An observation of cooperative breeding in the Ovenbird

During June and July, 1999, we observed two male Ovenbirds (Seiurus aurocap illus) caring for recently fledged Ovenbird chicks from the same nest in wh at we believe was the outcome of a polyandrous relationship. If so, the cir cumstances surrounding this observation are similar to the only other publi shed account of polyandry in this species. We suggest that the reason for t he adoption of this behavior may be related to a shortage of females. If th is is the cast, then polyandry may be more widespread in Ovenbirds than pre viously thought because we regularly observed unmated mole Ovenbirds on our study plots, indicating that the conditions favoring polyandry (limited ac cess to females) occur relatively frequently.