Welcome to the Midwinter Bald Eagle Count Web Site!
site provides access to results of Midwinter Bald Eagle Surveys
conducted from 1986-2005 along 746 routes in 43 states. You can
retrieve raw count data as well as summary information (trends,
means, high and low counts) for survey routes using the buttons at
the top of the page. You can obtain model-based estimates of trends
for different regions and states by clicking on Summary
on the left sidebar.
The buttons at the top of the page allow
you to search for survey routes by
drainage/survey route name,
(latitude and longitude). You can retrieve summaries for one route at
a time or for multiple routes. An interactive help program will walk
you through the steps (How
to Use This Site).
The Midwinter Bald Eagle Survey takes place during the first
two weeks of January each year. The U.S. Army Corps of Engineers
(USACE) coordinates the Midwinter Bald Eagle Survey, in which several
hundred individuals count eagles along standard, non-overlapping
survey routes. For more details on the history of the count, see
of the Survey.
The data available from this website were used in an analysis
of count trends from 1986-2005. This 20-year analysis used the same
methods used in a peer-reviewed 15-year trend analysis (Steenhof, K.,
L. Bond, K.K. Bates and L.L. Leppert. 2002. Trends in midwinter
counts of Bald eagles in the contiguous United States, 1986-2000.
The extended analysis did not receive additional peer review because
of this consistency. Please note that data from routes that were not
surveyed consistently for at least four years and routes that never
had more than three eagle observations in a single year during the
20-year sampling period were not used in the trend analysis and are
not available from this website.
cite this Page as: Steenhof, K., L. Bond, and L. L. Dunn. 2008. The
midwinter bald eagle survey results and analysis 1986-2005.
U.S.Geological Survey, National Biological Information
Infrastructure, and Northwest Alliance for Computational Science and
Engineering. Available on-line at http://www.nacse.org/nbii/eagles.
(Indicate access date.)