Bald eagle | Oceana Canada

Seabirds

Bald eagle

Haliaeetus leucocephalus

Bald eagle

Also known as

American eagle

Distribution

Sub-tropical to sub-polar latitudes of North America

Ecosystem/Habitat

Nest in treetops; feed in freshwater and coastal waters

Feeding Habits

Foraging predator/scavenger

Conservation Status

Not at Risk

Taxonomy

Order Accipitriformes (raptors and relatives); Family Accipitridae (eagles, hawks, and relatives)

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Bald eagles are a large bird of prey that live along coastlines of both freshwater and marine waterways across North America. With a diet that consists mainly of fish, and sometimes even other seabirds and waterfowl, bald eagles rely heavily on the ocean. They are one of the most recognizable and iconic birds throughout North America. Although their white head is the inspiration behind the bald eagle’s common name, they are not actually bald. Like the rest of their body, their head is also covered in feathers.

Bald eagles are large birds of prey and can measure 71 to 106 centimetres long with an incredible wingspan of that can span over two metres! They weigh on average three to seven kilograms and females are typically about 25 per cent larger than males. Adult bald eagles are easily recognizable with their dark brown body, white head and tail, bright yellow irises, taloned feet and beak. Juveniles, on the other hand, are entirely brown except for their yellow feet, and start to molt into their adult plumage when they reach sexual maturity around four to five years of age.

Like all water birds, bald eagles nest on land. They reproduce via internal fertilization and lay eggs in very large nests. In fact, their nests are the largest tree nests in the world. They use the same nest year after year and, over time, these nests end up being up to four metres deep, two and a half metres wide and can weigh over one metric tonne. After elaborate and even beautiful courtship displays, that include both calls and acrobatics like cartwheels, roller-coaster swoops and chases, a bonded pair will build a nest together. Some bald eagles mate for life but if a partner dies, disappears or is unable to breed successfully, they may look for new mates. After mating, a female bald eagle will lay one to three eggs, with two being the most common number of eggs that a pair of bald eagles will care for at a time. After hatching, juveniles receive some form of parental care for at least five months although most are able to feed themselves after six or seven weeks. Once out on their own, bald eagles in the wild can live to be thirty years of age.

Although bald eagles eat mostly fish, they are also known to eat other birds, especially seabirds and waterfowl. And while bald eagles have a reputation for being impressive predators, they often scavenge dead animal matter or steal kill from other predators, especially in cold winter months.

Although bald eagles are not directly targeted by fisheries or other hunting activities, they could be negatively impacted by the depletion of wild fish populations. Specifically on the Pacific coast, where salmon species make up a large part of their diet, declines in wild salmon populations may be contributing to a decline in high quality food sources for Pacific bald eagle populations, impacting over-winter survival rates.

Bald eagles cannot be legally hunted anywhere throughout their range, and populations are currently thought to be stable or even increasing. They have been assessed by the Committee on the Status of Endangered Wildlife in Canada (COSEWIC) as Not at Risk since 1984. Notably populations declines that were observed in the past in southwestern Ontario and the Maritime provinces have been reversed. 

However, the species has not always been in such good shape. During the early to middle 20th century, bald eagle numbers plummeted, a result of intense directed hunting and significant accidental poisoning. Poisoning by the common pesticide DDT was considered one of the primary reasons that numbers in North America decreased from several hundred thousand to less than one thousand. DDT poisoning weakened this eagles’ eggs and reduced hatching rate significantly. Use of this chemical was restricted in Canada in the early 1970’s and eagle populations have started to rebound. This, coupled with other successful conservation and management efforts, has led to rapid expansion of the species, in both numbers and geographic area, and it is no longer threatened by with extinction. Bald eagles are just one example demonstrating that with strong policy and conservation measures in place, species at risk can recover to healthy levels.

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