Theses and Dissertations - UTB/UTPA

Date of Award


Document Type


Degree Name

Master of Science (MS)



First Advisor

Dr. Timothy Brush

Second Advisor

Dr. Robert J. Edwards

Third Advisor

Dr. Brian L. Fredensborg


During the breeding seasons of 2008 - 2009, 180 fixed-radius point-count surveys and broadcasts of host song were conducted in Santa Ana (SANWR) and Laguna Atascosa (LANWR, 2009 only) National Wildlife Refuges to identify Bronzed Cowbird (Molothrus aeneus) habitat use and test the predictions of the host activity hypothesis. Surveys demonstrated that Bronzed Cowbirds were distributed across all habitat types in both refuges, although there were differences in abundance between the sexes for interior and edge habitats and between habitat types. Bronzed Cowbirds responded differentially to host species playbacks based on suitability and abundance of the host species. The results of this survey are consistent with the predictions of the host activity hypothesis.


Copyright 2010 Mary Jennifer Gorton. All Rights Reserved.

Granting Institution

University of Texas-Pan American