Ontogeny of chick behavior: a tool for monitoring the growth and development of lesser adjutant storks.

We studied the behavioral development of seven lesser adjutant stork (Leptoptilos javanicus) chicks from hatching to fledging over three breeding seasons at the Bronx Zoo. We developed an ethogram and compared the rate at which behaviors appeared in relation to brood size, sex, and the conditions in which the chicks were raised by their parents. Although sample sizes were small, there seem to be sex-related differences in the rate at which behaviors develop, with females developing more rapidly than males.