Skip to Main Content
U.S. Forest Service
Caring for the land and serving people

United States Department of Agriculture

Home > Search > Publication Information

  1. Share via EmailShare on FacebookShare on LinkedInShare on Twitter
    Dislike this pubLike this pub
    Author(s): Teryl G. GrubbRoy G. Lopez
    Date: 2000
    Source: Journal of Raptor Research. 34(4): 287-292.
    Publication Series: Scientific Journal (JRNL)
    Station: Rocky Mountain Research Station
    PDF: Download Publication  (354.44 KB)


    We used pellets collected from roosts to supplement incidental foraging observations to identify prey species of Bald Eagles (Haliaeetus leucoughalus) and to evaluate spatial and temporal trends in their food habits while wintering in northern Arizona between 1994-96. We analyzed 1057 pellets collected from 14 roosts, and identified five mammal and 13 bird species. American Coot (Fulica americana, N = 447) and elk/deer (Cervus elaphus/Odocmleus hemoinus, N = 412) were the most common prey remains we identified and they varied annually and inversely with each other (11-58% for coots and 21-78% for elk/deer). Diving ducks (92%) were more heavily represented in pellets with identifiable bird prey (N = 701) than dabblers (1%), although Christmas Bird Counts indicated 64% divers and 36% dabblers in the study area (N = 18 202; x2 = 46.3, df = 1, P < 0.01). Almost all pellets consisted mostly of mammal or bird remains (N = 366 and 689, respectively). The overall ratio of mammal to bird pellets was 59:41, with relative class frequencies varying between years (x2 = 118.29, df = 2, P < 0.01). At roosts <3 km from water (N = 752), 90% of the pellets contained birds; whereas, at roosts >3 km from water (N = 303), 96% of the pellets contained mammals (x2 = 698.54, df = 1, P < 0.01). In three successive winters of varying weather conditions, wintering eagles foraged primarily on mammals, fish, and waterfowl, respectively; but only mammals and waterfowl were accurately represented in pellets.

    Publication Notes

    • You may send email to to request a hard copy of this publication.
    • (Please specify exactly which publication you are requesting and your mailing address.)
    • We recommend that you also print this page and attach it to the printout of the article, to retain the full citation information.
    • This article was written and prepared by U.S. Government employees on official time, and is therefore in the public domain.


    Grubb, Teryl G.; Lopez, Roy G. 2000. Food habits of bald eagles wintering in northern Arizona. Journal of Raptor Research. 34(4): 287-292.


    Bald Eagle, Haliaeetus leucocephalus, pellets, diet, food habits, winter roosts, winter habitat

    Related Search

    XML: View XML
Show More
Show Fewer
Jump to Top of Page