Brown-Headed Cowbird Control Middle Rio Grande, New Mexico 2001 Study Results.

摘要

The U.S. Bureau of Reclamation (Reclamation) implemented a brown-headed cowbird (Molothrus ater) (cowbird) control program in 1996 along the Middle Rio Grande in central New Mexico. The program involves trapping and removal of cowbirds from local populations in an effort to reduce brood parasitism on the endangered southwestern willow flycatcher (WIFL) (Empidonax traillii extimus). The control program has continued on an annual basis, and results are presented in this report. Several data sets are also regularly evaluated to determine the effectiveness of cowbird control efforts. These data include cowbird point counts (1997-2001), neotropical migrant songbird point counts and nest monitoring (1998-2001), WIFL presence/absence surveys (initiated in 1995), and WIFL nest monitoring (1997-2001).