Habitat use by endemic and introduced rodents along a gradient of forest disturbance in Madagascar

We used logistic and Poisson regression models to determine factors of fore st and landscape structure that influence the presence and abundance of rod ent species in the rain forest of Ranomafana National Park in southeastern Madagascar. Rodents were collected using live-traps along a gradient of hum an disturbance. All five endemic rodent species (Nesomys rufus, N. audebert i, Eliurus tanala, E. minor and E. webbi) and the introduced rat Rattus rat tus were captured in both secondary and primary forests, but the introduced Mus musculus was only trapped in secondary forest. The abundance of R. rat tus increased with the level of habitat disturbance, and it was most common in the heavily logged secondary forest. Furthermore, the probability of th e presence of R. rattus increased with decreasing distance from forest edge and decreasing canopy cover, while the probability of presence increased w ith increasing herbaceous cover, altitude and overstory tree height. The sp ecies was never observed farther than 500 m away from human habitation or c amp-site. N. rufus prefered selectively-logged forest at altitudes above 90 0 m a.s.l. Its probability of presence increased with increasing canopy cov er, herbaceous cover and distance from forest edge, and with decreasing den sity of fallen logs, overstory tree height and distance from human habitati on. N. audeberti prefered heavily-logged areas, while E. tanala was the onl y species occurring along the entire range of forest disturbance. We sugges t that in the Ranomafana National Park the spread of R. rattus is associate d with deforestation.