We tested the hypotheses that relative medullary thickness (RMT) and kidney mass are positively related to habitat aridity in rodents, after controlling for correlations with body mass. Body mass, mass-corrected kidney mass, mass-corrected RMT, mass-corrected maximum urine concentration, and habitat (scored on a semiquantitative scale of 1-4 to indicate increasing aridity) all showed statistically significant phylogenetic signal. Body mass varied significantly among habitats, with the main difference being that aquatic species are larger than those from other habitats.
Reig 1986). Esta hipótesis es puesta a prueba examinando la distribución geográfica y los datos citogenéticos de 35 especies, incluyendo la descripción de bandas G de Andinomys edax y Euneomys chinchilloides y su comparación con Phyllotis, bandas AgNOR y FISH para ADNr en siete especies, así como datos de electroforesis de proteínas (118 electroalelos en 12 especies) y de secuencias del gen para citocromo b en el ADNmt (407 pb en 14 especies). Todos los cariotipos resultaron cromosómicamente distintos, excepto dos en los que no se contó con bandas G. Se encontró una asociación general entre distribución altiplánica de las especies con estados de caracteres ancestrales (cromosomas telocéntricos, 2n altos, posiciones basales en las filogenias basadas en proteínas y secuencias de citocromo b), así como entre distribución no altiplánica y estados derivados. Se documentan aquí distintas combinaciones de brazos cromosómicos tipo Andinomys que se fusionarían para formar cromosomas metacéntricos en Euneomys y Phyllotis, y también una disminución del número de NORes estructurales en Auliscomys respecto de Loxodontomys, rasgos derivados que demuestran una diversificación hacia el sur y otra hacia el norte respectivamente, desde un centro en el Altiplano Sur]]>
Millions of Chinchilla chinchilla and C. lanigera were killed during the early twentieth century and they were nearly hunted to extinction. In order to establish the current range of distribution of these two wild species and to localize possible new colonies, we used the available scientific literature, technical reports, information from residents, and live trapping methods. Both species are ‘critically endangered’ since their current distribution is highly fragmented and all recognized colonies are small and isolated. We report a small new wild colony of C. lanigera in the Atacama region, Chile.
Examinamos los factores que influyen en la selección de presas por perros callejeros en el humedal Estero Culebrón (Coquimbo, Chile) y caracterizamos sus ataques durante 20 visitas en el año 2015. Utilizamos modelos lineales generalizados considerando el tamaño del ave, su abundancia relativa, el sitio y tipo de sustrato como variables explicativas. Registramos una jauría de siete individuos que realizaron 34 ataques sobre aves, de las cuales el pelícano presentó la mayor frecuencia de predación. El tamaño del ave y el sitio se relacionaron positivamente con los ataques. La selección del pelícano como presa podría estar relacionada con su baja distancia de inicio de vuelo y su gran tamaño, lo que facilitaría el ataque de los perros y, además, este mayor tamaño podría sostener energéticamente a la jauría, especialmente cuando es numerosa. Otras condiciones como la ausencia de totora (Typha angustipholia) y la baja profundidad del agua en el sector playa, facilitarían el desarrollo de los ataques al reducir los obstáculos a la persecución. Por último, debido al peligro que representan estos animales para las personas y la fauna de los humedales, es urgente desarrollar planes de manejo que consideren su retiro y traslado a centros de rescate, así como de implementar campañas de esterilización y educación.
The crustacean communities in Chilean seasonal pools have been poorly studied, and much of the existing literature is restricted to southern Patagonian plains, whereas there are no studies available about other sites. The aim of the present study is to describe the aquatic crustaceans in shallow pools in Huentelauquén (31°S, central northern Chile). The species reported upon include Daphnia ambigua, Simocephalus serrulatus, Boeckella gracilipes, Ostracoda, and two unidentified clam shrimps (genera Lynceus and Leptestheria), which latter ones represent the first record of these taxa for Chile. The ecological results revealed low species numbers and non-structured patterns in the various species associations. The exposed results are markedly different from observations on other Chilean seasonal pools, where no clam shrimps can be found, and where primarily cladocerans, copepods, and amphipods occur in the crustacean communities.
The pressures of road infrastructure on wildlife are among the eleven main threats to biodiversity conservation. Birds are one of the most threatened groups, mainly through direct collisions with road traffic and the fragmentation of their habitats. We characterized the assem- blage of raptors that were impacted on a coastal highway in central Chile and analyzed the possible relationship between areas with high impact density and some landscape variables. Between April 2016 and June 2017 we registered 86 raptor carcasses, nine species belonging to five different families, among which Tyto alba, Milvago chimango, and Bubo virginianus were the birds with a higher frequency of road- kills. These impacts were concentrated between February and April 2017. In the sections studied, we detected eight hot spots that included 37% of the impacts and found at least five variables related to these road kill hot spots: i) A larger surface covered with trees, ii) a small number of lighting poles, iii) sites closer to creeks, iv) road sections without curves, and v) double tracks would favor roadkills for these birds in the studied site. Additionally, collisions for the different species of raptors recorded in this study could be due to the availability of prey on the edges of the road, their foraging strategies, and the ecology of these birds, especially during breeding season.
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