BALD EAGLE

by Sandra Avant

This sidebar appeared in the Spring 1997 issue of New Mexico Resources, as an adjunct to the article "Wild New Mexico".
Photography: Jack H. McCaw III.

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Soaring to an altitude of 10,000 feet, our national symbol - the bald eagle - graces the Land of Enchantment each winter.

Bald eagles range throughout North America, from the northern reaches of Alaska and Canada to southern California and Florida. They winter in New Mexico from early November through March.

The best places to spot the more than 100 bald eagles that come to New Mexico are along the Rio Grande reservoirs - Elephant Butte and Caballo, and Bosque del Apache National Wildlife Refuge, says Phillip Zwank, wildlife specialist and leader of the Cooperative Fish and Wildlife Research Unit housed at NMSU. Eagles also have been seen along the San Juan River, at Maxwell National Wildlife Refuge, and Cochiti Reservoir.

"We don't actually have information on what happens to birds fledged from the few nests here in New Mexico," Zwank says. "We do see some of them for a few weeks after fledging, but then they disappear. Researchers in Arizona found that their young birds go as far north as Canada after leaving the nest."

Bald eagle sightings at Bosque del Apache alone are up considerably from last year, says John Taylor, management biologist at the refuge. "About 10 years ago, we might have had six or seven eagles on the refuge. Up until last year, the population had grown to about 25 wintering birds. This year's count is up to 60."

Once an endangered species, bald eagles are now listed as threatened in the lower 48 states, Zwank says. Wildlife experts believe that 25,000 to 75,000 eagles existed in these states when the bird was adopted as our national symbol in 1782. By the early 1960s, fewer than 450 eagle nesting pairs were found. The eagle had been decimated by disease, lack of food, habitat destruction, pesticides, and human interference.

Because of recovery efforts, bald eagles have made a remarkable comeback. In 1996, the U.S. Fish and Wildlife Service reported more than 4,000 adult bald eagle nesting pairs and an unknown number of young eagles in the United States. They perch in huge nests that can measure 10 feet across and weigh 2,000 pounds as they add sticks, weeds, and grasses each year.

A striking raptor, the eagle has large, pale eyes; a strong yellow beak; and great black talons. It is only when an eagle reaches the age of 4 or 5 that the dark brown plumage of the head and tail are transformed to pure white.

Opportunistic predators, eagles feed primarily on fish and carrion, but also eat a variety of birds, mammals, and turtles.

Bald eagles mate for life, but readily take a new mate if one member of the pair dies, Zwank says. They are believed to live 30 years or longer in the wild, and have been known to live 50 years in captivity.