Population Level Survey of Golden Eagles (Aquila chrysaetos) in the Western United States

Authors

Rhett E. Good
Ryan M. Nielson
H. Hall Sawyer
Lyman L. McDonald

Date of this Version

8-30-2004

Citation

U.S. Fish & Wildlife Service 4401 N. Fairfax Drive, Suite 212 Arlington, VA 22203.

Comments

U. S. government work.

Abstract

Some researchers have suggested Golden Eagle (Aquila chrysaetos) populations may be declining in at least part of their range (Bittner and Oakley 1999, Leslie 1992, Steenhof et al. 1997). However, there are little baseline data describing Golden Eagle populations across their range in the western United States (U.S.). The United States Geological Survey (USGS) Snake River Field Station recently prepared a preliminary plan for monitoring Golden Eagle populations (Fuller et al. 2001). Based on recommendations by Fuller et al. (2001), the United States Fish and Wildlife Service (USFWS) issued a request for proposals (Solicitation number 982103R041) to design and conduct Golden Eagle population surveys in Bird Conservation Regions (BCRs) 9,10,16, and 17 within the boundary of the U.S. The overall objective of the project was to estimate Golden Eagle population sizes in the study area using aerial transect procedures that would yield, if replicated annually, at least 80% power to detect an annual rate of total population change greater than or equal to 3 percent per year over a 20-year period using a test of size alpha = 0.1 (or 90% confidence interval).