Bats and marsupials as indicators of endemism in the Yungas forest of Argentina

SANDOVAL MARÍA L.; CLAUDIA SZUMIK; BARQUEZ, R. M.

Zoological Research

Chinese Electronic Periodical Service

Año: 2010 vol. 31 p. 633 - 644

0254-5853

Despite the fact that several studies have characterized the Yungas as a separate biogeographic unit, mainly based in floristic components, these characterizations were mainly qualitative and did not include faunal groups. The Yungas have been assumed to be a natural floral and faunal region, but without testing how well they are described by animal distributions. Our study consists of a formal analysis of endemism based on distributional records of species of small mammals in the southernmost portion of the Yungas, which is biogeographically very interesting because the Yungas are comprised of discontinuous fragments of forests that extend into temperate arid and semiarid habitats. As a first approximation, we contrasted a group of volant species (bats) versus a group of non-volant species (marsupials). Our results show that small mammals are efficient indicators of areas of endemism. Eighty percent of the species of small marsupials included in the analysis supported the identified areas as being zones of endemism. Regarding bats, almost 55 percent of the species supported a designation of endemism. The results also show that the areas we considered are congruent with the botanical definition of the Yungas of northwestern Argentina and their subdivisions, an assumption that had not been previously tested with a formal quantitative method. We also found that non-volant species are better indicators of endemism than volant ones at regional scales, but volant species are better indicators than was previously thought.