Partners Spotlight


Based at Oregon State University since its inception in 1995, the Northwest Alliance for Computational Science and Engineering (NACSE) is an interdisciplinary research coalition that works to make large scientific databases accessible to different user audiences.


The Snake River Field Station (SRFS) is part of the USGS Forest and Rangeland Ecosystem Science Center. Formerly the Raptor Research and Technical Assistance Center, the Station has been responsible for the Midwinter Bald Eagle Survey since 1992.

Midwinter Bald Eagle Count

Bald Eagle
Bald Eagle (Haliaeetus leucocephalus)
[Photograph: Dave Menke, U.S. Fish and Wildlife Service]

The Midwinter Bald Eagle Count database houses the results of Midwinter Bald Eagle Surveys conducted from 1986-2005. Survey data include observations of eagles collected during more than 8500 surveys along 746 routes in 43 states. These data can be accessed by several query methods: by state, route, name, or latitude/longitude.

Each January, 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. Since 1984, participants in each state have counted eagles along standard routes to provide data on count trends. Standard survey routes were defined as clearly described areas where eagles had been observed in the past. Federation guidelines stipulated that standard surveys be conducted by the same number of experienced observers using the same method (e.g., fixed-wing, helicopter, boat, vehicle) at approximately the same time of day each year.

For more details on the Midwinter Count Results, see: 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. Bird Populations 6:21-32. Midwinter Eagle Count Trends Publication (PDF)

The NBII Program is administered by the Biological Informatics Program of the U.S. Geological Survey
About NBII | Accessibility Statement | NBII Disclaimer, Attribution & Privacy Statement | FOIA
Science.gov Logo       USGS Logo       USAgov Logo