Bald Eagle
Midwest Region
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Draft Post-delisting Monitoring Plan


Photo of a pair of bald eagles and a chick in a nest.Section 4(g)(1) of the Endangered Species Act requires the Service, in cooperation with the States, to implement a monitoring program for not less than 5 years for all species that have been recovered and delisted. The Service is recommending to monitor bald eagles for 20 years.


Below is the Summary of the Monitoring Plan, go here to view the complete 64-page Draft Bald Eagle Post-Delisting Monitoring Plan (PDF) The draft post-delisting monitoring plan was available for public review and comment for 90 days. The comment period closed on October 9, 2007. Details about commenting on the plan are in the Federal Register: Notice of availability of draft post-delisting monitoring plan; request for comments


The Post-delisting Monitoring Plan (Plan) will monitor the status of the bald eagle over a 20 year period with sampling events held once every 5 years. The Plan will primarily be a continuation of State monitoring activities conducted by the States over the past 20 years. Historically, the States have attempted to census the bald eagle population by anually checking known occupied nests and by adding others found incidentally. For the purposes of this Plan, data from this set of known nest locations will be combined with area plot samples selected from eagle habitat areas across the lower 48 States to provide a dual frame estimate (Appendix 1). Statistically combining the results of these two data sets will provide an estimate that more closely represents the actual nesting population of bald eagles than either the traditional nest check for occupancy or area plot sampling alone, based on our pilot studies in Maine, Minnesota, Florida, Washington and Missouri (Appendix 1). In addition, dual observer sampling protocols are recommended to reduce bias (Appendix 2). However, some States, particularly those with sparse numbers of nesting pairs, are currently collecting data in a highly accurate manner and may not need to employ the dual frame methodology. Data from these states will be included as a complete census (Arizona, for example).


The Plan recommends that the State natural resource/wildlife conservation agencies continue the nest survey data collection while the Service offers technical assistance on incorporation of the dual frame sampling design. Sampling effort will depend upon the extent of State participation and/or funding available at that time. We will continue our mandated role of reporting the national results while working with the States to collate and analyze the data. This Plan is not intended to replace plans to manage eagles or monitor them more regularly or in a different manner for specific management purposes.


The goal of the Plan is to be able to detect a 25 percent change in occupied bald eagle nests on a national scale at 5 year intervals, with an 80 percent chance of detecting a 25 percent or greater difference between 5 year intervals. This will require updated nest lists and a minimum of about 200 area plots surveyed in States with habitats containing medium to high density of bald eagle nests. If the minimum participation necessary to meet this detection goal is not met, the Team will convene, and with State partners will determine participating States, partners, and funding as feasible to accomplish the Plan goal. If declines are detected, particularly those equal or exceeding the goal, the Service’s Bald Eagle Monitoring Team in conjunction with the States will investigate causes of these declines, including consideration of natural population cycles, weather, productivity, contaminants, habitat changes or any other significant evidence. The result of the investigation will be to determine if the population of bald eagles in the lower 48 States warrants expanded monitoring, additional research, and/or resumption of Federal protection under the Endangered Species Act. At the end of the 20 year monitoring program, we will conduct a final review. It is the intention of the Service to work with all our partners toward maintaining continued species recovery.


Go here to view the complete 64-page Draft Bald Eagle Post-Delisting Monitoring Plan (PDF)


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Last updated: September 1, 2010