Small mammals of the Cajas Plateau, southern Ecuador: Ecology and natural history

Abstract

We captured 483 small mammals (19 species: 1 insectivore, 2 marsupials, 16 rodents) from sites between 2700 and 4000 m on the Cajas Plateau, Azuay Province, Ecuador. Fifteen species were taken in montane forest and 10 on the páramo. Five species occurred in both habitats. One species was new to science, three were recorded for only the second time and three records were major range extensions, including one species new to Ecuador. Comparisons with other Andean sites show the species diversity of small mammals on the Cajas Plateau to be among the highest recorded in the Andes. Reasons for this are discussed. Data are presented on habitat preferences, reproduction, diet and pelage variation for each species. Litter sizes at the small end of a species' range were consistently observed. Adversity selection (sensu Southwood, 1977) at high altitude is suggested as an explanation. The natural history of several species is reported for the first time since their original discovery.