BEHAVIORAL-DEVELOPMENT AND PARENTAL INVESTMENT IN CAPTIVE BONGOS (TRAGELAPHUS-EURYCERUS)

The bongo is one of the least-studied of the Tragelaphini. In a study of five captive bongo calves, two males and three females, we measured several behaviors important to parental investment theory (Clutton-Br ock et al., 1982), in order to describe their pattern in a rare specie s, and add to the database pertaining to sex allocation theory. Variat ions in individual patterns of maternal investment, such as suckling r ate and bout length, were measured and graphed over time, with sex of calf, and age and dominance of dam indicated. Instances of ''thief suc kling'' by calves and juveniles were also described in terms of kinshi p among the animals involved. Only one measure of maternal investment was biased in favor of males, which had a somewhat higher birth weight than females. Other measures showed little sex difference. Among thes e calves, maternal care appeared to vary more with dominance and age o f the dam than with sex of calf. Data from these animals generally con form more closely to those of Byers and Moodie (1990). They found litt le evidence of sex-biased investment among pronghorn (Antilocapra amer icana) fawns, and postulated that many ungulates have such a high rate of development that further differential investment is impossible. Ro bust biological theories are supported by data obtained from a wide va riety of species, many of which are impossible to study closely in the wild. Additional studies on captive populations of sexually dimorphic species would contribute usefully to the accumulation of data pertine nt to parental investment theory.