Ontogeny of the separation call in Northern Bobwhite (Colinus virginianus)

Abstract

Selected frequency and duration characteristics were measured on sonograph tracings of lost and separation calls of two inbred familial lines of Northern Bobwhite (Colinus virginianus) chicks at 1 day, 1 week, then weekly to 12 weeks, and again at 1 year to determine the mode and rate of development of the separation call. Chicks separated from covey mates responded with a series of one-note calls until 4 weeks of age when the single note calls increased in duration and separated into the two-note call. A gradual increase in frequency modulation and duration of both notes continued until the adult form of the call was complete at 12 weeks. Starting frequency of the lost and separation calls differed significantly between familial lines from 1 day through 12 weeks. No other characteristics showed such consistent differences though differences did occur at some ages. However, though frequency characteristics might function for individual identification, potential for individual variation and modification is greater in duration characteristics.