Search

The blackish small-eared shrew, Cryptotis nigrescens (Allen, 1895), is a blarinine soricid that occurs in high-elevation premontane wet forest and cloud forest in the Central American countries of Costa Rica and Panama. The species is taxonomically monotypic, although it exhibits size variation that manifests as a gradual increase in size from northwest to southeast. Habitat loss is currently the greatest threat to the species' existence, although populations in the few areas where C. nigrescens has been studied appear to be healthy, and the International Union for Conservation of Nature (IUCN) classifies it as a species whose conservation status is "Least Concern" (LC). We include a complete synonymy for the genus CryptotisPomel, 1848. La musaraña negruzca de orejas pequeñas, Cryptotis nigrescens (Allen, 1895), es un sorícido blarinino que se encuentra en los bosques húmedos premontanos de gran altura y en los bosques nubosos de los países centroamericanos de Costa Rica y Panamá. La especie es taxonómicamente monotípica, aunque exhibe una variación de tamaño que puede manifestarse como un aumento gradual de tamaño del noroeste al sureste. La pérdida de hábitat es actualmente la mayor amenaza para la existencia de la especie, aunque las poblaciones en las pocas áreas donde se ha estudiado C. nigrescens parecen saludables, y la Unión Internacional para la Conservación de la Naturaleza (UICN) la ha clasificado como una especie cuyo estado de conservación es "Least Concern [Preocupación Menor]" (LC). Incluimos una sinonimia completa para el género CryptotisPomel, 1848. [ABSTRACT FROM AUTHOR]

With more than 1,400 species of bats described worldwide, the order Chiroptera is second only to rodents in ecological and taxonomic diversity. Bats play critically important roles in natural systems as seed and pollen dispersers, predators of invertebrates and vertebrates, and sanguinivores. The Central American countries of Costa Rica and Nicaragua have at least 123 species of bats (in nine families and 66 genera), or nearly 10% of the world's known species. Because of the importance of proper species identification for ecological and systematic studies and conservation efforts, we present a dichotomous key to the bats of this region. Our goal is the positive, in-hand identification of living bats that may be released unharmed after identification. Identifying Neotropical bats and understanding the taxonomic changes that affect the names used for the various species over time can be a challenge. This key includes the 123 species known to occur in Costa Rica and Nicaragua as well as three that are expected to occur in these countries but which have not yet been recorded. We provide illustrations of key characters useful for differentiating bats to species and updated taxonomic notes to assist the reader in assessing the literature. Con más de 1,400 especies de murciélagos descritos en todo el mundo, el orden Chiroptera es el segundo más diverso después de los roedores respecto a taxonomía. Los murciélagos juegan papeles de importancia crítica en los sistemas naturales como dispersores de semillas, polinizadores, depredadores de vertebrados e invertebrados, así como hematófagos. Costa Rica y Nicaragua presentan al menos 123 especies de murciélagos (en 9 familias y 66 géneros), casi el 10% de las especies conocidas en el mundo. Debido a la importancia de la identificación precisa de las especies para los estudios ecológicos, sistemáticos y de conservación, presentamos una clave dicotómica para los murciélagos de esta región. Nuestro objetivo es la identificación correcta con los murciélagos in vivo y que se pueden liberar sin daño después de la identificación. La caracterización de los murciélagos neotropicales y el seguimiento del estatus taxonómico de cada especie puede ser un reto en el proceso de identificación. Esta clave incluye las 123 especies conocidas en Costa Rica y Nicaragua, así como 3 no registradas pero con distribución potencial. Proporcionamos ilustraciones de características claves útiles para diferenciar murciélagos al nivel de la especie y notas taxonómicas actualizadas para ayudar al lector a la identificación. [ABSTRACT FROM AUTHOR]

The murine genus Rhynchomys includes the large-bodied Philippine "shrew-rats," highly specialized members of the vermivorous clade of Philippine murids. Four species are recognized, all of which are endemic to Luzon Island: R. soricoides from mountains within the Central Cordillera, R. isarogensis from Mt. Isarog on the Bicol Peninsula, R. banahao from Mt. Banahaw in south-central Luzon, and R. tapulao from Mt. Tapulao in the Zambales Mountains. Field surveys in 2006 and 2008 revealed two additional populations of Rhynchomys , one from Mt. Labo (1,544 m), a dormant stratovolcano at the base of the Bicol Peninsula, the other from Mt. Mingan (1,901 m), the highest peak in the central Sierra Madre of east-central Luzon. Assessment of external and craniodental features of available specimens from throughout Luzon support our description of the populations on Mt. Labo and Mt. Mingan as new species. All species of Rhynchomys are restricted to high-elevation, montane, and mossy forest habitats, separated by intervening lowlands. These discoveries highlight the importance of isolated highland areas in the historical diversification of Southeast Asian murines, and as current centers of endemism. [ABSTRACT FROM AUTHOR]

We name and describe a new species of long-tailed sigmodontine rodent of the genus Tanyuromys, based on 3 specimens collected from 3 different localities in northern Ecuador, during the period 1953-2008. All 3 localities are at middle elevations on the Pacific Andean slopes and specimens were taken both in intact and disturbed forest areas. Tanyuromys previously has been treated as including a single species-T. aphrastus (Harris, 1932); however, using morphological and molecular characters (mitochondrial cytochrome b [Cytb], 1,143 bp), we herein recognize 2 species: T. aphrastus proper, which, so far as known, occurs only in Costa Rica and Panama, and a new species known only from Ecuador. The Ecuadoran species, like T. aphrastus, is characterized by a long tail (ca. 1.5 × length of head plus body); large, complexly constructed, pentalophodont molars; braincase with beaded supraorbital margins continuous with raised temporal ridges; short, anteriorly constricted incisive foramina; short, narrow palatines; and small auditory bullae. Although similar morphologically, which explains why the 2 species have hitherto been regarded as 1, the few specimens available of each differ in that the new species has, among other traits, a narrower interorbital breadth, narrower zygomatic plate, invariably (thus far) distinct supraorbital bead continuing posteriorly over parietal to lambdoidal crests as a prominent raised ridge, relatively large lateral wing of the parietal, skull with more angular rather than more rounded contours. Molecular and morphological characters confirm that specimens of T. aphrastus from Costa Rica and Panama are quite similar; they differ in Cytb sequences by 1.2%. The new species from Ecuador, in contrast, differs from the Central American T. aphrastus in Cytb sequences by 10.2%. The 2 species form a well-supported clade; we infer the genus' phylogenetic associations within the Oryzomyini, based on the complete Cytb sequence. [ABSTRACT FROM AUTHOR]