Raptor Population Index







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  Assessments:

Species Assessment:
Cooper's Hawk (Accipiter cooperii)

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The 10-year migration count trends for Cooper’s Hawks suggest mostly stable populations across North America with 73% of 75 total sites showing stable counts during this span. There also have been decreasing observations at 24% of North American sites, and only 3% of sites showing an increase. Regionally, populations are mostly stable with some decreasing reports in the Central and East Regions. Two of the five sites showed declines in the Central Region or 33%, whereas 29% of 55 sites in the East showed declines. The West and Gulf Regions have not reported any declines (see pie charts and trend maps below). Twenty-year count trends (not shown) also reflect a mostly stable population except for the Gulf Region which had observed only decreases over this span (Central Region: 2 decrease; East Region: 13 stable, 2 increase, 8 decrease; Gulf Region: 5 stable; West Region: 5 stable, 1 decrease). Declines may suggest changes in migration behavior or declines in some sub-regions, but further research is needed to understand these patterns. Cape May, New Jersey recorded the highest average count for Cooper’s Hawk at 3,826, reported stable counts. Goshutes, Nevada, which averages 2,527 Cooper’s hawks per year, also reported stable counts.

Winter survey data from the Christmas Bird Count (CBC) show slightly increasing 10-year trends continent-wide with the annual percent change in population reported to be an increase of 2%. The Cooper’s Hawk is a species of least concern and has readily recovered from widespread North American raptor declines during the previous century, which is likely due to its ability to exploit human-altered landscapes. Some localized threats include contaminants, disease, and shooting.

Cooper's Hawk<br>Photo by Bill Moses

Photo by Bill Moses







Please cite this page as:
    D. Oleyar, D. Ethier, L. Goodrich, D. Brandes, R. Smith, J. Brown, and J. Sodergren. 2021. The Raptor Population Index: 2019 Analyses and Assessments.