Bald Eagle

 Bald Eagle

 Scientific Name: Haliaeetus Leucocephalus
Classification: Raptor or bird of prey 

Size:

The female is 35 to 36 inches tall. They have a wingspan which varies between 79 to 90 inches. The male is 30 to 34 inches tall with a wingspan ranging between 72 and 85 inches. They can weigh from 10 to 14 pounds.

 

Description:

Adults have a blackish-brown back and breast with a white head, neck and tail with yellow feet and bill. Immature birds are a mixture of white and brown with a black bill in very young birds. The adult coloration/plumage develops at about four or five years of age, when the bird becomes sexually mature.

 

Life Span:

While wild bald eagles may live to be 30 years old, the average life expectancy is probably between 15 and 20 years.

 

Habitat:

The bald eagle is known as a sea or fish eagle and is found along rivers and coastlines where tall trees are available for nesting. Most of the bald eagles found in Nevada are wintering here, though occasionally, nesting pairs are found in the northern part of the state.

 

Range:

Their range includes Alaska, Canada and a large part of the lower 48 states, extending as far south as southern California, Florida and even Mexico. 

 

Natural History:

Bald eagles live near waterways with large pine forests or other tall trees to build their nests in. Their home range is between 1,700 and 10,000 acres depending on food availability. They mate for life, though if one of the birds dies, the other may find a new mate. They have shrill high pitched vocalizations and twittering. They do migrate, though some migrations are only a hundred miles, while others migrate much further. They try to find places with open water during the winter so that food is available.


Food Habits:

The bald eagle primarily eats fish, though it is opportunistic and is often seen eating carrion. It also eats small mammals and birds and will steal food from other birds of prey.

 

Breeding:

Eagles lay from one to three speckled off-white or buff colored eggs between January and may, depending on how far north they live. After approximately 35 days of incubation, the eggs hatch. Both parents help incubate the eggs, though the female does most of the work. Once hatched the female spends most of the time at the nest, while the male provides most of the food. It is not uncommon for the oldest eaglet to kill the smaller ones and often only one eaglet survives. The eaglets grow quickly gaining a pound in weight every four or five days and by six weeks are almost as big as the parents. The first flight can take place between 10 and 13 weeks after hatching and more than a third of the eaglets do not survive their first flight. They are dependent on the parents for their food and spend the remainder of the summer learning how to hunt from their parents. The first winter is the most dangerous for a young eagle. If it survives that, then it can expect a long life. 

 

Status:

Threatened and protected under the bald eagle act.

 

Reason for Status:

Previously listed as endangered due primarily to bioaccumulation of ddt pesticides, numbers have rebounded and they have been down-listed to threatened in most of their range.

 

Management & Conservation:

100-150 birds in Nevada during the winter. Minimal nesting. Wintering populations are monitored on a triennial basis.

 

Fun Facts:

  • Almost 40% of fledglings don’t survive their first flight.
  • It is found only in north America.
  • The bald eagle has 7,000 feathers.
  • Its skeleton often weighs only ½ pound.
  • Ben Franklin thought the turkey was a smarter bird and wanted it for our national bird instead of the bald eagle which has been our national bird since 1782.
  • They use the same nest year after year adding new twigs and branches each year. One nest was found that had been used for 34 years and weighed over two tons! Nevada’s wintering eagles roost in permanent communal night roosts, sometimes five to ten birds in a tree.