Phyllostomid bats are a keystone group in the succession of Neotropical plant communities and knowledge of their diet is essential in the study of bat–plant interactions. The most used method to date has been taxonomic identification of the seeds found in bat feces, but this approach underestimates plant species with large seeds that cannot be ingested. With the aim of estimating how much our knowledge of the diet of frugivorous bats changes once we include those species of plants that are underrepresented, we determine the diet of 3 bat species using 18S rDNA V9 metabarcoding. Results were compared with those obtained from morphological identification of seeds found in feces. Using metabarcoding, we identified 20 plant species and with taxonomic identification of seeds, 10 species, with the latter being a subset of the first method. Metabarcoding made it possible to detect a greater number of interactions as well as a greater percentage of the samples were determined to species level. Fifty percent of the plant species (8 species) recorded in the diet of Sturnira hondurensis, 62% (8 species) for Carollia perspicillata, and 50% (4 species) for Artibeus lituratus were exclusively detected with metabarcoding. Plant species with fleshy fruits including Clusia lundellii, Annona cherimola, and Saurauia pedunculata were exclusively detected with metabarcoding and an important item in the diet. The incorporation of molecular biology to determine the diet of 3 species of frugivorous bats made it possible to demonstrate that their diet is more diverse than previously known. Hence, in the field of plant–bat interactions and knowledge of the natural history of species, it is important to consider this new form of analysis.

Los murciélagos filostómidos son un grupo clave en la sucesión de las comunidades de plantas neotropicales y el conocimiento de su dieta es esencial para el estudio de las interacciones murciélago-planta. El método más utilizado hasta la fecha, ha sido la identificación taxonómica de las semillas encontradas en las heces de murciélagos, pero este enfoque subestima las especies de plantas con semillas grandes que no pueden ser ingeridas. Con el objetivo de estimar cuánto cambia nuestro conocimiento sobre la dieta de los murciélagos frugívoros cuando incluimos aquellas especies de plantas que están subrepresentadas, determinamos la dieta de tres especies de murciélagos utilizando metacódigo de barras 18S rDNA V9. Los resultados fueron comparados con los obtenidos mediante la identificación morfológica de semillas encontradas en heces. Usando metacódigos de barras identificamos 20 especies de plantas y 10 especies mediante identificación taxonómica de las semillas; siendo este último, un subconjunto del primer método. Los metacódigos de barras permitieron detectar un mayor número de interacciones, y un mayor porcentaje de muestras fueron determinadas hasta el nivel de especie. El 50 % de las especies de plantas (ocho especies) registradas en la dieta de Sturnira hondurensis, el 62 % (ocho especies) en la dieta de Carollia perspicillata y el 50 % (cuatro especies) en Artibeus lituratus fueron detectadas exclusivamente con metacódigos de barras. Se destacan especies de plantas con frutos carnosos como Clusia lundellii, Annona cherimola y Saurauia pedunculata, porque son un elemento importante en la dieta de los murciélagos y porque fueron detectadas exclusivamente con el metacódigo de barras. Los murciélagos frugívoros son importantes dispersores de semillas y la presencia de estas últimas en las heces de los murciélagos son una clara evidencia de este servicio ecológico. Sin embargo, la incorporación de la biología molecular para determinar la dieta de tres especies de murciélagos frugívoros permitió demostrar que su dieta es más diversa de lo que se conocía hasta ahora. Por lo tanto, en el campo de las interacciones planta-murciélago y para el conocimiento de la historia natural de las especies, es importante considerar esta nueva forma de análisis.

Habitat loss is a leading cause of species endangerment, yet information about habitat is anecdotal for most mammals. The Least Chipmunk (Neotamias minimus) is the most widespread chipmunk in North America and is purportedly a habitat generalist, which should buffer it against habitat loss. However, the southernmost subspecies (Peñasco Least Chipmunk [N. m. atristriatus]) in the Sacramento Mountains of southern New Mexico has declined significantly and has been proposed for listing as endangered under the Endangered Species Act. The declining subspecies presents a conundrum because it could be either a habitat generalist experiencing declines due to factors other than habitat loss or a habitat specialist experiencing habitat loss. We investigated multiscale habitat selection by N. m. atristriatus at the landscape, home-range, and within-home-range scales. We hypothesized that habitat selection by the Peñasco Least Chipmunk would be influenced by plant community type, topography, disturbance, ecological edge, and understory structure. For the landscape scale we conducted surveys using remote cameras and tested predictions using occupancy models. At the home-range and within-home-range scales, we obtained used locations via radiotelemetry and tested predictions by comparing habitat features at used and available locations. At all 3 scales, chipmunks selected for open stands of relatively large trees interspersed with meadows containing low cover provided by shrubs. This specialized vegetation structure was principally provided by a distinctive Engelmann Spruce (Picea engelmannii)–Gooseberry Currant (Ribes montigenum) plant community. Chipmunks avoided disturbance including burnt forests, ski runs, and roads. We conclude that the Peñasco Least Chipmunk is a habitat specialist across multiple scales and that the loss of its required habitat has been the principal cause of its decline.

Availability of food resources is an important driver of survival. Populations must either relocate or adapt to persist in environments where food availability is changing. An optimal diet balances energy gain, water regulation, and nutrition. We used flow-through respirometry to characterize metabolic phenotypes of the desert-adapted Cactus Mouse (Peromyscus eremicus) under diurnally variable environmental conditions that mimic that of the Sonoran Desert. We treated mice with 2 different energetically equivalent diets, a standard diet and a low-fat diet, and measured energy expenditure, water loss rate, respiratory quotient, weight, and electrolyte levels. Mice fed the low-fat diet lost significantly more water than those on the standard diet. Despite being desert-adapted, our results suggest that cactus mice may have limited capacity to tolerate water deprivation if optimal foods become less abundant. Given that climate change is predicted to modify the distribution of food items, understanding these links may have important implications for long-term population viability for desert and non-desert-adapted animals alike.

La disponibilidad de recursos alimenticios es un factor crucial para la supervivencia. Las poblaciones deben reubicarse o adaptarse para persistir en entornos donde la disponibilidad de alimentos es cambiante. Una dieta óptima equilibra la obtención de energía, la regulación del agua y la nutrición Utilizamos respirometría de flujo continuo para caracterizar los fenotipos del ratón de Cactus (Peromyscus eremicus) bajo condiciones ambientales diurnas variables que imitan sus condiciones ambientales en el Desierto de Sonora. Alimentamos a los ratones con dos dietas energéticamente equivalentes, una dieta estándar y una dieta baja en grasas, y medimos el gasto energético, la tasa de pérdida de agua, el cociente respiratorio, el peso y los niveles de electrolitos. Los ratones alimentados con la dieta baja en grasas perdieron significativamente más agua que los que fueron alimentados con la dieta estándar. Aunque estan adaptados al desierto, nuestros resultados sugieren que los ratones de Cactus pueden tener una capacidad limitada para tolerar la deprivación de agua si los alimentos óptimos se vuelven menos abundantes. Dado que se predice que el cambio climático modificará la distribución de los recursos alimenticios, comprender estos vínculos puede tener implicaciones importantes para la viabilidad poblacional a largo plazo tanto de animales que están adaptados al desierto como los que no lo están.

Social monogamy is rare in mammals, but in those species in which it occurs, individuals frequently engage in extra-pair copulation (EPC). Numerous hypotheses have been proposed to explain EPC, but relatively few field studies have examined factors influencing EPC in socially monogamous mammals. Prairie voles (Microtus ochrogaster) are a socially monogamous rodent in which extra-pair paternity (EPP) is common. Using genetic data from a 3-year study of a natural population of prairie voles, we investigated whether the negative consequences of inbreeding and the structure of social units (male–female pairs vs. groups; adult sex ratio within groups) were factors affecting EPC. We found strong evidence that genetic similarity between males and females that produced offspring via EPC was less than that between social partners, as would be expected if avoiding inbreeding depression influenced the occurrence of EPC. Social unit structure was also a factor involved with extra-pair parentage. Contrary to our expectations, the greater the proportion of females in the group, the lower the chance of EPC resulting in offspring production by females, and, similarly, the chance of EPP by males declined as the proportion of males within the group increased. However, neither males nor females were more likely to produce offspring from EPC when they were living in pairs versus groups. One implication of these results is that EPC may be influenced more by female behaviors, such as mate choice, than male mate guarding. Overall, our results suggest that the proximate factors influencing EPC in prairie voles are complex but include the cost of inbreeding depression and the structure of social units.

Dispersal is common in mammals and can have an important role in shaping demography, genetics, distribution, and social structure. Dispersal entails potential costs but also potential benefits, and the dispersal decision is thought to be conditional; the potential disperser assesses prospects for success at its current location and disperses to improve its fitness. However, the costs and benefits of dispersal, as well as factors influencing the dispersal decision, are not well known. We used trapping and observation to study dispersal in the Golden-mantled Ground Squirrel (Callospermophilus lateralis), a species for which dispersal is largely unknown. We characterized the dispersal process by evaluating dispersal timing and distance, assessed factors that might influence the dispersal decision, and analyzed the fitness cost of dispersal after settlement. We found that most dispersal occurred during the summer of birth, as is expected for a small-bodied sciurid. However, some squirrels delayed dispersal until early in their yearling summer. Dispersal was male-biased in dispersal tendency, and it was also male-biased in dispersal distance, but only over shorter dispersal distances. The dispersal decision for juvenile females appeared to originate as soon as 10 days after they emerged from the natal burrow, and the decision was not associated with body mass or several measures of competition. Instead, dispersal of juvenile females was associated with the number of littermate sisters, with each sister present increasing the likelihood of dispersal by 26%. Littermate sisters might be a cue foretelling the effects of kin competition the following year. We did not find a significant difference in lifetime reproductive success between philopatric and dispersing females after settlement, suggesting that for golden-mantled ground squirrels, any cost of dispersal is experienced primarily during the transience phase.

Congeneric fox squirrels (Sciurus niger) and eastern gray squirrels (S. carolinensis) compete for resources within North American temperate forests. Both species exhibit regional variation in morphology and behavior—potentially due to differences in geography, community composition, or ecological pressures between forested regions. While many have studied these species in other forested regions of the United States, recent assessments of partitioning between these species in Central Hardwood forests remain scarce. We investigated spatial and temporal partitioning between squirrel species using photographic captures from camera traps at 2 scales (i.e., camera location and camera cluster) across a 16,058-km² region of southern Illinois, United States, during January to April 2008 to 2010. We fitted single-season single-species and co-occurrence occupancy models to assess spatial partitioning at both scales and used kernel density analysis to assess temporal partitioning. We recorded 3,044 photographic captures of focal species (n = 918 fox squirrels and 2,126 eastern gray squirrels). Fox Squirrel occupancy was 0.26 ± 0.09 (SE) and 0.50 ± 0.17 at the camera location and camera cluster scales, respectively. Eastern Gray Squirrel occupancy was 0.47 ± 0.07 and 0.84 ± 0.23 at the camera location and camera cluster scales, respectively. Fox Squirrel occupancy increased with further distances to roads and had scale-dependent relationships to forest structure. Eastern Gray Squirrel occupancy increased with more hardwood basal area. Co-occurrence was influenced by distance to road at the camera location scale. We found a moderate level of activity overlap between species (Δ = 0.63, CI = 0.60 to 0.67); however, no evidence of temporal partitioning was observed. Habitat characteristics and spatial scale appear more influential in partitioning eastern gray and fox squirrels in Central Hardwood forests than peak activity.

Urbanization is a key driver of habitat loss and fragmentation worldwide, yet many urban ecosystems contain vegetated habitat patches that support diverse wildlife communities. Managing urban systems to support robust wildlife communities requires us to understand the mechanisms that drive the response of species to the urban environment. Small mammals are key components of terrestrial ecosystems (e.g., seed predators, prey) and likely also carry out these roles in urban ecosystems; however, the effects of urbanization on small mammal communities are understudied. To identify how species-specific responses to urban environments shape community composition, we quantified both overall community and species-specific changes in small mammal abundance across an urbanization gradient in a Midwestern US metropolitan area. We combined small mammal trapping and land cover data to generate a hierarchical community abundance model. Species diversity increased with increasing proportional cover of human-modified land cover (i.e., impervious surfaces and turfgrass). This finding is driven by high species diversity on sites bordering streams in mowed parks and low diversity on sites with high tree canopy closure. Additionally, modeling results indicated that species responded differently to landscape attributes, leading to variation in small mammal community composition across the urbanization gradient: prairie-associated species tended to be more abundant in tall vegetation bordering mowed parks while habitat generalists tended to be more abundant on sites with greater canopy closure and shrub cover. Our results suggest studies that focus on community-level responses (e.g., species richness) to urbanization may miss important species-specific responses. It may be particularly important to assess both species-specific and community-level responses in cities at ecotones (e.g., between forest and grassland) where species with different habitat requirements may replace one another in different types of green spaces, thereby changing community composition without affecting species diversity or richness. Our findings also indicate that vegetated urban patches, especially patches with tall vegetation cover and low canopy cover, are important habitat for prairie-associated small mammal communities, providing conservation options in heavily altered landscapes.

Urbanization promotes habitat degradation because it involves irreversible processes that homogenize habitats and favor the exclusion of native species. This research evaluates rodent community structure at different levels of urbanization in Misiones, Argentina. We expect that rodent communities are less diverse in more highly urbanized areas and that communities differ between each level of urbanization. To assess these hypotheses, rodent capture sessions were carried out from July 2017 to March 2020, totaling 21,985 trap-nights. Alpha and beta diversity were calculated for each level of urbanization. We captured a total of 684 individuals belonging to 8 sylvan-native and 2 commensal-exotic species. Species richness was greatest and evenness was lowest in natural protected areas. The native species Akodon montensis was the most abundant, while the remaining 7 native species represented less than 23% of the total of captures. The rural area showed the second-highest richness, and the community was principally represented by 2 native and 2 exotic species. The periurban area was ranked third in richness and with the highest evenness, dominated by A. montensis followed by Mus musculus and Rattus rattus. The urban area exhibited the lowest richness represented only by the 2 commensal-exotic species. In agreement with our expectations, these results show a negative association between urbanization level and small rodent diversity, evidenced by a reduction in the number of native species in highly urbanized areas.

La urbanización promueve la degradación del hábitat porque implica procesos irreversibles que homogenizan los hábitats y favorecen la exclusión de especies nativas. Esta investigación evaluó la estructura de la comunidad de roedores en diferentes niveles de urbanización en Misiones, Argentina. Esperamos que las comunidades sean menos diversas en las áreas más urbanizadas y que las comunidades difieran entre cada nivel de urbanización. Para evaluar estas hipótesis, se realizaron campañas de captura viva de roedores desde julio de 2017 hasta marzo de 2020, totalizando 21,985 trampas-noches. Se calculó la diversidad alfa y beta para cada nivel de urbanización. Se capturaron un total de 684 individuos de ocho especies silvestres-nativas y dos comensales-exóticas. La riqueza de especies fue mayor y la equitatividad menor en el área natural protegida. La especie nativa Akodon montensis fue la más abundante, mientras que las siete especies restantes representaron, en conjunto, menos del veintitrés por ciento del total de capturas. El área rural fue la segunda en riqueza y la comunidad estuvo representada principalmente por dos especies nativas y dos exóticas. El área periurbana ocupó el tercer lugar en riqueza de especies de roedores, representada por A. montensis, seguida de Mus musculus y Rattus rattus, siendo la zona con mayor equitatividad. El área urbana presentó la menor riqueza de especies de roedores, representada únicamente por las dos especies comensales-exóticas. De acuerdo con nuestra hipótesis estos resultados muestran una asociación negativa entre el nivel de urbanización y la diversidad de pequeños roedores, evidenciada por una reducción en el número de especies nativas en las áreas más urbanizadas.

Animals that experience a food-scarce season can supplement their diet by scatterhoarding, or burying food around their home range, and then retrieving and consuming those food items at a later date. Theft, or pilferage, is considered the greatest risk to stored food; yet little is known about the pilferage risk of different types of seeds. We investigated the long-term relative pilferage risk of 793 artificially scatterhoarded seeds (Mockernut Hickory, Carya tomentosa (Lam. Ex Poir.) Nutt.; American Beech, Fagus grandifolia Ehrh.; White Oak, Quercus alba L.; Water Oak, Quercus nigra L.) buried in Alabama from October 2020 to February 2021 and exposed to hoarding populations of eastern gray squirrels (Sciurus carolinensis Gmelin, 1788) and eastern chipmunks (Tamias striatus (L., 1758)). We found evidence that animals can selectively pilfer whole, dormant seeds and whole seeds were pilfered more rapidly than those with excised embryos. Whole Water Oak acorns were more likely to be pilfered than all other seed types. All seeds had a combined pilferage risk of 0.98 over 182 days, and the risks for individual seed types were all greater than 0.97. Our findings indicate the importance of pilferage reduction strategies documented in hoarding species and may indicate an advantage to having a diverse supply of hoarded foods that include lower-value seeds with lower pilferage risk.

The threat of predation can influence the behavior of animals. To minimize the impact of predation, animals rely on antipredatory responses and effectively balance these responses with other activities to maximize survival. Boreal bats are nocturnal animals that must forage within a narrow time frame during short, light summer nights with unpredictable weather. Despite having no specialized predators, boreal bats are still subject to predation. However, whether they express antipredatory responses has not been established. We studied antipredatory responses and responses to climatic conditions in boreal bats in 2 settings: 1) during roost emergence; and 2) during foraging within Tawny Owl territories and at locations with no Tawny Owl sightings. Acoustic data were collected at 23 roosts and 10 foraging grounds. Two controlled predation threats were used—playbacks of Tawny Owl calls and fledgling calls. Fledgling calls were only played during roost emergence. In both experiments, music and no treatment were used as controls. We also incorporated weather variables in the model. According to our results, bats tend to delay their emergence by 16 min when Tawny Owl calls were played outside the roost, but this effect was not noticeable when weather variables were included. There was no difference in exit time when music or fledgling sounds were played. While foraging, bats reduced their activity in Tawny Owl territories when calls of owls or music were played compared to no treatment. These results suggest that bats might display variable antipredatory responses, but weather influences behavior of bats more than predation risk, highlighting the importance of energy-saving strategies at northerly latitudes.

Introduced species are one of the leading causes of declining global biodiversity and result in many billions of dollars of losses to the bioeconomy worldwide. Introduced species have become increasingly common due to globalization and climate change, and population genetics is a useful tool for the management of such species. The Eastern Fox Squirrel (Sciurus niger) is a highly successful invader that was introduced to many states in western North America throughout the 20th century. We used low-pass whole genome sequencing to evaluate phylogeographic structure across native and introduced ranges of this species and identify the putative number and geographic sources of introductions in California and Utah. We found minimal patterns of phylogeographic structure, consistent with recent range and population expansion since the Last Glacial Maximum. Additionally, we found evidence for multiple mitochondrial haplotypes in California and only 1 haplotype in Utah, which suggests that fox squirrels in California were sourced from multiple introduction events while those in Utah were likely sourced from a single event. Genomic resources generated in this study will be useful for future conservation efforts in this species and will assist with the ongoing management of its introductions across western North America.

Especies introducidas son una de las principales causes de la disminución mundial de la biodiversidad y resultan en pérdidas de miles de millones de dólares para la bioeconomía mundial. La genética de poblaciones es un instrumento útil para el manejo de estas especies, cada vez más comunes debido a la globalización y el cambio climático. La ardilla zorro oriental (Sciurus niger) es una especie invasora exitosa que se introdujo en muchos estados del oeste de América del Norte a lo largo del siglo XX. Utilizamos secuenciación de baja cobertura del genoma para evaluar la estructura filogeográfica de la ardilla zorro oriental a través sitios nativos e introducidos, para identificar el número de introducciones en los estados de California y Utah, y para determinar orígenes geográficos de estas introducciones. Encontramos una señal mínima de estructura filogeográfica, consistente con la reciente expansión de rango y población de esta especie desde el ultimo Máximo Glacial. Además, encontramos múltiples haplotipos mitocondriales en California y solo uno haplotipo en Utah. Esto sugiere que en California, la ardilla zorro oriental se originó de múltiples eventos de introducción, mientras en Utah se originó a partir de un solo evento. Los recursos genómicos de este estudio serán útiles para futuros proyectos de conservación de esta especie y ayudarán con la gestión de sus introducciones en el oeste de América del Norte.

The “small-eared” species group of Urocitellus ground squirrels (Sciuridae: Xerinae: Marmotini) is endemic to the Great Basin, United States, and surrounding cold desert ecosystems. Most specific and subspecific lineages in this group occupy narrow geographic ranges, and some are of significant conservation concern; despite this, current taxonomy remains largely based on karyotypic or subtle pelage and morphological characteristics. Here, we leverage 2 multilocus DNA sequence data sets and apply formal species delimitation tests alongside morphometric comparisons to demonstrate that the most widespread small-eared species (U. mollis Kennicott, 1863 sensu lato; Piute Ground Squirrel) is comprised of 2 nonsister and deeply divergent lineages. The 2 lineages are geographically separated by the east-west flowing Snake River in southern Idaho, with no sites of sympatry currently known. Based on robust support across the nuclear genome, we elevate populations previously attributed to U. mollis from north of the Snake River to species status under the name Urocitellus idahoensis (Merriam 1913) and propose the common name “Snake River Plains Ground Squirrel” for this taxon. We delimit 2 subspecies within U. idahoensis; U. i. idahoensis (Merriam 1913) in western Idaho and U. i. artemesiae (Merriam 1913) in eastern Idaho. Urocitellus idahoensis is endemic to Idaho and has a maximal range area of roughly 29,700 km² spanning 22 counties but occurs discontinuously across this area. Our work substantially expands knowledge of ground squirrel diversity in the northern Great Basin and Columbia Plateau and highlights the difficulty in delimiting aridland mammals whose morphological attributes are highly conserved.

Kit foxes represent a small canid in semi-arid and arid regions in the southwestern United States. The San Joaquin Kit Fox (Vulpes macrotis mutica) is listed as federally endangered, and based on more recent studies, populations of the Nevada Kit Fox (V. m. nevadensis) are declining in Utah. These 2 subspecies show a loss of genetic variation in response to population declines. Various anthropogenic activities threaten kit foxes throughout other regions of their distribution, but less is known about the basic biology and genetics of other subspecies of kit foxes. Here, we used sequences from the mitochondrial cytochrome b (Cytb) gene and 12 DNA microsatellites to investigate patterns of genetic variation and test for mating fidelity in a population of the socially monogamous Desert Kit Fox, V. m. arsipus. In the current study, the mitochondrial haplotype diversity (Hd) was higher than or comparable to other canids and terrestrial mammals. The mitochondrial results also provided evidence for male-biased dispersal and female philopatry. Expected heterozygosity (He) and number of alleles per locus (Na) for the 12 microsatellite loci were higher relative to other species of foxes and canids. As seen for nearly all species of socially monogamous canids, 17% of the pups of the mated pairs of the Desert Kit Fox revealed evidence of extra-pair mating, a value like small canids. Additionally, we observed 1 case of mate switching between breeding seasons, even though the previous mate was still alive. These data suggest that long-term pair bonding may not be as extensive as once thought.

Texas exhibits one of the richest levels of pocket gopher diversity in the United States. Three genera (Cratogeomys, Geomys, and Thomomys) and 11 species are found in Texas. It is not surprising given the diversity of the Texas landscape (ecoregions, life zones, substrates, and vegetation) that these species are further subdivided into 29 subspecies in Texas alone. Pocket gopher distributions are determined by availability of suitable soil types and therefore often occur in small, isolated populations. For some taxa, limited distribution and ultimately small deme sizes result in populations that may require attention from a regulatory and management perspective. For many Texas pocket gopher subspecies, insufficient information exists to make sound recommendations relative to conservation status and needs despite decades of research collecting and evaluating data based on morphometrics, distributions and habitat preferences, karyotypes, allozymes, and mitochondrial DNA. As such, there is precedent for elevating pocket gopher subspecies to species after evaluation of available data, as well as subsuming subspecies into a broader taxonomic group. We used genomic techniques to identify genetically defined operational taxonomic units (OTUs) of pocket gophers to improve knowledge and understanding of pocket gopher distributions within the state. Using tens of thousands of single nucleotide polymorphisms, we determined the number of OTUs in each genus to be 5 for Thomomys bottae subspecies, 8 for Geomys species, and 5 for Cratogeomys castanops subspecies in Texas. In general, these data agree with current taxonomic hypotheses regarding Geomys and C. castanops; however, many T. bottae groups present similar genetic patterns that do not merit subspecies status based on these data, suggesting a more conservative classification of T. bottae in Texas and southeastern New Mexico that could facilitate conservation efforts, should they be necessary.

Texas presenta uno de los niveles de diversidad de tuzas (gofers de bolsillo) más altos de los Estados Unidos de América. En Texas se encuentran tres géneros, Cratogeomys, Geomys y Thomomys, y once especies. Esto no es sorprendente, dada la diversidad del paisaje de Texas (ecorregiones, zonas de vida, sustratos y vegetación), que estas especies estén subdivididas en 29 subespecies. Las distribuciones de las tuzas están determinadas por la disponibilidad de tipos adecuados de suelo y, por lo tanto, a menudo corrresponden a poblaciones pequeñas y aisladas. Para algunos taxones, la distribución limitada y, en última instancia, los grupos de pequeño tamaño resultan en poblaciones que pueden requerir atención desde una perspectiva regulatoria y de gestión. Para muchas subespecies de tuzas de Texas existe información insuficiente para hacer recomendaciones sólidas sobre el estado y las necesidades de conservación, a pesar de décadas de investigación que recopilan y evalúan datos basados en morfometría, distribuciones y preferencias de hábitat, cariotipos, alozimas y ADN mitocondrial. Así pues, existe un precedente para elevar las subespecies de tuzas a especies después de evaluar los datos disponibles, así como para incluir las subespecies en un grupo taxonómico más amplio. Utilizamos técnicas genómicas para identificar unidades operativas de taxonomía definidas genéticamente (OTUs) de tuzas para mejorar el conocimiento y la comprensión de las distribuciones de dentro del estado. Usando decenas de miles de polimorfismos de nucleótido único (SNPs), determinamos que el número de OTUs en cada género es 5, 8 y 5, para las subespecies de Thomomys bottae, las especies de Geomys y las subespecies de Cratogeomys castanops, respectivamente, en Texas. En general, estos datos coinciden con las hipótesis taxonómicas actuales sobre Geomys y C. castanops; sin embargo, muchos grupos de T. bottae presentan patrones genéticos similares que no justifican el estatus de subespecie basado en estos datos, lo que sugiere una clasificación más conservadora de T. bottae en Texas y el sureste de Nuevo México que podría facilitar los esfuerzos de conservación, si fueran necesarios.

Vespertilionidae is a species-rich family of bats that experienced rapid diversification events and contains many morphologically conserved taxa, resulting in challenges to taxonomic and phylogenetic resolution for members of this family. One example of a challenging group is the pipistrelles, which several studies have recovered as paraphyletic. Pipistrellus nathusii is noteworthy for being recovered either as sister to other European Pipistrellus species, more closely related to Nyctalus, or sister to the clade comprising Nyctalus and European Pipistrellus species. Using a core data set of 6 nuclear introns, and an extended data set of 10 nuclear introns, we employ multiple independent phylogenetic methods that are robust in the presence of incomplete lineage sorting or hybridization to resolve the placement of P. nathusii. In addition, our data confirm the distinction of the Asian Pipistrelle taxa which form a distinct genus sister to the clade comprising Vansonia, Pipistrellus, and Nyctalus.

The Tricolored Bat (Perimyotis subflavus) has suffered significant population declines in much of its geographic range due to white-nose syndrome (WNS). Our aim was to describe the torpor patterns of tricolored bats within the southeastern United States to further our understanding of their winter ecology and potential susceptibility to WNS in currently unimpacted areas based on data from bats in both a WNS-affected hibernaculum and an unaffected hibernaculum. We placed temperature-sensitive radio transmitters on tricolored bats in a site in northwestern South Carolina that was WNS-positive and another site in northwestern Florida that was WNS-negative, and determined torpid and arousal skin temperatures (T_SK), torpor bout duration (TBD), and arousal duration (AD) during 3 winters. Mean hibernacula temperature (T_H) and vapor pressure deficit (VPD_H) in both hibernacula were within the range of optimal Pseudogymnoascus destructans (Pd) growth (T_H = 12.7 to 13.6 °C, VPD_H = 0.028 to 0.059 kPA). Mean torpid T_SK was 15.7 ± 0.1 °C and mean TBD was 4.1 ± 0.2 days across sites. Sex was the best predictor of TBD with males having significantly longer TBD than females. Torpid T_SK was positively related to T_H and negatively related to VPD_H. Because the T_SK of a bat was similar to the optimal growth temperatures of Pd, our findings suggest that even though winters in the southeastern United States are more benign than in other parts of the Tricolored Bat range, the warmer temperatures in southern hibernacula may provide optimal conditions for the growth of Pd. Greater understanding of the physiological responses of tricolored bats in hibernacula across their range will provide important data on the potential for WNS morbidity and mortality in unaffected areas and allow for a better distribution of resources for prevention and treatment of WNS.

El pipistrelo del este americano (Perimyotis subflavus) ha sufrido importantes disminuciones poblacionales en gran parte de su distribución geográfica debido al síndrome de la nariz blanca (WNS). Nuestro objetivo fue describir los patrones de torpor del murciélago tricoloreado en el sureste de EE. UU. para mejorar nuestra comprensión de su ecología invernal y su susceptibilidad potencial al WNS en áreas actualmente no afectadas, con base en datos de murciélagos en sitios afectados y no afectados por el WNS. Colocamos transmisores de radio sensibles a la temperatura en pipistrelos del este americano en dos hibernáculos, uno en el noroeste de Carolina del Sur que fue positivo para WNS, y el otro en el noroeste de Florida que fue negativo para WNS, y determinamos las temperaturas cutáneas (T_SK) de torpor y al despertar, la duración del evento de torpor (TBD) y la duración del despertar (AD) durante tres inviernos. La temperatura media del hibernáculo (T_H) y el déficit de presión de vapor (VPD_H) en ambos hibernáculos estuvieron dentro del rango de crecimiento óptimo del hongo patógeno Pseudogymnoascus destructans [Pd] (T_H = 12.7-13.6 °C, VPD_H = 0.028-0.059 kPA). La T_SK media durante el torpor fue de 15.7 ± 0.1 °C y la TBD media fue de 4.1 ± 0.2 días en todos los sitios. El sexo fue el mejor predictor de la TBD, con los machos teniendo una TBD significativamente más prolongada que las hembras. La T_SK durante el torpor tuvo relación positiva con la T_H y negativa con el VPD_H. Debido a que la T_SK de los murciélagos fue similar a las temperaturas óptimas de crecimiento de Pd, nuestros hallazgos sugieren que, aunque los inviernos en el sureste de EE. UU. son más benignos que en otras partes de la distribución del murciélago tricoloreado, las temperaturas más cálidas en los hibernáculos del sur pueden proporcionar condiciones óptimas para el crecimiento de Pd. Una mejor comprensión de las respuestas fisiológicas de los murciélagos tricoloreados en hibernáculos en toda su área de distribución proporcionará información importante sobre el potencial de morbilidad y mortalidad por WNS en áreas no afectadas y permitirá una mejor distribución de recursos para la prevención y el tratamiento del WNS.

Within the diverse carnivore guilds of eastern and southern Africa, Black-backed Jackal (Lupulella mesomelas) populations are stable and thriving, unlike hundreds of mammal species in Africa that are adversely affected by human-mediated habitat loss and hunting. Population stability may be due to the extremely broad diet of the Black-backed Jackal or behavioral flexibility allowing dietary shifts to more prevalent resources. To assess geographic, seasonal, and historical dietary variation and change, we analyzed the diet in the Cape (L. m. mesomelas) and East African (L. m. schmidti) subspecies of Black-backed Jackal through dental microwear texture analysis from 1896 to 1970. We found no significant differences across geographically distinct subspecies or season. However, greater complexity was observed in the East African Black-backed Jackal after 1920—a period of population growth and industrialization in Sub-Sharan Africa. Our results imply that despite local differences in habitat, prey, and carnivorous contemporaries, dietary mechanical properties of Cape and East African black-backed jackals were relatively similar, representative of truly expansive and variable diets or similar utilization of different food items. Higher complexity over time implies a shift toward greater brittle food utilization, possibly in the form of bones and hard seeds, or greater contact with exogenous grit. We discuss these results in the context of mammal habitat loss and population decline, as well as increasing anthropogenic impact in Sub-Saharan Africa.

To study patterns in behavior, fitness, and population dynamics, estimating the age of the individuals is often a necessity. Specifically, age estimation of young animals is very important for animal rehabilitation centers because it may determine if the animal should be taken in and, if so, what care is optimal for its rehabilitation. Accurate age estimation is also important to determine the growth pattern of an individual, and it is needed to correctly interpret the influence of early body condition on its growth trajectories. The purpose of our study was to find body measurements that function as good age estimators in young (up to 3 months old) harbor seals (Phoca vitulina vitulina), placing emphasis on noninvasive techniques that can be used in the field. To meet this goal, body mass (BM), dorsal standard length (DSL), upper canine length (CL), body condition (BC), and sex were determined from 45 Harbor Seal pups of known age. Generalized additive mixed models were fitted to find how well these morphometric measures predicted age, and the results from the selected model were used to compute growth curves and to create a practical table to determine the age of young animals in the field. We found that both DSL and CL—and to some extent sex—were useful predictors for estimating age in young harbor seals and that the growth rate of pups raised in captivity is significantly lower than for those raised in the wild. In addition, we found no evidence for compensatory growth, given that animals that arrived at the center with a poor BM or BC continued to show lower BM or BC throughout almost the entire rehabilitation period.

Para estudiar patrones de comportamiento, eficacia biológica y dinámica poblacional, a menudo es necesario estimar la edad de los individuos. Específicamente, la estimación de la edad de animales jóvenes es muy importante para los centros de rehabilitación, ya que puede determinar si el animal joven debe ser ingresado y, en caso afirmativo, qué cuidados específicos serían los óptimos para su rehabilitación. La estimación precisa de la edad también es importante para determinar el patrón de crecimiento de un individuo, y es necesaria para interpretar correctamente la influencia de la condición corporal temprana en sus trayectorias de crecimiento. El propósito de nuestro estudio era encontrar medidas corporales que funcionen como buenos estimadores de edad en focas comunes jóvenes (de hasta 3 meses de edad; Phoca vitulina vitulina), poniendo énfasis en técnicas no invasivas que puedan usarse en el campo. Para alcanzar este objetivo, se ha medido la masa corporal (BM), la longitud dorsal estándar (DSL), la longitud del canino superior (CL), la condición corporal (BC) y el sexo de 45 crías de foca común de edad conocida. Se ha aplicado modelado estadístico para determinar la eficacia de las medidas morfométricas para predecir la edad, y los resultados del modelo seleccionado se han usado para calcular las curvas de crecimiento y crear una tabla práctica para usar en el campo. Descubrimos, por un lado, que tanto DSL como CL, y hasta cierto punto el sexo, parecen ser predictores importantes para estimar la edad en focas comunes jóvenes, y, por otro, que la tasa de crecimiento de las crías alimentadas en cautividad es significativamente menor que la de las criadas en la naturaleza. Además, no encontramos evidencia de crecimiento compensatorio, dado que los animales que llegaron al centro con una mala masa o condición corporal continuaron mostrando una masa o condición corporal más baja durante casi todo el período de rehabilitación.

In mammals, a temporary endocrine gland called the corpus luteum forms on the ovary shortly after ovulation and is required for the initiation and maintenance of early pregnancy. However, the corpus luteum persists even when fertilization or pregnancy does not occur, and species-specific variation in the length of this persistence remains enigmatic. Here we perform a comparative evolutionary study across 72 species and show that corpus luteum lifespan in nonpregnant females is positively correlated with gestation length. We argue that the most likely explanation for this correlation is physiological inertia. The corpus luteum begins secreting progesterone prior to implantation, and when pregnancy does not occur it takes time for females to degrade it and prepare the next reproductive cycle. Our study suggests that this physiological inertia is stronger in species with long gestation times.

The morphological plasticity of the Sus scrofa wild–domestic species complex is evident in both free-ranging morphotypes and domestic breeds. The Brazilian Pantanal feral hog (“porco-monteiro”) evolved after a long-term feralization process and represents a significant proportion of the mammalian biomass in the region. Its coexistence with native fauna brings several ecological impacts, which are mitigated by the Brazilian Pantanal wetland vastness and resource availability. They are a local subsistence game resource but also impact crops and pastures. Around the 2000s to mid-2010s, numerous European wild boar were introduced in Brazil to fulfill a demand for gourmet meat. Wild boar was also introduced to the Brazilian Pantanal as a game species and to breed with porco-monteiro feral hogs in a commercial venture to produce an even more exotic meat. The craze for wild boar meat has since dwindled, but their populations remain widespread and uncontrolled. Moreover, the full impact of the wild boar introduction on feral hog populations is still unknown. This study analyzes the skulls of porco-monteiro feral hogs from the 1990s, 2000s, and 2010s to assess possible morphological and functional variations along with skulls of wild boar and hybrids from Argentina, Uruguay, and Southern Brazil. The results indicate a trend of broadening of feral hog skulls at the coronal plane and a progressive reduction of the semispinalis capitis muscle scars over the decades. Biomechanical analysis denoted a decrease in head-elevation force that could affect the rooting performance of the latest feral hog morphotypes. Taken together, results show that wild boars likely influenced the evolution of the Pantanal feral hog skull. The magnitude of ecomorphological implications of these morphofunctional changes is unknown, as well as its effects in the Brazilian Pantanal wetland ecology.

A plasticidade morfológica da espécie Sus scrofa fica evidente na complexidade dos morfotipos de vida livre e das raças domésticas. O porco feral do Pantanal brasileiro (porco-monteiro) evoluiu após um processo de feralização de longo prazo e tem peso significativo na biomassa regional de mamíferos. Sua convivência com a fauna nativa traz diversos impactos ecológicos, que são mitigados pela vastidão do Pantanal brasileiro e pela disponibilidade de recursos. Eles são um importante recurso como caça de subsistência, mas também impactam plantações e pastagens. Por volta dos anos 2000 e meados de 2010, o javali europeu foi massivamente introduzido no Brasil para atender uma demanda por carne gourmet. Também foi introduzido no Pantanal brasileiro como espécie cinegética e para procriar com o porco-monteiro em um empreendimento comercial para produzir uma carne ainda mais exótica. A mania pela carne de javali diminuiu, mas diversas populações ficaram dispersas e sem controle. Ainda assim, a extensão total do impacto da introdução de javalis nas populações de porcos selvagens é desconhecida. Este estudo analisou crânios de porcos ferais pantaneiros das décadas de 1990, 2000 e 2010 para avaliar possíveis variações morfológicas e funcionais. Também analisamos crânios de javalis e híbridos da Argentina, Uruguai e Sul do Brasil. Os resultados indicam uma tendência de alargamento no plano coronal do crânio dos porcos ferais, mas uma redução progressiva das cicatrizes do músculo semispinalis capitis ao longo das décadas. A análise biomecânica indicou uma diminuição na força de elevação da cabeça que poderia afetar a eficiência no hábito de fuçar o solo nos morfotipos mais recentes de porcos-monteiros. O conjunto dos resultados demonstra que os javalis provavelmente influenciaram a evolução do crânio do porco-monteiro. A magnitude das implicações ecomorfológicas dessas mudanças morfofuncionais é desconhecida, assim como seus efeitos na ecologia do Pantanal brasileiro.

The process of describing a species has evolved considerably since the modern age of taxonomy was initiated with the publication of the 10th edition of Linnaeus' Systema Naturæ in 1758. Nevertheless, the basic unit of the taxonomic framework remains the species group (species and subspecies). As a result, it is incumbent upon individuals undertaking species-group descriptions to strive for the highest standards, just as it is for reviewers and editors to hold authors to those same standards. The clear and mounting biodiversity crisis, the increasing proliferation of journals, the multiplication of journals publishing only in electronic format, the decline in the number of trained taxonomists, and the complex and at times misinterpreted wording of the rules governing taxonomy have resulted in a growing number of species names that are unavailable because one or more aspects required of a species-level taxonomic description are lacking. Here, we present best practices for the required elements of a taxonomic description and identify some of the common pitfalls leading to an inadequate description resulting in an unavailable name. We also suggest best practices that would enhance taxonomic descriptions and make them more informative.

El proceso de descripción de una especie ha evolucionado considerablemente desde que se inició la era moderna de la taxonomía con la publicación de la 10^a edición del Systema Naturæ de Linneo en 1758. No obstante, la unidad básica del marco taxonómico sigue siendo el grupo de la especie, es decir: las especies y subespecies. Por ello, aquellos quienes realizan descripciones de entes en estas categorías taxonómicas deben esforzarse por alcanzar los más altos niveles de calidad, al igual que los revisores y editores, quienes deben exigir a los autores que se atengan a esos mismos niveles. La evidente y creciente crisis de la biodiversidad, la creciente proliferación de revistas, la multiplicación de revistas que publican sólo en formato electrónico, la disminución del número de taxónomos formados y la compleja y a veces malinterpretada redacción de las normas que rigen la taxonomía, conjuntamente han dado lugar a un número cada vez mayor de nombres de especies que no son disponibles desde el punto de vista taxonómico porque faltan uno o más aspectos requeridos por las reglas de nomenclatura taxonómica para una descripción taxonómica a nivel de especie. A continuación, presentamos las mejores prácticas para los elementos requeridos de una descripción taxonómica e identificamos algunos de los escollos comunes que conducen a una descripción inadecuada que resulta en un nombre no disponible, es decir, no válido taxonómicamente. También sugerimos buenas prácticas para mejorar las descripciones taxonómicas y hacerlas más informativas.