Food habits, home range and activity of Didelphis aurita (Mammalia, Marsupialia) in a forest fragment of southern Brazil

Relationships between food habits, home range and activity of the black-eared opossum, Didelphis aurita (Marsupialia, Didelphidae), were studied in an urban forest fragment (5 ha) of southern Brazil from February 1995 to January 1996. Captures were performed weekly using 30 live-traps placed uniformly in the study area, Diet was determined through faecal analysis, home ranges were calculated through the Minimum Convex Polygon method and the activity period was assessed from the time of captures in the night. The opossum proved to be an insectivorous-omnivorous marsupial consuming invertebrates (100%), fruits (78%) and vertebrates (59%). Birds, mammals, Coleoptera, Diplopoda, Opiliones and Solanaceous fruits were the main items consumed. Opossums foraged during the first hours of the night in part synchronizing their activity with that of small mammals occasionally preyed upon. Home ranges measured from 0.2 ha for a female to 3.0 ha for a male. Males appeared in the study area only during the wet season, increasing their home range size, whereas females revealed quite exclusive home ranges that could imply the defence of a territory.