PARENT SESSION

Systematics/Zoogeography 3 -- Session Chair: Phil Sudman-- Nelson Hall East, Goodwin Forum

DIVERSITY OF BATS ALONG AN ELEVATION GRADIENT IN THE EASTERN SLOPES OF THE ECUADORIAN ANDES. Juan P. Carrera^1,2 and René M. Fonseca^1,2. ¹ Museo de Zoología (QCAZ) — Escuela de Ciencias Biológicas, Pontificia Universidad Católica del Ecuador, Quito, Pichincha, Ecuador; ² Department of Biological Sciences and the Museum of Texas Tech University, Texas Tech University, Lubbock, Texas, USA.

ABSTRACT- The changes in the distribution patterns and community structure of some Ecuadorian bat species along an elevation gradient were analyzed. A transect from 600 m to 3 000 m above sea level, divided in five ranges of 400 m, was established in the eastern slopes of the Ecuadorian Andes. A total of 683 records from museum collections, literature, and captures provided information from 68 species of seven families and nine trophic guilds. A combination of diversity indices was used to compare similarity among the ranges established in the gradient. Species richness was also correlated to the altitude to determine trends of changes occurring in the study area. Bat diversity varied inversely with the increment of altitude, reaching its greatest level between 600 and 1 400 m. Families Molossidae, Phyllostomidae and Vespertilionidae showed a broad altitudinal distribution along the gradient, whereas Emballonuridae, Furipteridae and Noctilionidae were restricted to elevations below 1 500 m. Frugivorous, nectarivorous and aereal insectivorous bats were common along the gradient. Results support Steven's rule of an inverse relationship between diversity and elevation, being in agreement with former studies from Colombia, Mexico, and Peru. Nevertheless, differences in species richness found in this study may be the result of the habitat complexity of the eastern Ecuadorian Andes. New altitudinal records are reported for six species. Moreover, altitudinal substitution was recognized among species of the genus Myotis, Platyrrhinus and Sturnira.

KEY WORDS: Andes, Ecuador, Elevation gradient, Bats