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Article: Individual, brood, and sex variation in begging calls of Western Bluebirds.
- Article from:
- Wilson Bulletin
- Article date:
- June 1, 1997
- Author:
CopyrightCOPYRIGHT 1997 Wilson Ornithological Society. This material is published under license from the publisher through the Gale Group, Farmington Hills, Michigan. All inquiries regarding rights should be directed to the Gale Group. (Hide copyright information)
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Vocal differences in birds are often sufficient for recognition not only of species but of variables such as sex, age, genetic relatedness, and condition. Here we analyze begging calls of Western Bluebird (Sialia mexicana) nestlings and test for family, sex, and individual differences. The original impetus for this study was the finding by Gowaty and Droge (1990) that female Eastern Bluebird (Sialia sialis) nestlings were fed more often than were male nestlings and that female-biased broods were provisioned more frequently by the adult male attending the nest. If this result is due to an adjustment of parental behavior in response to the sex of the nestlings, then there must ...