Life Sciences Commons^™

An Investigation Of The Host Specificity Of The Brown-Headed Cowbird, Brian D. Peer

Masters Theses

We attempted to determine the factors associated with the lack of parasitism of the Common Grackle (Quiscalus quiscula) by the Brown-headed Cowbird (Molothrus ater). We investigated the breeding phenology of the two species, the responses of colonial- and noncolonial-nesting grackles to female cowbird models, the frequency of artificial egg rejection by grackles, incubation success of cowbird eggs transferred into grackle nests, and the survival rates of cowbirds cross-fostered into grackle nests.

By the time cowbirds began egg-laying at our study sites, 88.5 % of all grackle nests were beyond the point of successful parasitism. Grackles responded …

The Effects Of Nest-Box Visibility And Proximity On The Frequency Of Brood Parasitism In Wood Ducks, Roger W. Jansen

Masters Theses

I studied the effects of nest box visibility and clustering on the rate of intraspecific brood parasitism (IBP) in Wood Ducks (Aix sponsa) at Lake Shelbyville Fish and Wildlife Area in Moultrie County, IL from 2 March 1992 to 22 June 1992. Sixty-eight percent of the nest boxes sampled were used and 33% of the nests were destroyed by predators. Mean clutch sizes of unparasitized (x = 9.2) and parasitized (x = 15.2) nests were significantly different. The parasitism rate in Wood Duck nests was 54%. More visible boxes had a tendency to be parasitized at a higher rate than …