PATTERNS OF PREDATION BY CHIMPANZEES ON RED COLOBUS MONKEYS IN GOMBE-NATIONAL-PARK, 1982-1991

Predatory patterns in wild chimpanzees are important evidence in the c ontinuing debate about the role of hunting in the behavior of early ho minids. Data are presented on the predator-prey ecology of red colobus monkeys Colobus badius tephrosceles) and chimpanzees (Pan troglodytes schweinfurthii) in Gombe National Park, Tanzania, from 1982 through 1 991. During this period chimpanzees were observed to kill 429 mammalia n prey items, 350 of which were red colobus. Hunts were undertaken by chimpanzees in 71.5% of encounters with red colobus, and in 52.2% of a ll hunts at least one colobus was caught. Hunting occurred in all mont hs, but its frequency peaked in the late dry season months of August a nd September, and was lowest in the rainy months of April and May. The re was greater seasonality of hunting from 1982 to 1991 than previousl y reported for Gombe. Hunting success varied between 40% in the rainy season and 65% in the dry season. Sixty multiple kills of colobus were reported in which from two to seven colobus were killed. Approximatel y 75% of all colobus caught were immatures; juveniles were the most pr eyed upon age class. Adult and adolescent male chimpanzees made 89.3% of all kills; the 10.7% of kills made by adult females was an increase over the 4% figure for female kills reported in the preceding decade. Hunting showed a strong ''binge'' tendency, with the explanation for binges likely related to social rather than ecological factors. These results are discussed in light of earlier hunting data for Gombe chimp anzees, and compared with data from other chimpanzee field studies. (C ) 1994 Wiley-Liss, Inc.