|Title||A case of age-related territory usurpation in the American Redstart|
|Publication Type||Journal Article|
|Year of Publication||1974|
|Journal||Jack Pine Warbler|
In a discussion of age-specific differences in plumage, aggressiveness, and habitat use in the American Redstart (Setophaga ruticilla) Ficken and Ficken suggest that first-year males are excluded from "optimal" habitats by adult males. To my knowledge, however, no instance of an adult male displacing an established yearling male has been reported. In 1969 I observed such an incident at UMBS at Pellston, Michigan. This anecdotal evidence strongly supports the Fickens' claim that adult male redstarts are behaviorally dominant over yearling males. It is particularly interesting to note that an unmated adult displaced a mated yearling which later successfully reproduced, and that the displaced yearling kept its mate.