Observations of Heterospecific Courtship Behaviour in an Isolated Population of Ross’s Gulls (Rhodostethia rosea)

Abstract

Heterospecific sexual behaviour is notable because it should be strongly deterred by natural and sexual selection. Here we report observations of both male and female Ross’s Gulls (Rhodostethia rosea) routinely engaging in sexual displays directed towards other species during the breeding season at a small, remote colony in the Canadian High Arctic. We suggest that in small, reproductively isolated populations, directing stereotyped courtship displays towards heterospecific partners may allow individuals to advertise fitness and experience to both male and female conspecifics and also accelerate hormonal development and readiness to mate during the brief and unpredictable High Arctic breeding season.