Foraging vs. Territorial Vigilance: the Selection of Feeding Sites by Male Great Tits (Parus major L.)


Department of Biological Sciences, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada.


Captive male great tits (Parus major L.) were given a choice of feeding on a branch from which the site of a recent simulated intrusion could be monitored, or feeding from a branch with a higher prey density but from which surveillance was impossible. The males spent more time on the unprofitable surveillance branch after an intrusion had been simulated compared to trials with no simulated intrusion. This resulted in a lower feeding rate. Males of many songbird species shift to different feeding sites during the period of territorial defense, and this experiment supports the interpretation that these shifts are made to accommodate territorial vigilance.