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Bald Eagle Midwinter Survey

Enter 2014 Bald Eagle Midwinter Survey data here . Data entry should be completed by February 28 to be included in the 2015 summary.

Pennsylvania is home to more than 271 nesting pairs of bald eagles and others that migrate through or over winter. The Mid-winter Bald Eagle Survey is coordinated in Pennsylvania by the Pennsylvania Game Commission and nationally by the U.S. Army Corps of Engineers. The survey monitors the status of bald eagle wintering populations in the contiguous United States by estimating national and regional counts, overall and by age. Each January, several hundred individuals count eagles along standard, non-overlapping survey routes across the country. A subset of the routes are part of the federal Standard Survey Routes (SSR), additional routes are similar in format but not part of the national survey and trend analysis.

Thirty-eight to forty-nine states participate each year, completing 1 to 80 standard survey routes each. Twenty-seven states began surveying standard routes in 1986; other states began standard surveys in the mid-1990s. Other states stopped participating in the count in the 1990s.

Anyone can participate. The Game Commission coordinates the Pennsylvania survey. All prospective participants should contact Patti Barber, PGC endangered birds biologist, at to be a part of this survey. The Army Corps of Engineers conducts many mid-winter eagle surveys near its dams and locks. There is broad participation by birders, raptor-watchers, watershed organizations and government agencies.

Surveys are conducted in January during a period set nationally by the Army Corps of Engineers. There are two target dates selected each year when most routes are conducted. One of these dates is a weekday and the other is a weekend day to accommodate a greater variety of participants.

Surveys are conducted statewide – particularly waterways where bald eagles are expected to be found. There are several established eagle survey routes, some of which are part of the federal survey network and others conducted only for our state assessment.

Observers conduct surveys on standard routes. Sizes of survey routes vary from single fixed points to 150 miles. Due to weather and staffing limitations, not all standard routes are surveyed every year. Routes are conducted by foot, vehicle, boat and by air. Most Pennsylvania routes are conducted with vehicles to reach view-points where eagles can be sighted from land. Standard forms and instructions are used each year to ensure uniformity. The 2014 data can be entered online or data forms can be e-mailed.

How does my participation help? The main objective of the Mid-Winter Eagle Survey is to obtain bald eagle winter populations and distribution data. The survey helps agencies identify key eagle resources when access to open water is most restricted. There also is the added benefit of scouting for new eagle nests. Without leaves on trees, it is much easier to spot an eagle nest in January than when eagles are tending their young in spring and summer. Also, eagles build and repair their nests at this time of year and can be observed in this activity when the winter survey is conducted. Winter eagle roosts are a valuable resource and eagle surveys can assist with locating roost sites for further protection. With the growing nesting population, there is increasing competition for prime foraging and roosting locations. The activity centers of the state's eagles are constantly changing and the winter survey allows an assessment of how these changes are taking place. Tracking the eagle population is an important component of the Game Commission's Bald Eagle Management Plan. The agency's annual bald eagle report summarizes that year's winter eagle survey. For past results and information about the winter eagle survey, click here.

Get Involved! All prospective participants should contact Patti Barber, Game Commission endangered birds biologist, at to be a part of this survey. Participants can enter survey data at this link.