Scientifically named as the Haliaeetus leucocephalus, the bald eagle is one of the most popular birds of prey. 'Bald' in archaic English refers to 'a creature bearing a white head', hence the name. Otherwise, in actuality, the bald eagle is not 'bald'. It is native to North America and is generally found near large water bodies which are home to a large number of prey and the surroundings of which provide an environment full of natural vegetation and mangroves where they can nest themselves properly. A fully grown bald eagle bears a brown plumage with white head and tail. It has a yellow beak which is slightly hooked at its end. Their feet do not have feathers and their short toes have sharp and powerful claws which make them extremely well-equipped for catching their prey. They hold their prey in their claws and soar into the skies at immensely high altitudes. The males and females have identical features but the females are larger than the male birds. One can identify their genders if one happens to spot them together in a pair. Otherwise, a layman or a bird-watcher can only guess. Bald eagles generally weigh about seven to ten pounds and measure about three feet from head to tail. Adults have a wing-span of about seven feet. The females weigh about fourteen pounds. The bird gets its distinctive white face and tail only when it reaches about five years of age. The average lifespan of a bald eagle is 15 to 20 years. However, it may survive in the wild for about 30 years or so. An interesting instance of a captive bald eagle that died at the age of 48 comes from West Stephentown, New York and this was probably the only bald eagle to have survived for so long. The bald eagle predominantly feeds on fish which is precisely the reason why it resides near large aquatic, especially marine sources. It particularly devours salmon and trout. Apart from fish, which seems to be its favorite, it also consumes rodents and snakes. Because it is essentially a scavenging species, it also feeds on decaying animal carcasses as well as garbage. Other fauna such as rabbits, muskrats, deer, ducks, geese and owls also form part of the bald eagle's diet. They also sometimes steal food from other birds. The bird has a very interesting way of catching its prey. It hovers in the air over the water body and tracks its prey that is swimming underneath. It then descends into the waters speedily, grabs the prey in its claws and snatches it out with utmost force and soars back at high altitudes and goes to a convenient perch. All this happens in the matter of a few seconds. The most fascinating hunting feat is performed by bald eagles when two or three of them act in coordination while catching their prey. While one of them manages to distract the potential victim, the others, very comfortably hunt it down from behind. Notably enough, whenever a bald eagle pairs with a mate, they remain together for the rest of their life. However, if in course of time, one of them disappears or dies, the other one chooses another mate. Sexually, they become mature at the age of four or five years and this is when the females become capable of laying eggs and giving birth to their young ones. During this phase, both the male and the female built a nest of sticks, at a considerable height, generally on a treetop. In cases where the breeding place is short of trees, they nest on the ground itself with both the parent birds caring more for their eggs. Annually, females lay between one to three eggs and both parents tend to take turns to take care of them. That is to say that while one of the parent incubates the eggs, the other goes in quest of food and things required to build a nest. Unfortunately, not all bald eagle young ones can see the light of the day. According to studies, their mortality rate is estimated to be as high as 72%. The eggs as well as hatchlings and juveniles face hazards particularly from predators and from poisonous substances such as pollutants and pesticides. The bald eagle was once a common sight across entire North America, but it's population began declining at an alarming rate in the twentieth century, owing to various natural and human imposed changes. While their population was estimated to be around 300,000 to 500,000 in the 1700s, it fell drastically to around a 1,000 in the fifties. There were about 30,000 to 80,000 of nesting bald eagles when the bird was adopted as the national symbol of the United States in 1782. The following are the reasons why the species became endangered:

• Growth in human population made them hunt for newer lands in order to settle themselves. This resulted in deforestation on a large-scale which hampered the bald eagle's natural habitat which they eventually lost.
• There is an inverse relationship between the population of the humans and the population of the eagles. Excessive hunting and fishing by the ever-growing human population caused a shortage of prey, thus having an adverse effect on bald eagle numbers.
• Another important reason for the endangerment was reduction in the thickness of the egg shells, primarily caused due to the extensive use of DDT and other pesticides. This thinning of the egg shells caused them to break before they could hatch, thus resulting in a depletion of their population.
• Rampant illegal hunting, as well as poaching, also posed to be a major threat for their existence.
• The contamination of water and abundant use of harmful pesticides, added to the already increasing environmental pollution, threatened their sources of food by poisoning them to a great extent.
• Bald eagles also faced danger from farmers and fishermen. Numerous farmers seemed to hunt them down because they thought that the birds posed a potential threat to their livestock. A similar example comes from Alaska wherein around 100,000 bald eagles were put to death by the salmon fishermen who feared that they were a threat to their game.
• A large number of bald eagles were killed due to electrocution wherein the bird perched on a high-voltage power source or flew into it and died instantly.

Owing to all this, the bird was listed as an 'endangered species' in 1967 and were protected under the Endangered Species Preservation Act, 1966. They were also declared 'endangered' by the International Union for Conservation of Nature (IUCN) after which a lot of restrictions were imposed in the regions inhabited by bald eagles. The use of DDT was completely banned in Canada, and hunting of the species was declared illegal throughout North America. Fortunately enough, the bald eagle population then made an impressive recovery and so in 1995, the creature was shifted from the 'endangered' list to the 'threatened' list and eventually to the 'least concern' list, where it now lies. Today, there exist about five thousand nesting pairs of bald eagles. Alaska shelters about half the bald eagle population of North America due to the abundant availability of their food sources in the region. This bird of prey, the apex predator, is protected currently, by the Endangered Species Act of 1973, Bald Eagle Protection Act of 1940, Migratory Bird Treaty Act of 1918 and the Lacey Act.