Реферат: Bald Eagles And Golden Eagles Essay Research
Название: Bald Eagles And Golden Eagles Essay Research Раздел: Топики по английскому языку Тип: реферат |
Bald Eagles And Golden Eagles Essay, Research Paper Eagle is the common name for a number of diurnal birds of prey, some of which are the largest members of their family which also includes kites, hawks, buzzards, and certain vultures. The name eagle is somewhat loosely applied, as several of the groups are not particularly closely related to one another, and some birds called hawks are larger than some called eagles. The Bald Eagle (Haliaeetus Leucocephalus) and the Golden Eagle (Aquila Chrysaetos) are two eagles that have several of the same characteristics and have several different ones as well. The Bald Eagle is the only eagle species living strictly in North America, and has a presence in every state in the US except Hawaii. Young (immature) Bald Eagles are light gray when hatched, and turn dark brown before leaving the nest at about 12 weeks of age. During their third and fourth years, Bald Eagles have a mottled brown and white color under their wings and on their head, tail and breast. The distinctive white head and tail feathers do not appear until they are 4 to 5 years old. Bald Eagles range from about 29-42 inches long, and can weigh between 7-16 pounds, and have a wingspan of 6 to 8 feet. This makes them one of the largest birds in North America. Bald Eagles residing in the northern US are larger than those that reside in the south. They have a life span of up to 30-40 years in the wild and longer in captivity. Bald Eagles are monogamous and remain faithful to their mate until death. Females lay one to three eggs annually, and the incubation period is approxim! ately 35 days. Only about 50% of Eagles hatched survive the first year. Strong endangered species and environmental protection laws, as well as active private, state and federal conservation efforts have brought back the USA’s Bald Eagle population from the edge of extinction. There are now about 4500 nesting pairs and 20,000 total birds in the lower 48 states, and there are over 35,000 Bald Eagles in Alaska. America’s Bald Eagles are back in strong numbers today, but they are still a “threatened” species in the lower 48 states. Breeding season last from November to April. Bald eagles mate for life and use the same nest each year. They build a huge nest (aerie) of sticks and twigs in a tree, or on rocky cliffs and average in size of 2 feet deep and 5 feet across. The nest takes weeks to construct and is increased yearly. Eventually some nests reach sizes of more than 10 feet wide and can weigh several tons. Bald Eagles feed primarily on fish, but also eat small animals (ducks,! coots, muskrats, turtles, rabbits, snakes, etc.) and occasional carrion (dead animals). Eagles swoop down to seize fish in their talons and carry it off, but can only lift about half of their weight. Bald Eagles can even swim to shore with a heavy fish using their strong wings as paddles. However, it is also possible that they can drown if the fish weighs too much. The Golden Eagle is a large brown and golden colored eagle that can be found in a variety of habitats in the western North America region including mountainous areas, canyons, shrub-land and grasslands. The Golden Eagle can also be found in Europe, Asia and northern Africa. The breeding range in North America includes north central Mexico, the western United States as far east as the Dakotas, Kansas and Texas, also Alaska, and across northern Canada. This bird of prey can weigh up to 15 pounds and can have a wingspan of 6 to 8 feet and a length of 30-40 inches. Females are often more noticeably larger than males as is true with most birds of prey. Young (immature) Eagles have a patch of white on the tail, and the adult tail is gray and brown. The Golden Eagle also builds large their nest out of sticks and twigs in a tree or on a cliff. The female lays 1-4 eggs (usually 2) and often does most of the incubation. The males provide most of the food while the females feed and tend! the young. Golden Eagles feed primarily on mammals such as rabbits and hares as well as larger rodents. Up to 20% of their diet is comprised of birds and reptiles. Golden Eagles feed mostly on food that they catch, although they will use carrion. Golden Eagles are considered to be fairly common in the western U.S., Canada, and Alaska (some estimates range up to 70,000 birds). Golden Eagles are still subject to illegal shooting due to the erroneous belief that they are a serious threat to ranch animals. The Second Continental Congress officially declared the Bald Eagle the USA’s National Emblem in 1782. The founding fathers selected it because it is unique to North America. Ben Franklin actually wanted the wild turkey to be the USA’s national bird. On the national seal the eagle is shown with its wings spread, holding an olive branch in one claw and arrows in the other. The Bald Eagle has since become the living symbol of the USA’s freedoms, spirit and pursuit of excellence. |