Responses of Bell's Vireos to brood parasitism by the brown-headed cowbird in Kansas

I studied patterns of cowbird parasitism and responses to this parasitism by Bell's Vireos (Vireo bellii) in Kansas. Bell's Vireos abandoned parasitized nests at a significantly higher rate than unparasitized nests. Lower probability of brood parasitism later in the season may help make abandonment followed by renesting beneficial. Burial of cowbird eggs by vireos was also observed in several cases. I did not detect a strong relationship between nest site vegetation characteristics and the probability of brood parasitism.