102 NORTH AMERICAN FAUNA 75 



lone individuals, most likely males, have been observed on several occasions. The 

 largest groups observed contained 15 to 20 individuals. Juveniles are first seen 

 in January. On 7 January 1987, seven adults and one juvenile were observed; on 



21 January 1987, seven or eight adults and two juveniles were observed; on 



22 January 1987, an adult female near term was seen. In May and June of 1986, 

 one or more troops ranging from five to nine adults with two infants were ob- 

 served on several occasions. On two occasions, troops of C. capucinus have been 

 observed in trees adjacent to troops of howler monkeys; on one occasion, a male 

 spider monkey was seen with a troop of capuchins and on another a mixed group 

 of C capucinus and Ateles geojfroyi was seen together. On 16 September 1982, 

 five C. capucinus were observed eating the fruits of Pourouma aspera (Moraceae). 

 They were seen eating Inga sp. (Mimosaceae) on 21 October 1982 and fruits of 

 Minquartia guianensis (Olacaceae) on 24 October 1982. White-faced monkeys were 

 seen eating the fruits of Dipteryx panamensis on 31 July 1983 and those of Welfia 

 georgii in April, July, August, and October. They feed by "breaking off entire 

 rachillae, chewing the exocarp off individual fruits, eating the mesocarp, and drop- 

 ping the undamaged seeds and the broken rachillae to the ground" (Vandermeer 

 et al. 1979:19). They are probably important dispersers of Welfia seeds. 



We observed Cebus capucinus on 14 occasions within Parque Nacional Braulio 

 Carrillo at elevations of 100, 300, 700, and 1,540 m. Group sizes of 10 or more 

 were seen between 100 m and 300 m, whereas group sizes were smaller at higher 

 elevations. White-faced capuchins at lower elevations were quiet when approached 

 and frequently retreated quickly and quietly, whereas at higher elevations they often 

 would display aggressive behavior. We interpret this to indicate greater hunting 

 pressures on these monkeys at lower elevations. 



ORDER XENARTHRA 



Family Bradypodidae 



Bradypus variegatus 

 Three-toed Sloth, Perezoso de Tres Dedos 



Three-toed sloths are found from extreme eastern Honduras southward through 

 much of tropical South America (Fig. 80). Two subspecies of three-toed sloths 

 are found in Costa Rica, Bradypus variegatus castaneiceps in the north and east, 

 the race at La Selva, and B. v. griseus in the west. In Costa Rica, they are abun- 

 dant in moist forests from sea level to elevations of 500 to 600 m. Bradypus 

 variegatus is officially protected in Costa Rica as an endangered species, although 

 we suspect that these animals are found in good numbers in appropriate habitats 

 as indicated by Montgomery and Sunquist from their studies of three-toed sloths 

 on Barro Colorado Island, Panama. Their apparent rarity probably stems from the 

 fact that they are often difficult to see. 



Three-toed sloths have been sighted on many occasions at La Selva. Interesting- 

 ly, most of these records are from the dry season (December through April). This 



