The moose (Alces alces) is the most intensely managed game species in Fennoscandia; approximately one-third of the population, ca. 160,000 animals, is harvested annually. Despite the species' biological and socioeconomic importance, there are knowledge gaps with respect to its intraspecific diversity and genetic structure. Recent studies of moose in neighboring countries report 2 genetic groups in Finland, 3 in Norway with one of them suggested to be of ancient origin, and no indications of bottlenecks. To delineate the spatial genetic landscape of the Swedish moose, we used allozyme variability from over 20,000 georeferenced moose collected all over Sweden in combination with 12 microsatellites (n > 1,200) and mitochondrial DNA (mtDNA) sequences (n = 44). We combined individual-based and traditional statistical approaches with coalescence-based simulations. The results indicate a complex history with bottlenecks and recent expansions that is consistent with historical records. Swedish moose are separated into 2 major genetic groups, a northern and a southern one, where the southern group is further divided into 3 subgroups. The 2 main subpopulations are moderately differentiated (F_ST = 0.1; R_ST = 0.07) and separated by sharp genetic discontinuities occurring over a relatively narrow transition zone in central Sweden that coincides with a similar, previously reported transition zone in Norway. This differentiation is not reflected in mtDNA variation, where no significant divergence was observed. Together with the F_ST and R_ST similarities, this suggests that the 2 major subpopulations in Sweden reflect divergence shaped after the postglacial recolonization of Scandinavia. Neighborhood size assessments indicate that gene flow is relatively restricted with an estimated average dispersal distance of 3.5–11.1 km, and spatial autocorrelograms suggest that genetic similarity decreases almost linearly over space resulting in continuous genetic clines within major subgroups. Management areas largely coincide with genetic clusters, simplifying the integration of genetic information into management.

Bats rely heavily on echolocation for orientation and prey detection, hence acoustic signals that interfere with echo reception are problematic. When flying in the presence of other bats, some species adjust their echolocation to avoid frequency overlap with the calls of nearby conspecifics, known as a jamming avoidance response (JAR). One aspect of JAR that has not been thoroughly examined is how the spectral structure of the jamming signal impacts the jamming response. Our objective was to examine how the structural characteristics of an echolocation broadcast impact JAR in free-flying Brazilian free-tailed bats, Tadarida brasiliensis. We created 4 echolocation playbacks that differed only in call shape and frequency modulation. We examined the response of bats when flying in the presence of an unchanging broadcast (static stimulus) and when the playback signal was abruptly switched as the bat approached the speaker (dynamic stimulus). Results revealed that the bandwidth of the interfering signal impacted the strength of the observed JAR, while the presence and/or length of a terminal quasiconstant frequency section in the interfering signal did not. Our results agree with laboratory studies documenting JAR in the presence of white noise, as well as field studies demonstrating extensive variability in the echolocation calls of Brazilian free-tailed bats. We relate these results to previous findings on JAR, including a recent study documenting no JAR in a bat species and suggest further experiments to tease apart the physiological limitations of JAR. Overall, this study provides additional insight into the signal processing capabilities of bats and improves our understanding of how bats are able to orient using sound in a noisy world.

In contrast to birds, the contribution of body reserves to sustain reproductive activities of migratory bats has not being examined. We used C stable isotope analysis to track the importance of nutrients stored in body tissues of the lesser long-nosed bat (Leptonycteris yerbabuenae) in Central Mexico. The bat migrates seasonally between areas dominated by vegetation types with contrasting C stable isotope values: in spring–summer, it forages in cactus forests before commuting to dry and wet forests, where mating and births occur. We collected breath and whole blood from nonreproductive individuals in a cactus forest in spring–mid-summer, from mating individuals in an evergreen forest in mid-late summer, and from lactating females in winter in a tropical deciduous forest. We also collected hair and milk from lactating females and several tissues from naturally aborted fetus in late autumn. We tested the hypothesis that nutrient reserves accumulated in cactus forest contribute to the maintenance of adults when they commute to their reproductive grounds, to the construction of offspring tissues during pregnancy, and to the production of milk. The importance of energy stores accumulated in cactus forests to fuel oxidative metabolism was marginal for mating males but it was high for some mating females. Nutrient stores accumulated in cactus forests contributed to ∼50% of synthesis of fetus tissues but their contribution for milk production was negligible. Female lesser long-nosed bats can be described as capital-income breeders in relation to the development of offspring during gestation and as incomer breeders in relation to lactation.

Estimating population densities of small mammals (< 100 g) has typically been carried out by intensive livetrapping, but this technique may be stressful to animals and the effort required is considerable. Here, we used camera traps to detect small mammal presence and assessed if this provided a feasible alternative to livetrapping for density estimation. During 2010–2012, we used camera trapping in conjunction with mark-recapture livetrapping to estimate the density of northern red-backed voles (Myodes rutilus) and deer mice (Peromyscus maniculatus) in the boreal forest of Yukon, Canada. Densities for these 2 species ranged from 0.29 to 9.21 animals/ha and 0 to 5.90 animals/ha, respectively, over the course of this investigation. We determined if hit window—the length of time used to group consecutive videos together as single detections or “hits”—has an effect on the correlation between hit rate and population density. The relationship between hit rate and density was sensitive to hit window duration for Myodes with R² values ranging from 0.45 to 0.59, with a 90-min hit window generating the highest value. This relationship was not sensitive to hit window duration for Peromyscus, with R² values for the tested hit windows ranging from 0.81 to 0.84. Our results indicate that camera trapping may be a robust method for estimating density of small rodents in the boreal forest when the appropriate hit window duration is selected and that camera traps may be a useful tool for the study of small mammals in boreal forest habitat.

Knowing whether a species has been extirpated, or if it ever inhabited a specific geographic area, has direct importance for planning conservation activities. The taruka (Hippocamelus antisensis) is one of the largest Neotropical mammals; it is distributed in the central Andes, and there are published records of this species in Ecuador. Recently, missing museum specimens have cast doubts on the validity of these Ecuadorian records. Here, we examine whether the taruka ever inhabited Ecuador by analyzing multiple sources of information. Our approach consists of 3 components: 1) we surveyed archaeological collections and literature for any biological remains and cultural artifacts that may represent tarukas, 2) we searched mammal collections for specimens reported in publications, and 3) we generated ecological niche models (ENMs) of current and past climates to determine whether Ecuador offers suitable habitats for the taruka. Our results suggest that the taruka never inhabited Ecuador. We did not find any reliable supporting evidence in the form of specimens nor convincing literature reports. Furthermore, ENMs revealed that Ecuador has not supported suitable climates for the taruka. We suggest that published records of taruka in Ecuador may have been due to improper identifications of specimens. The methods used here may also prove useful in determining the presence of species that are either thought to be extinct, or suspected to be recently introduced into a new geographic area.

Human-altered landscapes are thought to reduce habitat quality for many forest-dependent species, but some omnivorous, opportunist species take advantage of human-related food sources, such as garbage and crops. It is unknown, however, whether anthropogenic foods can sustain populations in areas with relatively little natural habitat. We studied (2007–2012) a population of American black bears (Ursus americanus) at the western periphery of their range in Minnesota, in a landscape that was heavily impacted by agriculture (∼50%). We estimated the dietary contributions of corn and sunflowers (2–4% of the landscape) versus seasonally available natural foods (spring vegetation, ants, deer, fruit, and nuts) with stable isotope analyses (δ¹³C and δ¹⁵N) of 110 hair samples from 51 bears. We identified associations between diet and sex, age, body size and condition, reproductive status, space use, habitat connectivity, and natural food abundance. At the population level, adult males and adult females without cubs consumed considerable crops in fall (95% credible intervals: males = 19–46% of diet, females = 10–40%), but females with cubs and juvenile bears rarely consumed crops. Individual estimates of crop consumption were positively correlated with the proportion of GPS-collar locations in crop fields. Females, but not males, decreased crop consumption in years with high availability of natural fall foods. Further, the degree of crop consumption was more closely tied to local crop availability and landscape composition in females than in males. Weight and fat were positively correlated with crop use for both sexes, and males' use of crops also increased with their physical stature, suggesting that crops provided substantial caloric benefits to bears and that social dominance may have influenced foraging decisions. However, a large segment of this bear population (44% of sampled bear–years) made little use of crops, and crops accounted for more than half the fall diet for only 14% of the population. Whereas some bears clearly benefited from consumption of crops, we conclude that a population of bears could be sustained in this largely agricultural region even without crops as a food source.

Swamp rabbits (Sylvilagus aquaticus) in southern Illinois exist as a metapopulation due to fragmentation of the bottomland hardwood forests in which they live. This fragmentation makes their persistence in Illinois uncertain. We used population viability analysis (PVA) to estimate the probability of persistence of the swamp rabbit metapopulation in Illinois, using a habitat suitability map we created and life history parameters drawn from the literature. We varied the parameters used in our PVA from 50% to 150% of the initial value to compare their effects on extinction risk and to direct future management and research. We tested the effects of potential habitat loss and fragmentation by 1) removing patches individually and in groups from the analysis and by 2) adding 60, 120, and 180 m to the edge of all patches. We also tested the potential effect of dispersal corridors by increasing dispersal between connected patches. Under baseline conditions, the model suggests a 0% chance of quasiextinction (90% metapopulation decline) of swamp rabbits within 25 (or even 50) years. Changes in fecundity values and the effects of catastrophic flooding had the greatest effect on extinction risk, and changes in no other parameter yielded any appreciable impact. Removing the largest patches from the population increased the 25-year risk of extinction to 4%, whereas any other modifications to the habitat did not change the extinction risk. We suggest that managers focus on sustaining habitat quality, particularly upland habitats adjacent to occupied bottomland hardwood forests to improve the likelihood of swamp rabbit persistence in Illinois.

Northern (Glaucomys sabrinus) and southern (G. volans) flying squirrels have glucocorticoid (GC; stress hormone) levels higher than most vertebrates but virtually no binding capacity for these GCs via the carrier protein, corticosteroid-binding globulin. Thus, their total GCs are essentially all free and biologically active. However, the GC estimates come from blood samples taken after squirrels had been in live traps, and thus in a stress-induced state. Obtaining baseline values for physiological variables is valuable for assessing the response of vertebrates to stressors in their environment. We compared baseline plasma total cortisol levels (within 3 min of capture) to stress-induced levels (after 30 min of trap restraint) in both flying squirrel species. We recorded baseline cortisol levels that were some of the highest ever reported for mammals, indicating their stress axes operate at a higher set point than most other species. As part of the stress response, we also measured 4 indices in addition to cortisol. Total cortisol and free fatty acids increased in both species, as predicted. In contrast with our predictions, blood glucose and neutrophil/lymphocyte ratio showed no overall change, and hematocrit decreased significantly. New World flying squirrels therefore appear to have a stress response that differs from many other mammals. The selective forces driving the physiology of these animals remain elusive, but this lineage may provide an interesting comparative system for the study of stress axis function and its evolution among vertebrates.

Salt drive is a seasonal phenomenon common to several classes of wild herbivores. Coincident with shifts of nutrient quality when plants resume growth in the spring, sodium is secondarily lost as surplus potassium is excreted. The beaver (Castor canadensis) is an herbivore whose dietary niche closely follows that of other herbivores that are subject to salt drive, but no published studies to date have assessed the likelihood of its occurrence. To quantify if beavers experience seasonal salt drive, we designed a field experiment to measure the foraging responses of beavers to sodium-enhanced foods. We used sodium-treated (salted) and control (no salt) food items (aspen [Populus tremuloides] and pine [Pinus spp.] sticks) during monthly feeding trials at beaver-occupied wetlands. If conventional ontogeny of salt drive was operant, we expected to observe greater utility of sodium-treated food items by beavers in May and June. Further, if water lilies (Nymphaea spp. and Nuphar spp.) supply beavers with sodium to meet dietary requirements as is widely speculated, we expected foraging responses to sodium-treated food items at wetlands where water lilies were absent to be greater than at wetlands where water lily was present. Aspen was selected by beavers in significantly greater amounts than pine. There was no difference between the mean percent consumed of salted and control aspen sticks by beavers at lily and non-lily wetlands, and no differences in temporal consumption associated with salted or control pine sticks at either wetland type. Salted pine was consumed in greater amounts than unsalted pine. We propose that the gastrointestinal or renal physiology of beavers may preclude solute loss, thereby preventing salt drive.

Resource selection by animals influences individual fitness, the abundance of local populations, and the distribution of species. Further, the degree to which individuals select particular resources can be altered by numerous factors including competition, predation, and both natural- and human-induced environmental change. Understanding the influence of such factors on the way animals use resources can guide species conservation and management in changing environments. In this study, we investigated the effects of a prescribed fire on small-scale (microhabitat) resource selection, abundance, body condition, and movement pathways of a native Australian rodent, the bush rat (Rattus fuscipes). Using a before-after, control-impact design, we gathered data from 60 individuals fitted with spool and line tracking devices. In unburnt forest, selection of resources by bush rats was positively related to rushes, logs and complex habitat, and negatively related to ferns and litter. Fire caused selection for spreading grass, rushes, and complex habitat to increase relative to an unburnt control location. At the burnt location after the fire, rats selected patches of unburnt vegetation, and no rats were caught at a trapping site where most of the understory had been burnt. The fire also reduced bush rat abundance and body condition and caused movement pathways to become more convoluted. After the fire, some individuals moved through burnt areas but the majority of movements occurred within unburnt patches. The effects of fire on bush rat resource selection, movement, body condition, and abundance were likely driven by several linked factors including limited access to shelter and food due to the loss of understory vegetation and heightened levels of perceived predation risk. Our findings suggest the influence of prescribed fire on small mammals will depend on the resulting mosaic of burnt and unburnt patches and how well this corresponds to the resource requirements of particular species.

An understanding of a species' diet is required to make sound conservation and management decisions. Traditionally, morphological analyses of undigested hard parts from food items remaining in scats have been used to assess diets. More recently, molecular analyses of scats have been used to identify plant and prey species' DNA, but no studies have compared morphological and molecular diet analyses for large, terrestrial carnivores. We used molecular tools to determine the percentage of black bear and coyote scats that contained 3 common prey species (caribou, moose, and snowshoe hares) in Newfoundland and compared the results to a traditional morphological analysis. We found that a ranking of relative prey frequencies was consistent between the 2 methods, but molecular methods tended to detect prey species in a greater percentage of scats for all prey species. However, there were individual scats in which a prey species was detected by morphological methods only, and we provide evidence that molecular methods could result in false negatives if prey DNA is not uniformly distributed throughout a scat or as a result of PCR inconsistency. We also found that the per sample cost comparison between morphological and molecular analyses was dependent upon whether or not a molecular test was needed to identify scats to the predator species, the cost of developing molecular methods, and the number of samples being processed. We recommend that controlled feeding studies be performed to validate molecular methods and investigate the utility of molecular techniques to estimate the proportions of food items consumed.

Population fluctuations are the result of the combined action of endogenous (feedback structure) and exogenous factors (large- and local-scale climate variables). In this paper, we used a 13-year time series to identify the feedback structure in a population of the brown 4-eyed opossum Metachirus nudicaudatus and to test a hypothesis on the effects of El Niño Southern Oscillation and rainfall using Royama's theoretical framework. Metachirus nudicaudatus was regulated by a strong 1st-order negative feedback, with intraspecific competition for food resources as the probable factor governing the endogenous system. Contrary to our expectations, El Niño did not explain the marsupial dynamics better than 1-year lagged rainfall, that may operate in 2 different manners: as a nonlinear perturbation effect influencing the strength of density dependence (intraspecific competition and intraguild predation) or as a lateral perturbation effect influencing the carrying capacity of the environment.

For bears, numerous associations between biotic and abiotic factors have been reported to correlate with the timing of den entry and emergence; however, an analysis showing which factors influence the timing of den entry and emergence has not been performed enough. In this study, a generalized linear mixed model was generated using 66 entry dates for 26 females and 40 entry dates for 26 males, and 56 emergence dates for 26 females and 25 emergence dates for 18 males between 1999 and 2012. Regarding factors for den entry, the average temperature in November and mast production of Mongolian oaks were significant for both males and females. For the date of den emergence, the average temperature in March affected strongly. For males, good mast production of Mongolian oaks in the previous year was found to be associated with early den emergence. For females, the presence of newborns had a significant influence on their den entry and emergence. This study indicated that denning behavior appears to be regulated by several abiotic and biotic factors and regulation factors are sex specific.

We compared patterns of core body temperature (T_b) change, including inter-individual synchrony, in 2 free-living arctic hibernators that differ in size and sociality, the Alaska marmot (Marmota broweri) and the arctic ground squirrel (Urocitellus parryii). We report overwinter T_b changes from 3 to 4 marmots from the same hibernaculum in each of 3 years and from 7 ground squirrels that hibernated at 2 nearby burrow sites in 1 year. Very close synchrony in the timing of torpor and arousal cycles in Alaska marmots indicates social hibernation and thermoregulation, while lack of synchrony in arctic ground squirrels further confirms solitary hibernation. The mean duration between the first and last marmot measured within the group to initiate an arousal was 3.7 ± 2.5 h and to recool to 30°C during torpor entrance was 5.7 ± 3.7 h. The minimum T_b recorded in marmots was 0.6°C and in ground squirrels was -2.0°C. Marmots entering torpor displayed an interrupted pattern of T_b change defined by 2 distinct rates of cooling, early and late during entry, that differed by 21-fold. Ground squirrels cooled in a continuous pattern, initially 3-fold slower than marmots during rapid cooling but 4-fold faster during slow cooling. Both species must minimize energy expenditure to survive long arctic winters; our results suggest that Alaska marmots do this through social thermoregulation, while arctic ground squirrels decrease T_b below freezing to minimize the difference between body and ambient temperatures.

Roads affect wildlife in many ways, with roadkills probably the most conspicuous. In Mexico, there is increasing interest in this effect on wildlife. Together, richness and abundance can be used to predict trends for wild populations, and our study analyzes these variables for rodents killed by vehicles and trapped along a 14-km stretch of an A-type roadway in Veracruz, Mexico, from June 2010 to March 2011. Our study area had 2 habitat types: shrubland on lava flow and grassland. Over the course of the study, we monitored this stretch of highway by car for 34 days of effective sampling. When we spotted an animal, we stopped to record it. In the surrounding habitats, traps were set for 28 nights with 36 traps per habitat (total effort: 1,008 trap nights). The richness of trapped rodents was 9 species and for roadkills it was 14. The 2 sampling methods shared 7 species. The differential contribution was 2 species in trapping and 7 in roadkills. The complementarity index was 99.36. For both methods, the dominant species were mice of the genus Peromyscus (Peromyscus difficilis for the shrubland and Peromyscus maniculatus for the grassland). Roadkills were a very representative source of information for the purposes of biological inventory and even for identifying the dominance pattern in species composition, thus offered a useful method for supplementing information obtained from traditional trapping. Highways threaten biodiversity mainly because they fragment habitats and further expose other habitats to impact by humans, but also because of their potential as a direct mortality factor. Careful interpretation of roadkill data can be a useful tool whose value for biologists has not yet been fully appreciated.

Evaluation of the fundamental niche under controlled conditions can provide relevant information about physiological, evolutionary, and ecological aspects of an organism, without the influence of external factors. We investigated how allometric, phylogenetic, and adaptive components contribute to arboreal walking performance by 7 sigmodontine rodents of the Brazilian savanna (Cerrado). We captured the rodents in the field and evaluated their performances by measuring stride length, stride frequency, and velocity on 5 horizontal supports: flat board and cylindrical plastic tubes with diameters of 5.0, 3.5, 2.5, and 2.0 cm. Arboreal rodents exhibited higher velocities than terrestrial species by increasing stride frequency and decreasing stride length on supports with smaller diameters. However, terrestrial species decreased both stride frequency and stride length or tended to maintain stride length and vary stride frequency. Our results reveal a strong association between realized arboreal walking performances (as inferred by proportion of arboreal captures) and stride length and frequency. However, performance metrics were weakly related to body mass and exhibited no phylogenetic effects. Our results are consistent with the hypothesis that dynamically stable arboreal walking is facilitated by increased velocity. Arboreal walking performance is likely related to ecological factors rather than phylogenetic constraints.

Various cutaneous glands have been identified as sources of chemical signals that mediate many social interactions in deer. The pampas deer, a species considered near threatened, inhabits grasslands of South America. In this work, the chemical compositions from preorbital, tarsal, and digital gland secretions of semi-captive males were characterized by gas chromatography-mass spectrometry. The composition of these secretions showed a great complexity, with 143 compounds detected. Hierarchical cluster and principal component analyses show no relation to age or secretion type. Five compound classes (esters, fatty alcohols, lactones, sterols, and sulphuretted) differed with glands. The chemical complexity of the secretions, the individual differences in the whole compounds composition, and the absence of clustering by age lead to the hypothesis that these secretions may encode at once for individual information and for social status information.

The Trivers–Willard hypothesis (TWH) predicts that in a polygynous mating system, when fitness of male offspring is more variable than fitness of female offspring, mothers should invest more heavily in the sex with the highest marginal fitness returns. Females in good condition or high social rank should benefit by investing in sons, and females in poor condition or low social rank should benefit by investing in daughters. Many empirical studies have tested different aspects of the TWH, but no study has tested the assumptions and predictions in a single polygynous species using measures of maternal condition and maternal social rank, while accounting for random effects that can also influence offspring growth and survival. Here, we followed individuals in an isolated population of pronghorn on the National Bison Range, Montana, over multiple generations and tested the assumptions and predictions of the TWH. Pronghorn females who were in good condition or were socially dominant weaned larger fawns that were in better condition, but this advantage did not increase male fawn survival or reproductive success. We detected a slight bias in birth sex ratios according to maternal social rank, but overall we did not detect any adaptive benefit to mothers adopting a sex-biased investment strategy.

DNA sequences from the mitochondrial cytochrome-b gene were obtained from 41 specimens of Neotoma albigula from the southwestern United States and northwestern México. Phylogenetic analyses depicted that samples of N. a. melanura from southern Sonora and northern Sinaloa formed a clade separate from representatives of the other sampled subspecies of N. albigula (albigula, laplataensis, mearnsi, seri, sheldoni, and venusta). Genetic distances detected between these clades (7.41%) approached divergence levels reported for other sister species of woodrats and indicated that N. a. melanura is presumably a cryptic and genetically differentiated species relative to N. albigula. Analyses of DNA sequences from a nuclear gene (intron 2 of the alcohol dehydrogenase gene, Adh 1-I2) indicated that samples of N. a. melanura formed a separate, monophyletic clade relative to the remainder of N. albigula. Further, habitat, geographic distinctions, and morphological differences were apparent between members of the 2 clades. Together, those data support the elevation of N. a. melanura to species status.

Forested wetlands are in decline, as are many species that are obligate residents. Big Cypress fox squirrels (BCFS; Sciurus niger avicennia) are a threatened endemic to wet pine and cypress forests in southwestern Florida. The region is characterized by development resulting in habitat loss, habitat fragmentation, and hydrological change that influence the quality of these wet forests. Through radiotelemetry and field observations, we examined the ecology and habitat use of BCFS in a natural cypress dome-pine forest mosaic. BCFS selected cypress domes for food and nests throughout the year. Cypress dome habitats were the only habitat type to be used more than available; however, the availability of nearby pine forest was also important. Home ranges were large relative to other tree squirrels, with male home ranges exceeding female ranges. Males overlapped more females than males, while sharing similar food preferences and use patterns with females, suggesting that the sexual dimorphism in home range size is related to mate searching. Roads and oil extraction pads were used less frequently than expected and were incorporated into home ranges less than randomly generated features. The importance of cypress domes within the wet forests and grasslands of Big Cypress National Preserve demonstrates the value of maintaining this delicate mosaic.

The ringtail (Bassariscus astutus) is a widely distributed small carnivorous mammal (Procyonidae) in Mexico and the southwestern United States. As in other procyonids, the ringtail is capable of rotating its hind foot to allow headfirst descent of vertical substrates. The osteological correlates of this process, termed hind foot reversal, are well documented, but potential myological correlates have never been investigated. We present the 1st detailed study of the muscular anatomy of the hind limb of B. astutus, including the 1st muscle maps of the pelvis and pes of any procyonid. Comparison of the hind limb myology of the ringtail with other arctoid carnivorans, including taxa incapable of hind foot reversal, indicates that the muscles responsible for the action of reversal do not differ significantly between nonreversing forms and taxa capable of partial or full reversal. This suggests that specific myological adaptations are not necessary to achieve hind foot reversal. However, increased development of the digital flexors, which maintain a grip while body mass is supported by the hind limb, may characterize taxa that make use of reversed postures. The hind limb myology of members of Procyonidae does not strongly support either morphological or molecular hypotheses of relationship, in part because relatively few differences among members of the family can be documented.

The white-tailed deer (Odocoileus virginianus) is an important, sustainable-use species in Mexico; 14 subspecies are widely distributed throughout the Mexican territory. The criteria for classifying subspecies is based on morphological features throughout their geographical range; however, the complete genetic characterization of Mexican subspecies has not been established. The objective of the present work is to report the mitogenomes of 9 of the 14 white-tailed deer subspecies from Mexico and identify their unique variations. Typical vertebrate mitogenomes structures (i.e., 13 protein-coding genes, 22 tRNA genes, and 2 rRNA genes) were observed in the studied subspecies. The greatest numbers of polymorphisms were identified in the D-loop, ND4, ND5, CYTB/ COI, ATP6, and COIII genes. Phylogenetic analyses showed that the southern and southeastern subspecies were distinct from the central and northern subspecies; the greatest genetic distances were also observed between these 2 groups. These subspecies-specific variations could be useful for designing a strategy to genetically characterize the studied subspecies.

Roost selection in mammals is an important selective pressure, and many animals find shelter in previously existing structures. Furthermore, the microclimate of roosts is a crucial element for bat survival, and modified leaves are used for roosting (“tents”) by 22 species of bats. Our objective was to determine whether the inverted boat tents used by Ectophylla alba and pinnate tents used by Uroderma bilobatum provide energetic benefits. We measured the ambient temperature under modified and unmodified leaves (UMLs) of Heliconia imbricata and Cocos nucifera. We also measured temperature with (simulated bat presence) and without a heat source, and finally we measured bat energy expenditure at different temperatures. Our results show that when a heat source is present tents conserve heat better than a UML. The energy expenditure of E. alba and U. bilobatum increased up to 55% and 48%, respectively, with a decrease of temperature from 25°C to 20°C. We concluded that since the temperature at our study site drops below 25°C every night and remains that way until mid-morning, using a “tent” that maintains a temperature higher than ambient temperature, or close to 25°C degrees, provides an energetic advantage.

Fragment size, isolation, and matrix properties have received considerable attention as predictors of species richness, abundance, and composition in habitat patches. However, measurements of habitat attributes or habitat quality are more directly related to the proximate effects of habitat fragmentation and may be more determinant of assemblages than traditional explanatory variables at local scales. We determine how habitat structure in fragments—a measure of habitat quality—compares to fragment size, isolation, and matrix properties as determinants of richness, abundance, and composition of non-volant small mammals in a fragmented landscape of Atlantic Forest. Small mammals were surveyed once in 25 fragments in the Macacu River watershed, Rio de Janeiro, Brazil, from 1999 to 2001 and 2005 to 2009. A total of 83 candidate models were formulated and compared by Akaike Information Criteria. Habitat structure was one of the main determinants of small mammal assemblages in fragments, as important as fragment isolation for species composition and climatic season for species richness. Rodents were more abundant in fragments with increased overstory and understory vegetation density and more fallen logs. The contrary pattern was found for overall species richness and for species of terrestrial habit, which were more abundant in fragments with more open forest: decreased overstory and understory vegetation density and less fallen logs. Habitat quality in fragments may be a more important determinant of assemblages of small mammals and other vertebrates than previously considered in landscape and land use studies.

Accounting for low and heterogeneous detection probabilities in large mammal capture–recapture sampling designs is a persistent challenge. Our objective was to improve understanding of ecological and biological factors driving detection using multiple data sources from an American black bear (Ursus americanus) DNA hair trap study in south-central Missouri. We used Global Positioning System telemetry and remote camera data to examine how a bear's distance to traps, probability of space use, sex-specific behavior, and temporal sampling frame affect detection probability and number of hair samples collected at hair traps. Regression analysis suggested that bear distance to nearest hair trap was the best predictor of detection probability and indicated that detection probability at encounter was 0.15 and declined to < 0.05 at nearest distances > 330 m from hair traps. From remote camera data, number of hair samples increased with number of visits, but the proportion of hair samples from known visits declined 39% from early June to early August. Bears appeared attracted to lured hair traps from close distances and we recommend a hair trap density of 1 trap/2.6 km² with spatial coverage that encompasses potentially large male home ranges. We recommend sampling during the late spring and early summer molting period to increase hair deposition rates.

Fishers in the western United States were recently proposed for listing under the U.S. Endangered Species Act because of concerns for loss of suitable habitat and evidence of a diversity of mortality risks that reduce survival. One of 2 remnant populations of fishers in California is in the southern Sierra Nevada region, where we studied them at 2 research sites in the Sierra National Forest. Our objectives were to evaluate whether survival was lower for male fishers and dispersal-aged individuals or if survival varied seasonally. We captured and monitored 232 radiocollared fishers from March 2007 to March 2014 and used model analyses to identify important predictors of survival. Fifty-two percent (n = 120) of the radiocollared fishers died, and survival varied by sex and season, but not by age or between study sites. There was no evidence that dispersal-aged fishers experienced lower survival than older fishers. Annual survival trended lower for male (0.62 [95% CI 0.54–0.70]) compared to female fishers (0.72 [95% CI 0.67–0.78]), was lowest in the spring to mid-summer season (0.83 [95% CI 0.78–0.87]), and highest in late fall and winter (0.92 [95% CI 0.89–0.94]). Lower survival among male fishers appeared linked to males moving over large areas to locate mates, while lower survival for females was potentially related to high energetic cost of reproduction. It was possible but unknown if lower survival among all fishers in spring was linked to secondary exposure to toxicants dispersed around illicit marijuana grow sites. Six-month survival of juvenile fishers was 0.85 for females and 0.79 for males, but lower at 0.62 for females and 0.57 for males when adjusted for deaths before late September. Annual survival among adult female fishers was 20% lower than 0.90, a value that prior modeling suggested was required for population expansion in the overall southern Sierra Nevada. Survival data from our study imply a greater challenge for maintaining self-sustaining fisher populations in the southern Sierra Nevada region, and resource managers are working to mitigate several of the human-associated factors that limit population growth.

Specimens and associated data in natural history collections (NHCs) foster substantial scientific progress. In this paper, we explore recent contributions of NHCs to the study of systematics and biogeography, genomics, morphology, stable isotope ecology, and parasites and pathogens of mammals. To begin to assess the magnitude and scope of these contributions, we analyzed publications in the Journal of Mammalogy over the last decade, as well as recent research supported by a single university mammal collection (Museum of Southwestern Biology, Division of Mammals). Using these datasets, we also identify weak links that may be hindering the development of crucial NHC infrastructure. Maintaining the vitality and growth of this foundation of mammalogy depends on broader engagement and support from across the scientific community and is both an ethical and scientific imperative given the rapidly changing environmental conditions on our planet.

Red foxes were absent or rare in the southeastern United States until the late 1800s. Their origins potentially include natural population increase/expansion, translocations from Europe, and, eventually, 20th century fur farming. Previous studies have found no European haplotypes in North America, but few samples were sourced from the Atlantic coastal plain, closer to the source of putative introductions. Through analysis of mitochondrial DNA in 584 red foxes from this region, we identified indigenous haplotypes in ≥ 35% of foxes, 1 of 2 European haplotypes in 17% of foxes and fur farm haplotypes in ≥ 13% of foxes; another 35% of foxes had haplotypes potentially indigenous or native. In contrast, only 3 of 135 (2%) male foxes carried a single European Y chromosome haplotype. Most European and fur farm haplotypes were found near the densely human-populated coastal plain and Hudson River lowlands; most red foxes of the Appalachians and Piedmont had native eastern haplotypes. Our findings suggest that the more remote, upland populations primarily reflect indigenous red fox matrilines, whereas urban-associated populations in and around the mid-Atlantic coastal plain and Hudson lowlands reflect an admixture of native and nonnative maternal sources. Autosomal markers are needed to further elucidate the extent of European and fur farm introgression in the Appalachians and further west.

The dusky dolphin Lagenorhynchus obscurus occurs in the Southern Hemisphere, where it is restricted to coastal temperate areas. This study aimed to characterize the feeding ecology of dusky dolphins inhabiting northern and central Patagonia by using δ¹³C and δ¹⁵N stable isotope ratios in skin samples. We searched for evidence of geographical and seasonal variation in diet and we explored dietary differences between sexes. Significant differences in the stable isotope ratios of dusky dolphins were found among the 4 gulfs under study. Skin samples from Golfo San Matías and Golfo San Jorge were ¹³C-enriched and ¹⁵N-depleted compared to those from Golfo Nuevo and Golfo San José. There was no seasonality in the diet at Golfo Nuevo, and no differences in the diet between sexes in any gulf. Furthermore, Bayesian ellipses of males and females were similar in size and the overlap was mostly symmetrical in Golfo San José and Golfo San Jorge, while in the Golfo San Matías and Golfo Nuevo, females had wider ranges of δ¹⁵N, suggesting the exploitation of a wider trophic niche. Finally, pelagic fishes and demersal pelagic squids were identified as the main prey for this species of dolphin, although the proportion of each prey varied regionally.