A PROBABLE CASE OF POLYTERRITORIAL POLYGYNY IN THE RED-EYED VIREO, VIREO-OLIVACEUS

A male Red-eyed Vireo (Vireo olivaceus) was observed to defend two ter ritories separated by more than 100 m and the territory of another mal e. The polyterritorial male fed nestlings (Brown-headed Cowbirds, Molo thrus ater) at a nest on one territory while association with a female that may have had an active nest on the other territory. This observa tion represents one of a small number of cases of polyterritorial beha viour among North American passerines and the first report of probable simultaneous polygyny in the Vireonidae.