Cimolodontan multituberculates were a diverse and long-lived group of mammals characterized by large, blade-like lower fourth premolars (p4). Blade-like (plagiaulacoid) dentitions have evolved numerous times in distantly related mammalian lineages. Here we investigate how p4-shape disparity changed through time in the Cimolodonta. We address two hypotheses: (H₁) blade-like dentitions constrain the ability of plagiaulacoid mammals to evolve novel dental morphologies, (H₂) cimolodontan dental evolution proceeded gradually along a morphocline during the Late Cretaceous. We quantify functionally important aspects of p4 shape, including ratios reflecting height (H:L), symmetry (L1:L), and mesial-face height (H1:H), in a large sample of cimolodontans spanning the mid-Cretaceous through early Paleogene of North America (ca. 100–35 Mya). Our results do not support the morphocline hypothesis (H₂) and, instead, show that cimolodontans evolved a wide range of p4 shapes by the mid-Cretaceous, and that p4-shape disparity remained stable through the Late Cretaceous. We hypothesize that the two-stage cimolodontan chewing cycle (slicing-crushing then grinding) imposed functional constraints on p4 morphology. After the Cretaceous-Paleogene boundary, p4-shape disparity increased sharply, driven by the appearance of the Taeniolabidoidea, Microcosmodontidae, and Eucosmodontidae, in the early Paleocene. We contend that the slicing-crushing functions of the p4 became less important in those taxa, relaxing functional constraints on p4 morphology. Cimolodontans that retained both the slicing-crushing and grinding function of the p4 had a more limited range of p4 morphologies, and probably were largely restricted to animal-dominated omnivory. Taxa that shifted the initial slicing-crushing function from the p4 to the incisors had fewer functional constraints on p4 morphology, and were able to increase their molar grinding capacity to exploit plant-dominated omnivory and herbivory. That the p4 was reduced in herbivorous taxa rather than modified into a broader, multi-cusped tooth lends support to the morphological constraint hypothesis (H₁), and this relationship between p4 morphology and function suggests that retaining a large, blade-like p4 might have limited the range of herbivorous diets cimolodontans could exploit. These findings highlight the ecological and evolutionary limitations that specialized dentitions can impose on mammals by restricting their morphological and, in turn, functional diversification.

Environmental changes since the Pleistocene and commercial whaling in the last few centuries have drastically reduced many whale populations, including gray whales in the North Pacific. Herein we use complete mitogenome sequences from 74 individuals to evaluate gray whale phylogeography and historical demography, then use environmental niche modeling to assess how habitat availability has changed through time for Pacific gray whales. We identify a large degree of haplotype sharing between gray whales sampled in Russian and Mexican waters, coupled with very limited matrilineal population structure. Confirming previous studies, our environmental niche models showed a decrease in available habitat during the Last Glacial Maximum, but we find no genetic signals of recent population declines in mitochondrial genomes despite both sustained habitat loss and a commercial whaling bottleneck. Our results illustrate the complex dynamics of baleen whale biogeography since the Holocene as well as the difficulty in detecting recent demographic bottlenecks from mitochondrial DNA sequences.

During the dependency period in mammals with parental care, offspring must develop the behavioral skills that allow them to forage independently and thus survive into early adulthood. Deep-diving Weddell seals (Leptonychotes weddellii) are a model species for research on diving physiology, yet previous studies lack a thorough investigation into the diving behavior of dependent pups when they first begin to enter the water. To capture fine-scale dive behavior during the dependency period, we deployed time-depth recorders (TDRs) on Weddell seal pups (n = 18) from the age of 1 week through 7 weeks, during the 2017 and 2019 breeding seasons in McMurdo Sound, Antarctica. Dive parameters were correlated with time of day, age, sex, and weaning status, to characterize diving behavior, and we used raw wet/dry data to determine which times of the day pups were most likely to be in the water. Pups made their deepest and longest dives and had the longest post-dive durations in the morning hours. Pups were in the water more during the late night and morning hours than in the afternoon. Whereas dive depth significantly increased with age, dive duration significantly increased with age and after weaning. Post-dive duration significantly decreased with age and after weaning. We discuss how dependent pups may prioritize the development of swimming and navigational abilities as opposed to building and practicing foraging skills.

Marine apex predators, such as coastal dolphins, are key components of ecosystem function and dynamics; understanding their spatial use therefore is important for conservation planning. Here, we describe spatial use of the threatened Guiana dolphin, Sotalia guianensis, within a mosaic of protected areas at their southern range in the Paranaguá estuarine complex (PEC), Brazil. Based on environmental characteristics and S. guianensis population densities, individual photo-identification surveys were focused on two sectors of the northern mouth of the PEC between 2013 and 2015. We photo-identified 107 individuals and recorded 351 groups of Guiana dolphins; nearly 50% of which contained calves. Group sizes were small (mean ± SD: Sector 1 = 3.4 ± 2.7; Sector 2 = 3.6 ± 2.0) and ranged from 1 to 30 individuals. Clustering algorithms were applied to resighted, photo-identified Guiana dolphins to classify individuals as “residents” (sighted in 87% of surveys, n = 11) and “transients” (two clusters; 62%, n = 22; 95%, n = 72). All individuals predominantly were observed foraging (90% in Sector 1 and 76% in Sector 2), but spatial use by transient individuals differed from the residents in terms of environmental (slope, water depth, and rainfall) and behavioral factors (presence of calves and foraging behavior). Compared to transients, resident dolphins ranged over smaller areas, typically more suitable for feeding, calf caring, and more protected from predators and vessels. Because resident Guiana dolphins exhibit small home ranges, they are particularly vulnerable to local anthropogenic activities and habitat loss. These characteristics imply a strong need for regionalized management plans to reduce negative impacts and to maintain the ecological functionality of the species.

Understanding the diving behavior of semiaquatic mammals, particularly in relation to estimated aerobic dive limits and diet, is important to understand their adaptability and potential vulnerability to changes in prey type and distribution. The diving behavior of African clawless otters, Aonyx capensis, and spotted-necked otters, Hydrictis maculicollis, is poorly known, and no estimates of their dive performance in relation to targeted prey and calculated dive limits have been reported previously for freshwater environments. We investigated the diving behavior of both these otter species in freshwater environments within South Africa through video recordings of direct observations and subsequent video analyses where dive and recovery durations and dive function were recorded. African clawless otters were found to perform longer dives (mean ± SD = 26.9 ± 12.2 s), compared to spotted-necked otters (8.5 ± 7.6 s). African clawless otters showed substantial variation in dive durations, with the shortest dives sometimes lasting < 5 s, and the longest recorded dive being 70 s. The majority of spotted-necked otter dives lasted < 10 s, with the shortest recorded dive lasting 0.66 s and the longest recorded dive lasting 50.9 s. Spotted-necked otters performed different dive types that were evidently dependent on prey targeted, with dives targeting crabs (16.10 ± 1.91 s) being longer than dives targeting rainbow trout, Oncorhynchus mykiss (5.58 ± 0.17 s). The theoretical dive durations of African clawless otters were exceeded during play dives, while spotted-necked otters sometimes exceeded their theoretical dive durations when performing successful foraging dives. The results of this study suggest that spotted-necked otters can vary behavior in relation to prey and exceed theoretical dive duration during successful foraging dives to maximize the net rate of energy gain. Furthermore, when considering known individual-level dietary specialization and plasticity in these species, it may be predicted that dive behaviors are likely to vary substantially among individuals, and in relation to prey availability and localized habitat conditions.

The role of predation by large carnivores in suppressing prey populations and structuring ecosystems is highly debated, calling for a detailed understanding of carnivore diets. Wolves (Canis lupus) roam across three continents and persist throughout widely different ecosystems. Their diet is flexible and may vary spatially as well as seasonally, which requires analysis of diet on different spatial and temporal scales. Few studies have investigated the summer diet of wolves, which is more variable, consists of smaller prey, and requires different methods than studying their winter diet. To better understand the summer diet of wolves, we combined three independently collected wolf scat data sets from three distinctly different portions of the Greater Yellowstone Ecosystem: Yellowstone National Park (2009), Grand Teton National Park (2003 – 2009), and the Absaroka-Beartooth Wilderness (2009 – 2010). These areas represent different ecological conditions and management regimes, which may impact wolf diet. We estimated relative biomass and compared occurrence of different prey species among packs, years, as well as the three regions. In total, we analyzed 1,906 wolf scats and found that neonate cervids, adult elk, and adult deer were the most important prey species in the summer diet of the wolves. We found dietary variation among packs residing in the same area, as well as across years. The occurrence of neonate cervids displayed the most variation, and low occurrence of this prey type often was associated with a more diverse diet. Wolf packs within the national parks had a higher occurrence of medium-sized prey (∼ 50 – 70 kg) and lower occurrence of small-sized prey (≤ 20 kg) compared to wolves in the Absaroka-Beartooth Wilderness. These results demonstrate flexibility in summer diet across packs, years, and between regions within the Greater Yellowstone Ecosystem.

The space use strategies animals use to acquire resources needed for survival and reproduction reflect life history traits and individual behaviors. For large solitary carnivores, such as cougars (Puma concolor), prey, mates, and safe habitat in which to raise offspring, are resources that influence space use. Most animal home range studies investigate differences between sexes but fail to explore the space use patterns among individuals. We first used 95% minimum convex polygon (MCP), kernel density estimate (KDE), and Brownian bridge estimator (BB), to estimate the home range of 43 cougars satellite-collared in west-central Alberta, Canada, in 2016–2018. We found that adult males (MCP = 498 km²; KDE = 623 km²; BB = 547 km²) had home ranges that were more than twice the size of those of adult females (MCP = 181 km²; KDE = 273 km²; BB = 217 km²). We then used net squared displacement, path segmentation analysis, and multi-response permutation procedure, to examine the space use patterns of 27 female and 16 male cougars. We constructed a decision tree and found that 23% of cougars were dispersers (12% of females and 44% of males), 47% were residents (58% of females and 31% of males), 9% were seasonal home range shifters (12% of females and 6% of males), and 19% shifted to a new area during the study period (19% of females and 19% of males). We learned that dispersers all were subadults, whereas all residents, seasonal shifters, and shifters, were adults, except for one subadult male. Our study provides insights on animal home ranges with methods to categorize different space use strategies which could be used to help assess the dynamics of a population.

The Large Treeshrew, Tupaia tana , is a small mammal (∼205 g) from Southeast Asia with a complicated taxonomic history. Currently, 15 subspecies are recognized from Borneo, Sumatra, and smaller islands, and many were originally differentiated based on minor pelage differences and small sample sizes. We explored intraspecific variation in T. tana using quantitative osteological data obtained from the hands and skulls of museum specimens. Multivariate analyses reveal extensive overlap among T. tana populations in morphospace, indicating that the majority of currently recognized subspecies are not morphometrically distinct. In contrast, the separation between Bornean and Sumatran populations of T. tana is sufficient to recognize them as different subspecies. Comparisons of Bornean specimens to those on small, offshore islands reveal that the latter average smaller body size. This pattern is inconsistent with Foster's island rule, which predicts that island populations of small mammals (< 5 kg) will average larger body size relative to mainland forms. A similar lack of support for ecogeographic rules has been noted in T. glis (), suggesting that these “rules” are poor predictors of geographic variation in treeshrews.

Fundamental knowledge on free-ranging animals has been obtained through capture-based studies; however, these may be logistically intensive, financially expensive, and potentially inconsistent with local cultural values. Genetic mark–recapture using remote tissue sampling has emerged as a less invasive alternative to capture-based population surveys but provides fewer opportunities to collect samples and measurements for broader ecological studies. We compared lipid content, fatty acid (FA) composition, and diet estimates from adipose tissue of polar bears (Ursus maritimus) obtained from two collection methods: remote biopsies (n = 138) sampled from helicopters and hunter-collected tissue (n = 499) from bears harvested in Davis Strait and Gulf of Boothia, Nunavut, 2010 – 2018. Lipid content of adipose tissue was lower in remote biopsies than harvest samples likely because remote biopsies removed only the outermost layer of subcutaneous tissue, rather than the more metabolically dynamic innermost tissue obtained from harvest samples. In contrast, FA composition was similar between the two collection methods with relatively small proportional differences in individual FAs. For diet estimates in Davis Strait, collection method was not a predictor of prey contribution to diet. In Gulf of Boothia, collection method was a predictor for some prey types, but the differences were relatively minor; the rank order of prey types was similar (e.g., ringed seal; Pusa hispida was consistently the primary prey in diets) and prey proportions differed by < 6% between the collection methods. Results from both methods showed that diets varied by geographic area, season, year, age class, and sex. Our study demonstrates that adipose tissue from remote biopsy provides reliable estimates of polar bear diet based on FA analysis and can be used to monitor underlying ecological changes in Arctic marine food webs.

Age is a basic demographic characteristic vital to studies of mammalian social organization, population dynamics, and behavior. To eliminate potentially confounding ontogenetic variation, morphological comparisons among populations of mammals typically are limited to mature individuals (i.e., those assumed to have ceased most somatic growth). In our morphometric studies of treeshrews (Scandentia), adult individuals are defined by the presence of fully erupted permanent dentition, a common criterion in specimen-based mammalogy. In a number of cases, however, we have had poorly sampled populations of interest in which there were potentially useful specimens that could not be included in samples because they lacked associated skulls. Such specimens typically are associated with external body and weight measurements recorded by the original collectors, and we sought to determine whether these data could be used successfully as a proxy for age or at least to establish maturity. We analyzed four traditional external dimensions (head-and-body length, tail length, hind foot length, and ear length) and weight associated with 103 specimens from two allopatric populations of the Lesser Treeshrew (Tupaia minor Günther, 1876) from Peninsular Malaysia and from Borneo, which we treated as separate samples (populations). Individuals were assigned to one of eight age categories based on dental eruption stage, and measurements were compared among groups. In general, mean sizes of infants and subadults were smaller than those of adults, but the majority of subadults fell within the range of variation of adults. The large overlap among infants, subadults, and adults in external measurements and weight indicates that such measures are poor proxies for age in this species, probably for treeshrews in general, and possibly for other small mammals. This has significant implications for any investigation wherein relative age of individuals in a given population is an important consideration.

The Heteromyidae (pocket mice and kangaroo rats) are a group of extant small rodents abundant in western North America, as well as in fossil assemblages over the last 20 million years. Two genera of heteromyids, Chaetodipus and Perognathus, share similar tooth morphology and teeth are the primary fossil remains. Previous genetic studies show these extant sister genera likely diverged in the middle Miocene (∼16 million years ago); however, the Chaetodipus fossil record starts in the Pleistocene (∼2 million years ago). In this study, we asked whether two-dimensional geometric morphometrics on complete dentition and isolated premolars can accurately identify Chaetodipus and Perognathus specimens at the genus and species level. We landmarked the occlusal surface of the upper and lower tooth rows of modern Chaetodipus (n = 83) and Perognathus specimens (n = 80), including 12 of the 26 extant species across the two genera. We ran a canonical variates analysis to investigate whether principal component variation could predict known taxonomic identifications. The morphospace using complete dentition can identify specimens to genus with 90 – 92% accuracy and to species with more variable accuracy. We found an isolated premolar provides sufficient information for genus-level identification (69 – 84% accuracy), but not for species-level identification (26 – 56% accuracy). This morphospace of modern specimens can be used to identify the skeletal remains of Chaetodipus and Perognathus in museum collections, raptor pellets, or middens, to refine our existing knowledge of heteromyid evolutionary history.

Pallid bats, Antrozous pallidus, despite being primarily insectivorous gleaning predators, consume nectar of the cardón cactus, Pachycereus pringlei, in the Sonoran Desert. It is unknown whether nectar feeding occurs in the Chihuahuan Desert of Texas, where pallid bats covered in pollen have been captured. We collected pollen samples from 67 pallid bats in Brewster County, Texas, United States, between April and August 2018. Pollen-covered pallid bats were captured in every month sampled. Pollen densities were three times higher on wings than on the head or ventral body. In all samples collected, the pollen was homogeneous and identified as Agave pollen. Although two species of Agave, A. havardiana and A. lechuguilla, occur in this region of Texas, linear discriminant analysis classified 701 of 723 (97%) of pollen grains analyzed as A. lechuguilla. Additional evidence from infrared video footage collected in August 2018 indicated that pallid bats became covered in A. lechuguilla pollen while consuming nectar. Pallid bats might be engaging in facultative nectarivory across their range and could be important nocturnal pollinators.

Recent studies have revealed that western populations of little brown bats (Myotis lucifugus) in North America exhibit different hibernation behavior than their eastern counterparts. Understanding these differences is essential for assessing the risk white-nose syndrome (WNS) poses to western bat populations. We used acoustic monitoring and radiotelemetry to study the overwintering behavior of little brown bats near Juneau, Alaska during 2011–2014. Our objectives were to identify the structures they use for hibernation, measure the microclimates within those structures, and determine the timing of immergence and emergence and the length of the hibernation season. We radiotracked 10 little brown bats to underground hibernacula dispersed along two ridge systems. All hibernacula were ≤ 24.2 km from where the bats were captured. Eight bats hibernated in the “Milieu Souterrain Superficiel” (MSS), a network of air-filled underground voids between the rock fragments found in scree (talus) deposits. Two bats hibernated in holes in the soil beneath the root system of a tree or stump (rootball). At least two hibernacula in the MSS were reused in subsequent years. Average MSS and rootball temperatures were warmer and more stable than ambient temperature and were well below the optimal growth range of the fungus that causes WNS. Temperatures in the MSS dropped below freezing, but MSS temperatures increased with depth, indicating bats could avoid subfreezing temperatures by moving deeper into the MSS. Relative humidity (RH) approached 100% in the MSS and under rootballs and was more stable than ambient RH, which also was high, but dropped substantially during periods of extreme cold. Acoustic monitoring revealed that bats hibernated by late October and began emerging by the second week of April; estimates of minimum length of the hibernation season ranged from 156 to 190 days. The cold temperatures, dispersed nature of the hibernacula, and close proximity of hibernacula to summering areas may slow the spread and reduce the impacts of WNS on local populations of little brown bats.

We report the results of an 11-year (2008–2018) community science project (also known as citizen science) designed to document the use of hummingbird feeders by two species of nectar-feeding bats, the lesser long-nosed bat (Leptonycteris yerbabuenae) and the Mexican long-tongued bat (Choeronycteris mexicana), in the Tucson area of southern Arizona. From 50 to > 100 households participated in this project each year. We supplemented their reports with occasional mist-netting of bats at 21 observer sites to determine age and sex composition of bats at feeders. Our results indicate that L. yerbabuenae was more widespread and common at feeders than C. mexicana, which occurred mainly at sites close to mountains. In the Tucson area, the geographic extent of feeder visitations by bats, mostly L. yerbabuenae, expanded since 2007 and by 2018, covered most of the city and its suburbs. Most bats of both species visited feeders between late August and late October with little year-to-year variation in timing; some individuals of both species continued to visit feeders during winter. The number of bats observed at many sites during September (the month of peak visitations) was relatively stable for at least 10 years; modal numbers of nightly visitors per site in most years was 6 – 10 bats. Capture data indicated that L. yerbabuenae that visited feeders in the Tucson area were not a random sample of the species' age and sex composition in southeastern Arizona, where their food plants are located in late summer and fall. In Tucson, most bats visiting feeders were subadult females (juveniles and yearlings). We suggest that hummingbird feeders have substantially increased food availability for nectar bats in southern Arizona prior to their migration south into Mexico. However, reasons for the increased use of feeders by L. yerbabuenae, particularly subadult females, beginning in 2007 are not yet clear.

Home range size is a fundamental measure of animal space use, providing insight into habitat quality, animal density, and social organization. Human impacts increasingly are affecting wildlife, especially among wide-ranging species that encounter anthropogenic disturbance. Leopards (Panthera pardus) provide a useful model for studying this relationship because leopards coexist with people at high and low human densities and are sensitive to human disturbance. To compare leopard home range size across a range of human densities and other environmental conditions, we combined animal tracking data from 74 leopards in multiple studies with new analytical techniques that accommodate different sampling regimes. We predicted that home ranges would be smaller in more productive habitats and areas of higher human population density due to possible linkage with leopard prey subsidies from domestic species. We also predicted that male leopards would have larger home ranges than those of females. Home ranges varied in size from 14.5 km² in India to 885.6 km² in Namibia, representing a 60-fold magnitude of variation. Home range stability was evident for 95.2% of nontranslocated individuals and 38.5% of translocated individuals. Leopard home range sizes were negatively correlated with landscape productivity, and males used larger areas than females. Leopards in open habitats had a predicted negative correlation in home range size with human population density, but leopards in closed habitats used larger home ranges in areas with more people.

Carnivores face important anthropogenic threats in agricultural areas from habitat loss and fragmentation, disturbance by domestic free-roaming dogs and cats, and direct hunting by humans. Anthropogenic disturbances are shifting the activity patterns of wild animals, likely modifying species interactions. We estimated changes in the activity patterns of the mesocarnivore guild of agricultural landscapes of the La Araucanía region in southern Chile in response to land-use intensification, comparing intra- and interspecific activity patterns at low and high levels of forest cover, fragmentation, and land ownership subdivision. Our focal species comprise the güiña or kod-kod (Leopardus guigna), two fox species (Lycalopex culpaeus and L. griseus), a skunk (Conepatus chinga), and one native mustelid (Galictis cuja), in addition to free-roaming dogs (Canis lupus familiaris) and cats (Felis catus) and their main mammalian prey species (i.e., Rodentia and Lagomorpha). In 23,373 trap nights, we totaled 21,729 independent records of our focal species. Our results show tendencies toward nocturnality at high land-use intensification, with potential impacts on species fitness. Nocturnal mesocarnivores decreased their diurnal/ crepuscular activity, while cathemeral activity shifted to nocturnal activity at high land-use intensification, but only when in sympatry with a competitor. High land-use intensification decreased the activity overlap between native and domestic mesocarnivores but increased the overlap between native mesocarnivores. High intensification also reduced overlap with prey species. Notably, foxes displayed peaks of activity opposing those of dogs, and plasticity in activity pattern when in sympatry with dogs, such as strategies to avoid encounters. We stress the need to suppress the free-roaming and unsupervised activity of dogs to mitigate impacts of high land-use intensification on mesocarnivores.

Human-dominated landscapes contain fragmented natural land cover interspersed throughout an urban matrix. Animals that occupy human-dominated landscapes often grow and reproduce differently than conspecifics. Female American black bears (Ursus americanus) produce litters for the first time usually at age 4 years; 2-year-olds rarely give birth. We visited winter bear dens and trapped bears in spring and summer to compare the reproductive output and weight of female black bears within the city limits of Asheville, North Carolina, and three forested rural sites in North Carolina and Virginia representative of the undeveloped habitat of Asheville. Urban yearling females weighed nearly double (45.0 kg ± 8.1 [± SD]; n = 36) that of yearling females from the three rural study sites (23.2 ± 8.5 [Pisgah], 23.6 ± 8.3 [Virginia SW], and 23.9 ± 9.7 [Virginia NW]; n = 95). Across all sites, hard mast production during the autumn, when females were cubs, did not affect their weights as yearlings. Seven of 12 (58%) 2-year-old urban bears produced 11 cubs (mean litter size = 1.6 ± 0.8), but no 2-year-old rural females produced cubs. Production of hard mast in the autumn, when females were yearlings, did not influence cub production by 2-year-old female bears at the urban site. We hypothesize that reproduction by 2-year-old bears is linked to the availability of anthropogenic food sources associated with urban environments. To inform population level management decisions, managers and researchers should quantify urban food sources and the effects on black bear life history. If high fecundity allows urban populations to sustain relatively high mortality rates, then urban bear populations may be source populations for surrounding, rural areas. Alternately, if reproduction in urban populations cannot match high time-specific or age-specific urban mortality rates, then urban populations may be sinks for the surrounding areas.

Competition with livestock over forage resources has been identified as a potential threat to the survival of the African wild ass (Equus africanus) in the Danakil ecosystem (Eritrea). The Messir Plateau is an important breeding area for the African wild ass but also hosts cattle, sheep, goats, donkeys, and camels. Locations and fecal samples of African wild ass and livestock were collected in dry and rainfall months. Stable carbon isotopes [δ¹³C ‰] in fecal samples were used to assess diet composition and overlaps with domestic herbivores. Fecal samples also were used to assess the nutritional quality of African wild ass and domestic donkey diets. During the dry months, African wild ass were concentrated in the northern section of the Messir Plateau, approximately 9 km from the permanent water source, and overlapped spatially with local livestock. During the rainfall months, African wild ass dispersed throughout the Messir Plateau (124 km²) when a high number of livestock, particularly cattle from the highlands with herders, were concentrated in the northern section. During the rainfall months, the northern section had relatively better vegetation cover and access to seasonal water. The grass contribution to the diet of the African wild ass in both dry and rainfall months overlapped significantly with that of domestic donkeys and cattle. In rainfall months, the percent fecal nitrogen and phosphorus contents of African wild ass were significantly lower than those of domestic donkey samples. The lower nutrient levels in fecal samples of African wild ass during rainfall months may be due to their displacement from the northern sector by the high number of immigrant highland cattle with people. Our work provides evidence as to how the presence of domestic herbivores, particularly cattle, may negatively impact the nutrient level of wild equids and threaten the survival of the critically endangered African wild ass.

Long-term population dynamics are essentially unknown for the western heather vole (Phenacomys intermedius), a relatively rare microtine species. Our objectives were to provide a description of demographic changes in populations of P. intermedius and determine possible causes of these changes. We analyzed four detailed 12- to 22-year data sets that recorded changes in abundance of P. intermedius in a variety of managed forests in south-central British Columbia, Canada from 1993 to 2018. We evaluated three hypotheses (H) that may help explain population changes: heather voles will (H₁) have higher populations in sites with (i) abundant dwarf shrubs or (ii) cover of woody debris; (H₂) colonize new clear-cuts as dispersal sinks for young voles; and (H₃) be at lower abundance when other Microtus species are present at equal or higher numbers. Populations of P. intermedius occurred commonly at ≤ 1 animal/ha (as a density index). However, in favorable habitats such as some new clear-cuts and in “open” pine stands, P. intermedius occurred at mean annual peak numbers of 5–6/ha (as a density index). There were two relatively high populations of P. intermedius in 1994–1995 and 1998, and possibly again in 2002 in the open pine stands. Mean numbers of lactating females and recruits per year tended to follow the pattern of changes in abundance. High populations of P. intermedius occurred in stands with abundant dwarf shrubs in open pine stands but not those with a cover of woody debris structures in clear-cuts, H₁, therefore, was only partially supported. A relatively higher proportion of adult than juvenile heather voles on clear-cuts did not support H₂: that these harvested sites would be dispersal sinks for young voles. Mean annual numbers of P. intermedius were positively correlated with those of M. longicaudus, at least on clear-cut sites, hence H₃ was not supported. Phenacomys intermedius was essentially absent from our closed-canopy mature/old-growth forests but occurred in many managed forest habitats at low abundance (density index of ≤ 1/ha). In early successional habitats after clear-cutting and in open young pine stands this species occurred at moderate abundance and generally appeared stable in numbers across these forest landscapes.