Determinants of home range size and spatia overlap of Gracilinanus agilis (Mammalia: Didelphidae) in central-western Brazil

The use of space in mammals may vary according to sexual dimorphism, mating system and territorial behavior in order to ensure optimization of the reproductive success of each sex and the interactions with other species. In the present study, the determinants of home range (HR) size of males and females of Gracilinanus agilis (Burmeister 1854) were evaluated in a savanna remnant in central-western Brazil. We used live traps and capturemark-recapture to estimate HR size. Using the method of minimum convex polygon, we estimated the HR of 24 individuals. The species showed sexual dimorphism, with males showing larger body size. The HR estimated was 0.38 +/- 0.41 ha and the highest estimated HR was for a male, with 2.08 ha. Females' HR sizes varied according to body mass, food availability and number of captures. The more important predictor for males was the number of females found within their HRs. The overlapping areas between pairs of males were larger than those between pairs of females, suggesting that females have territorial behavior as they had mostly exclusive HRs. Considering that food availability was an important predictor for female HR size, we hypothesize that the territorial behavior in females is related to food resource.