The reintroduction of gray wolves (Canis lupus) to Yellowstone National Park is the most celebrated ecological experiment in history. As predicted by population models, the rapid recovery of a wolf population caused both temporal and spatial variability in wolf–ungulate interactions that likewise generated temporal and spatial variation in the expression of trophic cascades. This has amplified spatial variation in vegetation in Yellowstone, particularly with willow (Salix spp.) and cottonwood (Populus spp.) in riparian areas, with associated changes in food webs. Increasing influences of grizzly bears (Ursus arctos), cougars (Puma concolor), and bison (Bisonbison) are making what initially was predominantly an elk–wolf interaction into an increasingly complex system. Outside Yellowstone, however, humans have a dominant influence in western North America that overwhelms trophic cascades resulting in what appear to be bottom-up influences on community structure and function. Complex and unexpected ecosystem responses to wolf recovery in Yellowstone reinforce the value of national parks and other protected areas as ecological baseline reserves.

Cross-fostering offspring with nonbiological parents could prove useful to augment populations of endangered carnivores. We used cross-fostering to augment captive-born and wild-born litters for the endangered red wolf (Canis rufus). Between 1987 and 2016, 23 cross-fostering events occurred involving captive-born pups fostered into captive litters (n = 8 events) and captive-born pups fostered into wild recipient litters (n = 15 events). Percentage of pups surviving 3 and 12 months was 91.7% for captive-born pups fostered into captive recipient litters. For pups fostered into wild litters, percentage of pups surviving 5 months was > 94% among fostered pups (pups fostered into a wild red wolf litter or replaced a hybrid litter), pups in recipient litters (wild-born litters receiving fostered pups), and pups in control litters (wild-born litters not in a fostering event) when using pups with known fates. Including pups with unknown fates as deaths, percentage of pups surviving 5 months was > 54% among fostered pups, pups in recipient litters, and pups in control litters. Among wild litters, percentage of pups surviving 12 months was > 82% among fostered pups, pups in recipient litters, and pups in control litters when using pups with known fates. Including pups with unknown fates as deaths, percentage of pups surviving 12 months was > 48% among fostered pups, pups in recipient litters, and pups in control litters. Although survival to 12 months was similar among the groups, average life span was different with pups in control litters living 3.3 years, pups in recipient litters living 4.6 years, and fostered pups living 5.6 years. Of fostered pups surviving > 12 months in the wild, 9 animals whelped or sired 26 litters. Cross-fostering was successful at augmenting litter size for red wolves without any deleterious effects on recipient litters, illustrating fostering as a tool for increasing populations of endangered carnivores.

Bats in the family Phyllostomidae exhibit the most diverse dietary ecology of any mammalian family and the link between their morphology and diet is well-studied. However, the morphology of phyllostomids has yet to be placed into a broader context by comparing them to bats from other families through the use of geometric morphometrics. Using geometric morphometrics, we examined shape trends, disparity, and links between shape and diet using the crania and dentaries of 176 species from 3 of the largest bat families: Vespertilionidae, Molossidae, and Phyllostomidae. Results indicate that cranium shape in insectivorous phyllostomids does not overlap with non-phyllostomid families, suggesting at least 2 insectivorous cranial morphotypes have evolved within Chiroptera and phyllostomid cranial shape had already diverged from other bat families prior to developing their broad dietary range. Further, phyllostomids have higher cranium shape (1.5×) and dentary shape (1.89×) disparity than molossids and vespertilionids, whose dentary and cranium shape disparity is roughly equal. Although the cranium is constrained in many ways (e.g., housing the brain, vision, olfaction), we suggest the fact that dentary shape is limited to food processing allowed it to expand into larger regions of morphospace. Finally, a preliminary dietary analysis based on prey hardness indicates substantial shape overlap within families except for those species with extreme diets (e.g., liquid, very-hard food). Many bats are dietary generalists that eat a wide variety of food types of varying hardness. The data from the 3 large families of bats presented here suggest that eating foods of intermediate hardness may not require substantial cranial reorganization.

When functionally similar species co-occur, they are expected to differ in at least 1 niche axis to avoid competition. In bats, small differences in body size can influence ecology, potentially reducing niche overlap. We used yellowshouldered bats (genus Sturnira) in Mexico as a model to investigate whether interspecific differences in body size increase when 2 related and ecologically similar species occur in sympatry. We hypothesized that size divergence would take place in sympatry, following known patterns whereby larger bats eat larger fruits and smaller bats forage and roost in more cluttered habitats. We collected data on body mass, forearm length, and skull size from museum specimens to characterize the overall dimensions of these bats. Using linear mixed effect models and permutation tests, we tested for differences between areas where these species occur in sympatry or allopatry, while controlling for the confounding effect of environmental variables and sexual dimorphism. Contrary to our original hypothesis, we detected size convergence in sympatric areas, an uncommon pattern in bats. We found no evidence of character displacement for forearm length and body mass, but an effect of co-occurrence on overall skull size and head length. Convergence in overall skull dimensions may reflect shared environmental pressures and similar food resources, which may not represent a limiting factor. Interspecific differences in forearm length remain constant in sympatry or allopatry. These differences likely preceded the 2 species coming into contact and could have allowed initial and ongoing coexistence by influencing wing properties and flight. We highlight the need for multivariate approaches in the study of character displacement, as selective pressures can act differently on different traits allowing both local adaptation and coexistence.

Researchers often use simple body condition indices (BCI) to estimate the relative size of fat stores in bats. Animals determined to be in better condition are assumed to be more successful and have higher fitness. The most common BCI used in bat research are the ratio index (body mass divided by forearm length) or residual index (residuals of body mass-forearm length regression) of size-corrected body mass. We used data from previous and ongoing studies where body composition (fat mass and wet lean mass) was measured by quantitative magnetic resonance to test basic assumptions of BCI, determine whether BCI is an effective proxy of fat mass, and whether other approaches could be more effective. Using data from 1,471 individual measurements on 5 species, we found no support for the underlying assumption that, within species, bats with longer forearms weigh more than bats with shorter forearms. Intraspecific relationships between body mass and forearm length were very weak (R² < 0.08 in all but one case). BCI was an effective predictor of fat mass, driven entirely by the relationship between fat mass and body mass. With little variation in forearm length, calculation of BCI is essentially equivalent to dividing body mass by a constant. We evaluated alternative approaches including a scaled mass index, using tibia length, or predicting lean mass, but these alternatives were not more effective at predicting fat mass. The best predictor of fat mass in our data set was body mass. We recommend researchers stop using BCI unless it can be demonstrated the approach is effective in the context of their research.

Migratory species that cross geopolitical boundaries pose challenges for conservation planning because threats may vary across a species' range and multi-country collaboration is required to implement conservation action plans. The lesser long-nosed bat (Leptonycteris yerbabuenae) is a migratory pollinator bat that was removed from the Endangered Species List in the United States in 2018 and from threatened status in Mexico in 2013. The seasonal ecology and conservation status of the species is well understood in the core part of its range on mainland Mexico and in the southwestern United States, but relatively little is known about the species on the Baja California peninsula in northwestern Mexico, a part of its range range separated by the Gulf of California. We studied the seasonal ecology of lesser long-nosed bats on the Baja peninsula at 8 focal roosts along a 450-km north-to-south transect to test hypotheses about migratory or residential status of the species on the Baja peninsula. We provide evidence of an extensive population of lesser long-nosed bats on the Baja peninsula that is primarily seasonally migratory and includes 2 mating roosts with males on the southern part of the peninsula. Seasonal ecology of lesser long-nosed bats was closely associated with the flowering and fruiting season of the cardón (Pachycereus pringlei), the dominant columnar cactus on the peninsula. However, we discovered that some female lesser long-nosed bats arrive and give birth at southern roosts in mid-February, about 2 months earlier than other migratory populations in more northern Sonoran Desert habitats. We documented the loss of nearly a third of the known maternity roosts during the study, demonstrating that action to protect key roosts remains a high priority. Migratory pollinators are particularly vulnerable to climate and land-use changes and we recommend continued monitoring and research to guide effective range-wide conservation of the species.

To determine if salinity of water and presence of vegetation influence use of wetlands by bats, acoustic detectors were used to record echolocation calls of bats over wetlands in Charleston County, South Carolina, during June– October 2014. Abundance and diversity of insects were determined using a light trap and environmental conditions were measured with a portable weather station to determine if availability of insects or environmental conditions, respectively, played a prominent role in where bats were active. Bats were significantly less active over wetlands with vegetation compared to open-water habitats. Salinity of water played a less significant role than presence of vegetation in where bats were active; however, freshwater sites had the greatest activity. Abundance and diversity of insects were not related to activity of bats. Environmental conditions were related less to activity of bats than features of the habitat. Maintaining open-water areas devoid of vegetation is critical for encouraging activity of bats over wetlands.

We scored pelage coloration of pigs and peccaries and matched them to socioecological variables to assess the relative strengths of protective coloration and signaling in driving coat coloration. Using phylogenetically controlled analyses, we found that faces, bellies, and perhaps flanks are lighter in larger species; ear coloration is lighter in less-shady environments and in more-social species; white facial spots are associated with less shade and with nighttime activity; and white body spots are associated with greater sociality. There is a marginal association between striped natal coats, a classically cryptic pelage, and litter size. These findings indicate that the body coloration of Suiformes has been selected to match overall background lighting conditions in both adults and neonates, but that specific areas and color patches on the body are associated with signaling. Our study suggests that small areas of contrasting pelage coloration are superimposed on classically cryptic body plans to allow both protective coloration and signaling to operate simultaneously.

The resilience of a given species to hunting is conditioned by the effect of potential threats upon the more sensitive periods in its life history, such as when animals are breeding. We investigated the environmental drivers of breeding seasonality in the lowland paca (Cuniculus paca), and the potential impact of hunting on the species. As part of a participative study with hunters in 2 Amazonian sites, we obtained reproductive organs of pacas as well as information on the hunters' daily wild meat extraction. Using data on rainfall, river water level, and fruiting phenology from the 2 study sites, we applied generalized additive models for location, scale, and shape (GAMLSS) to examine the effect of climatic and environmental factors on paca reproduction. Forest fruiting was directly linked to higher pregnancy rates in pacas, and when lactation and weaning of offspring mostly occurred. Hunting was highly seasonal in all studied years and positively correlated with higher levels of river water. The coincidence between hunting patterns and paca reproductive cycles during the wet season resulted in more pregnant females being harvested. In addition to the known slow reproductive rate of pacas, the disproportionate offtake of pregnant females may affect the long-term sustainability of hunting of this species. Reducing hunting during the flooded season may not be feasible because the lowland paca provides most of the wild meat consumed by thousands of rural Amazonians during this period. However, options to offset the negative effects of killing of pregnant females could include the zoning of hunting areas or encouraging hunters to target primarily males. Our results indicate that strategies for the sustainable harvest of pacas and other heavily hunted Amazonian mammals should consider the interaction between the species' reproductive cycles and hunting by local people in order to enhance conservation and management efforts.

Several cetacean species have demonstrated epimeletic behavior that relies on the tight social bonds between conspecifics. These behaviors and the corresponding vocalizations were recorded during a rare encounter with a group of Indo-Pacific humpback dolphins (Sousa chinensis) that included a presumed mother and deceased calf, in Sanniang Bay, China. The observed dolphins were divided into 2 apparent groups: 1) a central group with the presumed mother and her deceased calf, along with 1 to 6 other individuals swimming in synchrony with the presumed mother; and 2) a following group of several individuals, dispersed over varying distances from approximately 20 to > 300 m, that swam in the same direction as the central group. The mother was seen mostly supporting the calf's body using her back, anterior to the dorsal fin and posterior to the melon, while the other members of the central group exhibited standing-by behaviors (i.e., remaining close to the deceased calf but not providing aid). Whistles in this context were of a longer duration and a higher complexity in the frequency modulation compared to social contexts. Several whistle types were also repeated frequently. This paper provides a detailed description of epimeletic behavior and the whistles possibly associated with that behavior in an endangered population of Indo-Pacific humpback dolphins.

We investigated the hypothesis that trophic competition between a top predator and a smaller predator can create refuge from predation for small mammalian prey, using the dingo (Canis lupus dingo) and feral cat (Felis catus) in the MacDonnell Ranges of dryland Australia as a case study. We analyzed the diets of the 2 predator species for evidence of potential competition. There was no evidence of exploitation competition between the 2 carnivores— cats consumed mostly small mammals and particularly larger rodents, whereas the diet of dingoes was dominated by 1 species of large macropod. There was also no evidence of a shift in diet of cats, as their diets in refuges and non-refuges were highly overlapping. Consistent with interference competition, cats were the third most frequently consumed mammal species by dingoes. Although predation by dingoes could limit densities of cats across the MacDonnell Ranges, this alone does not explain why the most rugged habitats in the region are a refuge for rare mammals. We conclude that habitat complexity most likely underpins the refuge and that possible effects of dingo predation on the cat population would be of secondary importance.

The extirpation of marsupial predators and their replacement by eutherian carnivores are likely to have cascading ecological impacts on the trophic structure of arid Australia. Here, we assessed the diet and characterized the trophic role of the 3 largest remaining carnivorous marsupials (< 200 g body mass) in arid Australia: cresttailed mulgaras (Dasycercus cristicauda), kowaris (Dasyuroides byrnei), and brush-tailed mulgaras (Dasycercusblythi). The species show a high level of trophic connectivity; each is highly interactive, being predator or prey of numerous species across multiple phyla. The prey base of each of the predator species was broad and included vertebrates, invertebrates, and plants. Crest-tailed mulgaras consumed the most vertebrates including prey up to the size of the southern marsupial mole (Notoryctes typhlops). Kowaris consumed prey up to the size of the European rabbit (Oryctolagus cuniculus). Although capable of capturing or scavenging vertebrates, the diet of each species was dominated by arthropods < 2 g in body mass.

Understanding the impacts of rainfall and fire on the population dynamics of mammals in desert ecosystems has been hampered by a lack of long-term data. In this study, we use a 16-year data set to investigate these relationships in an assemblage of 8 small rodents and dasyurid marsupials in central Australia. We hypothesized that marsupial populations would be less variable and less responsive to rainfall than rodents, and would also exhibit lower capture rates. We also hypothesized that fire would decrease capture rates of both groups and that in the 5 years after fire, rodents would be more abundant on burned sites than marsupials. Our data show, however, that population fluctuations in rodents and marsupials were largely synchronous, albeit of greater absolute size in rodents, and only partly explained by antecedent rainfall. While fire initially reduced all mammal populations, postburn areas were preferentially exploited by both groups, with rodents displaying only a weak pattern of prolonged use of burned areas. Since both groups recovered well from drought and wildfire, protection of drought refuges and generation of new habitat through small prescribed burns may benefit both groups. Although dasyurid marsupials have been found previously to show inconsistent responses to rainfall and fire, we conclude that their dynamics may sometimes resemble the “boom” and “bust” cycles that typify rodent populations in Australia's arid interior.

The California mouse (Peromyscus californicus) inhabits semiarid oak (Quercus spp.) woodlands and shrublands of California's southern Coast Ranges and lower slopes of the western Sierra Nevada. From 1993 to 2014, we studied the demography of California mice in semiarid oak woodland in coastal-central California. Using capturemark-recapture (CMR) methods, we estimated apparent survival (ϕ), recruitment (f), and realized population growth (λ), and tested for the effects of climatic covariates on these demographic rates. Monthly ϕ averaged 0.869, but it varied temporally between 0.507 and 0.954. Monthly f averaged 0.146 and ranged from 0.027 to 0.556. Monthly λ averaged 0.996; however, λ also exhibited strong temporal variation, ranging from 0.636 to 1.373. Tests of singular covariate models revealed that ϕ was positively influenced by total rainfall (regression coefficient, β = 0.449), but negatively influenced by average temperature (β = -0.394) and by variability in temperature (β = -0.412) and rainfall (β = -0.147). Recruitment was positively affected by total rainfall (β = 0.203) and rainfall variability (β = 0.120); it was negatively affected by temperature variability (β = -0.162). However, the effect of rainfall and temperature on California mice varied across seasons. During winter, high temperature increased both ϕ (β = 0.690) and f (β = 0.754), but in summer these hot conditions reduced ϕ (β = -1.087) and f (β = -0.517). Rainfall positively affected ϕ in both seasons (β = 0.141 in winter; β = 0.614 in summer). Although rainfall positively affected f in winter (0.319), it had no discernible effect in summer. Warmer, drier, and more variable climatic conditions, together with increasingly pervasive habitat alterations, especially wildfire, may threaten the persistence of some California mouse populations.

Understanding animal performance at range edges has gained increasing interest due to climate change, but most efforts have focused on specialist species. Studying the breadth and plasticity of generalist resource acquisition strategies will provide important insight into how mammals adapt to and persist under a variety of environmental conditions. The North American porcupine (Erethizon dorsatum) is a widely distributed generalist herbivore with special adaptations to harsh climates and low-quality diets. However, on the north coast of California, which has a mild climate and abundant vegetation, porcupine populations are patchily distributed and may be in decline. We studied seasonal resource use of porcupines in a coastal dune ecosystem by measuring changes in body mass, home range size, habitat selection, and diet. Both female and male porcupines lost body mass between summer and winter (= 8.3% and 17.2%, respectively), although less than reported elsewhere. Their home range sizes were 31% larger during summer than winter. Porcupines selected swales and marshes during the summer, when they fed primarily on willow leaves, and switched to conifer forests and coastal scrub during winter, when they fed on bark, conifer needles, and leaves of evergreen shrubs. Porcupines exploited 2 novel food sources common in Pacific coastal lowlands: coast manroot fruits and California wax myrtle leaves. We suggest that porcupines employ a similarly flexible resource acquisition strategy across their range, and although it appears to be broadly effective, they may face challenges from plant phenology, low broad-leaved tree diversity, and high winter precipitation in Pacific coastal climates.

Many forest-dependent animals require complex branch and bole structural features as substrates for nesting, and these features may take decades or centuries to develop. In young forests, lack of suitable nest substrates may limit occurrence and abundance of arboreal rodents. To test this hypothesis, we measured the response of arboreal rodents to installation of 429 artificial nest platforms at 17 young forest sites in the Coast Range of Oregon, United States. We compared the percentage of 100-m² plots at sites containing nests before and after installation of nest platforms, and examined 5 a priori hypotheses of spatial patterns of use using logistic regression. One year after installation, we observed a 5.8-fold increase (95% CI = 2.4–9.2) in plots containing nests of red tree voles (Arborimus longicaudus) and a 2.9-fold increase (95% CI = 1.3–4.4) of tree squirrels (Glaucomys oregonensis, Tamiasciurius douglasii). In addition, we captured 37 adult red tree voles (30 females, 7 males). Presence of conspecific nests < 75 m away increased the odds of use by red tree voles but not by tree squirrels. Our results support the hypothesis that lack of suitable nest substrates limits occurrence of red tree voles in young forests, but results were ambiguous for tree squirrels. Increasing the availability of nest substrates via installation of nest platforms may increase abundance of red tree voles in young forests. However, we do not know if this will allow red tree voles to persist in young forests that are subjected to repeated commercial thinning and clear-cut harvesting.

Sidewinders (Crotalus cerastes) and Saharan horned vipers (Cerastes cerastes) have evolved to hunt desert rodents on different continents in evolutionarily independent communities. These species are remarkably convergent, except that sidewinders possess heat-sensitive pit organs that enable them to “see” in the dark. As a constraintbreaking adaptation, this may give sidewinders an advantage when hunting in the dark. How will introducing a novel predator with a constraint-breaking adaptation affect the local species? We allowed Saharan horned vipers to hunt Allenby's gerbils (Gerbillus andersoni allenbyi) in patches with or without sidewinders at full and new moon. When horned vipers hunted alone, moonlight did not affect their foraging behavior. However, in the presence of sidewinders, horned vipers increased their activity on bright nights, but dramatically decreased it on dark nights. Although gerbils foraged equally when hunted by either snake, the combined effect of the 2 predators synergistically decreased gerbil foraging, especially during full moon when both snakes were most active. Thus, sidewinders facilitated horned vipers in full moon, but interfered on darker nights when possessing pit organs were most advantageous for sidewinders. Gerbils quickly learned and adjusted their behavior to manage risks from the novel predators, but the combined effects of both local and novel predators may prove detrimental in the long run. Comparing convergent species that differ in a constraint-breaking adaptation allows us to study the effectiveness of these key adaptations and their potential roles in biological invasions.

Spatial memory can improve cache recovery in scatter-hoarding mammals; however, we lack knowledge about how spatial memory affects scatter-hoarding behavior. Captive-reared Siberian chipmunks (Tamias sibiricus) were orally dosed with docosahexaenoic acid (DHA) and uridine-5-monophosphate (UMP) for 6 weeks to test if improved spatial memory affects scatter hoarding. Oral administration of DHA and UMP significantly increased the relative size of hippocampi of the chipmunks and increased concentration of hippocampal DHA and eicosapentaenoic acid (EPA). Consequently, spatial ability of chipmunks in a Y-maze was significantly improved after administration of DHA and UMP. More importantly, chipmunks that received DHA and UMP scatter hoarded more seeds than control animals. This study shows that scatter hoarding in a mammal is associated with improvement in spatial memory, suggesting the potential role of spatial memory in determining food-hoarding behavior.

Understanding how organisms adapt to aridity is a central theme in traditional desert ecology research. However, many of the pioneering studies were conducted before detailed phylogenies were available to provide evolutionary context and before the accumulation of accurate bioclimatic and species distribution data to provide geographic and environmental context. We tested the desert-adaptive value of changes in skull and dental morphology in rodents after phylogenetic correction. In addition, we estimated that across the evolutionary history of more than 2,400 rodent species, transitions between mesic and desert habitats have been very frequent, with a directional bias toward the mesic-to-desert transition. This suggested that derived desert specialization is an “evolutionary deadend” that limits further evolution. After correcting for the strong phylogenetic signal, we still find a significant and strong correlation between habitat aridity and specializations associated with auditory sensitivity (auditory bulla inflation) and respiratory water retention (nasal passage elongation) but not in characters associated with dietary specialization (lower incisor shape). No other significant associations were found between habitat or aridity and any other cranial, jaw, or dental traits. Bullar hypertrophy is among the strongest patterns of convergent cranial desert adaptation in rodents and indicates that adaptation plays a similar role in shaping the evolution of this structure in different desert rodent clades.

The musculo-tendinous system is responsible for generating and transmitting forces necessary to produce and control body movements. The focus of this study was to investigate ontogenetic patterns in the growth of forelimb muscles and tendons in 4 sigmodontine rodents (ambulatory Akodon, quadrupedal saltatorial Eligmodontia, scansorial Oligoryzomys, and semifossorial Oxymycterus) and to discover if these patterns differ with respect to species-locomotor mode. We examined forelimbs of 64 specimens including juveniles, young adults, and adults, and removed and measured 12 muscles and 7 tendons. The evolution of morphology is reflected in both static and ontogenetic allometric patterns. The general allometric pattern revealed by our data is one of decreased growth rate with larger size, because all morphological variables exhibit negative allometry. Patterns of allometry in the musculo-tendinous system may represent adaptations to specific habitat requirements. These patterns differed among species, and hence among locomotor types: 7 morphological variables showed subtle differences between species–locomotor types, while the trends within 3 species–locomotor types did not differ. The strongest patterns were associated to the muscles and tendons related to extension of the arm and flexion of the wrist.

During the Pleistocene, red fox (Vulpes vulpes) populations in North America were isolated in glacial refugia and diverged into 3 major lineages: the Nearctic-Eastern subclade of eastern Canada, the Nearctic-Mountain subclade of the western mountains, and the Holarctic clade of Alaska. Following glacial retreats, these genetically distinct populations of foxes expanded into newly available habitat. Along with subsequent translocation from fur farms, these expansions have resulted in red foxes now occupying most of the continent. The origin of foxes that colonized the Great Lakes Region, however, remains unknown. Furthermore, it is unclear whether contemporary populations inhabiting this region are the result of natural range expansion or if foxes released from fur farms colonized the landscape in the 1900s. To determine the origin of red foxes in the Great Lakes Region, we collected genetic samples from 3 groups: 1) contemporary wild foxes, 2) historical wild foxes collected before fur farming, and 3) fur-farmed foxes from a contemporary fur farm. We constructed a network of mtDNA haplotypes to identify phylogeographic relationships between the 3 sample groups, and examined genetic signatures of fur-farmed foxes via the androgen receptor gene (AR) associated with tame phenotypes. Historical wild foxes demonstrated natural colonization from all 3 major North American lineages, which converged within the Great Lakes Region, and contemporary wild foxes maintained the historically high genetic diversity. Most contemporary wild foxes also matched haplotypes of fur-farmed foxes; however, AR was not useful in distinguishing fur-farm origins in samples of contemporary wild foxes. Our results show that geographically disparate populations naturally merged in the Great Lakes Region before fur-farmed foxes were introduced. Due to the historically high genetic diversity in the Great Lakes Region, any introductions from fur farms likely contributed to, but did not create, the genetic structure observed in this region.

We assessed the genetic variability of the eastern spotted skunk (Spilogale putorius) throughout the range of the species, with an emphasis on the potentially endangered plains spotted skunk subspecies (S. p. interrupta). Tissue samples from a variety of sources including field surveys, state agencies, and museum tissue collections allowed a detailed assessment of the genetic variability in S. putorius using both microsatellite markers and cytochrome b (Cytb) gene sequences. Our analysis of 118 specimens established that genetic patterns were consistent with the currently accepted taxonomy of the 3 recognized subspecies: S. p. putorius, S. p. ambarvalis, and S. p. interrupta. The differentiation between S. p. putorius and S. p. ambarvalis was less pronounced (F_ST = 0.178; Cytb sequence divergence = 1.2%) than between these subspecies and the plains spotted skunk (average F_ST = 0.278; Cytb sequence divergence = 2.9%). Overall, genetic variability in the plains spotted skunk was lower than that seen in common carnivores (e.g., striped skunks, Mephitis mephitis, and raccoons, Procyon lotor), but slightly higher than in the endangered black-footed ferret (Mustela nigripes). The heterozygosity levels more closely resemble those found within the island spotted skunk (S. gracilis amphiala) from the Channel Islands of California and other vertebrates that have a “threatened” conservation status.

Population declines and extirpations of large mammalian carnivores are major concerns for global biodiversity conservation. Many large carnivores are vulnerable to conflict with humans and attract conservation attention for their flagship appeal and ecological importance. Coexisting with carnivores requires an understanding of carnivore distribution and abundance relative to human activities and disturbances. Such knowledge is often hindered by the rare and elusive nature of carnivores and the lack of systematic ecological surveys in biodiverse regions facing high levels of threat. The Caucasus Ecoregion is one such biodiversity hotspot harboring several threatened mammal species for which there is a paucity of reliable data, including brown bears (Ursus arctos). Caucasus brown bear populations have declined significantly from historical times and may be isolated and vulnerable to disturbance from development activities such as mining, as well as increasing hunting pressure. To inform land-use planning and bear conservation in the Caucasus Ecoregion, we conducted systematic surveys in May–October 2015 in the foothills of the Caucasus Mountains within the Vayots Dzor region of Armenia. We used noninvasive genetic sampling, camera trapping, and statistical models that account for imperfect detection to estimate density and distribution of the bear population in the 1,000-km² study area. Across 34 sampling sites, we obtained 3,163 camera-trap photos of brown bears and genotyped 28 individual bears (7 males and 21 females). Spatially explicit capture-recapture models revealed an unexpectedly high density of bears (59.4/1,000 km²; females = 44.6, 95% confidence interval, CI = 25.4–78.4; males = 14.8, 95% CI = 6.6–34.0), and multi-method occupancy models indicated that bears were distributed across most of the study area (ψ = 0.85; SE = 0.07). These results provide robust evidence that a significant population of brown bears persists in Armenia's Vayots Dzor region, despite a history of hunting and habitat loss that have driven declines in brown bear populations throughout much of the Caucasus Ecoregion. Continued persistence of this flagship species may be threatened by mining, poaching, and other anthropogenic pressures in the region, underscoring the urgent need for strategic conservation planning, impact mitigation, and expanded ecological monitoring within this biodiversity hotspot.

Dogs (Canis familiaris) are among the most abundant and widely distributed carnivores worldwide, and their presence can have negative impacts on native fauna. This study investigated the invasion of cacao agroforests by free-ranging dogs in Brazil. By monitoring the behavior of dogs using direct observations, we assessed whether direct (chasing and predation) and indirect (urine and fecal deposition) interactions with wildlife are more common when dogs enter the agroforests with humans than when they stay outside. We also compared the time that dogs spent inside versus outside the agroforests, and estimated their areas of use. The dogs (n = 10) spent a small fraction of the time without their owners, and only when moving inside the cacao agroforests. The dogs fed and rested more in open habitats and house surroundings than in agroforests, but they were more active and depredated wildlife exclusively in the latter. Kernel estimates of space use at the 50% and 95% levels ranged from 1 to 46 ha and 6 to 202 ha, respectively. Most of the area used by dogs was within cacao agroforest, while core areas were concentrated near human residences and in places of owner permanence in cacao agroforest. Human movement was a key determining factor in the use of space by the dogs. Changes to human behaviors toward their dogs must be considered if the direct and indirect impacts of dogs on wildlife are to be mitigated.