Habitat use by a Neotropical desert marsupial (Thylamys pallidior): A multi-scale approach

Abstract

a b s t r a c tIn South America, most didelphid marsupials are associated with tropical and moist forests; however, a few species are adapted to more extreme environments such as desert systems. The desert mouse opossum, Thylamys pallidior, is a small marsupial which inhabits the arid regions of South America and has the broadest distribution of the genus. The objective of this research was to assess the habitat use and selection by the desert marsupial T. pallidior considering different scales and habitat levels of analysis, as well as seasonality. We considered two habitat levels (macro and microhabitat) and the microhabitat was analyzed at two spatial scales (1 ha and 4 m 2 ). We recorded 95 captures of mouse opossums in 27,600 trap-nights. Our study showed that habitat type was not a significant factor for selection; instead mouse opossums selected areas with low complexity and high grass cover. The scale of analysis was also important since the selection was stronger in larger areas. Habitat selection by T. pallidior occurred mainly during the dry season. During the wet season, the species used all habitat areas and types indistinctly. The present study highlights the importance of performing analyses which include multiple spatial and temporal scales for a better understanding of the patterns involved in habitat use and species distribution.

Scaling the relative dominance of exogenous drivers in structuring desert small mammal assemblages

“…musculinus, T. pallidior, Phyllotis xantophygus) use structurally simple habitats, or are indifferent to habitat complexity (G. griseoflavus, Akodon sp. ), there being less species who prefer structurally complex habitats (Akodon molinae, Salinomys delicatus) (Corbal an, 2004;Corbal an and Debandi, 2006;Tabeni and Ojeda, 2005;Ojeda and Tabeni, 2009;Albanese et al, 2011;Albanese and Ojeda, 2012;Rodríguez et al, 2012). In some cases it was observed that there was a differential use of tree strata among species; for example, in the central Monte, desert rodents use the lower more than the upper parts of trees, whereas the marsupial T. pallidior is more selective, preferring the upper parts of trees (Albanese et al, 2011).…”

Nuevo registro y ampliación de la distribución del género Thylamys (Didelphimorphia: Didelphidae) en la región pampeana de Argentina

“…Al igual que en otras áreas de su distribución, una parte de las especies de Thylamys encontradas en Argentina presentan asociación con ambientes áridos (Albanese y Ojeda, 2012). Sin embargo, existen varios registros de estas comadrejas en otro tipo de ambientes, como es el caso de la región pampeana.…”

“…; Burkart, Bárbaro, Sánchez y Gómez, 1999;Cabrera, 1976). En este sentido, resulta interesante que todos los registros de Thylamys en la región pampeana correspondan a individuos de T. pallidior encontrados en ambientes subhúmedos serranos, lo cual contrasta con las condiciones de aridez o subaridez presentes en otras regiones de la distribución de esta especie (Albanese y Ojeda, 2012). Estudios basados en un número suficiente de individuos serían importantes para determinar tanto su entidad taxonómica como aspectos básicos de su biología en esta región marginal de su distribución.…”