Predation on red-winged blackbird eggs and nestlings

TitlePredation on red-winged blackbird eggs and nestlings
Publication TypeJournal Article
Year of Publication1979
AuthorsShipley, FS
JournalThe Wilson Bulletin
Pagination426 -433
Accession NumberKNZ0025
Keywordsblackbird, predation

The contents of red-winged Blackbird (Agelaius phoeniceus) nests are subject to extensive and highly variable losses. Normally, most red-wing eggs fail to produce young that are able to leave the nest. Most researchers have found 60 to 100% of the losses to be due to predation on nest contents, where the entire brood or clutch is lost at once. Fewer than 5% of the losses normally appear to be related to starvation of nestlings or nestling competition. The remainder of the losses (under 40%) result from a variety of causes, including egg infertility, nest desertion, and nest tipping due to growth of the supporting vegetation. In this study, I relate predatory losses of red-wing nestlings and eggs to water depth at nest-sites, habitat type, and number of young in the nest. My studies were done in east-central Kansas; several previous authors have presented data from similar studies in other parts of the range of the Red-winged Blackbird