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The insular radiation of hutias is remarkable among mammals for its high rate of extinction during the Holocene (∼58% of species), yet fragments of intact habitat throughout the West Indies retain a critical portion of endemic diversity needing assessment. Cuba contains 8 of the 11 recognized living species of hutias, with surviving forms also on Hispaniola, Jamaica, and the Bahamas. Herein, we performed molecular phylogenetic analyses across populations of Cuban hutias in the genera Capromys, Mesocapromys, and Mysateles to address major gaps in our understanding of their species limits, phylogenetic structure, and geographic distributions. Comparing sequences of mitochondrial genes (cyt-b, COI, 12S rRNA) from 41 individuals and 21 sites across the archipelago, we found evidence that Capromys pilorides contains a major species-level subdivision from western to eastern Cuba, spanning a greater geographic region than previously hypothesized. Populations of Capromys in each clade last shared a common ancestor ∼1.1 million years ago (Ma; 5.2% cyt-b divergence). The western clade is further subdivided between mainland hutias (C. p. pilorides) and those on Isla de la Juventud plus Cayo Cantiles (C. p. relictus has priority). The eastern clade contains all Capromys east of Sierra del Escambray in central Cuba, including mainland and insular forms. However, without paired analyses of morphology and genetics or data from type localities, we cannot assign a name to the eastern Capromys sp. nov. at this time. Divergencetime analyses across 9 named species of hutias (plus 1 extinct), including nuclear genes (GHR, vWF, RAG1), dates the Capromyidae split from their South American relatives (Echimyidae) at 15.5 Ma. The crown radiation of hutias was 8.8 Ma, with successive divergences at 5.4 Ma (Geocapromys), 3.1 Ma (Capromys), and 2.2 Ma (Mysateles–Mesocapromys). Detailed surveys are needed to assess the conservation status of these evolutionarily distinct Cuban taxa.

The majority (90%) of native terrestrial mammal species living in the Dominican Republic are bats, and two-thirds of these species are endemic to the Caribbean. However, recent molecular studies using DNA barcoding of the mitochondrial cytochrome c oxidase subunit 1 gene have suggested at least a 25% underestimation of biodiversity in bats throughout the world. A recent survey of bats in the Dominican Republic documented 15 of the 18 known species on the island of Hispaniola. Phylogenetic analysis of 132 individuals resulted in well-supported monophyletic species-level clades (maximal bootstrap values) with intraspecific variation ranging from 0% to 4.7% and interspecific variation ranging from 14.1% to 32.5%. A phylogeographic pattern separating the northern and southern Dominican Republic was recovered in 3 species of bats (Macrotus waterhousii, Pteronotus parnellii, and Pteronotus quadridens). The inclusion of broader geographic sampling across the Neotropics indicated that 3 widely distributed species (Eptesicus fuscus, Molossus molossus, and Monophyllus redmani) have high sequence divergence among insular or between insular and continental populations. Further systematic study is needed to identify morphologically cryptic species and their implications for conservation priorities in the Caribbean.

Analyses of morphological and molecular data indicate the existence of an unrecognized and unnamed species of soft-haired mouse, genus Abrothrix. Here, we name and describe this new species, which inhabits the Valdivian ecoregion, from the north of Chiloé Island onto the mainland in the Chilean regions of Los Lagos and Los Ríos; it also occurs at a single locality in the Argentinean province of Neuquén. Long confused with A. sanborni, the new species presents a unique combination of characters that differentiate it in external, cranial, phallic, and dental terms from its congeners. Phylogenetic analysis, based on cytochrome-b gene sequences, indicates that the new species is sister to a clade formed by the austral species A. lanosa and A. sanborni and differs on average from them by 5.7% and 5.2%, respectively. Results based on the nuclear Fgb-I7 locus are less conclusive regarding the phylogenetic position of the new species but also show its distinction. We comment on the conservation significance of our findings, considering that forests of the Valdivian ecoregion are suffering substantial human disturbance through intensive logging. Análisis de datos morfológicos y moleculares indican la existencia de una especie nueva e innominada de ratones del género Abrothrix. En este trabajo nominamos y describimos esta nueva especie que habita la ecorregión Valdiviana, desde el norte de la Isla de Chiloé hasta áreas continentales adyacentes de las regiones chilenas de Los Lagos y Los Ríos; la especie también ha sido registrada en una localidad de la provincia argentina del Neuquén. Largamente confundida con A. sanborni, la nueva especie presenta una combinación única de caracteres, incluyendo: coloración dorsal negruzca marrón oscuro a marrón-oliva; coloración ventral marrón grisácea a grisácea; cráneo delicado, con la constricción interorbital en forma de reloj de arena y caja craneana redondeada; rostro angosto y largo; nasales y premaxilares proyectados más anteriormente que los incisivos; placa cigomática estrecha; paladar extendiéndose apenas más allá del plano definido por el margen posterior de los M3; molares mesodontes; en adultos M1 sin flexo anteromedio; parastilo y mesolofo presentes; estómago unilocular-hemiglandular; cráter terminal del pene dirigido ventralmente; elementos apicales cartilaginosos ausentes. Análisis filogenéticos basados en secuencias del gen del citocromo b indican que la nueva especie es hermana de un clado formado por las especies australes A. lanosa y A. sanborni y que difiere de éstas en promedio 5.7 % y 5.2 %, respectivamente. Resultados basados en el locus nuclear beta fibrinógeno son menos conclusivos en relación a la posición filogenética de la nueva especie, aunque también muestran su distinción. Considerando que la ecorregión Valdiviana está sufriendo un impacto antrópico substancial, finalizamos el trabajo comentando sobre la relevancia de nuestro hallazgo para la biología de la conservación. Fil: D Elía, Guillermo. Universidad Austral de Chile; Chile Fil: Teta, Pablo Vicente. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; Argentina Fil: Upham, Nathan S.. Integrative Research Center; Estados Unidos. McMaster University; Canadá Fil: Pardiñas, Ulises Francisco J.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico; Argentina Fil: Patterson, Bruce. Integrative Research Center; Estados Unidos

Rodents make foraging decisions by balancing demands to acquire energy and mates with the need to avoid predators. To identify variations in the risk of predation, nocturnal rodents may use moonlight as a cue of risk. Moonlight avoidance behaviors have been observed in many nocturnal rodent species and are widely generalized to small mammals. However, most prior studies have been limited to 1 species or 1 study site, or occurred in modified habitats. We evaluated desert rodent activity patterns in natural habitats from 1999 to 2006 at 62 study sites across the Great Basin Desert of western North America. Rodent activity was examined by livetrapping in open habitats, using the presence of the sand-obligate kangaroo mouse (Microdipodops) as a habitat indicator. Activity patterns were assessed on 69 nights with clear skies and compared to corresponding moonlight values (moon phase and brightness) to evaluate the frequency of moonlight avoidance. Analyses of total activity of all species in the rodent assemblage relative to moonlight showed a distinct nonrandom (triangular-shaped) pattern but no significant correlations. However, individual genera of desert rodents responded differently to moonlight. Only kangaroo rats (Dipodomys) displayed significant moonlight avoidance patterns; they were maximally active at significantly different moonlight levels and avoided bright moonlight to a greater extent than co-occurring rodents. Moonlight seemed to limit the activity of kangaroo rats most strongly on bright nights during waxing moon phases and summer seasons, but not significantly during the spring or fall seasons, or during waning moons. Rather than avoiding moonlight, the activity of deer mice (Peromyscus), pocket mice (Perognathus), and kangaroo mice may be governed by changes in competition with kangaroo rats. Differences in the body size, locomotion, and space use of kangaroo rats relative to other rodents may explain why different moonlight responses were detected, especially if these traits alter how rodents perceive risk from bright moonlight. These findings indicate that moonlight avoidance may be a specialized trait of kangaroo rats rather than a general behavior of nocturnal desert rodents in the Great Basin.