Home‐range use by the tufted capuchin monkey (Cebus apella nigritus) in a subtropical rainforest of Argentina

Abstract The pattern of home‐range use by seven groups of tufted capuchin monkeys Cebus apella nigritus is described in the Iguazú National Park, Argentina, during 1991–94. The seasonal changes in home‐range use by one of these groups between August 1997 and December 1998, are correlated with changes in food distribution and availability. Fruit availability was estimated with fruit traps, and the abundance and distribution of food was experimentally changed within the home range of one group by using feeding platforms filled with bananas. Average home‐range size is 161 ± 77 ha (range = 81–293 ha, n= 7). There is a positive relationship between the number of females per group and home‐range size. Neighbouring groups have partially overlapping home ranges and aggressive relationships. Fruit abundance is scarce during the winter and peaks during the spring and early summer. The pattern of home‐range use by the main study group of capuchins was consistent with the hypothesis that fruit distribution and availability is the most important factor affecting the spatial use of their range. This is evidenced by the changes in range size and in range use as the distribution and abundance of their main fruit sources change seasonally. Range use shifted dramatically during the experimental phase of this study; the capuchins reduced their range and most frequently visited the areas where the feeding platforms were located. For most populations of frugivorous monkeys, fruit distribution and availability are the main factors that determine the pattern of home‐range use. However, in some populations the availability of water sources and sleeping sites can have some effect on range use. For capuchin monkeys in particular, within‐species variation in home‐range size, degree of range overlap and interactions between neighbouring groups are large and do not serve to characterize any species of Cebus monkeys.