The social behavior of the smaller fox species is poorly known compared with that of larger and more gregarious canids that can be directly observed. We studied social relationships and reproductive behavior of island foxes (Urocyon littoralis) on San Clemente Island (SCI) and San Miguel Island (SMI), off the coast of Southern California, using proximity logging collars. On both islands, pair members interacted more frequently and spent more time together than other types of dyads. On SCI, a high contact rate identified the same 10 mated pairs that were identified by a high degree of home-range overlap. A high contact rate also identified 3 mated pairs on SMI, 2 of which were associated with large pups 9–10 months old. On SMI, the number of contacts and amount of time that mates spent together per day varied across months and peaked in February, when most conceptions occur. Mates spent much less time together in April to June, the pup-rearing season. More unpaired male–female and male–male dyads interacted during January and February than in subsequent months. Paired males appeared to guard their mate during the period when she was receptive. The average duration of estrus was approximately 40 h. Paired females were in contact with other males in addition to their mate near the time they were presumably in estrus, and paired males were in contact with other females in addition to their mate. The relatively short duration of estrus, combined with asynchrony of estrus among females, enabled paired males to leave their mate and seek extrapair copulations without risk of cuckoldry. Proximity logging collars provide a new opportunity to learn about these temporal aspects of social and reproductive behavior in canids.

Forests in the Sierra Nevada, similar to those across the continent, have been substantially altered by logging, fire exclusion, and other human activities. Current forest management emphasizes maintenance or restoration of resiliency in the face of contemporary disturbance factors that include wildfire, climate change, continued urbanization, and invasive species. We evaluated responses of small mammals to forest management by monitoring a series of 12 replicate trapping grids in compositionally homogeneous forest over 8 years, and implemented 2 levels of canopy thinning. Livetrapping efforts (119,712 trap-nights) yielded 15,613 captures of 2,305 individuals of 13 species, and although forest structure was significantly influenced by canopy treatments, small mammal numbers and assemblage composition were not. To better understand this we assessed habitat associations of small mammals at 599 census points on 75 transects established in a stratified random manner throughout Plumas National Forest. We analyzed these data with 2 complementary forms of constrained ordination (canonical correspondence and canonical correlation) that extract major gradients in 1 data set (e.g., distribution of small mammal captures) and explain these in terms of measured variables from a 2nd data set (e.g., habitat and environmental measurements). Over 3 years and 57,504 trap-nights of effort we captured 1,367 individuals of 11 species. Both forms of ordination exposed significant associations between small mammals and underlying habitat metrics, but they explained remarkably little variation in these data, suggesting that small mammals are responding only modestly to habitat variation as expressed by the available environmental variables measured at each plot. We followed this with stepwise multiple Poisson regression to build models of habitat associations of these species. We applied model-averaging and employed Akaike's information criterion corrected for small sample size (AIC_c) to evaluate candidate models. Reflecting ordination results, competitive models (e.g., those with Akaike differences [ΔAIC_c] < 2.0) cumulatively explained little variation (12–36%) and regression coefficients were very low. Hence, both ordination and Poisson multiple regression suggest that the limited response by small mammals to canopy thinning primarily reflects the generalist habits of the common species in this forest. We propose that anthropogenic influences have led to structural homogenization of these forests, even across > 800 m of elevation, such that habitat specialists (e.g., old-forest–dependent species such as Myodes [Clethrionomys] californicus and Glaucomys sabrinus) have become less common due to the lack of suitable habitat. Further efforts should target nonforested habitats (meadows and riparian corridors), but results presented here suggest that managers should strive to increase heterogeneity at large spatial scales and especially to promote the development of mature forest structure.

Investigating social learning in free-ranging mammals is gaining popularity among researchers. Natural experiments are ideal for studying social learning, but are rare compared to captive studies because of practical limitations and ethical concerns. Such experiments are often restricted or forbidden because they require manipulation of the environment, ecology, or behavior of free-ranging species. As a result, developing new methods to investigate social learning in the field is essential. The main goal of this study was to use genetic data and a new testing framework to determine if social learning from mothers to their offspring is at least partly responsible for free-ranging black bears foraging on human foods in Yosemite National Park. I estimated a relatedness coefficient and the most probable relationship for all combinations of 2 bears (n = 150) sampled in 2004–2007. I then grouped these pairs by their foraging behavior to test predictions deduced from asocial learning, transmission, genetic inheritance, and social learning hypotheses. Results from both analyses suggest that mother–offspring social learning is the primary mechanism responsible for black bears foraging on human food in Yosemite. In addition, results also suggest that some bears are innovators, learning to forage on human food as independents. I found no support for the genetic inheritance hypothesis.

The gray wolf (Canis lupus) exhibits both genetic and morphologic clinal variation across North America. Although shape variation in wolf populations has been documented, no study has been made to exhaustively quantify it, or to correlate morphologic variation with environmental variables. This study utilizes a large historical database of wolf skull linear measurements to analyze shape, and attempts to correlate it with wolf ecology. A variety of statistical tests are employed; size and shape are examined through a principal component analysis and a calculation of allometry vectors. Multiple regression analysis (both global and stepwise) are then used to test the resulting principal components against various biotic and abiotic factors. In addition, the effects of sexual dimorphism and taxonomy on morphology are explored through 1-way analysis of variance and canonical variates analysis, respectively. Several patterns are revealed, including size increase with latitude in accord with Bergmann's rule. Static allometry is significant, the fundamental pattern being a decrease in the robusticity of the basicranium relative to the viscerocranium. Sexual dimorphism, allometry, and a correlation with precipitation are other key factors driving morphological variation. Examination of these patterns has allowed us to make conclusions about the direct and indirect ways the environment has affected clinal variation in wolves.

For many herbivorous mammal species across the world, geophagy, the consumption of soil, is an important method for obtaining minerals, especially sodium. However, this behavior has not been recorded in marsupials. The eastern grey kangaroo (Macropus giganteus), an intensively studied macropod species, is known to use physiological and micromorphological adaptations to conserve sodium. We present results of another adaptation, the use of natural licks, by this species and 3 other macropod species at Sundown National Park, Australia. Natural licks had significantly higher levels of sodium, magnesium, and sulfur than surrounding soils. We examined patterns of lick use by kangaroos to test 3 possible proximate causes of geophagy: whether lick use was affected by dietary mineral content, life-history stage, and thermoregulation. The number of kangaroos visiting the licks increased with temperature and mean cloud cover, varied among months, and was marginally significantly influenced by dietary mineral content. Visit durations to one lick increased with temperature and were influenced by month and life-history stage; females with high lactation demand and large males spent the most time at the lick. The proportion of time spent in geophagy when at a focal lick varied with month and reproductive state. Therefore geophagy is not restricted to eutherian mammals, and kangaroos, like many eutherian species, appear to adjust this behavior in response to their mineral demand. Geophagy in kangaroos is facultative, rather than obligative, and has not been detected in other intensively studied populations. In areas of Australia with low levels of sodium, high temperatures, and suitable lick sites, geophagy may play a key role in marsupial ecology.

We used carbon and nitrogen isotopes measured in hair to compare the diets of 2 sympatric species of wild mice, Peromyscus californicus and P. boylii, in Santa Cruz County, California. The ability of these 2 Peromyscus species to coexist is thought to be the result of spatial partitioning through canopy plant associations as well as possible dietary niche partitioning. We used stable isotope analysis to determine the trophic level at which each species is feeding and stable isotope mixing models to estimate dietary contributions of various arthropod and plant-derived food sources. We found P. californicus to be omnivorous, specializing mainly on arthropods and consistently feeding at a higher trophic level than P. boylii. P. boylii is omnivorous as well, but specializes mainly on tanoak (Notholithocarpus densiflorus) acorns. Dietary niche partitioning appears to be seasonal; in the fall, partitioning breaks down to some degree, likely because food is so abundantly available, and both species consume a larger, overlapping array of acorns and arthropods. These findings coupled with other studies on habitat niche partitioning present a clearer picture of how these 2 sympatric species can coexist.

Like some species of pika (Ochotona) and tree squirrel (Tamiasciurus), the banner-tailed kangaroo rat (Dipodomys spectabilis) is a solitary, philopatric larder-hoarder that practices unisexual territoriality. Seeking to understand how this unusual combination of traits might influence the mating system, we used systematic trapping at mounds (burrows) and spool-and-line tracking to examine male and female visits to each other. Where genetic data exist, unisexual larder-hoarders such as D. spectabilis have been found to be polygynandrous. We asked whether the fact that females sometimes mate with more than 1 male is a passive side effect of imperfect mate defense by males, or whether females actively engage in behaviors that encourage multiple mating. During the nonbreeding season, adults of both sexes were rarely captured at mounds other than their own. In contrast, during the breeding season females as well as males were significantly more likely to be captured away from their home mounds, most often at mounds belonging to adults of the opposite sex. Spool-and-line tracking during the breeding season confirmed these results. Consistent with the expectation that they engage in competitive mate searching, adult males visited adult females' mounds significantly more than expected by chance and without regard to age, size, or relatedness. More surprisingly, adult females exhibited similar behavior, expanding their home ranges and disproportionately visiting the mounds of large adult males during the nights preceding estrus. Increased (and apparently directed) female mobility during the days preceding estrus may serve as a means of shaping the pool of competing mates and is worthy of more attention in this and other, ecologically similar species.

Mating systems and factors affecting reproductive success are much studied especially for mammals that are large bodied, have marked sexual size dimorphisms, and have a female-defense mating system. For species that deviate from these patterns, we need more information on mating systems and reproductive success. Here, we study mating system and factors related to reproductive success in a solitary rodent, the Siberian flying squirrel (Pteromys volans). In contrast to most other mammals, males are not larger than females in flying squirrels. Similarly to most mammalian species, we observed multimale paternity within litters and reproductive success of males being positively related to body mass. Variation in reproductive success was clearly higher for males than for females, although remained lower than observed in species with highly male-biased sexual size dimorphism. Female flying squirrels lived in nonoverlapping home ranges and reproductive success was positively related to body mass, in line with earlier predictions for large female size in mammals.

Nests play a crucial role in the life history of tree squirrels, and can be a critical component of their biology that enables them to be a successful invasive species. Red-bellied squirrels (Sciurus aureogaster) were introduced to Elliott Key, Florida, in the late 1930s, and spread to nearby islands. Red-bellied squirrels were believed extirpated by Hurricane Andrew in 1992, but were rediscovered on Elliott Key in 2005. In 2006 and 2007, we surveyed for squirrel nests and measured vegetation to evaluate forest characteristics associated with nest-site selection by squirrels, and compared these data to measurements collected at random locations. Squirrels placed nests in large trees with more canopy linkages in mixed-hardwood forest, and the nest trees were in areas with large trees, high tree density and canopy cover, and lower recent hurricane damage. Red-bellied squirrels selected characteristics of nest trees and forest structure in similar ways to individuals in their native range, and to other species of tree squirrels in general. Results from our research allowed land managers to assess possible management actions and provided important information for them to develop an effective management strategy. Park officials are currently working toward complete eradication of the introduced population of red-bellied squirrels from the Florida Keys. We suggest that behaviors of individuals in native ranges may elucidate patterns for individuals introduced to novel environments; however, we also caution that care must be taken in further extrapolation. Our findings emphasize the importance of understanding ecology of introduced species for effective management.

A quarter of all lagomorph species worldwide are threatened with extinction. Captive breeding programs, such as that developed for the Columbia Basin (CB) pygmy rabbit (Brachylagus idahoensis), sometimes are implemented as emergency conservation measures to restore small, genetically distinct populations. However, small source populations also may have low genetic diversity, which may influence attributes related to fitness, including growth, survival, and reproduction. We used mixed-effects regression models to explore the influence of genetic pedigree (% CB) on pairing success, growth, and survival during the 10-year captive breeding program at Washington State University, which included controlled pairings and outbreeding with pygmy rabbits from Idaho. Pairing success, juvenile growth, and juvenile survival declined with increasing CB pedigree of 1 or both parents, suggesting inbreeding depression among the small number of related founders. Demographic variables such as age, sex, and previous pregnancies, and environmental variables such as month and temperature at birth also were associated with production of pygmy rabbits. Our study illustrates the difficulty of retaining a unique genome of a small source population while simultaneously producing enough rabbits for restoration into natural habitat as part of endangered species recovery programs.

Body size affects almost every aspect of the biology of a species, with considerable intraspecific variation. Cheetahs (Acinonyx jubatus) reportedly vary in body size across their geographical range. However, because morphometric measurements were not taken in a standardized manner, it is impossible to rule out differences in measurement protocols as the cause. Our study differed from previous ones in that we made use of a standardized methodology for taking morphometric measurements in cheetahs. Free-ranging cheetahs in Namibia were shorter (3.5–4.1%) and slimmer (4.0–7.0%) than those in neighboring Botswana. Cheetah density was more than 3 times higher and home-range sizes were more than 3 times smaller in Botswana compared to Namibia. This suggests that variation in resource availability may be the main driver of the fine-scale spatial differences in morphometric measurements. Overall, our study promotes the use of standardized protocols for measuring morphological traits in free-ranging animals.

Body size and growth rate are among the most important traits characterizing an organism, influencing niche occupancy, life-history patterns, mortality rates, and many other fitness components. Sexual size dimorphism is common among animals; in most species females are on average larger than males. In contrast, male mammals are usually larger on average than females of the same species, and the spotted hyena (Crocuta crocuta) may be one of the rare species of mammal in which females are generally larger than males. Nevertheless, some have argued that the evidence is equivocal regarding this reversal. This disagreement may reflect differences in traits measured, methods used, or ontogenetic differences among individuals sampled for these studies. We quantified size at various points during ontogeny in 651 individuals, the largest sample used in size analyses of spotted hyenas to date. We measured 14 morphological traits as well as 4 linear combinations of the traits that provide multivariate estimates of size; these were used to examine growth patterns among males and females measured in a free-living population in Kenya. We demonstrate that female spotted hyenas are larger than males for most, but not all traits, and that females are larger because they grow faster, rather than exhibiting a prolonged period of growth. Early in life males and females appear to grow similarly, but between weaning and reproductive maturity their multivariate ontogenetic trajectories diverge. Traits that mature before divergence of these ontogenetic trajectories are monomorphic, whereas traits that mature later are dimorphic. Furthermore, dimorphism is generally greatest in traits that cease development latest. We propose that later-maturing traits are more dimorphic because of a systemic increase in female growth rates during adolescence that persists through morphological maturity, which varies among traits. We also assess body-size data obtained from captive hyenas to show that adult female hyenas are larger than adult males for some traits even when they are fed identical diets throughout development, allowing us to rule out a strictly environmental explanation for this dimorphism.

The partitioning of resources within communities is commonly associated with variation in morphological characteristics between species. However, communities containing morphologically similar species, such as the endangered Indiana bat (Myotis sodalis) and the little brown bat (M. lucifugus) must partition resources in different ways. We examined sympatric populations of M. sodalis and M. lucifugus to determine whether they partitioned their resources through the selection of foraging habitat. Foraging ranges, estimated using 100% minimum convex polygons (MCP) and 95% fixed kernel (FK) models, and foraging habitat selection, estimated using Euclidean distance-based habitat selection analyses, were examined and compared between the species using radiotelemetry. M. sodalis had a mean foraging range area of 375 ± 39 ha and 285 ± 32 ha (MCP and 95% FK, respectively), whereas M. lucifugus had a mean of 2,739 ± 456 ha and 515 ± 78 ha. Both species selected for similar hydric habitats at the landscape level. However, although M. lucifugus specifically selected for open water and bottomland hardwood forests within their expansive foraging ranges, M. sodalis used land cover types as they were available within their smaller home ranges, suggesting that these species use different foraging strategies, partitioning foraging resources through variation in their selection of land cover.

Subsampling is used to process scat collections in diet and pollination studies involving nectarivores, but what constitutes a sufficient sampling effort is undetermined. We analyzed entire scat samples from 3 bat species (Pteropodidae) and recorded all pollen; we then tested various levels of subsampling to determine the most efficient regimes. Secondary subsampling (5 fields of view) was inappropriate for plants with low pollen loads (rare pollen); however, abundant pollen morphospecies were detected reliably with little effort. Similarly, the rarer the pollen, the higher was the chance of missing pollen in primary subsampling. Low subsampling effectiveness occurred for scats with high incidences of singletons (= rare pollen); they required the greatest effort to identify ≥ 80% of pollen morphospecies. Diet homogeneity varied among bat species, and subsample efforts should relate to diet strategy and ecology of target species. We recommend using a standard volume of material per subsample; avoiding secondary subsampling unless screening for abundant pollen morphospecies; analyzing fully 20% of material if ≤ 80% of pollen morphospecies need to be detected; and increasing subsampling effort for studies targeting plants with low pollen loads. Subsampling effort needs to match study objectives, or flower species will be greatly underrepresented or missed completely.

All known species of extant tapirs are allopatric: 1 in southeastern Asia and 3 in Central and South America. The fossil record for tapirs, however, is much wider in geographical range, including Europe, Asia, and North and South America, going back to the late Oligocene, making the present distribution a relict of the original one. We here describe a new species of living Tapirus from the Amazon rain forest, the 1st since T. bairdii Gill, 1865, and the 1st new Perissodactyla in more than 100 years, from both morphological and molecular characters. It is shorter in stature than T. terrestris (Linnaeus, 1758) and has distinctive skull morphology, and it is basal to the clade formed by T. terrestris and T. pinchaque (Roulin, 1829). This highlights the unrecognized biodiversity in western Amazonia, where the biota faces increasing threats. Local peoples have long recognized our new species, suggesting a key role for traditional knowledge in understanding the biodiversity of the region.

Todas as espécies conhecidas de antas viventes são alopátricas: 1 no sudeste da Ásia e as 3 na América Central e América do Sul. Entretanto, o registro fóssil para antas é mais amplo geograficamente, incluindo Europa, Ásia, América do Norte e do Sul, encontrados desde o Oligoceno tardio, tornando a distribuição atual um relicto da original. Descrevemos aqui uma nova espécie de Tapirus vivente da floresta amazônica, a primeira desde T. bairdii Gill, 1865, e o primeiro novo Perissodactyla em mais de 100 anos, a partir de caracteres morfológicos e moleculares. O novo táxon é menor em estatura do que T. terrestris (Linnaeus, 1758) com morfologia distinta do crânio, sendo basal ao clado formado por T. terrestris e T. pinchaque (Roulin, 1829). Esta descoberta destaca a biodiversidade oculta no oeste da Amazônia, onde a biota enfrenta ameaças crescentes. Alguns povos locais há muito tempo reconheceram esta nova espécie, sugerindo um papel fundamental para o conhecimento tradicional na compreensão da biodiversidade da região.

Seven species are included in the genus Hylaeamys. Their limits and distribution, however, are uncertain. We used morphometric analyses performed in univariate (Dice–Leraas diagrams) and multivariate (size-free principal component analysis) approaches, along with qualitative analysis, as well as information on the karyology, to make an assessment on the status of populations of the genus in the Atlantic Forest. On the basis of the evidence we found, it was possible to corroborate the hypothesis that there are actually 2 species in this biome: H. oniscus, a species distributed on the northern bank of the São Francisco River, from the State of Alagoas to the State of Paraíba; and H. seuanezi, which occurs on the southern bank of the São Francisco River, from the southern portion of Bahia State to the northern part of Rio de Janeiro State. Hylaeamys laticeps, the name formerly used for this entity, was allocated to the synonymy of H. megacephalus, a species that inhabits the Cerrado and Amazon Forest biomes. Hylaeamys oniscus exhibits a longer and more robust skull, with a longer rostrum and the 1st upper molar narrower, and a karyotype with 2n = 52 chromosomes and fundamental number (FN) = 62 autosomic arms, whereas H. seuanezi is smaller and more delicate, with a karyotype of 2n = 48 and FN = 60. The São Francisco River and the associated dry vegetation probably have played an important role in the origin of these species and today may still play a role as a barrier to gene flow between these species.

Atualmente, sete espécies estão alocadas no gênero Hylaeamys, mas as suas delimitações e respectivas distribuições ainda permanecem incertas, principalmente na Floresta Atlântica brasileira. Através de análises morfométricas, realizadas através de abordagens univariadas (diagramas de Dice-Leraas) e multivariadas (análise canônica discriminante), somadas a análises qualitativas e a informações citogenéticas avaliamos a variação existente entre as populações do gênero ao longo da Floresta Atlântica. Foi possível corroborar a hipótese de que existem duas espécies do gênero neste bioma: H. oniscus, que encontra-se distribuída na margem norte do Rio São Francisco, na Floresta Atlântica ao norte do Rio São Francisco, desde o Estado de Alagoas até o Estado da Paraíba, e H. seuanezi, que se distribuí na margem sul do Rio São Francisco, desde o sul do Estado da Bahia até o norte do Estado do Rio de Janeiro. Hylaeamys laticeps, o nome empregado anteriormente para esta entidade, foi alocado à sinonímia de H. megacephalus, uma espécie que habita os biomas Cerrado e Floresta Amazônica. A primeira espécie possui um crânio maior e mais robusto, com rostro mais longo e o primeiro molar superior mais estreito, e um cariótipo com 2n = 52 cromossomos e NF = 62 braços autossômicos, quando comparada a H. seuanezi, que é uma espécie menor, com rostro mais curto e molares levemente mais largos e cariótipo com 2n = 48 cromossomos e NF = 60 braços autossômicos. O Rio São Francisco, bem como a vegetação mais seca associada à foz deste rio, pode ter desempenhado um papel importante na origem destes táxons, ou pode desempenhar um papel de barreira ao fluxo gênico para as populações atuais, mantendo-as como unidades evolutivas independentes.

Palavras - Chave: América do Sul, citogenética, morfologia, morfometria, Oryzomyini, Taxonomia, variação geográfica.

We evaluated how American badgers (Taxidea taxus) might exert selective pressure on black-footed ferrets (Mustela nigripes) to develop antipredator defenses. In a colony of black-tailed prairie dogs (Cynomys ludovicianus) in South Dakota, badgers concentrated their activities where burrow openings and prairie dogs were abundant, a selective behavior that was exhibited by ferrets in the same colony. Badgers excavated burrows more often when in areas recently used by a ferret, suggesting that badgers hunt ferrets or steal prey from ferrets, or both. We also conducted an analysis of survival studies for ferrets and Siberian polecats (M. eversmanii) released onto prairie dog colonies. This polecat is the ferret's ecological equivalent but evolved without a digging predator. Badgers accounted for 30.0% of predation on polecats and 5.5% of predation on ferrets. In contrast, both polecats and ferrets have evolutionary experience with canids, providing a plausible explanation for the similar relative impact of coyotes (Canis latrans) on them (65.0% and 67.1% of predation, respectively). We hypothesize that ferrets and badgers coexist because ferrets are superior at exploitation competition and are efficient at avoiding badgers, and badgers are superior at interference competition.

Male cervids face trade-offs in allocating resources to body mass (linked to survival) and antlers (linked to reproductive success). Reindeer (Rangifer tarandus) are unique among cervids because females also possess antlers, providing an opportunity to investigate sex- and age-specific patterns of resource allocation to body mass and antlers. Using long-term (1996–2011) data on 560 reindeer, we examined how body mass and antler length varied with age and sex, and the relative allocation of resources toward antlers using scaling analysis. Body mass and antler length increased through age 5 years in males but plateaued in females at age 3 years, with males 59% greater in body mass and 146% longer in antler length by age 5 years. All age and sex categories, except yearling males and mature females, had a positive scaling (a scaling exponent greater than isometry) of antlers with body mass, with the highest relative allocation of resources toward antlers in female calves. Relative allocation toward antlers tended to increase with age in males but decrease with age in females. The observed patterns in antler and body growth are likely a reflection of sex-specific life-history strategies of reindeer whereby females have offspring yearly from puberty and males have an increased number of offspring as they mature.

Prey often react to predation risk by foraging preferentially in the safety of cover rather than in more risky open patches. Yet this pattern of patch use also can be caused by dominant interspecific competitors. We develop a simple theory of this form of apparent predation risk that describes the patch use of an optimal forager confronted with dominant individuals. The theory predicts that subordinate animals should increase their use of safe foraging patches as the density of nearby dominants increases. We tested the theory with meadow voles (Microtus pennsylvanicus) and southern red-backed voles (Myodes gapperi). We used dyadic encounters to confirm that meadow voles are dominant over red-backed voles. We then evaluated their respective foraging patterns in pairs of covered and open patches in 4 adjacent subgrids in an old-field enclosure. Subordinate red-backed voles foraged indifferently between covered and open patches when few meadow voles were present. Red-backed voles increased their use of both patches as the number of nearby meadow voles increased. Giving-up densities were lowest, and harvesting efficiency highest, in covered patches when the number of nearby meadow voles was high. These results document competition between the 2 species and suggest that vigilance toward dominant meadow voles magnifies the risk experienced by red-backed voles in open patches. Investigators assessing foraging behavior between “safe” and “risky” patches might misinterpret the competitive effect as predation risk unless they 1st account for competition among foraging individuals.

The East African root rat (Tachyoryctes splendens) is a solitary fossorial rodent occurring in the eastern parts of central Africa. Unlike bathyergid mole-rats, T. splendens occasionally goes aboveground to feed and consequently it is periodically exposed to the natural light–dark cycle. The locomotor activity of T. splendens was assessed under various light regimes. T. splendens entrains its activity to light cycles and displays distinct nocturnal activity with the total percentage of activity during the dark phase at 87.78% ± SD 11.01%. In constant darkness, T. splendens shows free-running rhythms of slightly shorter than 24 h (2340 ± SD 013 h), while still exhibiting most of its activity during subjective night. Upon inversion of the light cycle, time of reentrainment was exceptionally long. Nocturnal activity time (α) was shortened in response to a shorter night length from 1129 to 0746 h; however, when the dark phase was lengthened, α remained roughly similar to that of the 12L:12D photoperiod at 1124 h. A difference in circadian activity is apparent from the laboratory and field findings, thus in a natural situation, other environmental factors may influence activity patterns.

Live-capture and translocation are methods to deal with nuisance eastern gray squirrels in North America, but it is unknown how these methods affect squirrel physiology or survival. In this study we validated an enzyme immunoassay (EIA) to measure fecal cortisol metabolites (FCMs) in gray squirrels; assessed their stress response relative to the positioning of the live trap (sun, shade, or control); and assessed the impact of translocation on their long-term stress, movement patterns, and survival using FCM levels, body mass changes, and radiotelemetry. We found that a 5α-pregnane-3β,11β,21-triol-20-one EIA reliably detected acute stress in gray squirrel feces 12–24 h after the stressor; live traps positioned in the sun resulted in higher peak FCM levels compared with traps positioned in the shade; translocated squirrels experienced a 10% mortality rate, compared with no mortality in the controls, although overall fates were the same; translocated squirrels initially explored more and dispersed farther than controls, but after 2 weeks made similar movements; and after controlling for the effect of season, translocation did not affect long-term FCM levels or body mass; this conclusion must be tempered by the low number of recaptures. Our study demonstrates the utility of the FCM assay; that gray squirrels are extremely sensitive to capture, handling, and confinement; and that live-capture must be done in a way that minimizes exposure to additive environmental stressors.

Knowledge of the diversity and relationships of species in many groups of plants and animals in Southeast Asia is severely limited, preventing an integrative understanding of evolutionary and ecological processes in island archipelagos. We generated a 3-locus DNA sequence data set to estimate phylogenetic relationships among species and populations of Maxomys, a genus of rodents endemic to Southeast Asia. Our inclusion of Crunomys as a potential outgroup supported the monophyly of Crunomys, but the genus was deeply nested within Maxomys. Because of the relatively ancient divergences (mean uncorrected p-distances up to 0.15 in cytochrome-b sequences) among species of Maxomys and short branch lengths among basal lineages of the phylogeny, we obtained little support for the oldest relationships in Maxomys Crunomys. However, our analyses revealed unrecognized diversity in the form of divergent populations both between and within islands and the presence of 2 potentially undescribed species from Sulawesi. The Maxomys and Crunomys of Sulawesi belonged to 4 clades sister to extralimital species, suggesting that repeated overwater dispersal between Sundaland–Philippines and Sulawesi was an important isolating mechanism in the history of this group.

Ontogeny is an important source of morphological changes. The combination of size and shape analyses throughout ontogeny helps us to better understand the importance of size and shape from an evolutionary and developmental point of view. Combining geometric and traditional morphometric analyses, we compared skull ontogenetic trajectories of 2 New World didelphimorphian marsupials, Didelphis and Philander. We obtained 32 landmarks and 35 Euclidean distances between these landmarks. Despite secondary sexual dimorphism in both genera, we obtained similar results for both sexes. Allometric comparisons showed similar skull growth patterns and rates. Most of the skull regions had negative allometric growth, except for the zygomatic region. The positive allometric growth of the zygomatic region is possibly related to the transition from lactation to solid food. We investigated size influence in separating genera, comparing analyses based on original and size-free data. Although original data separated both genera, size-free data failed to do so. We found a significant positive correlation between character changes (shape) and size when analyzing growing trajectories, suggesting an allometric change pattern. Geometric morphometrics also corroborated the notion of generic differences being mainly size-related (either scale or allometry). Vectors describing the ontogenetic trajectory were highly similar, both between genera and within each genus throughout ontogeny. Didelphis and Philander share the same orientation in their ontogenetic trajectories because of similar growth rates. However, Didelphis trajectories are relatively longer, indicating an extended growth period. Isometric size changes are responsible for 98.36% of all differences between genera in adult specimens, whereas 1.43% of differences is due to allometric shape variations, and 0.21% is due exclusively to shape variation.

A ontogenia é uma importante fonte de mudanças morfológicas. A análise conjunta do tamanho e forma, ao longo da ontogenia, nos ajuda a entender melhor a importância destas características sob um contexto evolutivo e de desenvolvimento. Usando morfometria tradicional e geométrica, comparamos as trajetórias ontogenéticas cranianas de dois gêneros irmãos de marsupiais Neotropicais da ordem Didelphimorphia, Didelphis e Philander. Utilizando um digitalizador tridimensional, obtivemos 32 marcadores geométricos e 35 distâncias Euclideanas. Observamos dimorfismo sexual secundário em ambos os gêneros, mas ainda assim obtivemos resultados muito similares para cada sexo em algumas análises. Análises alométricas entre os dois gêneros indicaram uma similaridade nas taxas e no padrão de crescimento do crânio. A maioria das regiões cranianas tem crescimento negativamente alométrico, com exceção do zigomático, que é positivo (possivelmente associado a mudança de lactação para ingestão de itens sólidos). Para investigar a importância do tamanho na diferenciação entre os gêneros, comparamos os resultados obtidos a partir dos dados originais e após a remoção do tamanho entre os espécimes. Dados originais separaram os gêneros, o que não ocorreu nos dados livres do tamanho. Análises das trajetórias de crescimento mostraram correlações positivas entre as mudanças nos caracteres (forma) e mudanças no tamanho, indicando um padrão alométrico de crescimento. A morfometria geométrica mostrou que a maior parte das diferenças entre os gêneros está relacionada ao tamanho, seguido por mudanças alométricas. Vetores que descrevem o crescimento de cada gênero mostraram-se altamente similares, tanto entre gêneros, quanto para cada gênero ao longo da ontogenia. Pudemos concluir que Didelphis e Philander compartilham suas trajetórias ontogenéticas, principalmente no que se refere taxas de crescimento. Entretanto, as trajetórias de Didelphis são maiores, indicando que estes e

Reproductive phenologies of populations are strongly molded by environmental variation because natural selection favors individuals that time energetically demanding portions of their life cycle to correspond with periods of high resource availability. To evaluate how seasonal variation in abiotic characteristics and resources affects reproductive strategies, comparison among reproductive phenologies of species that use different resources and across geographic locations is crucial. To facilitate comparisons, it is essential to employ a rigorous and consistent classification scheme. Yet, few studies on the reproductive phenologies of bats, important seed dispersal and pollination agents in the tropics, have employed a clear or consistent classification scheme. We employed concise criteria to classify reproductive phenologies of frugivorous (Artibeus jamaicensis, A. watsoni, Carollia castanea, C. perspicillata, and C. sowelli) and nectarivorous (Glossophaga soricina) bat species, as well as 3 feeding ensembles of phyllostomids in northeastern Costa Rica. All 6 species exhibited bimodal phenologies (2 peaks). Each of the 3 ensembles exhibited different phenologies (i.e., frugivores: bimodal; nectarivores: polymodal [3 peaks]; and gleaning animalivores: unimodal [1 peak]). Bat species that consume plant material evinced pregnancy peaks in the late dry season and middle wet season, whereas gleaning animalivores exhibited a single peak in the middle to late dry season. Examination of geographic and temporal variation in phenologies revealed that strategies of frugivorous and nectarivorous species were geographically and temporally invariant, whereas strategies of gleaning animalivores differed among geographic locations.

Los patrones reproductivos de las poblaciones se ven afectados por la variabilidad en el ambiente. La selección natural favorece a los individuos que sincronizan las fases de su ciclo de vida que son energéticamente costosas con los periodos de alta disponibilidad de recursos. Para evaluar como la variación estacional en factores abióticos y recursos afecta las estrategias reproductivas, es vital realizar comparaciones entre los patrones reproductivos de especies que usan diferentes recursos y diferentes ubicaciones geográficas. Para facilitar comparaciones, es esencial emplear un esquema de clasificación riguroso y constante. Sin embargo, muy pocos estudios sobre fenologías reproductivas de murciélagos, los cuales son agentes importantes de polinización y dispersión de semillas en los bosques tropicales, han empleado esquemas de clasificación claros o consistentes. En el presente estudio, empleamos criterios concisos para clasificar las fenologías reproductivas de 5 especies de murciélagos frugívoros (Artibeus jamaicensis, A. watsoni, Carollia castanea, C. perspicillata, y C. sowelli), un murciélago nectarívoro (Glossophaga soricina), y 3 ensamblajes de phyllostomidos en el noreste de Costa Rica. Las 6 especies exhibieron patrones bimodales (2 picos). Cada uno de los ensamblajes mostro diferentes patrones reproductivos (i.e., frugívoros: bimodal; nectarívoros: polimodal [3 picos]; y insectívoros de follaje: unimodal [1 pico]). Las especies de murciélagos que se alimentan de material vegetal, mostraron picos de gestación al final de la estación seca y a mediados de la estación lluviosa, mientras que los insectívoros de follaje muestran solamente un pico de gestación a mediado

Seeds are an important food resource for many rodents, but the decision to consume or cache seeds when they are encountered can be influenced by numerous factors such as their abundance, nutritional value, and plant secondary compound (PSC) contents. Although previous studies on rodent foraging behaviors have focused on the effects of specific seed characteristics, the combined impact of seed quality and abundance is unclear. Here, we used artificial food patches in the field to examine the foraging behaviors of deer mice (Peromyscus maniculatus) in response to varying abundances of high– and low–nutritional-quality conifer seeds. We also used a variant of giving-up densities to assess mouse perception of the quality of seeds in patches. Mice treated white spruce (Picea glauca) seeds as a high-quality food source in the field, whereas subalpine fir (Abies lasiocarpa) seeds were treated as low quality, corresponding to their nutrient and PSC contents. Observations of foraging behaviors showed a strong interaction between seed abundance and quality on foraging decisions. Caching, but not consumption, rates of spruce seeds varied with seed abundance, but abundance did not influence the frequency or nature of use of fir seeds, which were mostly ignored. High abundance did not confer any value to fir seeds, and even when exaggeratedly abundant relative to naturally available seed densities, mice almost completely disregarded these low-quality seeds as a valuable resource for both current and future use. Our results highlight the relative importance of seed quality in this foraging interaction.

The Drakensberg Midlands, South Africa are experiencing unprecedented levels of habitat change. Despite the serval (Leptailurus serval) being a near-threatened wetland specialist, no studies have investigated their response to land use. To assess their abundance, we used camera trapping at 3 sites differing in intensity of farmland use with capture–recapture models. A total of 1,320 camera trap nights across the 3 sites yielded 26 and 28 servals. We detected no major difference in servals/100 km² among the 3 sites using spatially explicit maximum-likelihood (7.6 ± 2.3; 6.5 ± 2.7; 6.5 ± 2.6) and Bayesian (7.7 ± 1.6; 6.2 ± 1.9; 6.9 ± 2.1) methods in sites A, B, and C, respectively. Servals were mainly crepuscular and nocturnal. The Mardia–Watson–Wheeler test showed significant difference in activity in A and C compared with B, whereas it showed no difference between A and C. Servals avoided activity during the day in the intensively farmed B. Abundance analysis at the broader habitat scale may not have detected variation among sites. Differences need to be tested at smaller spatial scales. The statistical approaches in this study provide the 1st robust estimation of serval population size. This estimation of a medium-sized felid with changing land use can assist their management and conservation.