Last updated: November 8, 2012
Eagle Permit Definitions
Buffer: Distance buffers are the minimum distances the activity should be conducted relative to the nest. Landscape buffers include natural or human-made landscape features that screen eagles from human activity (e.g., strip of trees, hill, cliff, berm, sound wall).
Disturb or Disturbance – to agitate or bother a bald or golden eagle to a degree that causes, or is likely to cause, based on the best scientific information available, (1) injury to an eagle, (2) a decrease in its productivity, by substantially interfering with normal breeding, feeding, or sheltering behavior, or (3) nest abandonment, by substantially interfering with normal breeding, feeding, or sheltering behavior.
In addition to immediate impacts, this definition also covers impacts that result from human-caused alterations initiated around a previously used nest site during a time when eagles are not present, if, upon the eagle’s return, such alterations agitate or bother an eagle to a degree that injures an eagle or substantially interferes with normal breeding, feeding, or sheltering habits and causes, or is likely to cause, a loss of productivity or nest abandonment.
Fledge – To leave the nest and begin flying. For bald eagles, this normally occurs at 10-12 weeks of age.
Fledgling – A juvenile bald eagle that has taken the first flight from the nest, but is not yet independent.
Inactive nest – An eagle nest that is not currently being used by eagles as determined by the continuing absence of any adult, egg, or dependent young at the nest for at least 10 consecutive days immediately prior to, and including, at present. An inactive nest may become active again and remains protected under the Bald and Golden Eagle Protection Act.
Nest – A structure built, maintained, or used by eagles for the purpose of reproduction. An active nest is a nest that is attended, built, maintained or used by a pair of eagles during a given breeding season, whether or not eggs are laid. An alternate or inactive nest is a nest that is not used for breeding by eagles during a given breeding season.
Nest Visibility - Nests may be shielded by rolling topography, trees, or other screening factors. Visibility is a factor because, in general, eagles are more prone to disturbance when an activity occurs in full view. For this reason, we recommend that people locate activities farther from the nest structure in areas with open vistas, in contrast to areas where the view is shielded by rolling topography, trees, or other screening factors.
Similar Activity or Similar Scope – The continued presence of nesting bald eagles in the vicinity of similar existing activities indicates that the eagles in that area can tolerate a greater degree of human activity than we can generally expect from eagles in areas that experience fewer human imacts.
In the vicinity of a bald eagle nest, an existing activity is a similar activity or of similar scope to a new activity where the types of impacts to bald eagles are similar in nature, and the impacts of the existing activity are of the same or greater magnitude than the impacts of the potential new activity. Examples: (1) An existing single-story home 200 feet from a nest is similar in scope to an additional single-story home 200 feet from the nest; (2) An existing multi-story, multi-family dwelling 150 feet from a nest has impacts of a greater magnitude than a potential new single-family home 200 feet from the nest; (3) One existing single family home 200 feet from the nest has impacts of a lesser magnitude than three single family homes 200 feet from the nest; (4) an existing single-family home 200 feet from a communal roost has impacts of a lesser magnitude than a single-family home 300 feet from the roost but 40 feet from the eagles’ foraging area. The existing activities in examples 1 and 2 are of similar scope, while the existing activities in example 3 and 4 are not.