Recently hatched altricial nestlings rely on their parents for food and warmth. Honest signalling theory predicts that offspring produce reliable, yet costly, signals to communicate their current state of need to the parent. Parents respond to these signals to address the homeostatic requirements of their young. Although empirical studies on begging in various avian species support honest signalling theory, evidence is lacking on the pattern of development of this behaviour. A study designed to test whether spontaneous begging of young American white pelican ('Pelecanus erythrorhynchos') chicks is influenced by feeding on a fixed schedule, as opposed to on demand, was conducted under controlled conditions. A second study investigated the interactive nature between a young pelican's nutritional need and warmth. The effects of feeding schedule and rearing temperature on chick growth are considered. Future research possibilities are discussed. (Abstract shortened by UMI.)