Autor: Rosana Gentile

Home ranges of Philander frenata (= P. opossum) (Didelphimorphia, Didelphidae) and Akodon cursor (Rodentia, Sigmodontinae) in Barra de Maricá, Rio de Janeiro, were estimated and analysed in relation to sex, age, both dry and wet, and breeding and nonbreeding seasons, and correlated with population densities and body weight. In P. frenata, home ranges were predominantly affected by the breeding season, while in A. cursor they were mostly affected by sex. There was no correlation between body weight and home range size within species. No effects of population densities on home range size were found in both species, but we detected an increase in the number of overlapping points of capture with the increase of population densities. Females of A. cursor presented territoriality while males did not. This seems to be a general behaviour in akodontines. Males would have contact with many females, and females would defend nesting and food resources. In P. frenata, neither females nor males seemed to be territorial, presenting a mating system without permanent
couples.