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): C. John Ralph
    Date: 1981
    Source: Studies in Avian Biology 6:265-270
    Publication Series: Miscellaneous Publication
    PDF: View PDF  (331 KB)

    Description

    Intensive variable distance circular-plot censuses and timed activity budget data were used to compare the effects of conspicuousness upon census results. In six of ten species no correlation was found, suggesting that all birds within the "Effective Detection Distance" (EDD) were seen. In four species there were significant correlations. Multiple regression analyses confirmed these results. Generally larger correlations were found with the number of birds per station than with density per ha; the latter is presumed to correct for changes in conspicuousness, possibly through changes in the EDD. However, a completely unexpected result showed that the EDDs themselves, while showing cycles, did not correlate with the activity variables. This indicates that, although they probably have biological meaning and are relevant to censusing, EDDs are not simply related to obvious changes in conspicuousness as measured by activity patterns.

    Publication Notes

    • You may send email to psw_communications@fs.fed.us 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.

    Citation

    Ralph, C. John. 1981. An investigation of the effect of seasonal activity levels on avian censusing. Studies in Avian Biology 6:265-270

    Related Search


    XML: View XML
Show More
Show Fewer
Jump to Top of Page
https://www.fs.usda.gov/treesearch/pubs/31132