Our national symbol, the bald eagle (haliaeetus leucocephalus) displays many outstanding characteristics - exceptional vision, a striking appearance, and a commanding presence. Sadly, by the later half of the 20th century, the bald eagle was classified as an endangered species. Through the diligent efforts of wildlife biologists and a concerned public, the bald eagle population is coming back and is no longer on the federal endangered species list. Its federal and state status is now delisted but it is still in a federal monitoring stage for five years.
The adult bald eagle is one of the most easily recognized species of wildlife. It has snow white feathers covering its head down to the neck area. The tail feathers of the mature bald eagle are also white. The body color is very dark brown, almost black. Yellow eyes, beak, and feet accent the bird’s appearance. The white of the head and tail distinguish the fully mature eagle from immature birds of the species. Young eagles do not have this appearance until they reach the age of five or six years. Until that time, they are decidedly duller in appearance and, to the inexperienced observer, probably would not be recognized as a bald eagle. Immature eagles are almost uniformly dark brown from head to tail feather. Their undersides are mottled white with buff and cream blotches.
Pair bonding activity for both new and established pairs begins in the fall. Courtship behavior and nest building can occur anytime between October and early December. The female lays one to three eggs in mid-February to late March. Both she and her mate spend time on the nest incubating and share the feeding responsibilities. The 1-3 eggs usually incubate for 35 days, from February through April. The young are altricial (helpless and dependent on parents) and usually leave the nest after 10-13 weeks. A female will produce 1 brood each year, but if a nest is destroyed, some pairs will "recycle" and initiate a second nest within the same year.
Habitat & Behavior
The bald eagle can be found in small concentrations throughout the U.S., particularly near sizable bodies of water, natural and man-made. In Ohio, the bald eagle’s stronghold is the marsh region of western Lake Erie. For the bald eagle, the ideal site is one where water with ample food (fish) is located within two miles of the nest. The eagle shows a preference for a somewhat secluded homesite. This is particularly critical when the nest is being established and young raised. Eagles are highly territorial and too much interference from other eagles can result in problems at the nest site.
Adults are, in general, year-round residents. Immature birds, however, sometimes migrate during spring and fall.
Research & Surveys
Bald Eagle Aerial Nest Surveys:
Aerial surveys are conducted in March in an established statistical panel design of survey blocks. Block surveys are run by helicopter to search for nest structures and their occupancy. Nests are not approached at close range unless unoccupied. Nests are recorded with a global positioning unit (GPS) for future reference and monitoring.
Bald Eagle Aerial Production Survey:
All nests found in the March Block surveys are inspected by helicopter in late May or early June to access productivity. This survey, including information from volunteer reports, enables us to estimate annual production and eaglet mortality for the breeding season.
2020 Breeding Update
The bald eagle occurs in marshes, swamps, and river systems throughout Ohio. Eagles have continued to recover from a low of 4 breeding pairs in 1979. In 2020, the statewide nest census documented 707 nests throughout the state of Ohio. Bald eagles were documented as nesting in all but three of Ohio’s counties (see map). This number was much higher than previous years, largely because 2013-2019 nest numbers (orange diamonds) were estimated from a sample of survey areas, and were not able to capture the expansion and increase of nests across the state. The 2020 nest census indicated a 150% increase in nests from the last nest census in 2012.
Productivity surveys were not conducted in 2020 due to the COVID-19 pandemic. However, in recent years, productivity measures have been robust, with an average of 1.4 eaglets per nests from 2010-2019. This is well above the 1 eaglet per nest needed to maintain the population, thus we likely had approximately 1,000 eaglets hatched in 2020.
Please remember that even though eagles are no longer listed as state or federally endangered or threatened, they are still protected by the federal Bald and Golden Eagle Protection Act and state law. The mid-late winter nesting period is a critical time for eagle reproduction and every effort should be made to reduce interference at that time. Many nests are in State Wildlife Refuges so access is restricted. Other areas may also be posted as “No Trespassing” areas. Lastly, please observe posted signs and remember that private property may not be entered without the landowner’s permission.
2020 Mid-winter Flight Survey
Although mid-winter may seem like a cold and dreary time to be outdoors, it can be one of the most rewarding times to view one of our nation’s symbols, the bald eagle. In mid-winter, frozen lakes and rivers often force eagles to expand their hunting grounds in search of food. Also, many of the species preyed upon by eagles are hibernating or hiding under a thick blanket of snow. Because of this, eagles are often seen in non-traditional areas during this period. They can be seen roosting along rivers, sitting on frozen lakes or even in open farm fields. Their large size and dark bodies are easy to spot against the white snow and ice.
Along with other state and federal agencies, the Division participates in an annual mid-winter survey of bald eagles. In January 2020, the Division staff counted a record-setting number of 320 immature eagles and 233 adult eagles, for a total of 553 bald eagles. This is a 26% increase over last year’s total of 440 eagles.