The diurnal activity patterns of caged migratory white-crowned sparrows in late winter and spring.

Abstract

Continuous automatic recordings were made of the diurnal (24 hour) activity of caged male White-crowned sparrows of the migratory race Zonotrichia leucophrvs gambelii during late winter and spring of 1952 and 1953. The birds were from the population which winters in the Snake River Canyon of southeastern Washington. Findings reported here are based on 598 bird days of recording. There was a pronounced increase in nocturnal activity (Zugunruhe) at the time of the normal migration of this race. This activity pattern developed gradually from its inception in April at the time when the spring molt is becoming less intense, with its max. about the 1st week in May. Increased nocturnal activity occurs during a period of gradually improving metabolic state, as indicated by increased fat deposition, and in the course of photoperiodically induced increasing pituitary activity as indicated by the developing testes.