Ontogeny of behavior of hand-reared and hen-reared captive houbara bustards

The ontogeny of behavior of hand-reared and hen-reared captive houbara bustards (Chlamydotis undulata) was recorded between hatching and fledging and compared to determine ways to improve the behavioral and physiological health of individuals destined for release into the wild. Chicks from both groups were able to walk and run on the first day after hatching, although they were least active during the first 5 days. Thereafter, time spent prone with the head down, in a half-crouch position (resting on the tarsi) or being brooded during the day (in the case of hen-reared chicks), decreased quickly, and time spent walking and standing increased. Pecking and some preening and comfort behaviors were expressed from the first day in both groups, but increased after similar to 15 days. Simple threat displays were first expressed at 6 days in both groups, but developed into more complete displays with age. The only differences found between the two rearing techniques were in time spent walking and in the half-crouch position: hen-reared chicks spent more time walking and less time in a half-crouch position than hand-reared chicks, because the hen stimulates the chicks to move. Lack of exercise during growth may result in poor development of locomotive structures, which may compromise the survival of chicks destined to be released to the wild. However, hand-reared juveniles were equally likely to survive as hen-reared juveniles after being released, suggesting that hen-rearing by captive-bred birds in a confined and artificial environment did not confer appreciable advantages. Zoo Biol 17:245-255, 1998. (C) 1998 Wiley-Liss, Inc.