Electronic Thesis and Dissertation Repository


Master of Science




Dr. Liana Zanette


Even in the absence of direct killing, predators have a pervasive effect on prey populations through costly anti-predator behavioural responses. In high risk environments, animals can reduce conspicuous behaviours such as courtship displays decreasing exposure at the cost of reproduction. Previous studies typically looked at male behaviour immediately following a predator cue, thus, not considering temporal variations in risk or the impact of female receptivity on male courtship. I placed male and female brown-headed cowbirds under chronically elevated predation risk with periods of high and low risk. Under high predation risk, females performed fewer chatter calls and were more likely to reject courting males. Females also spent less time searching for host nests. Males greatly attenuated courtship displays, but male-male interactions were unaffected. I suggest that females perceive a greater risk associated with these reproductive behaviours and that it is the females that drive the predation risk effects on courtship.