Small mammals of Santa Cruz province, Argentina

FORMOSO ANAHÍ E.; ULYSES F.J. PARDIÑAS

Mendoza

Congreso; IMC 10 International Mammalogical Congress; 2009

With an area of 243,843 km2, Santa Cruz province is the most poorly known with respect to small mammal assemblages of Argentinean Patagonia. Patagonian phytogeographic province is the single major unit of vegetation represented in its non-Andean territory; three main rivers cross the vast territory covered by shrub steppes and composed by basaltic plateaus and hilly systems. With the goal of contributing to the understanding of the taxonomy and ecogeography of the small mammals that inhabit Santa Cruz, more than 50 owl pellet samples from 28 localities were collected and studied. Available samples cover almost all the provincial territory and were collected between 1995 and 2008. We analyzed 7,236 individuals of small mammals recording at least 16 species, 13 of which were sigmodontine rodents, 1 marmosine marsupial, and at least 2 caviomorph rodents. A preliminary biogeographic approach using cluster analyses retrieved two main groups of localities. One included the northeastern portion of Santa Cruz territory (3 localities), characterized by the occurrence of several sigmodontines (e.g., Akodon iniscatus, Graomys griseoflavus) typically associated with the arid semideserts of the Monte biome. The other grouped the remainder localities (25) distributed over most of the provincial territory sharing typically occidental species that characterize the Austral Patagonia. We also found remarkable low values of specific richness (range 4 to 7) in localities close to the Atlantic coast.