West Nile virus antibody prevalence in red-winged blackbirds (Agelaius phoeniceus) from North Dakota, USA (2003-2004).

Maternal Yolk Steroids: A Potential Compensatory Mechanism for Red-winged Blackbirds (Agelaius phoeniceus) In North Dakota

Predators on Red-winged Blackbird nests in eastern North Dakota

Predation has consistently been identified as the most common cause of nest failure for Redwinged Blackbirds (Agelaius phoeniceus). During May and June, 2000 and 2001, we used infrared-triggered camera systems to identify potential nest predators on artificially relocated Red-winged Blackbird nests in eastern North Dakota. For some of the species observed, these observations represent the first...

Life History Trade-Offs Between Longevity and Immunity in the Parasitic Brown-Headed Cowbird?

Life history theory predicts evolutionary trade-offs between investing in immune defense and other traits. We investigated whether reduced longevity was associated with increased investment in immunity in an avian brood parasite, the brown-headed cowbird (Molothrus ater). Previously we had found that the brown-headed cowbird was unusually resistant to infection with West Nile virus and other pa...

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 ...

Spring Arrival, Aggression and Testosterone in Female Red-winged Blackbirds (Agelaius Phoeniceus)

Female-female aggression among polygynously breeding Red-winged Blackbirds (Agelaius phoeniceus) has been reported by many researchers (e.g. Nero 1956, Roberts and Searcy 1988), but there is little agreement as to its function. A female Red-winged Blackbird might behave aggressively towards other females to deter or delay the settlement of potential competitors (I-Iurly and Robertson 1985, but ...