Didelphimorphia and Rodentia (Mammalia) from Sierras de Tecka and surrounding areas, northwestern Chubut, Argentina

Mauro I Schiaffini,Gabriel M Martin,Analía L Giménez

doi:10.15560/11005

Abstract

The small mammal fauna from northwestern Chubut Province (Argentina) is poorly known. We herein report small mammal assemblages from three new localities: Sierras de Tecka, an extra-Andean system elevated 900 m.a.sl.; Estancia La Mimosa on the Tecka river valley (at ca. 650 m.a.sl.); and Arroyo Pescado (at ca. 620 m.a.sl.) 40 km north of the other sites. Specimens were recovered from disaggregated owl pellets. Total species richness includes 16 native (13 sigmodontine and two caviomorph rodents, and one marsupial) and one introduced species. Estancia La Mimosa had the highest richness (n = 14), while Arroyo Pescado the lowest (n = 11). Four species were only recorded at Estancia La Mimosa (Akodon iniscatus, Calomys musculinus, Oligoryzomys longicaudatus and Mus musculus), two in Sierras de Tecka (Notiomys edwardsii and Microcavia australis) and one in Arroyo Pescado (Geoxus valdivianus). This work also adds new localities for Akodon iniscatus, Geoxus valdivianus, Lestodelphys halli and Notiomys edwardsii in western Chubut Province.

Highlights

Argentina can be considered a country with a great number of native mammal species; its diverse topography, climate and vegetation conform to a high environmental diversity (Ojeda et al 2002)
Some of these ecosystems are separated by extreme environmental gradients, primarily in precipitation and topography
The results of this study come from owl pellet assemblages that were collected at four sites in northwestern Chubut Province (Argentina), north of the town of Tecka (Figure 1)

Summary

Introduction

Argentina can be considered a country with a great number of native mammal species; its diverse topography, climate and vegetation conform to a high environmental diversity (Ojeda et al 2002). Some of these ecosystems are separated by extreme environmental gradients, primarily in precipitation and topography. The Patagónides include the Sierras de Tecka, which are located between 43°00’ – 43°30’ S, 70°50’ – 70°40’ W and reach a maximum altitude of 1500 m Because of these geographically complex conditions, an extended ecotone between forest-steppe ecosystems is formed, which allows for the development of a unique community of small mammals (Pearson 1995)

Objectives

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Methods