The family Aplodontiidae contains a single, monotypic extant genus, Aplodontia (mountain beaver), which was first described by Rafinesque in 1817. Phylogenetic studies have shown that it is the sister lineage to squirrels. Aplodontia rufa is endemic to the Pacific Northwest and ranges from central California to British Columbia, Canada. Currently, 7 described subspecies are recognized based on morphological taxonomic studies. In this study, mitochondrial and nuclear genes were sequenced to infer molecular phylogenies of A. rufa. One of the goals of this study was to use molecular data to test the current taxonomic hypothesis based on morphology. Another goal was to incorporate geographic information to elucidate distributions of major clades. Our results support the previously held subspecies designations based on morphological taxonomy, with 1 main exception: we determined that within A. rufa, the subspecies A. rufa rainieri and A. rufa rufa north of the Columbia River represent a single lineage and should revert to the name A. rufa olympica. Although we revised geographic boundaries for some groups (A. r. rufa, A. r. olympica, and A. r. pacifica), only the conservation status and management of A. r. olympica (previously 2 subspecies) in Canada may be affected. Our findings support the continued conservation efforts for the isolated and endangered lineages present in coastal California.

Thomomys sheldoni Bailey, 1915 is resurrected to recognize a genetically divergent clade of smooth-toothed pocket gophers that inhabits the high-elevation pine–oak forests of the Sierra Madre Occidental in Mexico from northwestern Chihuahua through Durango to western Zacatecas and northeastern Nayarit. Analyses of DNA sequences from 8 genes and genotype assignment tests for 21 allozyme loci establish this clade as a genetically isolated taxon within the T. umbrinus (sensu lato) complex. In addition to the T. sheldoni clade (diploid number of 2n = 76), 3 genetic clades within T. umbrinus (2n = 78) and 1 newly discovered clade (2n = 76) also were recovered in the phylogenetic analyses. Individuals of T. sheldoni and T. umbrinus occur in close proximity with no evidence of gene flow and an average cytochrome-b genetic divergence of 15.6%. Analyses of cranial morphology reveal that skulls of T. sheldoni are, on average, broader and longer than skulls of T. umbrinus and T. atrovarius. We recognize and provide synonymies for 2 subspecies within T. sheldoni based on a weak genetic and morphological break that is coincident with a large, north–south gap in its distribution: T. s. sheldoni in the southern Sierra Madre Occidental, which includes specimens from the type locality and populations in Durango, Zacatecas, and Nayarit; and T. s. chihuahuae in the northern Sierra Madre Occidental, which is known only from Chihuahua.

Thomomys sheldoni Bailey, 1915 es resucitada para reconocer un clado genéticamente divergente de tuzas de dientes lisos que habitan los bosques de altura de pino–encino de la Sierra Madre Occidental en México desde el noroeste de Chihuahua a través de Durango hasta el oeste de Zacatecas y el noreste de Nayarit. Análisis de secuencias de ADN de 8 genes y pruebas de asignación de 21 establecieron este clado como un taxon aislado genéticamente dentro del complejo T. umbrinus (sensu lato). Además del clado de T. sheldoni (número diploide 2n = 76), 3 clados genéticos dentro de T. umbrinus (2n = 78) y un clado recientemente descubierto (2n = 76) también fueron recuperados en los análisis filogenéticos. Los individuos de T. sheldoni y T. umbrinus se encontraron en proximidad cercana sin evidencia de flujo genético y una divergencia genética promedio de citocromo-b de 15.6%. Los análisis de morfología craneal revelaron que los cráneos de T. sheldoni son, en promedio, más anchos y más largos que los cráneos de T. umbrinus y de T. atrovarius. Reconocemos y proporcionamos para 2 subespecies dentro de T. sheldoni basados en una discontinuidad genética y morfológica que coinciden con un vacio grande norte–sur en su distribución: T. s. sheldoni en el sur de la Sierra Madre Occidental, que incluye especímenes de la localidad tipo y poblaciones en Durango, Zacatecas, y Nayarit; y T. s. chihuahuae en el norte de la Sierra Madre Occidental, la que se conoce solamente de Chihuahua.

The genetic structure of animal populations is influenced by, among other factors, dispersal and relatedness. Limited dispersal may cause local spatial restrictions in gene flow, which can have important management and conservation implications. We used radiotracking and genetic data to verify the existence of a spatial structure in relatedness within a resident native Eurasian otter (Lutra lutra) population at a fine spatio-temporal scale, and to better understand dispersal in this species. We obtained 51 individual genotypes from 65 biological samples collected from 2007 to 2010 in an area of southern Portugal of 1,125 km². In addition, we radiotracked 7 (2 female, 5 male) young otters. Relatedness estimates and geographic distances were inversely related in females, whereas the relationship was not significant in males. Among the tracked subadult animals, only males dispersed, covering on average a distance of 21 km (SD = 6 km; range: 11–25 km). Both genetic and field data therefore revealed male-biased dispersal and suggested female philopatry. The observed overall pattern of genetic structuring was up to a scale of 21 km, although no putative landscape barriers were present. These findings concur with the few others previously available, indicating how restricted contemporary gene flow may occur at fine spatiotemporal scales within continuous carnivore populations, and can therefore constitute a cryptic cause of risk (being driven by mechanisms not necessarily related to the movement capabilities of the species), adding complexity to the conservation and management of these animals.

Many temperate bat species deal with harsh winter conditions by hibernating. Brief periods of arousal from torpor occur at regular intervals throughout hibernation, although energetically costly. Factors that increase arousal frequency, such as the recently discovered white-nose syndrome (WNS), can thereby greatly decrease survival rates of overwintering bats. Evidence increasingly suggests that evaporative water loss (EWL) may be an important driver of arousal behavior in infected bats. We examined the role that EWL could play in torpor arousals and energy expenditures by developing an individual-based energetics model using EWL as the stimulus for arousal in populations of healthy and WNS-affected little brown myotis (Myotis lucifugus). Our model also examined how EWL could affect spatial distributions of healthy and infected bats within a cave throughout winter. We calculated mean torpor bout duration and survival of populations that inhabited 2 modeled caves typical of both northern and midrange hibernacula. In a northern cave, the mean torpor bout duration was 19.97 days ± 5.49 SD between arousals for healthy bats and 8.60 ± 2.11 days for WNS-affected bats, accompanied by survival rates of 0.80 ± 0.07 SD (healthy) and 0.04 ± 0.02 (infected). In a midrange cave, the mean torpor bout duration was 20.88 ± 6.22 days for healthy bats and 8.88 ± 2.47 for infected bats, and survival rates were 0.98 ± 0.02 (healthy) and 0.55 ± 0.05 (infected). When bats clustered, survival rates increased in both healthy and diseased populations; however, slight changes in relative humidity or the rate of EWL from infected skin counteracted these advantages. We show that, by causing an increase in arousal rates, EWL could play an important role in the pathology of WNS. Additionally, populations experiencing shorter southern winters could persist longer than their northern counterparts when faced with WNS, a fact that could be critical in maintaining viable populations for WNS-vulnerable species.

Motivated by conservation concerns, we assessed whether Sigmodon hispidus (hispid cotton rat) affects the realized niche of Peromyscus polionotus ammobates (Alabama beach mouse). After experimentally removing S. hispidus and accounting for spatial autocorrelation in our data, we found weak evidence for an increase in habitat use by P. p. ammobates at locations previously occupied by S. hispidus. This pattern is consistent with a niche-constriction hypothesis, and was not observed on 2 control grids where removals were not conducted. Our results suggest that removal of S. hispidus from habitat remnants immediately following catastrophic hurricanes ameliorates extinction risk of P. p. ammobates, but we also stress the inferential limitations of our data and the need for further investigation of competitive interactions between these species.

Arvicoline voles do not possess sophisticated mechanisms to tolerate prolonged fasting and can starve to death in less than 24 h. Two experiments were performed to determine if the common vole (Microtus arvalis) and the tundra vole (M. oeconomus) have thermoregulatory adaptations to enhance survival during food deprivation or in winter, and to reveal the possible presence of ultradian body temperature (T_b) rhythms. Laboratory-bred voles (n = 5–6 for both species) were equipped with intra-abdominal data loggers that registered T_b every 10 min and were subjected to 12-h fasting periods during photophase and scotophase. In addition, 10 animals of both species were placed in outdoor cages at natural ambient temperature (T_a) and their T_b was registered at 3-h intervals between October and June. Fasted voles did not enter torpor, but the average 24-h T_b decreased by 0.2–0.5°C in winter, yielding modest energy savings. The decrease in the T_b correlated with T_a but not photoperiod and could, thus, be interpreted as a response to cold. Tundra voles displayed short T_b rhythms of 3–8 h in the laboratory and their individual T_b fluctuations were synchronized. Arvicolines are suggested as promising models to study T_b rhythms in small mammals.

Caenolestids are a group of poorly known South American marsupials with a restricted distribution in páramo and subpáramo environments of the Andes from Colombia and western Venezuela to Bolivia (represented by the genera Caenolestes and Lestoros), and in Valdivian rain forest in southern Chile and Argentina where a single species (Rhyncholestes raphanurus) lives. The Incan shrew opossum, Lestoros inca, lives in mountains of southern Peru and extreme northwestern Bolivia. Despite being common in trapping surveys, little is known of its cranial and dental intraspecific variability, tooth eruption pattern, and dental anomalies. The objective of this work was to analyze the intraspecific variability of L. inca, which includes an anatomical description of the skull and dentition and analysis of clinal variation, tooth eruption patterns, and dental anomalies. The eruption pattern found in L. inca confirms the sequence P3 → m4 → p3 → M4 as the general pattern for living paucituberculatans. Missing teeth between the procumbent incisor and the 2nd lower premolar are the most common anomaly found (n = 14, 20% of the analyzed specimens). Comparisons with other living caenolestids, lack of clinal variation and significant differences between populations support L. inca as a separate, clearly distinct species. The information presented herein can be used in anatomical and paleontological studies dealing with caenolestids in particular and marsupials in general and also provides a sound basis for anatomical inferences made from fossils.

Los cenoléstidos comprenden un grupo poco conocido de marsupiales sudamericanos, cuya distribución se encuentra restringida a los ambientes de páramo y subpáramo en la Cordillera de los Andes desde Colombia y el oeste de Venezuela hasta Bolivia (representados por los géneros Caenolestes y Lestoros), y el bosque valdiviano del sur de Chile–Argentina donde habita Rhyncholestes raphanurus. Una de estas especies, el ratón runcho andino Lestoros inca, habita el páramo y subpáramo desde el sur del Perú al extremo norte de Bolivia. A pesar de ser común en trampeos, es poco lo que se conoce de esta especie en cuanto a variabilidad intraespecífica, patrón de erupción y anomalías dentarias, y otros rasgos anatómicos. El objetivo de este trabajo es analizar la variabilidad intraespecífica de L. inca, incluyendo una descripción anatómica del cráneo y dentición, analizar la variación clinal, patrones de erupción y anomalías dentarias. La falta de variación clinal o diferencias poblacionales significativas, brindó soporte al tratamiento de L. inca como una única especie. El patrón de erupción dentario encontrado en la especie (P3 → m4 → p3 → M4) confirma esta secuencia como el patrón generalizado para los paucituberculata vivientes. La falta de dientes, entre los incisivos procumbentes y el segundo premolar inferior, fueron la anomalía dentaria más comúnmente encontrada (20% de los ejemplares analizados). Comparaciones con cenoléstidos vivientes permiten considerar a L. inca como especie válida y claramente diferente del resto. La información aquí presentada podrá ser usada en estudios anatómicos y paleontológicos sobre cenoléstidos en particular y marsupiales en general, aportando, además, información anatómica que permitirá realizar inferencias en fósiles.

Bears from the family Ursidae are the only terrestrial mammals that go through gestation, parturition, and lactation during hibernation. This is the 1st study to examine the influence of reproductive status (i.e., nonpregnant, pseudopregnant, or pregnant) on body temperature and blood biochemical profiles in hibernating black bears. Pregnant bears appeared to have higher and more stable body temperatures (37–38°C) than nonpregnant ones (34–36°C) during pregnancy, which was followed by a rapid drop to levels comparable to those of nonpregnant individuals after parturition. In midpregnancy (i.e., January), pregnant bears had higher blood glucose and lower triglyceride concentrations than did nonpregnant ones, whereas blood concentrations of free fatty acids, glycerol, and ketone bodies did not differ significantly. Plasma urea, creatinine, and urea/creatinine levels were significantly lower in pregnant bears than in nonpregnant ones. Pseudopregnant bears showed similar changes in body temperature and blood profiles to pregnant ones, but blood glucose levels in January were significantly lower than those in pregnant bears. These results suggest that pregnant bears maintain homeothermic conditions and supply nutrients to the fetus by stimulating thermogenesis, gluconeogenesis, and urea recycling during hibernation. In addition, these physiological changes appear to be mainly caused by corpus luteum–derived factors (e.g., progesterone) but also were facilitated by placental factors.

Recently it was proposed that Centurio senex specializes on hard fruit because of its strong bite compared to other similar-sized frugivorous bats; however, this hypothesis has not been tested. We tested the hardness of 5 fruit species eaten by bats, including Sideroxylon capiri (Sapotaceae), here reported for the 1st time as part of the diet of C. senex. Results show that S. capiri is the hardest fruit of the species evaluated. This is the 1st evidence of C. senex eating hard fruit in the wild, which supports the theory of a skull adapted to eating hard fruit.

Recientemente se planteó que Centurio senex se especializa en frutos duros, ya que posee una fuerte mordida comparada con otros murciélagos frugívoros de talla similar; aunque no se ha probado. Pusimos a prueba la dureza de 5 especies de frutos consumidos por murciélagos, incluyendo Sideroxylon capiri (Sapotaceae), que reportamos por primera vez en la dieta de C. senex. Los resultados muestran que S. capiri es la especie con semilla más dura de las estudiadas. Esta es la primera evidencia del consumo de un fruto duro por C. senex en la naturaleza, lo cual apoya la teoría de un cráneo adaptado para el consumo de frutos duros.

Understanding the structure and evolution of ecological communities requires an examination of the factors that influence plant–animal mutualistic interactions. These interactions are affected by factors that are both extrinsic and intrinsic to the animals. We used a meta-analysis technique to examine such factors affecting the interactions between frugivorous animals and the plants they feed upon, using 3 common Neotropical frugivorous bat genera (Carollia, Sturnira, and Artibeus) as a model. We assessed whether latitude, altitude, ecoregion, and bat body size were related to the proportions of the most important plant genera in the diet of the bats. Our results show that extrinsic factors did not affect the proportion of Piper in the diet of Carollia. The proportion of Solanum in the diet of Sturnira was positively correlated with latitude and decreased in the mountain, moist, and bahia interior ecoregions. The proportion of Ficus and Cecropia in the diet of Artibeus decreased in high-elevation ecoregions and was negatively correlated with altitude. The large Artibeus species featured more Ficus and Cecropia in their diets compared to the small species of this genus. Our work demonstrates that mutualistic interaction between Neotropical bats and their core plant taxa is mediated by geographic and morphological factors.

Entender la estructura y evolución de las comunidades ecológicas requiere de la evaluación de los factores que influyen en las interacciones mutualistas entre plantas y animales. Estas interacciones son afectadas por factores extrínsecos e intrínsecos a los animales. Usamos técnicas meta-análiticas para evaluar los factores que afectan las interacciones entre animales frugívoros y las plantas que consumen, usando 3 de los géneros más comunes de murciélagos frugívoros Neotropicales (Carollia, Sturnira y Artibeus) como modelos. Evaluamos si la latitud, altitud, ecoregion y tamaño corporal estaban relacionados con la proporción de los géneros de plantas más importantes en la dieta de estos murciélagos. Nuestros resultados muestran que factores extrínsecos no intervienen en la proporción de Piper en la dieta de Carollia. La proporción de Solanum en la dieta de Sturnira se correlaciona positivamente con la latitud, y es menor en las ecoregiones húmedas, montañosas y bahía. La proporción de Ficus y Cecropia en la dieta de Artibeus disminuyó en las ecoregiones de mayor altitud y se correlacionó negativamente con la altitud. Las especies grandes de Artibeus incluyeron más Ficus y Cecropia en su dieta en comparación con las especies pequeñas de ese género. Nuestro trabajo demuestra que las relaciones mutualistas entre murciélagos Neotropicales y las plantas que comprenden el núcleo de su dieta es mediado por factores geográficos y morfológicos.

All 16 species of bats known to occur in western Colorado are found at Mesa Verde National Park (MVNP) in the southwestern United States. Since 1996, wildfires have burned more than 70% of MVNP (>15,000 ha), potentially altering food and roosting resources for bats. During the summers of 2006–2007, we investigated roost use by reproductive female western long-eared myotis (Myotis evotis). We located 33 bat roosts in rock crevices and 1 in a juniper snag. All but 2 of the roosts were in unburned habitat. Bats roosted alone or in small groups (≤3 individuals) and switched roosts frequently (1–7 roosts per bat, median = 1.5 roosts per bat, SE = 0.5 roosts per bat). We compared occupied roosts with randomly selected unoccupied crevices and used an information theoretic approach to determine which variables were most important in determining roost use at microhabitat and landscape scales. At the microhabitat scale, maternity roosts were higher above the ground and deeper than random, unoccupied rock crevices. At the landscape scale, roosts were closer to water and farther from burned habitat than random crevices, providing reproductive female M. evotis with the best opportunities to drink and forage for insects. Tree roosts are apparently not a vital resource for reproductive female M. evotis during the summer months at our study site, presumably because of the extensive availability of rock crevices. Understanding site-specific roosting behavior is important for proper management of bat populations because differences can exist between geographic regions, even among areas with similar plant communities.

LaVal's myotis (Myotis lavali) was recently described from the M. nigricans complex based on specimens from the Caatinga of northeastern Brazil. We present new distributional records for the Alto Chaco in Paraguay and for the Atlantic Forest of Brazil and Paraguay. These new records extend the distribution of the species approximately 2,000 km southwest and 400 km east, and document its co-occurrence with M. nigricans. Both results have taxonomic and ecological implications for M. lavali. Additionally, we provide comments on its natural history and reproduction.

Myotis lavali Moratelli et al., 2011, foi recentemente descrita a partir do complexo M. nigricans com base em amostras da Caatinga do nordeste do Brasil. Assim como muitas espécies recém-descritas, seus limites de distribuição e sua biologia ainda são pouco conhecidos. Fornecemos novos registros de distribuição de M. lavali para o Alto Chaco no Paraguai e para a Mata Atlântica no Brasil e Paraguai. Esses registros ampliam a distribuição da espécie na América do Sul em aproximadamente 2,000 km para o sudoeste e 400 km para o leste, revelando ainda a sintopia de M. lavali e M. nigricans no Alto Chaco paraguaio. Esses resultados têm implicações taxonômicas e ecológicas para M. lavali. Fornecemos ainda comentários sobre a história natural e reprodução dessa espécie na Caatinga do nordeste do Brasil.

Evidence has recently emerged that migratory birds are among the prey taken by 2 large insectivorous bat species in Europe and India. This raises the question of whether large aerial-hawking bats in other temperate regions also make use of this food resource. We analyzed the diet of the birdlike noctule (Nyctalus aviator), one of the largest aerial-hawking bats in Japan, and found bird remains in pellets collected in spring, autumn, and early winter, but not in summer. Predation on birds may be a widespread behavior among large, fast-flying insectivorous bats in temperate regions. Our results would provide new perspectives on the ecological and evolutionary interactions between bats and birds.

Virtually no information exists on the impacts of urban areas on island endemics. We examined the spatial distribution of island foxes (Urocyon littoralis clementae) associated with 3 small anthropogenically developed (i.e., “urban”) areas and nonurban areas on San Clemente Island, California. Annual home range size averaged 0.84 km² (n = 25, SE = 0.07). Our top model indicated that foxes that spent a greater proportion of time in urban areas had significantly smaller home ranges (β_PUrb = −0.009, 95% confidence interval [CI] = −0.0180–−0.0002). We found no effect of sex (β_Sex = 0.0135, 95% CI = −0.1430–0.1700), age (β_Age = 0.0502, 95% CI = −0.2730–0.3734), or whether or not a fox was considered a “road” fox (β_Road = −0.0063, 95% CI = −0.2638–0.2513) on home range size. We noted considerable overlap of home ranges of foxes that used urban areas. Foxes used urban areas a greater proportion of time during the night than during the day (t₂₄ = −6.13, P < 0.001); however, foxes did not spend a greater proportion of time in urban areas than expected overall (t₂₄ = −0.59, P = 0.560). We observed 13 of 25 (52%) foxes that utilized urban areas feeding on anthropogenic food resources. Foxes that used urban areas were heavier (n = 35, X̄ = 1.98, SE = 0.05) than foxes that did not use urban areas (n = 26, X̄ = 1.81, SE = 0.04; t₅₉ = −2.69, P = 0.009). Our study is the first to demonstrate the effects urban areas on islands may have on canid populations. Our findings were similar to those reported for urban canid populations on the mainland, suggesting that future conservation and management of carnivores on islands may benefit from strategies that have been successful with mainland species.

Little is known about demographic parameters of the southern flying squirrel (Glaucomys volans) or the factors influencing those parameters. We conducted capture–mark–recapture studies from January 2005 to September 2009, and from May to November 2010 to provide rigorous estimates of survival rates for the southern flying squirrel in a longleaf pine ecosystem. We also examined the effect of experimental food supplementation, prescribed fire, and mammalian predator exclusion on survival rates. Monthly apparent survival rates estimated from the 2 studies were 0.85 ± 0.01 SE and 0.81 ± 0.04, respectively. Prescribed fire positively influenced survival; survival increased for a period up to 9 months after burns. Evidence that food supplementation and mammalian predator exclusion substantially affected survival rates was weak. These results suggest that the southern flying squirrel population in our study site during the study period was not food-limited, and that mortality due to mammalian predators is insubstantial. However, we do not know if any reduction in mortality due to mammalian predator exclusion could have been compensated for by an increase in mortality due to predation by raptors and snakes.

Optimal timing of reproduction is critical to ensure adequate conditions for raising young. However, factors influencing timing of reproduction may differ between sexes. Harsh seasonal environments offer unique opportunities to link timing with resource availability and strategies of the sexes. The Arizona gray squirrel (Sciurus arizonensis) inhabits arid forests in which precipitation is highly seasonal and exceptionally variable; however, no data are available on diet or reproduction. We investigated annual variation in foraging and reproductive habits of Arizona gray squirrels to assess responses to extreme seasonality. We found that Arizona gray squirrels have a diverse diet, with consumption of major food items shifting between years. Reproduction also varies between years. Reproductive output was greater in 2008, with more females successfully reproducing and males remaining in reproductive condition for extended periods. Males shifted timing of reproductive behaviors in response to female receptivity, which tracked food availability. This shift likely reflects variation in food production due to precipitation, because rainfall varied greatly, with most years prior to and during our study recording below-average rainfall. With drought conditions and extreme rainfall events predicted to increase with climate change, understanding the relationship between climatic events, phenology of food production, and impacts on reproduction is critical when attempting to manage and conserve species.

Defining biologically relevant seasons is a critical issue in the interpretation of animal space-use studies. Moreover, understanding the effects of extrinsic (e.g., predation risk) and intrinsic (e.g., age and sex) factors on individual differences in seasonal transition dates will deepen our understanding of the mechanisms driving animal movement and potentially population dynamics. We used nonlinear modeling of movement rate over time using global positioning system–collared nonmigratory elk (Cervus elaphus manitobensis) and white-tailed deer (Odocoileus virginianus) in southern Manitoba, Canada, to derive species- and sex-specific seasonal transition dates. In addition, we used variables known to influence timing of migration in migratory populations to explain individual differences in seasonal transition dates. We found ecologically important differences in start and length of seasons between male and female elk and white-tailed deer. Individual differences in seasonal transition dates were large, and could be explained by a combination of intrinsic and extrinsic factors. Age-class of the individual animal and elevation influenced timing of winter, spring, and date of parturition, whereas predation risk from wolves (Canis lupus) influenced onset of spring, summer, and autumn. Our findings suggest that similar extrinsic and intrinsic factors can influence both large- (i.e., migratory) and small-scale movement patterns and can be used effectively to empirically define biologically relevant seasons for sympatric large herbivores.

We investigated predation by nonnative coyotes (Canis latrans) on endemic Olympic marmots (Marmota olympus) in Olympic National Park, Washington, in 2005 and 2006. Although nearly the entire marmot range is protected within the park, declines and local extirpations of the species have been documented. Through analyses of carnivore scat across the range of the Olympic marmot we determined the distribution and relative density of coyotes and characterized the extent to which coyotes and native carnivores preyed on marmots. We used mitochondrial DNA analysis of scats to determine carnivore species, and microsatellite markers for individual coyote identification. Scat analysis indicated that invasive coyotes are widespread and the numerically dominant carnivore on sampled trails within the Olympic highlands—71% (301 of 426) of all scats verified to species arose from coyote. Out of all carnivore scats collected, 11.6% (111 of 958) contained marmot remains. For 85% of the samples with marmots, coyotes were confirmed as the predator. The remainder arose from bobcat (13%) and cougar (2%). Coyotes were the predominant marmot predator across all months and in most regions of the park. Twelve out of 13 coyote individuals identified with genetic markers preyed on marmots. Marmots ranked 5th in frequency of coyote diet items, after snowshoe hares (Lepus americanus), mountain beavers (Aplodontia rufa), voles, and cervids. Scat analysis indicated that in the Olympic Mountains, the coyote as an invasive generalist predator is subsidized by abundant multiple prey, and appears to be the primary terrestrial predator on the endemic Olympic marmot. We conclude that predation by coyotes on marmots is widespread and substantial across the marmot's species range, and therefore likely driving observed marmot declines and extinctions.

Habitat specialization is considered one of the most important determinants of species vulnerability to habitat loss and fragmentation because it defines species dispersal ability and thus the degree of isolation of populations. Further, dispersal success of habitat-specialist species depends on the distance between fragments, which is conditioned on the total amount of habitat in the landscape. Here, we compared the influence of total habitat amount on dispersal success and abundance patterns of 2 habitat specialists and 1 generalist Atlantic Forest rodent. We investigated short-term population dynamics in a continuous forest landscape as well as in 6 small forest fragments located in 2 landscapes differing in the amount of forest cover (30% and 50%). Further, we analyzed the influence of fragment size on population density in the fragmented landscapes. Number of immigrants and abundance of both habitat-specialist species decreased remarkably in small patches of the 30% forest cover landscape compared to both more-forested landscapes, and both species showed a patch-area effect on density in this landscape. In contrast, the generalist species showed similar immigration rates in continuous forest and patches of the less-forested landscape, high temporal and spatial variability in abundance, and no patch-area effect in any of the landscapes. The results provide empirical support for the interaction between habitat specialization and habitat amount in determining the response of species to habitat loss, showing that the response of habitat specialists—in contrast to generalists—is governed by the landscape-wide amount of habitat.

Especialização de habitat é considerada uma dos mais importantes determinantes da vulnerabilidade das espécies à perda de habitat e fragmentação uma vez que define a capacidade de dispersão e consequentemente o grau de isolamento das populações. Além disso, a dispersão bem-sucedida de espécies especialistas de habitat depende da distância entre fragmentos, a qual é condicionada pela quantidade total de habitat na paisagem. Neste estudo comparamos a influencia da quantidade total de habitat no sucesso de dispersão e padrões de abundância de 2 espécies especialistas de habitat e 1 generalista de roedores da Mata Atlântica. Nós investigamos a dinâmica populacional em um estudo de curta duração em uma paisagem florestal contínua assim como em 6 pequenos fragmentos florestais localizados em paisagens que diferiam quanto à quantidade de cobertura florestal (30% e 50%). Adicionalmente, nós analisamos a influência do tamanho do fragmento na densidade populacional em paisagens fragmentadas. O número de imigrantes e abundância de ambas as espécies especialistas de habitat diminuíram consideravelmente em pequenos fragmentos da paisagem com 30% de cobertura florestal comparados com ambas as paisagens com maior cobertura florestal e ambas as espécies apresentaram um efeito patch-area em suas densidades nesta paisagem. Ao contrário, a espécie generalista apresentou taxas de imigração similares em florestas e fragmentos da paisagem com menor cobertura florestal, alta variabilidade temporal e espacial na abundância e nenhum efeito patch-area em nenhuma das paisagens. Os resultados fornecem apoio empírico para a interação entre a especialização de habitat e a quantidade de habitat na determinação da resposta das espécies à perda de habitat, mostrando que a resposta dos especialistas de habitat—ao contrário dos generalistas—é regulada pela quantidade de habitat numa escala mais ampla da paisagem.