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. Larger clutch size may be associated with slower growth rate because the single male developed faster than the two males in 2004. The slowest growth rate, observed in a single male chick in 1999, was most likely owing to nutritional deficiencies and other health complications. More research is needed, but these results can be used to help evaluate the age and health of lesser adjutant stork chicks in captivity and in the wild. Zoo Biol 26:533-538, 2007. (c) 2007 Wiley-Liss, Inc.