Background
The bald eagle (Haliaeetus leucocephalus) is protected by the Bald and Golden Eagle Protection Act and the Migratory Bird Treaty Act, which protects eagles from harm and disturbance, including disturbance from utility construction and maintenance[2]. Eagles are unlikely to be disturbed by routine activities that occurred in an area prior to nesting; thus, these activities do not warrant special concern.
Utilities frequently have to perform construction and maintenance activities during the Bald Eagle Nesting season, which is not considered routine for a given area.
Bald Eagle nesting season in Florida ranges from October 1–May 15. During that time, any nest within 330–660 feet of construction or maintenance must be monitored during the breeding season. This is typically done three times per week while the disturbance is occurring. Monitoring is not required if a disturbance is not occurring during the nesting season.
Nest Disturbance Monitoring Approach
Eagle nest monitoring aims to determine if eagles exhibit any abnormal behavior in response to the surrounding human activities.
During the early nesting season, previously active nests must be monitored to determine if eagles return to re-nest. This initial monitoring must occur once/week for a minimum of 2 hours, starting ½ before sunset. Initial monitoring may stop if no eagle nesting has been attempted by February 1 and no evidence exists of eagles constructing a new nest within 660 feet (201 meters) of construction.
Once the nest is determined to be active, surveys three times/week for four hours each day (starting ½ hour before sunset) are required during the breeding season while disturbance occurs.
Five weeks after hatching, nest monitoring can be reduced to 1 day/week but should continue until fledging or until May 15, whichever occurs first.
During monitoring, behavioral observations collected in 15-minute intervals include the following:
- Timing of adult nest attendance
- Courtship, mating, or nest-building observations
- Incubation and brooding
- Feeding and nestling care
- Flights to and from the nest
- Fledgling of nestlings
Behaviors that would indicate eagles are being disturbed by human activities include the following:
- Adult eagles standing up in response to noise or other disturbance
- Increased time away from the nest
- Flight changes
- Distress calls
- Flushing behavior when a disturbance occurs
- Altered feedings schedule
- Premature fledgling[1]
Eagle Nest Disturbance Reporting
Assuming no disturbance is observed, progress reports are provided monthly to the utility for distribution to the U.S. Fish and Wildlife Service. Progress reports include a summary of any eagle activity observed (e.g., flights to nest, feeding young, agitation, etc.) and any evidence the eagles were disturbed while the monitoring occurred. A final report is required within one month after completing the monitoring for the nesting season.
If eagle disturbance is observed during the monitoring, the utility, U.S. Fish and Wildlife Service, and the Florida Fish and Wildlife Conservation Commission must be notified immediately. All data sheets must be provided for review.
Field data sheets are kept on file for a minimum of 3 years.
References
[1] U. S. Fish and Wildlife Service. 2007a. Bald eagle monitoring guidelines.
[2] U. S. Fish and Wildlife Service. 2007b. National bald eagle management guidelines.
