Passage Rate, Energetics, and Utilization Efficiency of the Cedar Waxwing

Abstract

male displaying towards a receptive female in another male' s territory.Also, territory switches occur during the season.There was' also an instance in which a male Dickcissel left his territory for 3 weeks and returned with a female.Some female Red-winged Blackbirds on territories of vasectomized males have still been known to produce young (Bray et al., Wilson Bull.87:195-197, 1975).Keller (M.S. thesis, Univ.North Dakota, Grand Forks, North Dakota, 1979) suggests that in Chipping Sparrows (Spizellu passerina) an alternative strategy to holding a good territory could be to sneak copulations, provided that the male does not spend much time off his territory or his female may be inseminated by other wandering males.The role of distant flight and switching territories needs further investigation.In birds such as the Dickcissel, both strategies could increase fitness.Acknowledgments.-I am