Guidelines for use of wild mammal species in research are updated from Sikes et al. (2011). These guidelines cover current professional techniques and regulations involving the use of mammals in research and teaching; they also incorporate new resources, procedural summaries, and reporting requirements. Included are details on capturing, marking, housing, and humanely killing wild mammals. It is recommended that Institutional Animal Care and Use Committees (IACUCs), regulatory agencies, and investigators use these guidelines as a resource for protocols involving wild mammals, whether studied in the field or in captivity. These guidelines were prepared and approved by the American Society of Mammalogists (ASM), in consultation with professional veterinarians experienced in wildlife research and IACUCs, whose collective expertise provides a broad and comprehensive understanding of the biology of nondomesticated mammals. The current version of these guidelines and any subsequent modifications are available online on the Animal Care and Use Committee page of the ASM website ( http://mammalogy.org/uploads/committee_files/CurrentGuidelines.pdf). Additional resources pertaining to the use of wild animals in research are available at:  http://www.mammalsociety.org/committees/animal-care-and-use#tab3.

Allonursing, the nursing of nonoffspring, is a form of cooperative breeding. To test the kin-selection allonursing hypothesis, we selected 2 experimental groups, based on genetic relatedness, to assess whether evidence of individual and daily patterns of kin-related allonursing would emerge. Each group consisted of 8 mother– offspring pairs, and observers monitored each group over 5 weeks, starting when the offspring were between 8 and 23 days old. One group of 8 mothers was selected to be closely related, and the other group of 8 mothers was selected to be distantly related, based on genetic relatedness. We recorded 1,652 solicitations, of which 869 were nursing bouts and 161 were allonursing bouts. All mothers nursed their own offspring, and 15 of the 16 mothers allonursed. In both groups, 7 of the 8 offspring were allonursed. The offspring of closely related mothers were allonursed more often than the offspring of distantly related mothers, and we found evidence for this pattern at the individual level and daily over 5 weeks. Our results supported the kin-selection hypothesis but not the compensation hypothesis. We suggest that allonursing may have provided adaptive and nutritional benefits related to kin selection, and offspring from the closely related group may have gained more nutritional benefits and more mass than offspring from the distantly related group. We presented evidence that allonursing contributions detected can depend upon the research design. Furthermore, we suggest that the indirect fitness benefits of alloparental care may have been overestimated, and that kin selection alone is not sufficient to explain alloparental care in cooperative breeding social systems.

Myotis planiceps (flat-headed myotis) was known from only 3 specimens collected from 3 different sites in the states of Coahuila, Nuevo Leon, and Zacatecas, Mexico, since its discovery in 1952. The last specimen was collected in 1970; in 1996, after efforts to recollect samples failed, the species was listed as extinct. However, an expedition in 2004 rediscovered a population of M. planiceps and the species was relisted as endangered. Members of this species have a conspicuously flattened cranium, speculated to be an adaptation for living in crevices; however, little is known about its biology and, to date, little work has been done to clarify its phylogenetic relationships with other members of the genus Myotis. In order to elucidate the placement of M. planiceps within the Myotis phylogeny, we sequenced 1,140 base pairs (bps) of the mitochondrial cytochrome-b gene (Cytb) and 1,148 bps of the nuclear Recombination Activating Gene 2 (rag2) from 7 samples collected from 4 different localities in north-central Mexico. We found 4 different haplotypes for Cytb that differed by 0.14% mean sequence divergence and 13 alleles for rag2 within samples of M. planiceps. We performed maximum parsimony, maximum likelihood, and Bayesian analyses to compare these samples with Myotis sequences available on GenBank. All reconstructions placed M. planiceps within a strongly supported clade including several Nearctic Myotis (M. volans, M. sodalis, M. lucifugus, M. thysanodes, and M. evotis). M. planiceps forms a paraphyletic relationship with M. volans, despite significant differences in skull morphology between the 2 species.

Myotis planiceps (Myotis de cabeza plana) era conocido a partir de sólo 3 especímenes recolectados en 3 sitios diferentes en los estados de Coahuila, Nuevo León y Zacatecas, México, desde su descubrimiento en 1952. El último ejemplar se colectó en 1970 y la especie fue declarada extinta en 1996, después de que fallaron los esfuerzos para recolectar más muestras. Sin embargo, durante una expedición en 2004 se redescubrió una población de M. planiceps y la especie fue recategorizada bajo Peligro de Extinción. Los miembros de esta especie tienen un cráneo visiblemente aplanado, rasgo que se especula sería una adaptación para vivir en las grietas; sin embargo, se sabe poco sobre su biología y, hasta la fecha, poco se ha hecho para aclarar sus relaciones filogenéticas con otros miembros del género Myotis. Con el fin de dilucidar la posición de M. planiceps dentro de la filogenia de Myotis, secuenciamos 1140 pb del gen mitocondrial citocromo-b (Cytb) y 1148 pb del gen nuclear Activador de la Recombinación 2 (rag2) a partir de 7 muestras recolectadas de 4 localidades diferentes en la región nortecentral de México. Encontramos 4 haplotípos diferentes para Cytb que presentaron un promedio de divergencia de secuencia de 0.14%, y 13 alelos del gen rag2 en muestras de M. planiceps. Realizamos análisis de máxima parsimonia, máxima verosimilitud y Bayesiano para comparar estas muestras con otras secuencias de Myotis disponibles en GenBank. Todas las reconstrucciones ubican a M. planiceps dentro de un clado bien soportado que incluye también a varios Myotis del Neártico (M. volans, M. sodalis, M. lucifugus, M. thysanodes, y M. evotis). M. planiceps forma una relación parafilética con M. volans, a pesar de diferencias significativas en la morfología del cráneo entre estas especies.

Defaunation is a key ecological issue that has only recently been given sufficient attention. As predicted, evidence so far indicates loss of larger species followed by medium-sized species, leading to cascading effects that propagate throughout entire communities and ecosystems. The Atlantic Forest is among the most important global biodiversity hotspots. These regions have historically been impacted by habitat loss and fragmentation, resulting in landscape changes and negative impacts upon animal communities. This study evaluates community characteristics of medium- and large-sized mammals in subtropical Atlantic Forest, southern Brazil. We gathered data on mammal occurrence using 108 cameras traps located across 8 protected areas. We then tested whether landscape differences impact mammal richness, composition, and community complexity. Specifically, we used a regression tree to evaluate compositional differences as a function of landscape configuration. We analyzed data for 26 species in total, with the number of species per area ranging from 9 to 17. Changes in mammal composition at the landscape scale were most strongly associated with human occupation. Areas with strong human occupation had low species richness, with a predominance of medium-sized omnivores and insectivores species; these conditions led to high defaunation indices. Community complexity was greater in areas with low human occupation, where carnivores (Felidae) were more abundant. Differences in species composition were also linked to altitudinal bands and the ratio of period of time with protected status versus history of land exploitation in a particular area. Analysis of functional groups indicated that intense human occupation had negative effects on larger species, a process that may have impending consequences. Despite defaunation being a serious ecological issue, we assert that taking prompt action may limit or potentially reverse effects of defaunation before the most dramatic changes take place.

Complex animal–plant interactions are present in the Neotropical bat family Phyllostomidae. Many of these interactions are still unknown, mainly due to the paucity of information available on the diet and habits of these species. The wrinkle-faced bat, Centurio senex, has been always considered as an enigmatic species. However, emerging evidence has partially elucidated the feeding ecology of this bat, confirming adaptations to consume hard food items. In addition to this information, here we show evidence of the predation of the seeds of Sideroxylon capiri (Sapotaceae) by C. senex. Bats employed principally deep unilateral bites to process the seeds. Our observations show that endocarp hardness has important implications on the ecological interaction between C. senex and S. capiri, due to the bats inability to puncture seeds with harder endocarps, causing an alternation between predation and dispersal of seeds. Nutritional rewards could be related to the predatory behavior documented. However, additional information is needed to clarify seed predation and seed dispersal patterns that exist between the 2 species.

Carrying capacity is 1 driver of wildlife population dynamics. Although in previous studies carrying capacity was considered to be a fixed entity, it may differ among locations due to environmental variation. The factors underlying variability in carrying capacity, however, have rarely been examined. Here, we investigated spatial heterogeneity in the carrying capacity of Japanese sika deer (Cervus nippon) from 2005 to 2014 in Yamanashi Prefecture, central Japan (mesh with grid cells of 5.5 x 4.6 km) by state-space modeling. Both carrying capacity and density dependence differed greatly among cells. Estimated carrying capacities ranged from 1.34 to 98.4 deer/km². According to estimated population dynamics, grid cells with larger proportions of artificial grassland and deciduous forest were subject to lower density dependence and higher carrying capacity. We conclude that population dynamics of ungulates may vary spatially through spatial variation in carrying capacity and that the density level for controlling ungulate abundance should be based on the current density level relative to the carrying capacity for each area.

Large-scale studies on population-level sex ratios are few, even though sex ratio is an important determinant of population viability and dynamics. Mechanisms driving large-scale sex ratio variation include spatially autocorrelated resources and scale differences in local versus global Fisherian feedback of the operational sex ratio. In this study, we reanalyze historic data on sex ratios based on 187,404 hunted subadult and adult red squirrels (Sciurus vulgaris) capturing spatial sex ratio variation in 50×50 km squares throughout Finland over a period of 8 years. Overall, sex ratio was slightly male biased (50.9%) and relatively more 50×50 km squares showed a bias toward males (19% of squares) compared to females (8% of squares). Sex ratio was spatially autocorrelated at distances up to 200 km and in some years showed a U-shaped pattern: regions that were in close proximity and those that were far apart had similar sex ratios, but regions in-between had opposite sex ratios. We found no evidence that food supply (spruce cone crop) drives regional red squirrel sex ratio. Our findings add to the scarce evidence that vertebrate sex ratios show spatial patterns over large scales.

Adverse effects of light at night are associated with human health problems and with changes in seasonal reproduction in several species. Owing to its role in the circadian timing system, melatonin production is suspected to mediate excess nocturnal light. To test this hypothesis, we examined the effect of light pollution on the timing of seasonal reproduction on a strict Malagasy long-day breeder, the nocturnal mouse lemur (Microcebus murinus). We randomly exposed 12 males in wintering sexual rest to moonlight or to a light-mimicking nocturnal streetlight for 5 weeks. We monitored urinary 6-sulfatoxymelatonin concentrations (aMT6s), plasma testosterone concentrations, and testis size, and we recorded daily rhythms of core temperature and locomotor activity. In males exposed to light pollution, we observed a significant decrease in urinary aMT6s concentrations associated with changes in daily rhythm profiles and with activation of reproductive function. These results showed that males entered spontaneous sexual recrudescence leading to a summer acclimatization state, which suggests that light at night disrupts perception of day length cues, leading to an inappropriate photoentrainment of seasonal rhythms.

Exposure of individuals to novel environmental conditions generally favors locally adapted phenotypes and can influence the likelihood of successful dispersal or the success of translocation efforts. We used geometric morphometrics to characterize American marten (Martes americana) skull morphology for descendants of animals reintroduced to the Upper Peninsula of Michigan, USA (∼44,000 km²) from genetically distinct source populations. Using univariate and multivariate analyses, we quantified associations between interindividual variation in skull shape and size, genealogical relationships, past introduction history, local harvest density of competitors, and contemporary landscape features we hypothesized would be related to diet. Effects of other sources of variation including shared ancestry (source population, geographic distance, and coancestry among descendants), sex, and age were also evaluated. Descendant skull shape was related to progenitor source population, sex, and age. In contrast to strong associations between spatial genetic structure based on neutral molecular markers and measures of landscape effects on dispersal, variation in skull shape among descendants was not associated with geographic distance or landscape features. Our study addressed a critical issue regarding a widely used conservation prescription. Specifically, when individuals are transplanted to reestablish extirpated species, do their descendants retain the features of the source population(s), or do they adapt to local conditions? Marten skull shape following reintroduction events is most likely determined by a combination of differences in morphology of source populations and geographic variation in habitat, rather than being influenced by a single factor.

Lifetime reproductive success (LRS) in the form of number of descendants is a commonly used measure of individual fitness, but the life stage at which descendants are counted varies among studies. Conceptual and logistical trade-offs exist along the gradient of proximal-to-distal LRS metrics. Although proximal metrics, such as number of offspring weaned, are logistically easier to collect than distal metrics, such as number of reproductively mature offspring or grandoffspring, they may be of little evolutionary significance if stochastic events heavily influence the realized number of descendants. We use a 25-year demographic data set based on 954 adult female Richardson's ground squirrels (Urocitellus richardsonii) from 22 annual cohorts to characterize and compare 6 metrics for LRS: lifetime production of litters, numbers of weanlings, weanling daughters, adult daughters, weanling matrilineal granddaughters, and adult matrilineal granddaughters. Most adult females weaned only 0 (21%), 1 (47%), or 2 (22%) lifetime litters. All LRS distributions were right skewed, with 53% and 77% of adult female Richardson's ground squirrels having no adult female matrilineal descendants after 1 and 2 generations, respectively. Survival of daughters and mothers covaried with calendar year, and LRS was strongly influenced by the calendar year in which females recruited into the breeding population as yearlings. Catastrophic flooding in 2005 killed nearly all descendants from the 2004 and 2005 cohorts. Daughter survival to adulthood explained more variance in lifetime production of adult daughters and granddaughters than number, size, or sex ratio of litters. Overall, to have a ≥ 50% chance of 1 adult granddaughter, a female needed to produce 2 litters, 7 weanling daughters, or 2 adult daughters. All distal (response) versus proximal (predictor) LRS metrics had significantly positive relationships, but variability increased with each distal step in the response variable. Our long-term study highlights sampling issues with LRS studies, variability within and among cohorts, and the role of stochastic events in uncoupling a mammal's reproductive effort from realized number of descendants.

Female natal philopatry has often been implicated as an important factor in moose (Alces alces) home range formation, with many populations showing behavioral evidence of sympatric home ranges among related individuals. However, previous genetic studies have failed to detect genetic subpopulation structure, leading to questions as to whether philopatry is a significant factor contributing to intra- and inter-population genetic structure. Here, we examine calving location data from radiomarked individuals (n = 110) collected in 2 separate populations in Berners Bay and Gustavus, Alaska, to examine the extent to which genetic structure originating from philopatry is evident at fine spatial scales. When populations were combined, their overall relatedness correlogram was significant (P < 0.001), with mean r = 0.079 between 0 km and 1.5 km (P = 0.079). Additionally, 13% of the population shows significantly positive relatedness to their 4 nearest neighbors, with an overall average r = 0.19 of those focal individuals to their neighbors. We suggest that habitat structure, especially linear habitats (i.e., river valleys), or habitat bounded with barriers to dispersal, may be a factor in promoting the development of this structure. This study presents the 1st known evidence for fine-scale social genetic structure in moose and natal philopatry to calving locations in moose. In the context of natal philopatry within cervids, these findings identify several cervid-wide commonalities.

We compared feeding behavior of frugivorous civets with those of other sympatric frugivores in a Bornean rainforest. For each frugivore residing in 3 different species of fig trees (Ficus variegata, F. fistulosa, and F. benjamina), we recorded temporal visitation patterns, visitation length, and time spent searching for fruit spanning 1,758 h of observations. The civets were strict nocturnal visitors, whereas the other 5 frugivorous species were diurnal visitors. Civets visited F. variegata, F. fistulosa, and F. benjamina trees until 51, 26, and 0.3 days before the end of fruiting, respectively, whereas the other frugivores visited the trees until 84.5, 32, and 1.2 days before the end of fruiting. Civets foraged longer in the F. variegata, F. fistulosa, and F. benjamina trees at each visit (119.17, 109.37, and 97.77 min, respectively) than did the other frugivores (39.88, 17.06, and 40.2 min). Civet search times (62.61, 27.55, and 18.9 s) were longer than those of the other frugivores (34.34, 12.46, and 9.49 s), and civet search duration significantly increased over time. Our results indicate that nocturnality is the most important factor in avoiding contest competition with larger diurnal frugivores, thus enabling long visits at feeding patches although long search times decreased feeding efficiency. Long foraging visits of civets would be advantageous in fruit-deficient environments and may compensate for their morpho-physiological disadvantages for frugivory.

Time allocation by lactating mammals is a reconciliation of often opposing nutritional and thermal demands of both the offspring and mother. Here we test the hypothesis that nest attendance patterns of lactating red squirrels (Tamiasciurus hudsonicus) vary with environmental and biological traits that relate to the thermoregulation of mothers and their offspring. We used temperature dataloggers to continuously record nest attendance and activity of free-ranging females with neonatal (n = 45) and preemergent (n = 53) litters. Lactating red squirrels concentrated activity out of the nest around the warmest parts of winter days and the coldest parts of summer days. Both younger and lighter litters had mothers that spent more time in the nest and shorter periods of time out of the nest. Females matched timing of activity within a day to the hourly air temperatures closest to their thermal neutral zone, serving to reduce individual and offspring thermoregulatory costs associated with activity. Nest attendance patterns appear to be constrained by the thermal, and possibly nutritional, requirements of the litter with females fine-tuning behavior to match constantly changing environmental and biological conditions, consistent with reduced energetic costs.

We studied ranging and feeding behavior of Cypriot fruit bats during the summer and winter, which are critical periods with limited food supply and adverse conditions. Seasonal changes in ranging behavior were characterized by a steep increase in the size of core feeding areas and home ranges from summer to winter. Males and females did not differ in the size of summer and winter core areas and home ranges, but they differed in the distance they traveled to summer feeding sites. Summer food consisted of fruits of Ficus carica and flowers of Agave americana. Winter food consisted of dates, fruits of Melia azedarach, Citrus reticulata, C. limon, Myrtus communis, and the flowers of Eucalyptus spp. Males and females differed as to the proportion of time they spent feeding on different food types, which may be explained by sexual differences related to food quality requirements. Summer foraging activity tended to be in areas with water bodies and larger fruit orchards. Winter foraging activity occurred more in areas with larger fruit orchards, a higher number of citrus plantations and date palms, typically located in built-up areas. The body condition of the bats was worse during the summer, which we assume was the result of their more limited diet during this period, making summer a more stressful period for them than winter. Active conservation management of Cypriot fruit bats should include the construction of artificial water sources in the vicinity of fruit orchards, but also controversial practices such as supporting the occurrence of particular nonnative plant species, thereby enhancing food availability in critical times of the year.

Fossil data are ambiguous regarding the evolutionary origin of contemporary desert bighorn sheep (Ovis canadensis subspecies). To address this uncertainty, we conducted phylogeographic and population genetic analyses on bighorn sheep subspecies found in southwestern North America. We analyzed 515 base pairs of mtDNA control region sequence and 39 microsatellites in 804 individuals from 58 locations. Phylogenetic analyses revealed 2 highly divergent clades concordant with Sierra Nevada (O. c. sierrae) and Rocky Mountain (O. c. canadensis) bighorn and showed that these 2 subspecies both diverged from desert bighorn prior to or during the Illinoian glaciation (∼315–94 thousand years ago [kya]). Desert bighorn comprised several more recently diverged haplogroups concordant with the putative Nelson (O. c. nelsoni), Mexican (O. c. mexicana), and Peninsular (O. c. cremnobates) subspecies. Corresponding estimates of effective splitting times (∼17–3 kya), and haplogroup ages (∼85–72 kya) placed the most likely timeframe for divergence among desert bighorn subspecies somewhere within the last glacial maximum. Median-joining haplotype network and Bayesian skyline analyses both indicated that desert bighorn collectively comprised a historically large and haplotype-diverse population, which subsequently lost much of its diversity through demographic decline. Using microsatellite data, discriminant analysis of principle components (DAPC) and Bayesian clustering analyses both indicated genetic structure concordant with the geographic distribution of 3 desert subspecies. Likewise, microsatellite and mitochondrial-based F_ST comparisons revealed significant fixation indices among the desert bighorn genetic clusters. We conclude these desert subspecies represent ancient lineages likely descended from separate Pleistocene refugial populations and should therefore be managed as distinct taxa to preserve maximal biodiversity.

In the Canadian Rocky Mountains, the gray wolf (Canis lupus) has experienced range contractions and expansions, which can greatly affect pack stability as well as population structure. In addition, this area has a highly heterogeneous landscape that may form barriers to dispersal. To understand factors affecting pack structure and large-scale gene flow across the Rocky Mountains, we examined wolf genetic structure using 1,981 noninvasive and invasively collected samples. We sampled over 44 packs in Alberta and British Columbia and, from these, identified 540 individuals based on 12 microsatellites. Relatedness of individuals within packs was greater than between packs, and female relatedness was greater than males suggesting strong pack structure and female philopatry. Relatedness within packs was greater near major roads suggesting decreased dispersal from natal packs with proximity to roads. Across the study area, 2 significantly differentiated genetic clusters were identified, corresponding to a north/south split. Landcover distance was a significant correlate for 2 of 4 genetic distance measures, where packs in the north were in areas of dense coniferous forest, while packs in the south were primarily in open coniferous forest. These landcover differences suggest natal associations or could relate to prey distribution. Fine-scale investigation of pack dynamics across this continuous distribution, together with large-scale estimators of population structure, highlights different drivers of gene flow at the pack and population level.

The short-beaked echidna Tachyglossus aculeatus is a seasonally breeding mammal with a near ubiquitous distribution throughout Australia. In Tasmania, breeding follows a period of deep hibernation, and males begin mating approximately 30 days after the termination of hibernation. The echidna has exceptionally large testes, which may reach a maximum of 1% of body mass during the mating period. As involution of gonads is considered a prerequisite for entering hibernation and hibernation typically suppresses all reproductive function, this raises questions about the timing of testes recrudescence in the Tasmanian echidna. We measured plasma testosterone concentrations and used ultrasonography to measure testicular and crural gland volume through the annual cycle in wild Tasmanian echidnas. Testes were at their minimum size (0.06% of body mass) in December (early summer); testes recrudescence occurred prior to entry into hibernation when plasma testosterone concentrations were low; and testes were maintained at 75% of their maximum volume throughout the hibernation period. The crural glands, which are secondary reproductive structures in the echidna, also exhibited an annual pattern of recrudescence and involution, with recrudescence occurring after males emerged from hibernation, when plasma testosterone was rising. We suggest that the unusual strategy of testes recrudescence occurring prior to hibernation in the Tasmanian echidna is a consequence of extremely high competition between males.

We describe a new species of Rattus, from 3 modern specimens collected on Manus Island in the Admiralty Group, Papua New Guinea, between 2002 and 2012. Subfossil specimens of early to late Holocene age from the Pamwak archaeological site on Manus Island are referred to the new species on morphological criteria; these confirm the species as a long-term resident of Manus Island. The new species is distinguished by its combination of large size; short tail; dorsal pelage that is coarse, spiny, and dark, with prominent black guard hairs; and sharply contrasting cream ventral pelage. Based on its overall body form, the species is almost certainly terrestrial. The dentition combines robust incisors with relatively small molars and the cranium displays a distinctive mé;lange of characters—including an elongate and anteriorly expanded rostrum and a mesopterygoid fossa that is narrow anteriorly and broadens to the rear. Sequence data from the mitochondrial control region and 3 nuclear genes place the new species as a highly divergent member of the Australo–Papuan Rattus radiation, with no identified close relative among sampled taxa. Morphological comparisons are made between the new species and other pertinent species of Rattus from the region, including R. sanila, a species known only from Late Pleistocene fossil to Late Holocene subfossil remains from an archaeological site on New Ireland. The conservation status of the new species is discussed in the light of a recent survey that failed to locate surviving populations in 2 areas of natural forest on Manus Island. Further survey work is urgently needed to identify any surviving populations and to assess the role of potential threats to the species.

Sex identification of adult cetaceans is an important ecological parameter that should be incorporated into studies such as population dynamics and animal behavior. In Cuvier's beaked whale (Ziphius cavirostris), sex determination may be achieved through genetics, observation of genitals, the presence/absence of erupted teeth, and calf association. However, these features are difficult to ascertain due to the shy behavior of this species. Therefore, this study aimed to create a robust sex identification method using only external characteristics. Particularly, this work analyzed pigmentation patterns and levels of natural marks from adult individuals of known sex in order to identify gender differences, using frequency analysis and generalized linear models. Photographic captures of 73 free-ranging animals were utilized. The frequencies of the individual pigmentation patterns were found to be sex dependent. The 63% of the animals could be classified into either a “soft” or “sharp” pigmentation cluster. The “soft” cluster was only displayed by females, while the “sharp” cluster was present in both the sexes. However, the model selection process indicated that natural marking is the best determinative factor for sex classification. The density of the visible intraspecific natural marks was found to differ between the sexes (P value < 0.001) and was incorporated as a predictor variable into several candidate models. All candidate models had a high predictive power (mean area under the curve 0.973) and correctly predicted the sex, by means of a density threshold value, in 85–90% of the analyzed animals. The density threshold ranged from 4.1% to 6.4% according to the different body area analyzed. These density threshold values represent a robust post hoc sexing method to classify individuals to sex from opportunistic photos in the absence of other sexing methods.

The swift fox (Vulpes velox) is a small grassland canid native to the North American Great Plains. A reintroduced swift fox population in Canada and northern Montana appears to be isolated from those existing in the central and southern Great Plains. We developed a swift fox habitat suitability model for southeastern Montana, the region between the 2 populations. The resulting model indicated that 67.9% of the study area consisted of highly suitable habitat. We conducted a least-cost path analysis to evaluate the connectivity of swift fox habitat in the study area to existing swift fox populations in the region. We identified a potential dispersal corridor through southeastern Montana that could facilitate movement between swift fox populations in northern Montana and northern Wyoming and identified 4 prairie dog complexes in Rosebud, Custer, and Powder River Counties, Montana, that could serve as potential swift fox reintroduction sites. Each site comprised several prairie dog colonies in close proximity and encompassed ≥ 95 km². We evaluated the effect that swift fox populations established in each potential reintroduction site could have on population connectivity. Our results as well as future surveys could inform swift fox management and reintroduction programs in Montana.

Franks et al. (2016) consider that the degree of error in estimated ages used to define survivorship patterns of northern and southern resident killer whale (Orcinus orca) populations is of insignificant impact to estimates of the species' postreproductive lifespan (PRLS). We provide evidence that survival probabilities for killer whales using a dataset comprising estimated age animals differ significantly from that determined using data collected from known-age animals in the Pacific Northwest over the past 40 years. Consequently, our findings indicate that the degree of error in age estimates and ensuing survivorship patterns do not support the notion by Franks et al. (2016) of a prolonged PRLS in the female killer whale that is comparable to the PRLS observed in humans.

Robeck et al. (2015) claim that reproductive and actuarial senescence is common in mammalian species and therefore not an unexpected finding in killer whales. However, in most mammals, reproductive and somatic senescence are aligned, and reproduction gradually declines with age. In contrast, there is a substantial evidence that reproductive senescence is unusually accelerated relative to somatic senescence in resident killer whales, resulting in a prolonged postreproductive lifespan. We demonstrate that a postreproductive lifespan is a key component of resident killer whale life history, and is robust to reasonable error in age estimates.

We analyzed morphometric and molecular variation among 8 populations of Peromyscus zarhynchus grouped into 5 pooled samples representing separate physiographic regions across the range of this species in Chiapas, Mexico, and western Guatemala. Mitochondrial sequence data identify 2 well-supported and reciprocally monophyletic clades, separating all Chiapas specimens from those in Guatemala. These 2 clades group as a strongly supported monophyletic lineage aligned with other members of the Peromyscus mexicanus species group. The Chiapas clade is further subdivided into 4 subclades: 1) samples from the western part of the state, 2) specimens from a single locality in Northern Chiapas, 3) all central localities, and 4) those from a single locality in Eastern Chiapas. The molecular distance in the mitochondrial cytochrome-b gene (Cytb) between the 2 major clades is relatively low (mean p-distance = 3.66%); those between the 4 Chiapas subclades are even less (mean p-distance 2.73%). Multivariate analyses of external and craniodental morphometric variables also distinguish 2 major groups, separating Guatemalan from Chiapas samples but with the latter also divided into 2 subgroups, one that segregates the Northern Chiapas sample from those distributed elsewhere in that state. The Guatemalan and Chiapas samples differ in both cranial size and shape variables. The second-level separation of samples from within Chiapas (northern versus all others) is interpreted to result from the combination of local adaptation to distinct physiographic regions and geographic isolation generated by patches of suitable habitat. We describe the Guatemalan samples as a distinct species based on their molecular and morphological uniqueness, and argue that P. zarhynchus itself is divided into definable subspecies, with the nominotypical form P. z. zarhynchus, restricted to the vicinity of its type locality (Tumbalá) in Northern Chiapas, and P. z. cristobalensis with type locality of San Cristobal, over the remainder of the species range in the state.

Predator prey preferences shape the dynamics of predator–prey assemblages. Understanding the determinants of a predator's prey preferences is therefore important. Trends in prey preferences of the large African predators have been described at a species scale, limiting our ability to assess the influence of prey morphology (size and horns) and predator social structure (sex and sociality) on prey preferences. An analysis of cheetah Acinonyx jubatus kill and prey abundance information from throughout South Africa shows that the presence of prey horns and the type of cheetah social group interact with prey size to influence cheetah prey preference. The size threshold above which prey is avoided by cheetah is lower for horned prey than non-horned prey, providing evidence that horns are a predation deterrent in medium-sized prey. Horned females occur significantly more frequently in antelope species on the cusp of being too large for cheetah predation, supporting the hypothesis that horns evolved as an antipredator defense in the females of medium-sized prey. Male coalition cheetah have access to a broader weight range of prey than solitary cheetah, which may infer fitness benefits by way of expanded resource options. The prey weight range accessible to solitary male cheetah is similar to that accessible to solitary female cheetah, suggesting that, in the absence of cooperative hunting, the slightly larger size of the male cheetah infers no hunting advantage. These findings provide insight into the predation pressures driving the evolutionary selection for large body size and horns in prey, and expanded resource access leading to predator sociality.

The structure of mesopredators' communities is complex and results from a multidimensional web of interactions such as top-down and bottom-up regulation or intraguild interactions. However, these interactions may change geographically along species' distribution ranges. The pine marten (Martes martes) and stone marten (Martes foina) are 2 similar-sized mustelids with overlapping ecological traits and a wide distribution overlap. The absence of stone martens from potentially adequate areas has been advocated as resulting from competitive exclusion by pine martens. Particularly, the preference of both species for mammalian rodents could be the main driver of such competitive stress. However, their elusive behavior and morphological similarity of their scats often precluded the evaluation of their ecological traits in areas of co-occurrence. Using camera trapping and diet analysis on genetically identified scats, we evaluated the interactions between pine and stone martens in the southwestern limit of their range along 3 ecological niche dimensions: spatial, trophic, and temporal, under a hypothesis of competitive dominance of pine martens. We found no spatial segregation, and that coexistence was facilitated by seasonally adjusted shifts along the trophic and temporal axes. While both species often co-occurred, during the season of low food resources, pine martens exploited the less profitable feeding resource. Moreover, they not only displayed an activity pattern that limited their access to rodents, but also reduced the probabilities of direct encounters with stone martens. We suggest that the dominance position has changed in favor of the stone marten in our study area, probably as a result of habitat quality and range edge effects. These findings support the relative instability of interspecific interactions among similar-sized species, which should be evaluated using multidimensional and site-specific approaches.

Giraffes Giraffa camelopardalis are megafaunal browsers and keystone species in African savanna ecosystems. Range-wide population declines are suspected, but robust data are lacking. Tanzania holds the largest population of giraffe of any range state, and aerial surveys constitute most of Tanzania's giraffe population monitoring data, but their accuracy has not yet been assessed. An IUCN status assessment for giraffe is currently underway, and calibrating aerial surveys with ground-based surveys can quantify accuracy of the aerial surveys to ensure more reliable estimates of populations nationwide. We estimated giraffe density and abundance in the Tarangire Ecosystem in northern Tanzania using 2 ground survey methods, distance sampling and capture-mark-recapture, and compared our ground-based estimates with those from the most recent aerial survey in 4 sites. We found aerial survey estimates were biased low, while ground-based surveys were more precise and cost less. We computed correction factors to improve the accuracy of aerial surveys and suggested ways to further improve aerial survey methods.

A new early Pleistocene dwarf pocket gopher species is described from the Short Haul, Aries A, and Nash 72 assemblages in the Borchers Badlands of Meade County, Kansas. Geomys tyrioni is defined by its diminutive size and modern dental and mandibular masseter muscle configuration. G. tyrioni, currently known from the interval of about 2.0–1.70 millions of years ago (Ma), replaced the larger G. floralindae and G. quinni of the slightly earlier (2.11 Ma) Borchers assemblage. Mandibular and dental characters place G. tyrioni in the group of Geomys including the extant Great Plains G. bursarius. Within about 24,000 years after the Nash 72 assemblage, G. tyrioni was replaced by modern-sized Geomys cf. G. bursarius in the Rick Forester assemblage, the earliest record of the extant plains pocket gopher in the Meade Basin and North America. G. tobinensis Hibbard is synonymized with G. bursarius. An evolutionary scenario is provided for the Meade Basin geomyines based on current information, and it is suggested that ashfalls may have played a significant role in geomyine cladogenesis and turnover.

An unusual observation of a hagfish (Myxine glutinosa) anchored to a living bottlenose dolphin (Tursiops truncatus) was documented in an encounter with a group of about 80 dolphins during an ongoing long-term research program on cetaceans in the central Mediterranean Sea, Italy. The body of the hagfish was observed extruding from the blowhole of the bottlenose dolphin showing a stereotypical surfacing–breathing pattern. The observation lasted 2 h; photo-identification, acoustic, and behavioral data were collected. Succorant behaviors (i.e., “standing by”) from conspecifics and overlapping vocalizations during social phases were recorded. The dolphin was encountered again after 1 month in the same area without the hagfish, apparently in healthy conditions.

Whether large carnivores indirectly influence vegetation via prey behavior remains controversial because available evidence is largely correlational, and recent field experiments have found weak associations between risk experienced by prey and vegetative responses to herbivory. We combined observational data and a field experiment to test whether an ambush predator—the puma (Puma concolor)—affected the antipredator behavior of its primary ungulate prey—the vicuña (Vicugna vicugna)—which in turn had cascading effects on vegetation. We predicted that strong protective effects of pumas on vegetation would be most apparent in habitats where cover and terrain (i.e., physical complexity) facilitated the ambushing strategy of pumas. In 3 different habitats, we evaluated the relationships among predation risk, vicuña behavior, and—by deploying vicuña exclosures— vegetation structure and productivity. We also examined habitat-specific rates of vegetative regrowth. Risky habitats presented high physical complexity, a disproportionately large number of vicuñas killed by pumas, and high relative abundance of pumas. In these habitats, vicuñas displayed strong antipredator behaviors and exclosures did not affect vegetation, suggesting that pumas indirectly protected plants. Conversely, a safe habitat presented low structural complexity, a disproportionately low number of vicuñas killed by pumas, and low relative abundance of pumas. Here, vicuñas relaxed antipredator behaviors and exclosures had strong effects on vegetation. In 1 habitat deemed as risky, however, cascading effects were offset likely because water and nutrients were readily available to plants and regrowth was rapid. Our results show that large ambush carnivores can positively affect vegetation via nonconsumptive effects on their prey, and that these effects are habitat mediated. However, primary productivity modulated the strength of such effects, with high primary productivity dampening the observed cascading effects.

We document a new genus and species of rodent (Muridae) from the west-central region of Sulawesi Island, Indonesia. The new taxon is known only from the type locality at around 1,600 m elevation on Mt. Gandangdewata of the Quarles Range, in the district of Mamasa. With phylogenetic analyses of DNA sequences from 5 unlinked loci, we infer that the new taxon is sister to the Sulawesi water rat, Waiomys mamasae, and nested within a clade of rodents from Sulawesi that otherwise feed exclusively on invertebrates. The new species is distinguishable from other rodents of Sulawesi by the combination of its small, slender body; soft, gray–brown fur; small, rounded ears; long, sparsely haired tail; long, fine mystacial vibrissae; gracile cranium; short rostrum; pronounced lacrimal bone; prominent, sickle-shaped coronoid process; and pale orange enamel on labial surface of incisors. Unlike its closest relatives, the new species feeds on both plant and animal matter, and may represent a rare evolutionary reversal of traits associated with a carnivorous diet in murids.

We investigated age-specific variation in survival of dominant individuals in a long-lived and monogamous mammal, the alpine marmot (Marmota marmota), from a large dataset collected during a 24-year intensive monitoring of a free-ranging population. We found evidence of actuarial senescence in dominant individuals for both sexes. Survivorship was constant with age until dominant marmots were between 6 and 8 years of age and declined markedly thereafter. No between sex differences occurred in the intensity of actuarial senescence, which might be related to the weak intensity of sexual selection in this socially monogamous mammal. More investigations are needed to know whether cooperative breeding, hibernation, and monogamy, which are key features of the alpine marmot life history, could have shaped the patterns of actuarial senescence we report.