IS THE DISTRIBUTION OF STARLINGS STURNUS-VULGARIS WITHIN ROOSTS DETERMINED BY COMPETITION

Observations were made in five aviaries to determine the role of compe tition in roost site selection by captive Starlings Sturnus vulgaris. Their behaviour in selecting perches in a simple roost ''tree'' indica ted that (1) a dominance hierarchy exists in birds selecting roosting locations, (2) the roost positions occupied are determined through com petition, (3) higher and inner roost positions are preferred over othe rs and (4) dominant Starlings tend to occupy these most preferred posi tions.