Faculty Mentor(s)

Dr. Kathy Winnett-Murray, Hope College

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Parental investment and competition are two important elements of life history strategies affecting reproductive success. The effect of parental investment on reproductive success in a west Michigan population of Eastern Bluebirds (Sialia sialis) was investigated, including parameters such as feeding rates, sex of parent, type and size of items delivered to chicks, number of chicks, and age of chicks. We found all measures of parental investment related to provisioning of nestlings to be indistinguishable within mated pairs. We also determined that significantly more food was brought when parents had a large brood (3+ chicks) as compared with a small brood (1-2 chicks). Overall, there was only a 33% success rate for Eastern Bluebird nests during the summer of 2010, largely as a result of high nest predation. We found that Eastern Bluebirds avoided nesting near other Eastern Bluebirds, but not any other nestbox-using bird species. Also, identity of the nearest neighbor did not appear to have an influence on the reproductive success of Eastern Bluebirds. The results of this study can help in the understanding of specific ecological interactions among species that may be of conservation interest.

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