Composition and habitat use of rodents in different floristic sites of the Natural Reserve Otamendi, Buenos Aires, Argentina

EXPÓSITO, YANINA; PICCA, PABLO; SAN MARTÍN, ALVARO; GÓMEZ VILLAFAÑE, ISABEL

Mendoza

Congreso; International Mammal congress; 2009

ICC conicet sarem

COMPOSITION AND HABITAT USE OF RODENTS IN DIFFERENT FLORISTIC SITES OF THE NATURAL RESERVE OTAMENDI, BUENOS AIRES, ARGENTINA. Expósito, Yanina Andrea; Picca, Pablo; San Martín, Alvaro y Gómez Villafañe, Isabel Elisa. Lab. de Ecología de Poblaciones. Facultad de Ciencias Exactas y Naturales. Universidad de Buenos Aires. Argentina; yalei21@hotmail.com The Strict Natural Reserve Otamendi is a wetland of a great relevance for its fauna and flora composition. The aim of this study was described the abundance, composition and use of habitat of the rodent community in the reserve. Rodent trapping and vegetation survey were carried out in six floristic sites every three months (Septembre-07/August -08) and in March-08, respectively. The association between the presence-absence and annual abundance of rodents with vegetation characteristics was evaluated by means of multiple regression. One hundred fifty three individuals were captured with an effort of 3636 traps-nights. The species captured were: Oxymycterus rufus, Scapteromys aquaticus, Akodon azarae, Oligoryzomys flavescens, Deltamys kempi and Oligoryzomys nigripes. At macrohabitat scale, S. aquaticus showed a greater use of habitat in sites with major creeper cover; O. rufus, presented a greater use in sites with low broad leaf herbs cover, higher trees and ephyfites cover and a major presence of Metastelma diffusum. For other side, O. nigripes was negative associated with Carduus acanthoides. For A. azarae, O. flavescens and D. kempi did not show association with any variables analyzed. At microhabitat scale, we study the use of rodent species only in riparian forest. O. rufus was captured in traps surrounding with low grasses cover and low presence of Cissus aff Palmata and Ciperacea specie. Scapteromys aquaticus was captured in trap station with low trees cover and greater cover of broad leaf herbs. D. kempi, O. flavesces, A. azarae and O. nigripes did not associated with any variables studied. The rodent species that inhabit the Natural Reserve Otamendi showed a differential uses of habitat, resulting in differential rodent composition and abundance among the six floristic sites.