GEOGRAPHIC VARIATION IN BROWN-HEADED COWBIRD(MOLOTHRUS ATER) PARASITISM ON DICKCISSELS(SPIZA AMERICANA) IN GREAT PLAINS TALLGRASS PRAIRIE

The incidence of brood parasitism by Brown-headed Cowbirds(Molothrus ater; herea er ‘cowbirds’) within host species typically refl ects thecontinental pa ern in cowbird abundance across North America, where parasitismis heaviest in the Great Plains. However, we found considerable variation incowbird parasitism on Dickcissel (Spiza americana) nests within a subregion of theGreat Plains (the Flint Hills), where the highest levels of cowbird parasitism ongrassland bird nests had been previously reported.

William E. Jensen and Jack F. Cully jr., The Auk 122(2):648-660, 2005