutation importance in both models, indicating that plains spotted skunk habitat may persist in contiguous forest at the landscape scale. Regions predicted to have high presence occurred in northern, western, and southern Arkansas and southern Missouri, totaling >300,000 ha. The resulting plains spotted skunk distribution map can be used for research and management efforts in areas of high probability of occurrence, and future statewide survey efforts may validate our results. [ABSTRACT FROM AUTHOR]

Understanding factors that determine heterogeneity in levels of parasitism across individuals is a major challenge in disease ecology. It is known that genetic makeup plays an important role in infection likelihood, but the mechanism remains unclear as does its relative importance when compared to other factors. We analyzed relationships between genetic diversity and macroparasites in outbred, free-ranging populations of raccoons (Procyon lotor). We measured heterozygosity at 14 microsatellite loci and modeled the effects of both multi-locus and single-locus heterozygosity on parasitism using an information theoretic approach and including non-genetic factors that are known to influence the likelihood of parasitism. The association of genetic diversity and parasitism, as well as the relative importance of genetic diversity, differed by parasitic group. Endoparasite species richness was better predicted by a model that included genetic diversity, with the more heterozygous hosts harboring fewer endoparasite species. Genetic diversity was also important in predicting abundance of replete ticks (Dermacentor variabilis). This association fit a curvilinear trend, with hosts that had either high or low levels of heterozygosity harboring fewer parasites than those with intermediate levels. In contrast, genetic diversity was not important in predicting abundance of non-replete ticks and lice (Trichodectes octomaculatus). No strong single-locus effects were observed for either endoparasites or replete ticks. Our results suggest that in outbred populations multi-locus diversity might be important for coping with parasitism. The differences in the relationships between heterozygosity and parasitism for the different parasites suggest that the role of genetic diversity varies with parasite-mediated selective pressures. [ABSTRACT FROM AUTHOR]

Survival and cause-specific mortality of eastern spotted skunks (Spilogale putorius) was assessed for a radio-monitored population in the Ouachita Mountains of westcentral Arkansas, USA. We monitored 33 eastern spotted skunks over a 23 mo period. Mean annual survival was 0.354 (0.339-0.368, 95% CI), and survival estimates were similar across age and sex categories. Survival increased for males as measures of body condition index increased. This pattern was reversed tot females, although interpretation of the patterns is potentially confounded by female reproductive status. Of 19 mortality events, 63% (12) were caused by avian predators, most likely great horned owls (Bubo virginianus), 26% (5) were caused by mammalian predators, and 11% (2) were due to unknown causes. Although eastern spotted skunks are known to avoid open areas and forested areas where die understory is less dense and the canopy more open, 11 of 12 avian-caused deaths occurred in mature shortleaf pine stands with an open canopy and herbaceous understory. [ABSTRACT FROM AUTHOR]

Home range size is a fundamental measure of animal space use, providing insight into habitat quality, animal density, and social organization. Human impacts increasingly are affecting wildlife, especially among wide-ranging species that encounter anthropogenic disturbance. Leopards (Panthera pardus) provide a useful model for studying this relationship because leopards coexist with people at high and low human densities and are sensitive to human disturbance. To compare leopard home range size across a range of human densities and other environmental conditions, we combined animal tracking data from 74 leopards in multiple studies with new analytical techniques that accommodate different sampling regimes. We predicted that home ranges would be smaller in more productive habitats and areas of higher human population density due to possible linkage with leopard prey subsidies from domestic species. We also predicted that male leopards would have larger home ranges than those of females. Home ranges varied in size from 14.5 km2 in India to 885.6 km2 in Namibia, representing a 60-fold magnitude of variation. Home range stability was evident for 95.2% of nontranslocated individuals and 38.5% of translocated individuals. Leopard home range sizes were negatively correlated with landscape productivity, and males used larger areas than females. Leopards in open habitats had a predicted negative correlation in home range size with human population density, but leopards in closed habitats used larger home ranges in areas with more people. [ABSTRACT FROM AUTHOR]

Small carnivores are of increasing conservation concern globally, including those formerly thought to be widespread and abundant. Three weasel species (Mustela nivalis, M. frenata, and M. erminea) are distributed across most of North America, yet several recent studies have reported difficulty detecting weasels within their historical range and several states have revised the status of weasels to that of species of conservation concern. To investigate the status and trends of weasels across the United States (US) and Canada, we analyzed four separate datasets: historical harvests, museum collections, citizen scientist observations (iNaturalist), and a recent US-wide trail camera survey. We observed 87–94% declines in weasel harvest across North America over the past 60 years. Declining trapper numbers and shifts in trapping practices likely partially explain the decline in harvest. Nonetheless, after accounting for trapper effort and pelt price, we still detected a significant decline in weasel harvest for 15 of 22 evaluated states and provinces. Comparisons of recent and historical museum and observational records suggest relatively consistent distributions for M. erminea, but a current range gap of >1000 km between two distinct populations of M. nivalis. We observed a dramatic drop-off in M. frenata records since 2000 in portions of its central, Great Lakes, and southern distribution, despite extensive sampling effort. In 2019, systematic trail camera surveys at 1509 sites in 50 US states detected weasels at 14 sites, all of which were above 40o latitude. While none of these datasets are individually conclusive, they collectively support the hypothesis that weasel populations have declined in North America and highlight the need for improved methods for detecting and monitoring weasels. By identifying population declines for small carnivores that were formerly abundant across North America, our findings echo recent calls to expand investigations into the conservation need of small carnivores globally. [ABSTRACT FROM AUTHOR]

Baylisascaris procyonis is a nematode of significant concern to public and domestic animal health as well as wildlife management. The population genetics of B. procyonis is poorly understood. To gain insights into patterns of genetic diversity within (infrapopulation level) and among (component population level) raccoon ( Procyon lotor ) hosts, and specifically to assess the relative importance of indirect and direct transmission of the parasite for explaining observed population structure, we collected 69 B. procyonis from 17 wild raccoons inhabiting five counties in Missouri and Arkansas, USA. Informative regions of mitochondrial (CO1, CO2) and nuclear (28S, ITS2) genes were amplified and the distribution and genetic variability of these genes were assessed within and across raccoons. Concatenation of the CO1 and CO2 mtDNA sequences resulted in 5 unique haplotypes, with haplotype diversity 0.456 ± 0.068. The most common haplotype occurred in 94% of raccoons and 72.5% of B. procyonis. Sequences for 28S rDNA revealed four unique nuclear genotypes, the most common found in 100% of raccoons and 82.6% of B. procyonis . ITS2 genotypes were assessed using fragment analysis, and there was a 1:1 correspondence between 28S and ITS-2 genotypes. Infrapopulation variation in haplotypes and genotypes was high and virtually all hosts infected with multiple sequenced nematodes also harbored multiple haplotypes and genotypes. There was a positive relationship between the size of the analyzed infrapopulation (i.e., the number of nematodes analyzed) and the number of haplotypes identified in an individual. Collectively this work emphasizes the importance of indirect transmission in the lifecycle to this parasite. [ABSTRACT FROM AUTHOR]

Bears (Ursidae) have extensive home ranges and may move long distances, thereby potentially serving as hosts to, and vectors of, large numbers of ticks. We assessed the composition of the parasitizing tick community on American black bears (Ursus americanus) to discern hard tick species capable of successfully feeding, which is a necessary step for tick reproduction. We counted ticks from free-ranging, live-trapped, or road-killed black bears in southern Missouri, USA. during 2015, and collected a subset of engorged ticks (n = 967). All bears (n = 17) were infected with ticks (n = 6,993), with a mean intensity of 411 ticks/bear, of which 14% were engorged females. The infracommunity size of engorged ticks was 57 ticks/bear. From these engorged ticks, we identified 5 species: Amblyomma americanum, A. maculatum, Dermacentor variabilis, D. albipictus, and Ixodes scapularis. Amblyomma americanum was the most common species, collected on all surveyed bears, and represented 58.2% of engorged ticks, whereas D. albipictus and A. maculatum were the least common species, collected from only 3 and 4 bears, respectively, and representing 4.7% and 2.4% of engorged ticks, respectively. Our data suggest that individual black bears have the potential to host large numbers of ticks to engorgement, and may be important vectors for tick dispersal and for the maintenance of tick populations. [ABSTRACT FROM AUTHOR]