Differences in Habitat Use between Two Morphologically Similar Tropical Forest Rodents

Abstract

We examined differences in habitat use between two morphologically similar tropical forest rodents that have sympatric distributions. Mark-recapture techniques were used in Soberania National Park, Panama in a variety of forested habitats to characterize microhabitat use by Proechimys semispinosus (Central American spiny rat) and Hoplomys gymnurus (armored rat). P. semispinosus were distributed throughout the study area, but H. gymnurus were largely absent from ridgetops and the entire southern half of the study area. Canonical discriminant analysis showed that these two species used significantly different microhab-itats. H. gymnurus were restricted to very wet, steep, and rocky microhabitats along streams within relatively undisturbed forest. P. semispinosus did not use microhabitats that were different from the overall available microhabitat and therefore exhibited a generalized pattern of microhabitat use. P. semispinosus rarely were captured along streams where H. gymnurus were most abundant. Differences in microhabitat use suggested that these two species may have physiological adaptations to preferred habitats.