INFREQUENT COWBIRD PARASITISM ON COMMON GRACKLES REVISITED: NEW RECORDS FROM THE NORTHERN GREAT PLAINS

Authors

Brian D. Peer, Lawrence Univ., Appleton, WI
H. Jeffrey Homan, USDA/National Wildlife Research Center/Great Plains Field StationFollow
Spencer G. Sealy, Univ. of Manitoba, Winnipeg, MB, Canada

Date of this Version

June 2001

Comments

Published in Wilson Bull., 113(1), 2001, pp. 90–93.

Abstract

We report nine new records of Brown-headed Cowbird (Molothrus ater) parasitism on the Common Grackle (Quiscalus quiscula): six from Benson County, North Dakota, and three from Delta Marsh, Manitoba. These observations represent 30% of the total number of records of parasitism on this host. Parasitism frequencies were 0.8% of 727 nests in North Dakota, and 4.0% of 75 nests in Manitoba. The data from Manitoba, combined with previous data from this location (Neudorf and Sealy 1994), yields a parasitism frequency of 3.4% of 119 nests examined. These parasitism frequencies are the highest recorded for the Common Grackle.