Diversity and distribution of small terrestrial rodents along a disturbance gradient in montane Costa Rica

A total of 389 rodent captures in five unequally disturbed habitats in a Co sta Rican montane cloud forest corresponded to 185 individuals (seven speci es, two families). Species richness was similar for all habitats, averaging 4-5 species/habitat. Population density and capture frequency were higher in moderately disturbed habitats; Peromyscus mexicanus and Scotinomys xeram pelinus were four to five times more common than other murids. These specie s represented 79.4 % of all captures and 73.5 % of all captured individuals . Heteromyid species were rarely trapped. The importance of disturbance-med iated within-habitat microenvironmental heterogeneity for terrestrial small -sized rodent populations is stressed.