Biologists begin banding nestlings
PHOENIX – It’s two female offspring for proud bald eagles nesting at Lake Pleasant, as Arizona Game and Fish Department biologists discovered yesterday. The discovery was made during the department’s efforts to place identification bands on the eaglets before the birds fledge and leave the nest.
Each year as part of a highly successful program to manage and conserve bald eagles in Arizona, department biologists band as many nestlings as possible. Last year, nearly half of all the nestlings that reached fledging age had been banded. The identification bands help biologists learn more about population demographics and the species’ migration, reproduction and nesting behavior.
Gaining access to the nest and its 6-week-old occupants takes skill and requires biologists to rappel down to the cliff-side nest that sits high above the lake. The young birds are then placed in a specially-equipped “baby bag” and hoisted to the ground above to receive both a state and federal ID band, have measurements taken and feather samples collected for contaminants analysis.
“Arizona has both cliff nests and tree nests. Some nests cannot be safely accessed, but we try to band as many of the young as we can in order to continue learning about the species. The timing is critical; we have to band the nestlings when their legs are nearly full-grown, but they aren’t at risk for trying to prematurely fly from the nest, which occurs around 7 weeks,” said Kenneth Jacobson, head of the Arizona Game and Fish Department Bald Eagle Management Program.
Entering nests to band nestlings also allows biologists to collect and remove potentially lethal fishing line and tackle, addled (dead) eggs, eggshells, prey remains, rescue individuals, and to repair or reconstruct nests if they are falling apart.
The public is reminded that 23 high-use recreation areas across the state are closed this time of year to help bald eagles successfully reproduce. The exact restrictions depend on the area but can include closures to foot or boat traffic. Outdoor recreationists, aircraft pilots, drone operators and motorized paragliders are asked to stay out of closed areas. For a list of closures, visit www.azgfd.gov/baldeagle.
“Cooperation from outdoor recreationists has been a major reason that the bald eagle population continues to grow, and now we’re working to create more awareness among aircraft pilots, drone operators and motorized paragliders. Pilots should maintain the FAA-recommended 2,000-foot above ground level advisory when flying over bald eagle habitat, and drones and paragliders are asked to avoid the areas completely,” said Jacobson.
Bald eagles are sensitive to even short durations of low-flying aircraft activity near their nests and just a few minutes of disturbance can lead to a nesting failure.
Bald eagles were successfully recovered and removed from the federal Endangered Species Act but remain protected by the Bald and Golden Eagle Protection Act and other state and federal rules.