Top Threats to Bald Eagles
The bald eagle has served as the U.S.’s national symbol since 1782, when it was incorporated into the Great Seal by the Continental Congress. Today, the bald eagle also represents a conservation success story.
After their numbers were decimated by a pesticide called DDT , bald eagle populations rebounded from fewer than 500 nesting pairs in the lower 48 states to over 71,000 nesting pairs (U.S. Fish and Wildlife Service 2020). Bald eagles were among the first species offered protection from the newly minted Endangered Species Act, and their successful recovery was indeed contingent on protective legislature and the unified efforts of organizations and individuals to protect them.
Though bald eagles—and many of their bird of prey kin—are currently thriving, our work is far from over. We must prevent history from repeating itself and ensure that our national symbol’s population continues to soar for generations to come.
American Eagle Foundation has assembled the following resource to highlight the greatest threats facing bald eagles today, some of which are poised to undo our conservation efforts without a necessary course correction.
In 2022, a study partially funded by the Bald Eagle Research Grant rattled our understanding of bald eagles’ thriving populations.
According to this study, 47% of bald eagles and 46% of golden eagles had signs of chronic lead poisoning, which is the result of repeated lead exposure. As many as 33-35% of eagles had acute lead poisoning from exposure to high lead levels. These statistics came from samples taken across 38 states over the course of eight years (Slabe et. al, 2022).
A lead fragment the size of a grain of rice is lethal to a mature bald eagle, and the deadly metal accumulates in an eagle’s system over the course of their lives, meaning that there is no safe amount of lead exposure.
To learn more about the impacts of lead poisoning on bald eagle populations and what you can do to help, visit our Lead Toxicity page.
Habitat destruction is a common threat shared by most species of raptor. With bald eagles, Cornell’s Birds of the World posits that loss of shoreline habitat is especially pernicious because it limits nest sites, roosts, and scavenging opportunities in habitats suited for the eagles’ preferred aquatic food (Buehler 2020). Because bald eagles prefer nesting in super-canopies with a commanding view of their surroundings, deforestation also plays a role in dwindling nest site opportunities.
Bald eagle and golden eagle nesting habitats are protected by federal law. Some bald eagles have adapted to thriving in spaces near humans, and, if human persecution and disturbance can effectively be reduced, eagles’ adaptive nature may help alleviate some of the strain placed on their populations by decreasing habitat access.
Collisions cast a wide shadow over bald eagle populations because they categorically include both moving and solid man-made objects. Due to Bald eagle’s scavenging propensities, particularly with roadside carrion, vehicular collisions are always a concern.
The increasing role of wind energy is the most pressing of these collisions. Though the development of sustainable energy is crucial to preserving our nation’s biodiversity, wind energy projects generally overlap with heavy migration routes or wide, open habitats preferred by vulnerable species. According to the American Bird Conservancy, the annual loss of birds to wind turbines was an estimated 681,000 in 2021 alone. These numbers may increase to a devastating 1.4 million if the U.S. reaches its goal of wind energy contributing 20% of the states’ electrical energy by 2030 (American Bird Conservancy 2021).
Possible solutions include bladeless turbines, sensors for stopping the turbines when birds are approaching, or simply shutting the turbines down seasonally, but these solutions require testing and research to assess their effectiveness more thoroughly.
Entanglement with broken fishing line has become an increasing concern with multiple cases requiring intervention and rescue locally by the American Eagle Foundation. The use of unattended fishing lines (such as jug fishing, snag lines, or trout lines)—or when a fish snaps the line and escapes—pose an especially potent risk to eagles. If an eagle catches a fish with hook and line still attached, they may ingest the hook, become entangled themselves, or feed the dangerous prey to their offspring. In addition to the threat of the line, lead fishing weights are also thought to play a role in increasing lead toxicity cases (Buehler 2020).
American Eagle Foundation recognizes the longstanding contributions of anglers to conservation. With greater awareness around these unintended consequences of monofilament, we can work together to mitigate the threat it poses to wildlife via more conscientious treatment of snapped lines and by recycling monofilament in the proper receptacles.
What Can You Do
You can help us protect bald eagles by:
- Advocating for non-lead alternatives to ammo and fishing tackle, or by making the change yourself. The Non-Lead Partnership has compelling ballistic evidence supporting non-lead ammunition.
- Keeping an eye out for your local bald eagle populations. If you suspect that their nest is imperiled or see a bald eagle in need of rescue, call your local federally licensed rehabber. You can find an updated list on your state’s DNR site or through Animal Help Now
- Using your voice and vote to support efforts mitigating the impact of wind energy on migratory birds.
- Sign up for habitat cleanup events near your local waterways or host one yourself.
- Participate in our American Eagle Day festivities to honor the bald eagle’s conservation history and learn more about the threats facing them today.
American Bird Conservancy (2021). Wind Energy and Birds. https://abcbirds.org/program/wind-energy-and-birds/challenges/
Buehler, D.A. (2020). Bald eagle (Haliaeetus leucocephalus). Birds of the World. Cornell Lab of Ornithology, Ithica, NY, USA. https://doi.org/10.2173/bow.baleag.01
Slabe, V.A., Anderson, J.T., Millsap, B.A., Cooper J.L., Harmata A.R., Restani M., Crandall R.H., Bodenstein, B., Bloom P.H.,& Katzner, T.E. (2022). Demographic implications of lead poisoning for eagles across North America. Science, 375 (6582), https://doi.org/10.1126/science.abj3068
U.S. Fish & Wildlife Service (2020) Bald and Golden Eagle Management. https://www.fws.gov/library/collections/bald-and-golden-eagle-management