Accurate taxonomy is central to the study of biological diversity, as it provides the needed evolutionary framework for taxon sampling and interpreting results. While the number of recognized species in the class Mammalia has increased through time, tabulation of those increases has relied on the sporadic release of revisionary compendia like the Mammal Species of the World (MSW) series. Here, we present the Mammal Diversity Database (MDD), a digital, publically accessible, and updateable list of all mammalian species, now available online:  https://mammaldiversity.org. The MDD will continue to be updated as manuscripts describing new species and higher taxonomic changes are released. Starting from the baseline of the 3rd edition of MSW (MSW3), we performed a review of taxonomic changes published since 2004 and digitally linked species names to their original descriptions and subsequent revisionary articles in an interactive, hierarchical database. We found 6,495 species of currently recognized mammals (96 recently extinct, 6,399 extant), compared to 5,416 in MSW3 (75 extinct, 5,341 extant)—an increase of 1,079 species in about 13 years, including 11 species newly described as having gone extinct in the last 500 years. We tabulate 1,251 new species recognitions, at least 172 unions, and multiple major, higher-level changes, including an additional 88 genera (1,314 now, compared to 1,226 in MSW3) and 14 newly recognized families (167 compared to 153). Analyses of the description of new species through time and across biogeographic regions show a long-term global rate of ~25 species recognized per year, with the Neotropics as the overall most species-dense biogeographic region for mammals, followed closely by the Afrotropics. The MDD provides the mammalogical community with an updateable online database of taxonomic changes, joining digital efforts already established for amphibians (AmphibiaWeb, AMNH's Amphibian Species of the World), birds (e.g., Avibase, IOC World Bird List, HBW Alive), non-avian reptiles (The Reptile Database), and fish (e.g., FishBase, Catalog of Fishes).

Una taxonomía que precisamente refleje la realidad biológica es fundamental para el estudio de la diversidad de la vida, ya que proporciona el armazón evolutivo necesario para el muestreo de taxones e interpretación de resultados del mismo. Si bien el número de especies reconocidas en la clase Mammalia ha aumentado con el tiempo, la tabulación de esos aumentos se ha basado en las esporádicas publicaciones de compendios de revisiones taxonómicas, tales como la serie Especies de mamíferos del mundo (MSW por sus siglas en inglés). En este trabajo presentamos la Base de Datos de Diversidad de Mamíferos (MDD por sus siglas en inglés): una lista digital de todas las especies de mamíferos, actualizable y accesible públicamente, disponible en la dirección URL  https://mammaldiversity.org/. El MDD se actualizará con regularidad a medida que se publiquen artículos que describan nuevas especies o que introduzcan cambios de diferentes categorías taxonómicas. Con la tercera edición de MSW (MSW3) como punto de partida, realizamos una revisión en profundidad de los cambios taxonómicos publicados a partir del 2004. Los nombres de las especies nuevamente descriptas (o ascendidas a partir de subespecies) fueron conectadas digitalmente en una base de datos interactiva y jerárquica con sus descripciones originales y con artículos de revisión posteriores. Los datos indican que existen actualmente 6,495 especies de mamíferos (96 extintas, 6,399 vivientes), en comparación con las 5,416 reconocidas en MSW3 (75 extintas, 5,341 vivientes): un aumento de 1,079 especies en aproximadamente 13 años, incluyendo 11 nuevas especies consideradas extintas en los últimos 500 años. Señalamo

Synchrony between reproduction and food availability is important in mammals due to the high energetic costs of gestation and lactation. Female polar bears (Ursus maritimus) must accumulate sufficient energy reserves during spring through autumn to produce and nurse cubs during the winter months in snow dens. Adequate time in a den is important to optimize cub development for withstanding harsh Arctic spring conditions and to synchronize emergence with peak prey availability, which occurs in May and June. During 1985–2013, den phenology was investigated using temperature data collected on satellite collars deployed on adult female polar bears in the southern Beaufort Sea (SB) and Chukchi Sea (CS). We examined relationships between den phenology, reproductive success (cub production and post-emergence survival), and environmental factors (weather and sea-ice conditions). Females observed with cubs emerged later and remained in dens on average 15.0 ± 7.6 (SE) days longer than females seen without cubs. Females occupying land-based dens, where estimated snowfall was greater, had higher reproductive success. Recently, female polar bears have increased land-based denning in the SB. Females in CS emerged later from dens than SB females, consistent with better female body condition and higher cub survival in the CS. During years with a greater area of autumn sea ice, reproductive success was higher at land-based versus sea-ice dens, suggesting continued decline in sea ice could negatively affect recruitment. However, further research is needed to better understand mechanistic relationships. Because females emerging later from dens had higher reproductive success, den duration could be a useful metric in population monitoring.

Energetically costly lunge feeding at depth causes the respiratory patterns and feeding performance of rorqual whales (Family Balaenopteridae) to hinge in part upon prey patch depth. This contingency has the potential to precipitate differences in prey preference and habitat suitability for sympatric species and may be a factor in competitive interactions, but comparative respiration studies are a necessary first step in assessing this hypothesis. We concurrently sampled dive behavior in sympatric, euphausivorous humpback (Megaptera novaeangliae) and fin whales (Balaenoptera physalus), as well as prey depth distribution within a British Columbia fjord system over the course of 2 summers. Ventilation and dive patterns differed significantly between species, including differential respiratory response to increasing prey depth, despite their foraging upon a common prey resource. Thanks to longer dives and shorter surface recoveries, fin whales spent a greater proportion of their time on dives. This behavior, coupled with faster swim speeds during descent and ascent reported in previous studies, afford fin whales greater periods of time at the depth of their prey. These interspecific discrepancies in dive behavior determine the whales' relative temporal access to prey. Simulations based on our observations indicate that the fin whale's relative advantage in this fjord system increases with increasing prey depth when all other prey parameters are held constant. Simulation results emphasize the importance of swim speed in rorqual foraging strategy. Small differences in prey access per dive can have important implications over the course of a foraging season, which may precipitate differences in habitat suitability. Our findings, when coupled with the body of knowledge from tagging studies, highlight this link and point to its potential role in the habitat preferences of foraging whales.

Maternal habitat preferences of humpback whales (Megaptera novaeangliae) are well documented from decades of coastal research but oceanic areas have received less attention. Whales breeding in New Caledonia occupy both ecosystems: a coastal reef complex (South Lagoon) and oceanic seamounts (Southern Seamounts). Generalized additive models were applied to 20 years of boat-based whale observations (n = 1,526) to describe habitat preferences and permissive home range estimations were used to explicitly model spatial segregation in relation to social context. Groups with calves (n = 206) preferred shallow coastal waters throughout the season in the South Lagoon, whereas no habitat segregation was observed between groups with (n = 74) and without calves (n = 140) in the Southern Seamounts. As a result, spatial overlap between groups with and without calves was more common in the Southern Seamounts than the South Lagoon. Despite a lack of social segregation around seamounts, mother-calf pairs were proportionally more frequent in the Southern Seamounts (27%) than in the South Lagoon (16%). Photographs of the calves' dorsal flanks were analyzed to compare age and ecological markers across sites. Calves appeared older in the Southern Seamounts than in the South Lagoon but no difference in scarring or shark bites was found across sites, suggesting that calves experienced similar lifestyles and may move between offshore and coastal waters during the breeding season. This study highlights the flexible habitatuse patterns of breeding humpback whales and raises new questions about the environmental and social drivers of their presence in offshore breeding grounds.

Sexual segregation, the tendency to seasonally live in groups comprised of separate sexes, is widespread in sexually dimorphic polygynous ungulates. The causes for such segregation are still being studied and debated to arrive at a universal explanation. We assessed sexual segregation in the markhor, Capra falconeri—a dimorphic mountain ungulate inhabiting a seasonal temperate environment. We observed markhor herd composition, gender-specific diet, and habitat use over 3 years and multiple seasons. We tested the predictions of the Reproductive Strategy-Predation Risk Hypothesis (RSH) that focuses on offspring security, and the Forage Selection-Sexual Dimorphism Hypothesis (FSH) based on different foraging needs between the sexes due to size dimorphism. Generalized linear models were used to identify the important variables that best explained segregation in markhor. Male and female markhor showed a tendency to segregate throughout the year outside the mating season. Female markhor were confined to cliffs with relatively less forage cover, whereas males used areas with relatively better forage away from the security of cliffs. Females also occurred at lower elevations compared to males. Social segregation prevailed during pre-parturition and continued until autumn when the offspring were older, indicating a role of other factors besides predation risk. Sexual segregation in markhor was influenced by multiple mechanisms.

Intraspecific variation in ranging and social behavior can be perplexing, but also provides an opportunity to assess which behavioral attributes are labile in the face of geographic variation in resources. White-nosed coatis (Nasua narica) are group-living carnivores of tropical origin that possess an unusual social system. In the resourcerich tropics, larger-bodied males are solitary, whereas females live in groups (“bands”) along with young of both sexes, but leave them to give birth and wean their young. Males often disperse socially, but not spatially. We studied coatis in the Chiricahua National Monument, Arizona, a resource-poor, arid, and highly seasonal landscape. Using live capture and radiotelemetry in conjunction with microsatellite DNA analyses, we found that Chiricahua coatis exhibited the species-typical pattern of solitary males and gregarious females. Young males left their natal bands as yearlings, and some were found as adults within their natal home range. On the other hand, home ranges were expanded greatly. Bands, and some males, focused their movements in areas several km² in extent over periods of weeks or months but shifted those areas markedly among seasons. Some males followed the typical mammalian pattern of natal dispersal beyond their natal area. Rates of movement were higher and female associations appeared to be more flexible than in the tropics. Adult females sometimes ranged singly, not only around the time of parturition, but also when population density was low and occasionally otherwise. In addition, home range overlap was high among both sexes during some seasons, and female bands sometimes fused for prolonged periods. Core patterns of sociality are constant in both resource-rich tropical and resource-poor temperate populations, but coatis appear to make major adjustments in scale of movement and frequency of association in response to resource variation.

In biparental systems, sexual conflict over parental investment predicts that the parent providing care experiences greater reproductive costs. This inequality in parental contribution is reduced when offspring survival is dependent on biparental care. However, this idea has received little empirical attention. Here, we determined whether mothers and fathers differed in their contribution to care in a captive population of coyotes (Canis latrans). We performed parental care assays on 8 (n = 8 males, 8 females) mated pairs repeatedly over a 10-week period (i.e., 5–15 weeks of litter age) when pairs were first-time breeders (2011), and again as experienced breeders (2013). We quantified consistent individual variation (i.e., repeatability) in 8 care behaviors and examined within- and among-individual correlations to determine if behavioral plasticity within or parental personality across seasons varied by sex. Finally, we extracted hormone metabolites (i.e., cortisol and testosterone) from fecal samples collected during gestation to describe potential links between hormonal mechanisms and individual consistency in parental behaviors. Parents differed in which behaviors were repeatable: mothers demonstrated consistency in provisioning and pup-directed aggression, whereas fathers were consistent in pup checks. However, positive within-individual correlations for identical behaviors (e.g., maternal versus paternal play) suggested that the rate of change in all behaviors except provisioning was highly correlated between the sexes. Moreover, positive among-individual correlations among 50% of identical behaviors suggested that personality differences across parents were highly correlated. Lastly, negative among-individual correlations among pup-directed aggression, provisioning, and gestational testosterone in both sexes demonstrated potential links between preparental hormones and labile parental traits. We provide novel evidence that paternal contribution in a biparental species reaches near equivalent rates of their partners.

Partial migration is a common life-history strategy among ungulates living in seasonal environments. The decision to migrate or remain on a seasonal range may be influenced strongly by access to high-quality habitat. We evaluated the influence of access to winter habitat of high quality on the probability of a female white-tailed deer (Odocoileus virginianus) migrating to a separate summer range and the effects of this decision on survival. We hypothesized that deer with home ranges of low quality in winter would have a high probability of migrating, and that survival of an individual in winter would be influenced by the quality of their home range in winter. We radiocollared 67 female white-tailed deer in 2012 and 2013 in eastern Washington, United States. We estimated home range size in winter using a kernel density estimator; we assumed the size of the home range was inversely proportional to its quality and the proportion of crop land within the home range was proportional to its quality. Odds of migrating from winter ranges increased by 3.1 per unit increase in home range size and decreased by 0.29 per unit increase in the proportion of crop land within a home range. Annual survival rate for migrants was 0.85 (SD = 0.05) and 0.84 (SD = 0.09) for residents. Our finding that an individual with a low-quality home range in winter is likely to migrate to a separate summer range accords with the hypothesis that competition for a limited amount of home ranges of high quality should result in residents having home ranges of higher quality than migrants in populations experiencing density dependence. We hypothesize that density-dependent competition for high-quality home ranges in winter may play a leading role in the selection of migration strategy by female white-tailed deer.

Wild pigs (Sus scrofa) are among the most widespread and destructive invasive mammals in the world. Understanding the spatial ecology of this species is foundational to effectively mitigating further range expansion. We compiled size estimates of home ranges of wild pigs from 30 locations worldwide and modeled the relationship between home-range size and both abiotic (evapotranspiration, latitude, precipitation, and temperature) and biotic (vegetation productivity and mammal species richness) environmental factors. Size of home ranges varied markedly, ranging from 0.62 to 48.3 km². Mammal species richness was positively correlated with home-range size and was the only predictor in the best model; other abiotic factors typically correlated with richness, i.e., latitude and evapotranspiration, were not significant predictors of wild pig home-range size. Despite indicating correlation rather than cause, our analyses were conducted at the scale of the home range and therefore may support the invasion paradox hypothesis for mammals, which states that biotic interactions have a greater influence on invasive species at finer spatial scales. While we do not suggest that mammal species richness can preclude populations of wild pigs from continuing to spread in their native or non-native ranges, our correlative results suggest that areas with a diverse mammal community may be more resistant to invasion. This finding supports the intrinsic value of conserving native species and highlights the need for future work exploring the specific mechanisms by which species richness and biodiversity can influence the ecology of invasive species.

We compared isotopic niche widths of small mammals that co-occur across the Alexander Archipelago and adjacent mainland in southeastern Alaska to test the prediction that dietary niche widths will be greater for individuals living in communities with fewer potential competitors and predators. We quantified the carbon (δ¹³C) and nitrogen (δ¹⁵N) isotopic niche widths of 2 insectivorous shrews (Sorex cinereus and S. monticola), 3 primarily herbivorous rodents (Microtus longicaudus, M. oeconomus, and M. pennsylvanicus), and 1 omnivorous rodent (Peromyscus keeni) and combined these data with information provided by natural history accounts. We sampled islands that varied with respect to size and species richness to compare with localities on the adjacent mainland, where species richness is greatest. Consistent with our predictions, isotopic niche widths were significantly greater on islands relative to mainland localities. Our findings can help guide management strategies within this archipelago through increased understanding of how key community-level interactions vary across localities within this complex landscape.

Species reside in dynamic environments, simultaneously experiencing variations in climatic conditions, habitat availability and quality, interspecific interactions, and anthropogenic pressures. We investigated variation in foraging ecology of the small mammal community between land-use classifications (i.e., protected national parks and unprotected lands abutting them) in Mole National Park (MNP) and Digya National Park (DNP), representing distinct ecoregions of Ghana. In 5,064 trap nights, we sampled 153 individuals of 23 species within the 2 national parks and adjacent lands outside protected boundaries to describe variation in community composition. We also used δ¹³ C and δ¹⁵ N isotopic ratios from fresh feces to determine main effects and interactions between land use and ecoregion on trophic structure in species and communities of small mammals. Small mammals exhibited distinct community assemblages between ecoregions (i.e., national parks): Gerbilliscus guineae, Hybomys trivirgatus, Malacomys edwardsi, Lemniscomys bellieri, L. zebra, and Taterillus gracilis were only captured in the dry savanna ecoregion of MNP. Additionally, isotopic signatures for nitrogen were significantly lower in MNP (2.83 ± 0.17‰) compared to DNP (4.97 ± 0.33‰), indicating that small mammals occupied different trophic levels between ecoregions. The most common species, Praomys daltoni exhibited variation in isotopic signatures between ecoregions and land use, with higher δ¹⁵ N found within MNP boundaries. We found no distinction in δ¹³ C at the community or species level within or across protected areas. Ultimately, understanding shifts in the ecology of species can inform predictions about community structure and ecosystem function under future environmental and anthropogenic scenarios.

The bat wing is a highly adaptive airfoil that enables demanding flight maneuvers that are performed with robustness under turbulent conditions, and stability at slow flight speeds. The bat wing is covered with microscopically small, tactile hairs that have been shown to be involved in sensing air flow for improved flight maneuverability in 2 bat species, the frugivorous–nectarivorous Carollia perspicillata and the insectivorous Eptesicus fuscus. Here, we provide comparative data on the anatomy of these hairs and their distribution on the wing surface in 4 species of bats (C. perspicillata, Desmodus rotundus, E. fuscus, and Rousettus aegyptiacus), based on scanning electron microscopy analyses. Hairs were found on both the dorsal and ventral surfaces of the wing in all species, including the bony structures. They were generally sparsely distributed (1–3 hairs/mm²) and often found arranged in single file along elastin bands that extend through the wing membrane. Fringes of hairs also were found at the leading edge of the propatagium. The hairs were strongly tapered in all species. Their length varied from 0.08 mm (E. fuscus) to 3 mm (R. aegyptiacus). Hair length correlated positively with the body mass and wing loading value of each species, but not with aspect ratio, flight speed, or diet. We conclude that the hairs are spaced so that viscous coupling is negligible, at least for single-file hairs, and that they are scaled to the boundary layer of airflow limited to the first few millimeters close to the wing surface.

Anoura fistulata is the most specialized nectarivorous bat of the genus Anoura. Its relationships with other species of the genus are uncertain given its external morphological resemblance to all 4 species in the A. caudifer species complex. Here, we show how to properly diagnose A. fistulata and how the glossal tube, unique to this species, should be identified. We also reassess the putative presence of A. fistulata in Bolivia by revisiting the measurements and soft morphology characters of the specimen used for this published record. Our morphometric analyses show that the species in the A. caudifer complex overlap in their morphospace for 23 cranial and postcranial measurements and are indistinguishable using Principal Component Analyses or Linear Discriminant Functions. However, comparing dissections of A. fistulata from Ecuador to the Bolivian record show that it lacks the soft tissue characters unique to A. fistulata, indicating this specimen is an individual of A. caudifer rather than A. fistulata. Given that this was the only record for the country, A. fistulata is not known to occur in Bolivia.

The gray mouse opossum (Tlacuatzin canescens) is a poorly studied marsupial endemic to México. Phylogenetic or phylogeographic information on this species and its evolutionary history is scarce and scattered. We investigated the origin and the diversification of this taxon using molecular and morphological data. We examined mitochondrial (cytochrome-b) and nuclear (interphotoreceptor retinoid-binding protein) sequences to test species monophyly and assess phylogenetic relationships within the species. We also used multivariate statistical analyses of 13 craniodental variables to assess the phenotypic distinctiveness of mitochondrial haplotypic clades. Phylogenetic analyses revealed that T. canescens is a monophyletic group divided into 5 well-differentiated clades. Genetic divergence among clades was 3.1–8.9%, while the intragroup divergence was 0.5–3.7%. Our molecular clock estimates indicate that the diversification of this taxon occurred during the Pleistocene, which suggests that climatic changes and the presence of geographical barriers influenced the genetic differentiation of its populations. Morphological analyses also showed that there are cranial differences among these clades. Our results suggest the recognition of T. gaumeri, T. insularis, and T. sinaloae as valid species, and the recognition of 1 clade that we describe here as a new species.

The genus Dromiciops Thomas is the only living representative of the order Microbiotheria. Throughout the history of the taxon, it was considered to comprise a continental and an insular form (D. australis and D. gliroides), a single species (D. gliroides), or, as recently described, 3 different species (D. bozinovici, D. mondaca, and D. gliroides). I analyzed the morphometric and morphologic variability (differences in morphological characters within a sample or species) and variation (differences in morphological characters among samples or species) in Dromiciops. Comparisons to test for secondary sexual dimorphism were made within and between continental and insular samples for localities with the largest samples available. Due to the lack of sexual dimorphism, males and females were analyzed together to test for: 1) differences between continental and insular samples; 2) differences between the arrangement of recently described species using a larger series of available specimens; and 3) clinal variation. Results support Dromiciops as composed of 1 valid species (D. gliroides), without clinal variation. Based on the samples I examined, several characters previously used as diagnostic for the 3 species previously recognized (e.g., incisive and palatal fenestrae, mandibular height) vary intraspecifically and are not valid as diagnostic.

Oecomys tapajinus (Tapajós Oecomys) is currently a junior synonym of Oecomys roberti (Robert's Oecomys), a widely distributed Amazonian mouse, which probably represents a complex of cryptic species. We investigated the taxonomic status of O. tapajinus by integrating phylogenetic analyses of DNA sequences and morphological analyses of museum specimens. We were able to confirm that O. tapajinus is a valid species from eastern Amazonia and the transition to the Brazilian Cerrado, where it is sympatric with O. roberti. Oecomys tapajinus is characterized by a unique combination of morphological traits, high morphological variation, and genetic differentiation and structure related to the complex system of the Amazon River. Potential additional entities within the O. roberti complex emerged from our analyses, and further investigation with larger series may shed light on the taxonomic status of this species complex.

We describe a new species of murine rodent from a skull collected on Bisa Island and 3 specimens from Obi Island, North Maluku Province, Indonesia. Molecular and morphological data indicate a close relationship with Halmaheramys bokimekot (Fabre et al. 2013). The new species is characterized by its combination of large size; short tail with large scales; spiny, coarse, dark dorsal pelage with long black guard hairs; and a dark gray ventral pelage that contrasts slightly with the dorsum. The Bisa specimen displays unusual zygomatic arch morphology, which may be a disease-related deformity, or potentially a sexually dimorphic trait. The new species shares several external and cranio-mandibular features with its sister species from Halmahera that differ from those of Rattus species, including a spiny pelt, deep palatine sulci, a high rostrum and relatively flat dorsal profile, short incisive foramina, short palatal bridge, and molars with simple occlusal patterns. Although certain morphological characteristics of the new taxon suggest an affinity with the taxonomically diverse and geographically widespread Rattus, in other respects it clearly fits into the Wallacean clade containing Bunomys, Paruromys, and Taeromys, as indicated by molecular phylogenetic analyses. Along with the recent discovery of Halmaheramys, recognition of this new species from Bisa and Obi Islands underscores the north Moluccan region's high endemism, conservation importance, and the urgent need for a better inventory of its biodiversity.

Bats belonging to the subfamily Vespertilioninae are diverse and cosmopolitan, but their systematic arrangement remains a challenge. Previous molecular surveys suggested new and unexpected relationships of some members compared to more traditional, morphology-based classifications, and revealed the existence of taxonomically undefined lineages. We describe here a new genus and species corresponding to an enigmatic lineage that was previously identified within the genus Eptesicus in the Indomalayan Region. Phylogenetic reconstructions based on mitochondrial and nuclear genes relate the new taxon to Tylonycteris and Philetor, and show that specimens associated with this new genus represent 2 genetically distinct species. Although little is known about their ecology, locations of capture and wing morphology suggest that members of this new genus are tree-dwelling, open-space aerial insect predators. The new species has only been documented from Yok Don National Park in Vietnam, so its conservation status is uncertain until more surveying methods target the bat fauna of the dipterocarp forest in Southeast Asia.

Global positioning system (GPS) technology has revolutionized the study of carnivores. Researchers commonly estimate kill rates with GPS data using the following steps. Firstly, researchers mark individual animals and fit them with GPS collars. Next, they visit a subset of “GPS clusters” (aggregated location data) during field surveys and assign spatiotemporal covariates associated with predation and non-predation events. Lastly, they develop predictive models with data collected in the field to estimate the probability that each cluster they did not visit in the field was a predation event. Such predation models help reduce field efforts and save money; however, these models are prone to error when carnivores eat prey of different sizes or exhibit shorter-than-expected handling times. We simulated reduced field efforts to investigate the reliability of predictive modeling in determining diet composition and detecting predation events for 3 puma (Puma concolor) populations with different prey assemblages and potential effects on handling time of carcasses. We visited a total 1,896 clusters in Chilean Patagonia, Colorado, and California, of which 1,752 clusters (~92%) were included to build and test predation models. Across all study areas, the total time a puma spent at a cluster was the only reliable predictor of a cluster being a predation event. When we reduced field efforts by selectively removing GPS clusters < 12 and < 24 h in length, model performance improved but produced inaccurate results. Predation models underestimated the number of predation events in California and Colorado and significantly over- or underestimated the number of predation events in Patagonia. Selectively reducing field efforts also reduced the diversity and evenness of prey we recorded in puma diets. Randomly reducing field efforts, in contrast, reduced the precision of model estimates. Our results highlight the importance of conducting intensive fieldwork over predation modeling to measure prey selection and kill rates of carnivores.

American badgers (Taxidea taxus) are large members of the weasel family Mustelidae. Badgers are important predators and creators of burrows in ecosystems in which they occur, but they are not well studied. Their range occurs over most of North America; however, most studies of badgers have occurred in California and the northern portions of their range, while few have occurred in southern habitats. Badger density has been estimated in Utah, Idaho, Wyoming, and British Columbia with no estimates from desert habitats. To measure badger density in a desert habitat, we placed automatic cameras at anthropogenic water sources (drinkers) in the Chihuahuan Desert, identified individual badgers by their dorsal head stripes, and estimated density using spatially explicit capture-recapture analysis. We modeled the detection process for individuals as a function of time, survey region, a learned and trap-specific behavioral response, and a finite mixture model. We then hypothesized that soil composition, soil depth, and land cover influence variation in badger density. From 1,282 camera-nights, we recorded 301 badger visits (23.5 visits per 100 camera-nights) and identified 30 individuals 170 times. The top model included a trap-specific behavioral effect for λ0, a finite mixture model for the σ parameter, which controls the spatial scale over which the expected number of detections declines, and indicated that soil depth was an important covariate explaining variation in badger density. Estimated badger density was 0.10 badgers/km² (95% CI = 0.03–0.31), which is considerably less than the reported density estimates for nonendangered nondesert populations. Our method helps provide researchers with an ability to estimate density for American badgers in arid ecosystems. With modification, our method may be used across the geographic range of badgers, facilitating better understanding of an understudied species.

The eastern spotted skunk (Spilogale putorius) is a small, nocturnal omnivore that was once common throughout the eastern United States, but has declined over the last 75 years. We examined den-site selection of eastern spotted skunks in the southern Appalachian Mountains of Alabama from December 2014 to February 2016. We compared the local habitat characteristics of 97 den sites from 8 individual skunks with paired random sites. Dens were most frequently located in burrows, but were also found under uprooted trees, between rocks, in tree stumps, and in tree cavities. Skunks never communally denned and individuals frequently reused the same den. Den sites were located in densely forested areas with greater woody understory cover, midstory cover, and snag density and less overstory density than nearby random sites. Dense understory and midstory around skunk den sites likely provided protective cover from predators, particularly owls. Snags may provide additional cover for spotted skunks while offering possible denning or foraging habitat. Habitat management for eastern spotted skunks in the southern Appalachian Mountains should include retention and promotion of dense understory and midstory cover.

The Neotropical region currently harbors 8 recognized species of small cats, including the margay (Leopardus wiedii) and jaguarundi (Puma yagouaroundi). These similar-sized species have broad geographic distributions and commonly occur in sympatry. We constructed species occurrence databases and used the maximum entropy (Maxent) modeling approach to develop models of habitat suitability for each of these species. We identified the environmental predictors with the highest importance for species occurrence and evaluated how they influence habitat suitability for both wild cats. Variables related to temperature and precipitation were good predictors of species occurrence, with both cats responding similarly to them. However, margay showed higher variation in habitat suitability depending on local climatic predictors. The estimated models indicated high niche similarity (> 76%) between these cats, but despite this we identified different areas with the most favorable conditions for each species' occurrence. Approximately 50% and 72% of the entire suitable area were estimated as being moderately to highly suitable for margay and jaguarundi, respectively, with the margay model comprising a higher proportion of forest environments in comparison to that of the jaguarundi. These findings will be relevant in the context of conservation planning when indicating the priority areas for their long-term preservation.

Endemic to the central mountains of the Trans-Mexican Volcanic Belt, the volcano rabbit (Romerolagus diazi), known locally as the zacatuche, is a threatened species at risk of extinction. In the Ajusco-Chichinautzin Mountain Range, the Pelado and Tlaloc volcanoes are core distribution areas for this species; however, suitable habitat within these areas is patchy. We analyzed the habitat of this species at the landscape level, taking into account biotic, abiotic, and anthropogenic factors. We used geographic information systems for the habitat analysis and a linear mixedeffects model to identify the habitat patches available, analyze them in the FRAGSTATS program, and calculate their landscape metrics. To identify the habitat of the volcano rabbit, we used its relative abundance index in the context of land use and vegetation, elevation, slope, road and highway density, and distance to human settlements. The analyses indicated that the relative abundance index of this species decreases with increasing proximity to human settlements and with increasing road and highway density. At the landscape level, there are 957 patches of habitat available to the species, covering 75.44 km². Most of the patches are 2,500 m² in area and regular in shape (square); however, because they are small patches it is possible that they will disappear. The largest patches are located on the Pelado and Tlaloc volcanoes, and coincide with the core distribution areas of the volcano rabbit described in the literature.

Global biodiversity patterns are shaped by landscape structure and seasonality. Spatio-temporal patterns in bat assemblages are not well studied in grassland biomes but forest patches may provide important habitat for bats within these open grasslands. In the Greater Everglades Ecosystem (GEE), small fragments of diverse, critically imperiled pine rockland remain amidst a vast expanse of seasonally flooded grasslands (marl prairies). We used acoustic surveys to investigate the use of pine rocklands and marl prairies by bats across 2 distinct seasons (drycool and wet-warm). We detected higher mean bat activity in pine rocklands than marl prairies in the dry-cool season and higher bat species richness in pine rocklands in both seasons. Four of the 9 species of bats exhibited higher mean activity in pine rocklands than marl prairies and higher activity in the wet-warm season. The greater structural complexity of pine rocklands relative to marl prairies may be attractive to bats for roosting, foraging, and protective cover. Our finding of an interactive effect between vegetation community and season on bat activity suggests that pine rocklands may be more attractive to bats in the dry-cool season. This may be due to microclimate moderation, which likely leads to higher insect abundance for foraging bats. Pine rocklands in the GEE clearly provide ecological benefits that help support local biodiversity. These forest patches are important landscape elements for bats in grassland communities, where available roosts, prey, and protective cover may be limited.