Neotropical Primates 11(2), August 2003 104 Colombia, in all predation events described here the pos- sessor tolerated the proximity of conspecifcs; this created opportunities for food transfer, either direct and tolerated or, more often, through scrounging. Food transfer in this group was also registered in bird predation events, and scrounging was also the most common type of transfer (Ferreira et al., 2002). In a review of the genus by Freese and Oppenheimer (1981), vertebrate prey listed included only lizards, birds and rodents in the diet of C. capucinus, and frogs in the diet of C. apella. While John Oppenheimer was the pioneer in studies of this genus in the wild (C. capucinus in particular), this diet list refected the paucity of information available at the time. As new feld studies are conducted, our under- standing of the diversity of prey taken by tufted capuchins, and the dynamics of food transfer among them, will con- tinue to improve. Acknowledgements: We thank the staff of the Tietê Ecologi- cal Park for their support, and also Michele Verderane and Guilherme Imura, who helped in the description of the predation on the infant opossum. This work was funded by a grant from the Fundação de Amparo à Pesquisa do Estado de São Paulo – FAPESP (São Paulo State Research Support Foundation) (Process 99/11573-2). Briseida D. Resende, Vivian L. G. Greco, Eduardo B. Ottoni and Patrícia Izar, Departamento de Psicologia Experimental, Instituto de Psicologia, Universidade de São Paulo, Avenida Prof. Mello Moraes 1721, São Paulo 05508- 030, São Paulo, Brazil. E-mail: <briseida@usp.br>. References Ferreira, R. G., Resende, B. D., Mannu, M., Ottoni, E. B. and Izar, P. 2002. Bird predation and prey-transfer in brown capuchin monkeys (Cebus apella). Neotrop. Primates 10(2): 84-89. Freese, C. H. and Oppenheimer, J. R. 1981. The capu- chin monkeys, genus Cebus. In: Ecology and Behavior of Neotropical Primates, Vol. 1, A. F. Coimbra-Filho and R. A. Mittermeier (eds.), pp.331-390. Academia Brasilei- ra de Ciências, Rio de Janeiro. Galetti, M. 1990. Predation on the squirrel Sciurus aestuans by capuchin monkeys, Cebus apella. Mammalia 54: 152-154. Heymann, E. W., Knogge, C. and Herrera, E. R. T. 2000. Vertebrate predation by sympatric tamarins, Saguinus mystax and Saguinus fuscicollis. Am. J. Primatol. 51: 153-158. Izawa, K. 1978. Frog-eating behavior of wild black-capped capuchin (Cebus apella). Primates 19: 633-642. Newcomer, M. W. and De Farcy, D. 1985. White-faced capuchin (Cebus capucinus) predation on a nestling coati (Nasua narica). J. Mammal. 66: 185-186. Ottoni, E. B. and Mannu, M. 2000. Semifree-ranging tufted capuchins (Cebus apella) spontaneously use tools to crack open nuts. Int. J. Primatol. 22: 347-358. Rose, L. 1997. Vertebrate predation and food-sharing in Cebus and Pan. Int. J. Primatol. 18: 727-765. Terborgh, J. 1983. Five New World Primates. Princeton University Press, Princeton, NJ. INSECT-EATING BY SPIDER MONKEYS Andres Link Introduction Studies on the diet and feeding behavior of spider monkeys (Ateles spp.) have revealed they are primarily frugivorous, with fruits representing between 72% and 90% of their diet (Carpenter, 1935; Hladik and Hladik, 1969; Klein and Klein, 1977; Van Roosmalen, 1985; Chapman, 1987; Symington, 1988; Dew, 2001). Flowers and young leaves are also eaten frequently, especially when fruit is scarce (Van Roosmalen and Klein, 1988; Castellanos, 1995; Nunes, 1998; Stevenson et al., 2000). Bark, decaying wood, fungus, seeds, soil from salt-licks and termite nests, insects and other items are seldom consumed and represent only a small part of their diet (see Van Roosmalen and Klein, 1988). Insect-eating in spider monkeys has been reported in several studies and, except for passive consumption (for example, fg wasps in fg fruits), it represents a minor part of their feeding activities. Wagner (1956) reported that spider monkeys eat insects and insect larvae. Termites are eaten selectively (Klein and Klein, 1977; Van Roosmalen, 1985), but this behavior has been diffcult to separate from decaying wood or termite-nest eating (Castellanos, 1995) and has not been observed in several studies (Dew, 2001; Link, pers. obs.). They have been incidentally observed eating meliponid bees in Costa Rica (C. A. Chapman, pers. comm.) and Colombia (P. Stevenson, pers. comm.), and caterpillars are eaten intensively by spider monkeys during short periods of the year in a number of different sites (Van Roosmalen, 1985; Chapman, 1987; Symington, 1988; Cant, 1990). White-bellied spider monkeys (Ateles belzebuth) have been studied in the Tinigua National Natural Park in Colombia for several years and, until this study, no insect-eating be- havior had been observed except by Pablo Stevenson (pers. comm.), who reported it as a minor part of the diet of one of his study groups (MB-1); no individuals in his other groups had ever been seen actively consuming insects. During the study reported here, I observed white-bellied spider mon- keys eating insects on a number of occasions and, although it represents a small part of their total diet in the study year, it was an important food item at certain times. Study Site This research was carried out at the Centro de Investiga- ciones Ecológicas de La Macarena (CIEM), part of Tinigua National Natural Park in the northwestern Amazon, located