The Home Range and Movements of Giant Otters (Pteronura brasiliensis) in the Xixuan Reserve, Roraima, Brazil

A population of Giant otter was studied in the central Brazilian Amazon at the Xixuaú Reserve, Roraima (0o48’S, 61o33’W), in order to gather preliminary information on spatial use of habitat. Through the period 2000–2003, 80 animals have been recorded in the study area, of which 9 solitary (11.2%) and 71 (88.7%) in groups of an average of 4.46 individuals (n=15; biggest group=9). For 4 Giant otter groups, dry season home ranges were estimated at approximately 8 km in average (n=6; minimum size 4.6 km, maximum size 10.5 km), along watercourses of 52.8 m of average width (n=8). Groups’ home ranges in the study area can overlap. An expansion in direction of flooded forest areas has been observed during the flooded season as well as a temporary contraction during the period of cub rearing. The periodic and complete counting of the animals allowed estimating the density of the species in the study area (1 animal/1km).