Eavesdropping on Referential Yellow Warbler Alarm Calls by Red-Winged Blackbirds Is Mediated by Brood Parasitism Risk

A Comparative Study of Cowbird Parasitism in Yellow-headed Blackbirds and Red-winged Blackbirds

--We compared Yellow-headed Blackbirds (Xanthocephalus xanthocephalus) and Red-winged Blackbirds (Agelaius phoeniceus) to determine possible explanations for the lack of Brown-headed Cowbird (Molothrus ater) parasitism on Yellow-heads. Twenty-three cowbird eggs were cross-fostered from Red-winged Blackbird nests to Yellow-headed Blackbird nests. Eleven of the cross-fostered cowbird eggs hatched...

Interspecific brood parasitism in blackbirds (Icterinae): a phylogenetic perspective.

An 852-base pair region of the cytochrome-b gene was sequenced for the brood parasitic cowbirds and 20 additional taxa of the New World blackbirds (Icterinae). The goal of the study was to determine (i) whether interspecific brood parasitism is multiply derived within the assemblage and (ii) the nature of the evolutionary transformation between various forms of interspecific brood parasitism. C...

Male red-winged blackbirds distrust unreliable and sexually attractive neighbours.

In many species, territorial neighbours fight to establish their mutual border and then develop a truce, known as the dear-enemy phenomenon, characterized by reduced vigilance and aggression along the border. We present evidence that among male red-winged blackbirds (Agelaius phoeniceus) the dear-enemy relationship is a form of reciprocal conditional cooperation that is stabilized, at least in ...

Offspring sex ratio in red-winged blackbirds is dependent on maternal age.

In a marsh-breeding population of red-winged blackbirds, the sex ratio of offspring that survived to leave the nest varied with maternal age. Old mothers produced an excess of male fledglings, middle-aged mothers produced almost equal proportions of males and females, and young mothers produced nearly twice as many females as males. More males than females hatched from the eggs of old mothers, ...

A Program for Developing Male Chemosterilants for Red-winged Blackbirds