Many endangered species are affected by either predation or competition from other, more successful wildlife species. Arizona has sparse pronghorn populations despite an abundance of habitat. In some areas, their numbers are not increasing rapidly enough to sustain population levels. In other parts of the State, predation has severely limited opportunities to restore wildlife populations, such as bighorn sheep. Using results from extensive research has enabled the AZ WS program to team up with the AZ Game and Fish Department to protect native wildlife from predation. In areas where pronghorn herds are suffering from extensive fawn predation, WS works with the State wildlife agency to increase survival rates through selective coyote removal.
Wildlife Services wildlife biologists are partnering with the United States Fish and Wildlife Service and the Wisconsin Department of Natural Resources to trap brown-headed cowbirds from Kirtland's Warbler nesting sites. Brown-headed cowbirds have significantly impacted Kirkland's warbler nesting success by invading nests, replacing warbler eggs with cowbird eggs, and leaving Kirkland's to raise cowbirds. The trapping program has been a key component to at least 19 Kirkland's successfully leaving the nest this year.