Volume 105, Issue 6, December 2024

Leptonycteris yerbabuenae is a nectar-feeding bat and a colonially roosting species. Here, we assessed activity patterns among individuals to investigate how reproductive status, sex, and environmental conditions influence activity budgets.

Plateau pikas in heavily degraded meadows of the Qinghai–Tibetan Plateau consumed relatively high-quality protein foods. High-methionine foods improved individual fitness, suggesting that high-methionine foods in the heavily degraded meadows may be a key factor in generating and maintaining high-density populations of plateau pikas.

This study documented and contrasted food caching behavior of the Ladakh Pika and Nubra Pika for the first time from the Changthang Biotic Province of the Trans-Himalayas in the context of sociality and the microhabitats they occupy. The Ladakh Pika—which lives in large social groups at high densities in open landscapes, constructed large haypiles and guarded them against conspecific theft (larder-hoarding), while the Nubra Pika—which lives in smaller social groups at lower densities in closed landscapes, constructed small haypiles and scattered them on colonies (scatter-hoarding). While there was variability in the expression of the behavior, contents, and sizes of caches, we believe that food caching behavior is a flexible bet-hedging strategy in pikas that likely increases winter survival.

Using data on the reproductive phenology of Phyllostomidae bats sampled before and after an Amazonian mega-dam water filling, we tested if and how sex ratio, seasonal abundance, and reproductive patterns responded to impacts of the newly operating hydroelectric dam. The hydroelectric dam affected the abundance of both sexes equally, and effects were stronger in the rainy season, altering the timing of reproduction for females, delaying and shortening pregnancy and lactation.

Wild chimpanzees live in challenging, seasonal environments—and the population at Gombe National Park, Tanzania—show signs of chronic dehydration. Here we explore how hydration status varies based on socioecological variables such as sex, season, and dominance rank.

We mapped Plains Spotted Skunk distribution using ensemble modeling techniques. Our results indicate ~31,000 km² of suitable habitat, primarily in eastern South Dakota. Management efforts can focus on promoting sustainable farming practices and managing woodlands to facilitate species conservation in the region.

Fox squirrels (Sciurus niger) demonstrate variation in traits that may play an important role in their success across urban areas of variable human density. Specifically, fox squirrels at higher human densities were found to display a trend of increased social behavior over those at lower human densities. Other traits such as aggression, docility, and boldness did not vary over this scale, and may indicate more complex relationships between behavioral and environmental variation.

To shed light on invasive alien species success in urban areas, we studied the personality–urbanization relationship in the Eastern Gray Squirrel in Italy. In cities, squirrels differed in activity and sociability levels, which may favor their response to urbanization.

Coyotes are the primary predator of endangered black-footed ferrets, a species that selects similar resources and competes with American badgers for prairie dog prey. Our study found that coyotes use prairie dog colonies preferentially to surrounding grasslands, and on colonies, coyotes use areas more frequently that are also used by American badgers. This suggests that Coyote attraction to American Badger activity may influence where and how coyotes and black-footed ferrets interact.

We analyzed reproductive patterns of female Elk to better understand the relationship between previous reproductive effort and future reproductive output. Long-lasting costs of reproduction were associated with lactation, but costs were limited for highly productive individuals.

This study investigates the fine-scale foraging strategies of zebras in a South African savanna, focusing on their selection of green vegetation at plant and feeding patch levels. Results reveal adaptive foraging behavior varying with scale and season: during late-dry and early-wet seasons, zebras select greenness at both levels, while in mid-dry season, preference shifts to grass tuft level. These findings underscore the need for multilevel studies to comprehend factors influencing herbivore foraging decisions, emphasizing the complexity of their behaviors.

Cuvier’s Gazelle (Gazella cuvieri), Dama Gazelle (Nanger dama), and Dorcas Gazelle (G. dorcas) are 3 species that were historically abundant and widely distributed in northern Africa but have declined dramatically in the second half of the 20th century. The Conservation Strategy and Action Plan for Gazelle species in North Africa 2017 to 2026 developed by the International Union of Nature Conservation includes the study of their habitat use to support conservation strategies. We investigated the habitat use of the 3 species when foraging in spring and summer on a private reserve of Morocco. There was spatial segregation and seasonal differences among species. These specific preferences might permit stable coexistence among them and reflect their need for structural habitat diversity, which might be promoted in reforestation programs to improve their survival and coexistence in future reintroduction areas, accounting for climate (rainfall reduction decreases forage availability) and population dynamics.

Herein, we expanded previous studies in introduced Aoudad (Ammotragus lervia) by using genomic profiles. We identified phylogeographic structure, isolation by distance, and barriers to movement in Texas populations. MtDNA haplogroups and nuclear genotypes were discordant, indicating that current taxonomy needs refinement.

Hutias in the genus Capromys, the largest surviving endemic Caribbean land mammals, have traditionally been interpreted as the single species C. pilorides that occurs across Cuba. Ancient DNA analysis of historical museum samples instead identifies distinct western and central/eastern Cuban Capromys species, which we recognize as C. geayi and C. pilorides.

Unlocking the secrets of Mus musculus in Asia from ancient origins to recent population expansions. The findings reveal a complex history shaped by climate, geography, and human activities.

Across 3 mountain elevations in Borneo there were distinct elevation ranges for most species but this did not result in a clear pattern of species richness along the gradients. Species traits seemed to be important with herbivores being more abundant at lower elevations and carnivores/omnivores at higher elevations.

Observed abundance of hoary marmots has declined in the North Cascades National Park Service Complex. We studied Hoary Marmot behavior, predator diet, and predator occurrence. Coyotes used sites with less snow and predated on hoary marmots most often. Pacific martens were also frequent predators of hoary marmots.

Surveys of American pikas from 1972 to 2022 at a marginal locality (Bodie, California) found contrasting population responses; the northern population was stable, whereas the southern population experienced a metapopulation collapse; climate was not implicated in either situation.

The current work examines the scaling relationships between brain mass and body mass for one of the major mammalian clades, Euarchontoglires, the group that includes living primates, treeshrews, colugos, rodents, and lagomorphs. Previous work suggested that a similar scaling pattern of the brain was found between Lagomorpha and Primates. However, our results show that Lagomorpha scaled their brains more similarly to their closest relatives, Rodentia. One of the critical uses of brain–body size scaling equations is in calculation of metrics for relative brain size, of which the encephalization quotient (EQ) is the most familiar. Using clade-specific patterns, new EQ and phylogenetically accounted EQ equations are proposed, which should allow for effective comparison of brain sizes in analyses of euarchontoglirans at varying taxonomic scales.

Chinchilla rats (family Abrocomidae) are caviomorph rodents whose taxonomy and systematics have been based solely on external morphological characters, yielding unclear results. By analyzing mitochondrial and nuclear DNA sequences, we present new hypotheses regarding the number of species and genera in the family and their relationships. Furthermore, the late Miocene central Andean uplift, along with its climatic and geographic consequences, is suggested to have been the most important diversification driver in this family.

Peromyscus morphology is influenced by location, habitat, and climate. Depending upon habitat, colder January temperatures are associated with shorter crania and most appendages; likewise, warmer July temperatures are also often associated with shorter crania and appendages, suggesting that both extremes can limit cranial and appendage length. Furthermore, longitude, surprisingly, can also play a further role in morphology.

Illegal killing of wildlife is a problem that warrants objective investigation. Treves et al. (2017) estimated gray wolf mortality patterns for Wisconsin. We critiqued their work and identified five serious flaws worthy of consideration. Our critique corrects the record and calls into question the validity of their results.