We investigated the migratory movements of silver-haired bats (Lasionycteris noctivagans) across the eastern extent of the species' range. We conducted stable hydrogen isotope analysis of fur samples (δ²H_fur) from museum specimens collected across latitudes and at all times of the year. We first used these data to estimate the timing of fur replacement and to develop a model associating δ²H_fur with that of local precipitation (δ²H_precip) at the location where fur replacement occurred. We then used this model to 1) identify individuals that had migrated across latitudes, and 2) investigate the presence of continental-scale patterns in the estimated distance traveled. Bats were at their location of fur replacement between 20 June and 26 August, and there was a strong linear relationship between δ²H_fur and δ²H_precip in bats collected during this time. There was substantial variation in the migratory movements of this species. Twenty-four of 38 females and 14 of 30 males showed isotopic evidence of leaving the area where fur replacement occurred (i.e., migrating across latitudes), whereas the remaining bats were either sedentary or moved at a small spatial scale. Males appeared to migrate consistently, regardless of latitude of origin, whereas there was a partial leapfrog pattern in migratory movements of females. To our knowledge, this is the first evidence of leapfrog migration in bats.

Many temperate-climate bats migrate tens to hundreds of kilometers from hibernacula to summer habitat each spring and in the opposite direction each fall. Understanding the timing of migration can help reduce the risk of disturbance via anthropogenic activities, guide effective management, and determine future impacts of a changing climate. We examined the influence of weather and day of year on the arrival and departure of Indiana bats (Myotis sodalis) monitored at a summer maternity colony site in central Indiana from 1998 to 2014, using emergence count data to track the timing of bat presence during the spring and fall migration seasons. We used an information theoretic approach to compare 23 models that predicted bat presence as a function of weather, climate, and lunar illumination; these models predicted arrival of the first Indiana bat and the first observation of a colony in spring, and the last observation of a colony and the last bat observed in fall. Bats embarked on spring and fall migrations to the maternity colony area at approximately the same time each year (arriving ∼3 April and departing ∼7 October) and variation was accounted for by changes in weather. Spring arrival and colony formation were predicted by higher temperatures ( = 22.5°C for colony formation) and precipitation and lower wind speeds, whereas lower temperatures ( = 25.9°C for colony breakup) and precipitation and higher wind predicted colony breakup and departure in fall. Spring migration coincided with periods of increased winds and, thus, we advocate for higher cut-in speeds for wind turbines during bat migration seasons. Resource managers should consider the entire time that bats are on the summer landscape when defining regulations and implementing conservation measures.

Variation in weather and food availability impacts the energy budgets of endotherms, with some species using torpor as an energy-saving strategy during periods of negative energy balance. We evaluated how latitudinal differences in energy balance relate to variation in torpor expression and roosting sociality between populations. We monitored summer skin temperatures (T_sk) of individuals from 2 populations of New Zealand lesser shorttailed bats (Mystacina tuberculata) separated by 6° of latitude using temperature telemetry. Although mean summer T_a was only < 1°C lower for the higher-latitude than lower-latitude population, individuals living at the higher-latitude site used torpor on 36% of observation days compared to 11% for lower-latitude bats. None of the recorded weather variables affected the propensity to enter torpor or torpor bout duration; however, the minimum torpid T_sk of bats positively correlated with daily minimum T_a. Roosts occupied by solitary bats were warmer than T_a, and temperatures within them fluctuated less than T_a. Higher-latitude individuals roosted solitarily (38%) more frequently than lower-latitude individuals (17%) and individuals from both populations exclusively used torpor while roosting solitarily. Arousals from torpor by higher-latitude bats coincided with sunset and not daily T_a maxima suggesting that bats were not fully exploiting advantages of passive rewarming. Site-specific roost choice and torpor patterns were apparent between M. tuberculata populations during summer, demonstrating that small differences in T_a differentially affect energetic strategy. The thermoregulatory behavior of species inhabiting latitudinal gradients in climate is highly plastic, likely to meet the specific challenges of their environment.

Measuring rates and causes of mortalities is important in animal ecology and management. Observing the fates of known individuals is a common method of estimating life history variables, including mortality patterns. It has long been assumed that data lost when known animals disappear were unbiased. We test and reject this assumption under conditions common to most, if not all, studies using marked animals. We illustrate the bias for 4 endangered wolf populations in the United States by reanalyzing data and assumptions about the known and unknown fates of marked wolves to calculate the degree to which risks of different causes of death were mismeasured. We find that, when using traditional methods, the relative risk of mortality from legal killing measured as a proportion of all known fates was overestimated by 0.05–0.16 and the relative risk of poaching was underestimated by 0.17–0.44. We show that published government estimates are affected by these biases and, importantly, are underestimating the risk of poaching. The underestimates have obscured the magnitude of poaching as the major threat to endangered wolf populations. We offer methods to correct estimates of mortality risk for marked animals of any taxon and describe the conditions under which traditional methods produce more or less bias. We also show how correcting past and future estimates of mortality parameters can address uncertainty about wildlife populations and increase the predictability and sustainability of wildlife management interventions.

In rapidly changing environments, assessing the degree to which animals behaviorally respond to human disturbance can help identify activities of concern or populations at risk. We examined circadian activity patterns of bobcats (Lynx rufus), coyotes (Canis latrans), mule deer (Odocoileus hemionus), elk (Cervus canadensis), lagomorphs, and rodents during crepuscular, day, and night periods using data captured from 40 remote cameras distributed across a 162-km² area with starkly different levels of current and historical energy development. During the winter of 2015–2016, we obtained 3,067 independent detections from 7,185 camera days of our 6 target species. In mixed support of our hypotheses, bobcats, coyotes, and mule deer were less active during the day in the developed site compared to the undeveloped site, as were rodents, which was unexpected. In contrast, elk and lagomorphs did not show differences across sites. Bobcats demonstrated the greatest reduction in diurnal activity, with nearly 3 times less activity in the developed site. Coyotes and mule deer appeared to compensate for reduced activity during the day by increasing their activity during other periods, though bobcats did not. The mammal species captured in this study demonstrated strong differences in their plasticity and sensitivity to energy development approximately 4 years post high-intensity disturbance, which likely influences their susceptibility to human-driven landscape changes.

In late 2009, the Catalina Island Conservancy began using fertility control to replace periodic removals to manage an introduced population of American bison (Bison bison) on the island. Through the application of the immunocontraceptive vaccine porcine zona pellucida (PZP), population growth was slowed within 1 year, and halted over time. In response to lingering questions about the use of PZP to manage large, free-ranging wildlife populations, we sought to determine the reversibility of PZP by ceasing the annual application to a subset of 15 bison cows and monitoring for subsequent calf arrival, and to document changes in the timing and length of the breeding season in response to PZP by monitoring breeding behavior and assessing fecal progesterone (FP) levels for all 60 resident cows over a 13-month period. As of June 2017, no new calves had been observed on the island, suggesting that, following repeated annual treatment with PZP (3 or 4 years), bison do not resume normal reproduction for at least 4 or 5 years, and that fewer treatments would be advisable if a faster return to fertility is desired. Based on observations of bull and cow behavior, and FP levels, cows displayed estrous cycles consistently throughout the study period, indicating that bison may ovulate year-round when conception and its consequences, e.g., lactation and presence of calves, are blocked. Because there is little evidence that an extended breeding season would negatively impact the health of bulls or result in large numbers of out-of-season births on Catalina, PZP appears to be a highly effective tool for managing the population of introduced bison on the island. However, the extended period of contraception and breeding activity of both cows and bulls may make PZP less suitable in high-latitude, predator-rich environments where bison conservation remains a top priority.

Fecal glucocorticoid metabolites (FGMs) are commonly used as indicators of an animal's stress response in behavioral and ecophysiological studies. FGM assays provide a noninvasive and efficient means of assessing adrenocortical activity. We used 12 African buffalo (Syncerus caffer) temporarily maintained in an enclosure to evaluate 2 commercially available FGM assays as tools for assessing stress levels in buffalo in field studies. We also used the experiment to assess potential adverse effects of immobilizations on the study animals. Buffalo responded rapidly to stimulation with adrenocorticotropic hormone (ACTH), which stimulates the adrenal cortex to secrete glucocorticoids. ACTH-stimulated buffalo had higher plasma cortisol concentrations than saline-injected controls between 5 min and 1 h after injection. The ACTH-induced plasma cortisol peak was detectable in FGMs at 10–20 h post-injection. Both of the commercial test kits we evaluated were capable of detecting the ACTH-induced peak in FGM. However, the radioimmunoassay delivered more consistent detection across weeks than the enzyme immunoassay. We tested whether immobilization and handling elicited a stress response detectable by FGM, by comparing immobilized, saline-injected buffalo with controls that were not immobilized or handled. Adult buffalo mounted a stress response to immobilization and handling, whereas subadults did not, suggesting an age-related difference in response to chemical immobilization. Our study validates use of commercially available kits for quantifying FGMs under field conditions.

Because of massive conversion of natural habitat into cropland, the future of many tropical mammals depends on understanding how agricultural landscapes influence biodiversity. We assessed the effects of natural and anthropogenic land covers and disturbances on occupancy of gray brocket deer (Mazama gouazoubira) in 3 agricultural landscapes in the Brazilian Cerrado where sugarcane or managed forest cover most (> 50%) of the landscape. We used camera-trap surveys to quantify the relationships between deer occurrence and land cover, unpaved roads, urban areas, waterways, and degrees of legal protection. We found a strong and positive effect of managed forests, indicating that this land cover is good habitat for the brocket deer in our region. Native forests and sugarcane had, surprisingly, weaker effects on deer occupancy. Furthermore, the effect of sugarcane varied according to the amount of remaining natural forest: when the amount of natural forest surrounding the camera point was scarce, sugarcane had a negative effect on deer occupancy, but the effect was positive when natural forest was abundant. Our results confirm the ecological flexibility of gray brocket deer, even in landscapes where sugarcane monocultures or Eucalyptus plantations predominate. We caution however that the responses of deer might be different in landscapes more severely depleted of natural vegetation (< 20% at the landscape level). We therefore suggest that future research assess the population status of this deer in more deforested landscapes, and also consider the temporal dynamics of managed forests and sugarcane, as the vegetation cover can change drastically.

Devido à intensa conversão de habitats naturais em grandes extensões de plantios, o futuro de muitos mamíferos tropicais depende do entendimento de como paisagens agrícolas influenciam a biodiversidade. Avaliamos os efeitos de coberturas de terras naturais e antrópicas e distúrbios na ocupação do veado-catingueiro (Mazama gouazoubira) em 3 paisagens agrícolas no Cerrado brasileiro, onde a cana-de-açúcar ou florestas plantadas cobrem a maior parte (> 50%) da paisagem. Utilizamos armadilhas-fotográficas para quantificar as relações entre a ocorrência dos veados e o tipo de cobertura da terra, estradas de terra, áreas urbanas, cursos d'água e grau de proteção legal. Encontramos um efeito forte e positivo de florestas plantadas, indicando que essa cobertura da terra é um bom habitat para o veado-catingueiro na nossa região. Florestas nativas e cana-de-açúcar tiveram, surpreendentemente, efeitos mais fracos na ocupação dessa espécie. Contudo, o efeito da cana-de-açúcar variou de acordo com a quantidade de remanescentes naturais: quando a quantidade de florestas naturais no entorno da armadilha-fotográfica era escassa, a cana-de-açúcar teve um efeito negativo na ocupação dos veados, mas o efeito foi positivo quando as florestas naturais eram abundantes. Nossos resultados confirmam a flexibilidade ecológica do veado-catingueiro, mesmo em paisagens onde predominam monoculturas de cana-de-açúcar ou florestas plantadas de Eucalyptus. Vale ressaltar, porém, que a resposta desta espécie pode ser diferente em paisagensmais severamente esgotadas de vegetação natural (< 20% na escala da paisagem). Portanto, sugerimos que em futuros trabalhos seja avaliado o status populacional dessa espécie em paisagens mais desmatadas considerando, também, a dinâmica temporal das florestas plantadas e da cana-de-açúcar, à medida que a cobertura da vegetação muda drasticamente.

An allopatric population of big-eared climbing rats (Ototylomys) from the Northern Highlands of Chiapas, Mexico, is described as a new species. The new taxon is part of a unique montane rainforest community that includes several other endemic species in the limited geographic range between the Río Grijalva and the Central Depression of Chiapas. Several cranial, external, and molecular characters distinguish this new species of big-eared climbing rat from its more widely distributed congener, Ototylomys phyllotis. We performed principal component and discriminate function analyses of cranial measurements, and found that specimens of the new species consistently could be distinguished from other Ototylomys with strong statistical support. Compared with exemplars of Ototylomys from elsewhere in their range, the new species possesses a karyotype that differs by 3 additional biarmed chromosome pairs, is fixed or nearly fixed for distinct electromorphs at 12 allozyme loci, and the mean genetic distance exceeds 14%, based on comparisons of the mitochondrial cytochrome b gene between the new species of Ototylomys and representatives of O. phyllotis. The restricted distribution in montane karst rainforest suggests that the species and its habitat may be a matter of conservation concern.

Una población alopátrica de rata orejuda trepadora (Ototylomys) de las Tierras Altas del Norte de Chiapas, México se describe como una nueva especie. El nuevo taxón es parte de una comunidad única de bosque lluvioso montano que incluye varias especies endémicas en el área de distribución geográfica limitada entre el Río Grijalva y la Depresión Central de Chiapas. Varios caracteres craneales, externos, y moleculares distinguen la nueva rata orejuda trepadora de su congénere más ampliamente distribuido, Ototylomys phyllotis. Se realizaron análisis de componentes principales y de función discriminante de los caracteres craneales, y se encontró que los especímenes de La Pera fueron consistentemente distinguidos de otros Ototylomys con un fuerte soporte estadístico. En comparación con ejemplares de Ototylomys del rango, la nueva especie posee un cariotipo que difiere por 3 pares adicionales de cromosomas biarmados, está fijo o casi fijo por distintos electromorfos en 12 loci alozímicos. Adicionalmente, la media de la distancia genética comparada del gen mitochondrial citocromo b entre la nueva especie de Ototylomys y representantes de O. phyllotis, excede el 14%. La distribución restringida en el bosque lluvioso montano kárstico sugiere que la especie y su hábitat pueden ser de importancia para la conservación.

Cormura brevirostris is a rare and poorly known species of emballonurid bat that occurs in Central America and South America across the Amazonian region. Previous work showed that karyotypes of C. brevirostris from Colombia, Suriname, and the Brazilian Amazon presented 2n = 22 and FN = 40, although small differences in chromosome composition have been observed among these karyotypes. Phylogenetic studies using nuclear and mitochondrial markers also showed differences between Central and South American C. brevirostris individuals. We describe the karyotype of an adult male C. brevirostris from the Brazilian Amazon and compare it to other karyotypes reported for this species. We also investigate phylogenetic relationships within this species using 2 mitochondrial and 1 nuclear gene. Morphological characters and measurements of the Brazilian specimen matched those described for C. brevirostris. The karyotype displayed a C-banding pattern similar to those described for C. brevirostris from other localities. Phylogenetic analyses confirmed the monophyly of Cormura, but each marker showed a different relationship. Karyological data showing more than 1 lineage and deep intraspecific mitochondrial lineages suggest that this taxon could be a species complex, requiring additional taxonomic studies to elucidate species limits and phylogenetic relationships within the genus Cormura.

Cormura brevirostris é uma espécie rara e pouco conhecida de morcegos embalonurídeos que ocorre na América Central e em toda a região Amazónica da América do Sul. Trabalhos anteriores mostraram que os cariótipos de C. brevirostris da Colômbia, do Suriname e da Amazônia brasileira apresentaram 2n = 22 e FN = 40, embora pequenas diferenças na composição dos cromossomos tenham sido observadas entre esses cariótipos. Estudos filogenéticos utilizando marcadores nucleares e mitocondriais também mostraram diferenças entre os indivíduos de C. brevirostris das Américas Central e do Sul. Descrevemos o cariótipo de um adulto de C. brevirostris da Amazônia brasileira e comparamos com outros cariótipos relatados para essa espécie. Também investigamos as relações filogenéticas dentro desta espécie usando 2 genes mitocondriais e 1 nuclear. Medidas e caracteres morfológicos do espécime brasileiro coincidiram com as descritas para C. brevirostris. O cariótipo mostrou um padrão de bandas-C semelhante àqueles descritos para C. brevirostris de outras localidades. As análises filogenéticas confirmaram a monofilia de Cormura, mas cada marcador mostrou um relacionamento diferente.Os dados cariológicos que mostram mais de 1 linhagem e linhagens mitocondriais de profunda divergência intraspecífica sugerem que este táxon pode ser um complexo de espécies, necessitando de estudos taxonômicos adicionais para elucidar os limites das espécies e as relações filogenéticas dentro do gênero Cormura.

The taxonomic position of Annandale's rat, Rattus annandalei (Bonhote, 1903), has been uncertain given its mix of Rattus-like and Sundamys-like morphological features. Annandale's rat and all described species in Sundamys (the lowland S. muelleri, and the montane S. maxi and S. infraluteus) are endemic to Sundaland, a center of diversification and endemism for their tribe, the Rattini. Using mitochondrial genomes and 3 nuclear markers (rag1, rbp3, ghr), we provide the 1st phylogenetic framework for Sundamys. We find that R. annandalei is nested within Sundamys, and that the 4 species likely diverged during the Pleistocene. We move R. annandalei to Sundamys and provide an emended diagnosis for Sundamys. Using geometric morphometric analyses of skulls and mandibles, we identify morphological differences between lowland and highland species of Sundamys that may be associated with adaptations to distinct diets.

Animals often confine their movements to familiar areas and preferred habitats, resulting in increased fitness through enhanced survival and reproduction. However, the link between preferential habitat use and fitness is rarely tested, especially when individual phenotype is considered. Through multi-state modeling of markrecapture data, we assessed the influence of habitat type, sex, and body size on the daily survival and habitattransition probabilities of white-footed mice (Peromyscus leucopus). Habitat states tested were forest edge versus forest interior, and grassy versus shrubby habitat. Females were more likely to survive than males, and mass had a positive effect, whereas foot length a negative effect on survival. Females were more likely to exhibit habitat-type fidelity between edge and interior states than males. Body mass negatively affected daily transition between edge and interior, whereas foot length had a positive effect. Individuals were most likely to remain within the shrubby habitat and leave the grassy habitat. Mass had a negative effect on daily transition probability between grassy and shrubby habitats, foot length had a positive effect, and sex had no effect. Individuals with the greatest probability of moving between habitat types had the lowest probability of survival, likely a result of occupying unfamiliar space. Our results show that white-footed mice in general seem to select habitat types where fitness expectations are likely to be greatest, but that transitions between habitats often depend on phenotypic characteristics of individuals.

Our goals were to characterize multiannual population changes of the southern red-backed vole (Myodes gapperi) to determine potential cycling behavior, and to specify the possible causes of these changes. We analyzed a detailed, 21-year record of changes in abundance of M. gapperi in late successional coniferous forest in southern British Columbia, Canada, from 1995 to 2015. We evaluated 3 hypotheses (H), namely that population changes are related to: (H₁) changes in food supply from cone crops of coniferous trees; (H₂) changes in forest habitat associated with beetle-killed lodgepole pine (Pinus contorta) trees; and (H₃) territorial reorganization leading to breeding season declines in abundance. There were 3 cyclic population fluctuations (6- to 7-year periodicity) where red-backed voles reached mean fall numbers of 19–25, 15–16, and 26–27 per ha, respectively; in contrast, only 2–5 voles per ha occurred during population lows. Breeding season declines in abundance occurred in 17 of 21 years, with particularly precipitous drops ranging from 49% to 69% loss of voles. M. gapperi had more successful pregnancies, juvenile recruits, and adult recruits in the high than in the low population years. Mean index of early juvenile survival was 22% higher in low than high population years. Mean summer survival (58%) was consistently lower than that in winter (83%). Population increases were positively related to cone crops of 3 coniferous tree species. Thus, H₁ was partially supported in 3 of 4 seedfall events. Positive changes in forest habitat, resulting from seed rain as a food supply and fallen debris from beetle-killed pine trees as cover, may have supported high numbers of voles in 2011–2012 (H₂). A spring reorganization event limited the number of breeding animals by density-dependent inhibition of maturation and survival of juvenile voles, and led to breeding season declines (H₃). Rigorous field experiments are needed to test these hypotheses and their interactions as mechanisms driving population change.

Accurate age determination is a fundamental prerequisite for demographic studies as well as population monitoring efforts that provide information for management and conservation. Yet, common age determination methods suffer from low accuracy rates, impose additional handling and time costs on animals and biologists, or rely on invasive techniques such as tooth extraction. We introduce an alternative, mixture modeling approach for age determination that exploits mammalian growth patterns to classify newly encountered animals as juveniles or adults, and present an example analysis that classifies Allegheny woodrats based solely on their capture dates and mass at capture, in combination with data from known adults. We also introduce and validate a simulation-based heuristic to evaluate potential classification accuracy when no known-age test cases are available. In the Allegheny woodrat example, the mixture model achieved a 90-92% accuracy rate (heuristic range: 89–94%), far better than the 36–43% achieved with a fixed mass criterion, and comparable to accuracies reported for other species using more data-intensive, multivariate classification techniques. The model can be extended to classify multiple age groups, estimate chronological age, or further improve accuracy by including additional morphometric measures.

We examined external morphometric parameters in incidentally caught long-beaked common dolphins (Delphinus capensis) from the east coast of South Africa for evidence of sexual dimorphism. We evaluated sexual dimorphism and allometric growth in 26 external body measurements from 211 individuals and assessed size and shape dimorphism. Most characteristics analyzed showed a negative allometric relationship to total body length for both males and females. Twenty-one measurements showed significant differences between the sexes. Among these were the 3 girth measurements, the length of the dorsal fin base, the distance between the tip of the upper jaw to the midpoint of the umbilicus, and the distance between the tip of the upper jaw to the center of the anus. Fourteen of the 26 characteristics analyzed showed significant differences in body shape between the sexes. Our results indicated that moderate sexual dimorphism is present in long-beaked common dolphins from this region, with males being both significantly longer and more robust than females. Sexual dimorphism in this species may be related to their mating or foraging strategies.

Armadillos (Cingulata: Dasypodidae and Chlamyphoridae) are the only mammals bearing an osseous carapace. Most mammals have rapid growth rates and require high mineral levels. However, armadillos feed mainly on insects, a poor source of calcium and phosphate. This raises the question how lactating females obtain the needed minerals to provide their offspring sufficient quantities for the development and hardening of their carapace. The objective of this study was to evaluate whether there are differences in the mineral density of the carapace and endoskeleton of reproductive (especially lactating) and non-reproductive female armadillos, and those of males. We performed computed tomography of 32 female and 13 male dead pichis (Zaedyus pichiy) of different age classes and reproductive status and compared bone mineral density (BMD) of their marginal scutes, compact and spongy bone of the carapace, and femoral bone. Juveniles of both sexes had significantly lower BMD than adults. Average BMD values of the marginal scutes, compact and spongy bone of the carapace, femoral head, spongy bone, and femoral cortical bone of lactating females were similar to those of adult males and significantly higher than values of adult females without signs of gestation or lactation. We conclude that lactating females do not seem to lose bone density, at least from the carapace and femur, during lactation. However, our results suggest that a high BMD may be necessary to support reproduction in female pichis.

Intraspecific studies of morphology and performance are essential for understanding the factors that enable resource partitioning within ecological communities. The sea otter (Enhydra lutris) is one of the few mammal species in which individual-level dietary specialization has been documented, making them an ideal system to investigate the morphological basis of food resource partitioning. Here, we test if differences in food resource use within and between sea otter subspecies can be explained by differences in ecologically relevant metrics of bite performance that are mainly the product of variation in size, cranial morphology, or a combination of these traits. We use geometric morphometrics to evaluate variation in cranium size and morphology, and 2-dimensional models to estimate bite performance differences between 2 sea otter subspecies that differ in dietary ecology: the northern sea otter (Enhydra lutris kenyoni, a facultative generalist) and the southern sea otter (E. l. nereis, a specialist). We found significant differences in cranium shape and size between subspecies and between male and female sea otters. These differences were subtle yet consistent with most subspecies classifications and known sexually dimorphic traits. Cranial morphological differences did not translate into differences in estimated bite force between subspecies or sexes, but dentary strength differed significantly between male and female sea otters. Sea otters have short, blunt crania with pronounced sagittal and lambdoidal crests, and strong mandibles. These traits combine to produce high bite forces for their size. We propose that high bite performance capacity in sea otters enables resource-use variation by widening the diversity of available food resources they can procure from their environment; this allows them to behave as either generalists or specialists within different habitats.

While polygyny is the dominant mating system in mammals, it is increasingly recognized that promiscuity occurs in most species. Using a long-term genetic and space-use data set, we documented the mating system for 2 sedentary and uniparous species of tree sloths, brown-throated three-toed (Bradypus variegatus) and Hoffmann's two-toed (Choloepus hoffmanni) sloths. We predicted that the life history of these species facilitates female strategies that promote mating with multiple males across breeding seasons, and shape central features of the mating system in tree sloths. We found that many female sloths mated with different males during our study: 70% of female B. variegatus and 50% of female C.hoffmanni switched mates among years at least once during our study. Our observations of individual movements suggested that females employed 2 strategies that appeared to influence mate switching across breeding seasons: 1) selecting a male from a pool of males in their activity center, and 2) mating with different males by shifting their home ranges during estrus. Collectively, our findings suggest that individual variation in female reproductive strategies contributes to shaping the mating systems for a sedentary mammal like sloths, and highlights the need for long-term studies to effectively capture the mating systems of mammals with slow life histories.

Aunque la poligamia es el sistema de apareamiento dominante en los mamíferos, es cada vez más reconocido que las hembras en la mayoría de las especies de mamíferos se aparean con múltiples machos. Usando un set de datos genéticos y de uso de hábitat a largo plazo, se documentó el sistema de apareamiento de dos especies sedentarias y uníparas, el perezoso grisáceo (Bradypus variegatus) y el perico ligero (Choloepus hoffmanni). Se predijo que las características de estas especies, facilitan que las hembras presenten estrategias que promuevan el apareamiento con múltiples machos, determinando finalmente el sistema de apareamiento en estas especies. Se encontró que muchas hembras se aparearon con múltiples machos: 70% de las hembras de B. variegatus y el 50% de las de C. hoffmanni presentaron múltiples parejas por lo menos una vez durante esta investigación. Nuestras observaciones sobre movimientos individuales revelaron que las hembras cambian de pareja bajo diferentes escenarios: (1) apareamiento con machos diferentes en cada estro, de los que se superponen en su ámbito hogareño (2), apareamiento con machos diferentes al cambiar su ámbito hogareño durante el estro. Estas evidencias sugieren que las estrategias reproductivas individuales de las hembras ayudan a modelar el sistema reproductivo de especies sedentarias como los perezosos; finalmente, es importante destacar la necesidad de investigaciones a largo plazo para poder entender los sistemas de apareamiento de especies con lenta historia de vida.

Bat-eared foxes (Otocyon megalotis) are the primary vector and maintenance host species for rabies in the western half of South Africa. Reported cases of rabies in this species peak during the dry season, although reasons for this annual peak are unknown. Rabies transmission is dependent on contact rates, thus seasonal differences in social behavior or movements may facilitate increased contact rates in the dry season. During an ecological study of bat-eared foxes in South Africa from 2005 to 2008, we compared between the wet and dry seasons several aspects of the ecology of bat-eared foxes that presumably would influence contact rates. Bat-eared foxes had significantly larger group sizes in the dry season, which would presumably increase intragroup contact rates, and significantly greater home-range sizes, greater home-range overlap, and higher rates of excursions (i.e., short-term forays from their home range), which would presumably increase intergroup contact rates. Seasonal differences in behavior and movements of bat-eared foxes likely were related to their reproductive cycle and seasonal availability of food resources. In contrast to previous reports, we documented relatively high rates of physical contact between bateared foxes and dogs (Canis familiaris) and black-backed jackals (C. mesomelas), suggesting there is potential for bat-eared foxes to transmit the rabies virus to larger canids in the region. We provide recommendations for control of rabies outbreaks in bat-eared foxes if it becomes a health or management concern.

Species Distribution Models (SDMs) rarely incorporate biotic interactions, even though the latter may have great impacts on biogeographical patterns, because interactions can be difficult to model in time and space. In addition, the resolution of input data can have dramatic effects on results, with coarser resolutions unlikely to capture climatic variation at small scales, particularly in mountainous regions. Joint SDMs can be used to explore distributions of multiple, coexisting species and characterize modeled biotic interactions; however, the influence of scale on predictions is yet to be tested. We produced Joint SDMs for European lagomorph species at 3 hierarchical resolutions and calculated residual and environmental correlations that could explain why species may or may not co-occur, thereby suggesting biotic interactions. European lagomorph species exhibited similar environmental and biotic responses at all 3 resolutions (50 km, 25 km, and 10 km), with models at finer resolutions producing more precise estimates but requiring considerable computing time. The majority of pairwise residual responses were negative, indicating that European lagomorph species co-occur less than expected given their similarity in environmental responses, and suggesting modeled biotic interactions consistent with those reported in the literature. Fine-scale data and models offer greater precision but are not always necessary for multispecies models. However, caution is advised when inferring biotic interactions using data and models based on a coarser scale.

The temporal activity of sympatric carnivores reflects trade-offs between avoidance of competitors and predators, and optimizing foraging success. Closely related species may experience greater interspecific competition for resources due to similar morphologies and ecological requirements. Although the mechanisms by which lions (Panthera leo) and leopards (Panthera pardus) partition diet and habitat have been investigated, the degree to which they avoid each other temporally with possible compromises for foraging success remains less clear. In a wildlife conservancy in Zimbabwe, we used camera-trap data to investigate the factors influencing the diel activity of lions and leopards. We modeled diel activity using circular statistics and calculated coefficients of overlap using kernel density functions and non-negative trigonometric sums models. Both leopards and lions were predominately nocturnal, with highly overlapping diel activity. The diel activity of leopards also coincided with that of some prey species, especially common duikers (Sylvicapra grimmia). Therefore, we suggest that leopards may prioritize hunting success and prey acquisition over diel avoidance of dominant competitors like lions.

The rapidly declining tropical forests of Asia support a diversity of felid species, many of which are rare and little known. We used camera traps in Dampa Tiger Reserve (TR), Mizoram, northeastern India, to estimate population density and describe activity patterns of 2 rare felids, the clouded leopard (Neofelis nebulosa) and marbled cat (Pardofelis marmorata). With a survey effort of 4,962 trap nights, we obtained 84 photo-captures of clouded leopards and 36 of marbled cats. We used spatially explicit capture-recapture methods to estimate population densities of both species. Using the Bayesian approach implemented in SPACECAP, we derived estimates of 5.14 (± 1.80 SD)/100 km² for clouded leopards and 5.03 (± 2.07 SD)/100 km² for marbled cats. Using cameratrap images, we compared diel activity patterns and activity overlaps for these 2 rare felids, together with 3 other sympatric carnivores, by estimating a coefficient of overlap between species. Among felids, clouded leopards and golden cats (Catopuma temminckii) displayed the highest overlap in activity, whereas marbled cats and leopard cats (Prionailurus bengalensis) showed the lowest, with marbled cats being primarily diurnal and leopard cats nocturnal. Our study provides the first density estimates from continental Southeast Asia for marbled cats and one of the highest recorded densities for clouded leopards. These results are of special significance since Dampa sustains an ecosystem that has in recent times undergone near extirpation of large predators.

A greater understanding of how environmental factors and anthropogenic landscape features influence animal movements can inform management and potentially aid in mitigating human-wildlife conflicts. We investigated the movement patterns of 16 Florida black bears (Ursus americanus floridanus; 6 females, 10 males) in northcentral Florida at multiple temporal scales using GPS data collected from 2011 to 2014. We calculated bi-hourly step-lengths and directional persistence, as well as daily and weekly observed displacements and expected displacements. We used those movement metrics as response variables in linear mixed models and tested for effects of sex, season, and landscape features. We found that step-lengths of males were generally longer than step-lengths of females, and both sexes had the shortest step-lengths during the daytime. Bears moved more slowly (shorter step-lengths) and exhibited less directed movement when near creeks, in forested wetlands, and in marsh habitats, possibly indicating foraging behavior. In urban areas, bears moved more quickly (longer steplengths) and along more directed paths. The results were similar across all temporal scales. Major roads tended to act as a semipermeable barrier to bear movement. Males crossed major roads more frequently than females but both sexes crossed major roads much less frequently than minor roads. Our findings regarding the influence of landscape and habitat features on movement patterns of Florida black bears could be useful for planning effective wildlife corridors and understanding how future residential or commercial development and road expansions may affect animal movement.

We studied home range use, spatial activity patterns, and annual survival of southern flying squirrels (SFS; Glaucomys volans) across fragmented landscapes of west-central Illinois. We calculated seasonal home range sizes and annual survival from 67 animals (36 males, 31 females) captured during 2014–2016. Home range and core area sizes were similar (P ≥ 0.46) among males and females across summer (April–September) and winter (October–March) seasons. Average distance between consecutive animal locations did not vary by sex, season, or year. Similarly, cumulative distance between consecutive locations did not vary by sex, season, or year and ranged from 1,189 to 1,661 m between summer and winter seasons. Mean annual composite home range and core area sizes were 10.39 and 1.25 ha, respectively; estimated home ranges (10.3 ha) of females are the largest documented for this species. We documented 8 deaths, all attributed to predation, the majority (63%) of which occurred during winter; annual survival was 71%. Our results underscore effects of habitat productivity on seasonal home range dynamics and space use patterns of SFS in fragmented landscapes. SFS may compensate for reduced availability of overstory mast-producing trees that characterize unproductive habitats and low-density populations by exhibiting similar movement patterns and use of available habitat by both sexes throughout the year. Winter communal nesting appears to be influenced by availability of cavity trees, thereby confirming the importance of standing snags in contributing essential habitat to flying squirrel populations in fragmented forests.

Reintroductions are an important conservation and management technique used to restore extirpated populations. Negative genetic consequences (e.g., diversity loss, bottlenecks, inbreeding) are often an unintentional result of reintroductions, due to a small number of founders or suboptimal habitat at release sites. American martens (Martes americana) were extirpated from Michigan's Lower Peninsula in 1911 due to habitat loss and unregulated trapping. Martens were reintroduced into 2 areas of the Lower Peninsula in 1985–1986. The Lower Peninsula reintroduction was characterized by a relatively small number of founders (85 individuals) released into 2 geographically disparate, fragmented sites. We genotyped martens sampled at the 2 release sites approximately 20–25 years since reintroduction, using 11 microsatellite loci. We detected low average allelic richness (3.92 alleles per locus), moderate levels of inbreeding (mean F_IS = 0.106), and multiple loci with significant heterozygote deficiencies. Effective population size estimates were small, ranging between 6 and 27 individuals depending on the estimator and the sample group. We also detected significant population structuring between the release sites (F_ST = 0.093 using the most recent sample). With small population size and limited to no gene flow, we predict the 2 Lower Peninsula marten populations will continue to diverge and potentially further lose genetic diversity. This study highlights the importance of long-term genetic monitoring of reintroduced populations.

The Pyrenean desman, a threatened, semiaquatic mammal, is considered a specialist predator feeding on aquatic benthic invertebrates. This categorization comes from visual identification of prey in scat or gut contents, often based on a limited number of samples and locations. We combined diet analyses using next-generation sequencing methods with an extensive survey to explore the summer diet of Pyrenean desmans across the French Pyrenees. This study thus provides an unprecedented level of detail on the trophic ecology of Pyrenean desmans. Our results revealed a diverse diet containing a high proportion of rare prey and substantial consumption of terrestrial prey, which suggests a more generalist diet than previously understood. Three diet groups were identified, with significant differences in prey composition. These differences were not related to geographic location, but rather to local environmental variables. The spatial variation in diet was likely induced by local abiotic parameters that affect prey availability or use of foraging habitats.