Habitat use by Oryzomys subflavus (Rodentia) in an open shrubland formation in Restinga de Jurubatiba National Park, RJ, Brazil

Abstract

The Restinga de Jurubatiba has at least 10 plant formations, including open Clusia shrubland. This formation is composed of dense shrubs of many shapes and sizes, where Clusia hilariana is one of the most important plant species. Shrublands with Clusia (CC) are poorer in plant species and less dense than shrublands without Clusia (SC). Oryzomys subflavus (Rodentia) is the most abundant small mammal species in the open Clusia shrubland. We tested the hypothesis that the abundance of rodents would increase with the size of the patch and would be higher in SC shrublands. Rodents were captured, marked and released in three 780-m-long transects. At each capture site, we evaluated the shape of the shrubland patch, calculated the area and noted the category of the shrubland. Using ANCOVA, we ascertained whether the abundance of Oryzomys subflavus increased with the sampled area and used CC and SC shrublands differently. We also verified if the size of patches used by rodents varies in the same frequency as the size of available shrublands. Rodent abundance was found to increase significantly with the area. There were no differences in the size of the patches used by rodents and the frequency of the size of available patches. This finding indicates that O. subflavus, in the study area, is a generalist species that uses its habitat according to availability.

New species ofCerradomysfrom coastal sandy plains of southeastern Brazil (Cricetidae: Sigmodontinae)

“…nov. apparently exhibits higher densities in the open restinga shrublands that are distributed as vegetation islands throughout the sandy plains. These islands are of various sizes (2.84-1,348.1 m 2 ) and are composed of plant species that show remarkable abilities to colonize and survive arid habitats (Araújo et al 1998;Bergallo et al 2004Bergallo et al , 2005. Among these, Clusia hilariana (Cluseaceae) is the largest tree that usually develops in the center of the largest patches, providing a dense litter and shade cover.…”

Edge effects on small mammals: Differences between arboreal and ground‐dwelling species living near roads in Brazilian fragmented landscapes

“…However, in the tropics, some rainforest-dependent species of small mammals avoid edges (Goosem 2000(Goosem , 2007. A number of studies suggest that in the tropics, ground-dwelling species are prone to edge attraction behaviour (Bergallo et al 2005;Gomez et al 2010), whereas arboreal species are more dependent on the forest interior and show edge avoidance behaviour (Pardini 2004;P€ uttker et al 2008). Apart from the edge itself, the habitat structure (e.g.…”

“…We hypothesized that the grounddwelling species, being more tolerant of open environments (Bergallo et al 2005), would be positively affected by road edges (would show edge attraction behaviour), whereas the arboreal species, being more specialized to forest environments (Pardini 2004;P€ uttker et al 2008), would be negatively affected by road edges (i.e. would show edge avoidance behaviour).…”