Unlike nonhuman primates and some other species used in attempts to condition vocal
behavior, certain song birds display considerable facility at vocal imitation in the wild state …

Parameters used to characterize the course of growth are described, and calculated growth
parameters are presented for 105 species of birds of many taxonomic groups from a wide …

Abstract Naive 50-day-old white-crowned sparrows (Zonotrichia leucophrys nuttalli) were
placed in cages with two compartments in which they could see and interact with a single …

The most salient feature of the class Aves is the ubiquity of feathers. These structures play
vital roles in thermoregulation, protection, communication, and locomotion in birds …

Results of earlier studies indicated that hand-raised white-crowned sparrows exposed to
taperecorded songs learned conspecific song between ages 10–50 days, but not before or …

Because of their simplicity of structure and geographic variation, songs of crowned spar-
rows (Zonotrichia spp.) have been popular subjects of bioacoustical studies. DeWolfe et …

Several workers have proposed that avian breeding seasons may correspond to times of
greater food abundance so that young are produced when the food supply will support a …

MATERIALS AND METHODS The field observations reported in this study were made on the
Edwin S Reserve of The University of Michigan, approximately 4.5 miles west of P Livingston …

Mammals aims to present separate accounts of the means by which each of the major
groups of animals regulates its body temperature, heat production, and heat loss. Readers …

Develo** animals may face a cost–benefit tradeoff during growth mediated through
hormones such as glucocorticoids, as the hormone is essential for development but can …