Bald Eagles: Nesting

Right now in Alaska, it’s the season for bald eagles to be building their nests, and laying and incubating their eggs. I’m Jim Metzner, and this is the Pulse of the Planet, presented by the American Museum of Natural History. We’re listening to the sounds of nesting eagles.

Don Bruning is Chairman and Curator of the Department of Ornithology for the Wildlife Conservation Society.

“Bald Eagles are interesting in that they continue building frequently on the same nest. So that you may have a nest that may have been in the same location for 20 or 30 years. And the nest may weigh several ton because the eagles will carry new twigs and sticks up to the nest every year. So when they’re putting it on top of the old structure, it just gets bigger and bigger. Frequently what happens it eventually reaches a size in which the tree that it’s in can no longer support it and the whole thing crashes to the ground. But there are records of nests that have been occupied by eagles for over thirty years.

“Eagles will normally lay between one and four or maybe five eggs. Two or three is the normal number of chicks for an eagle. Egg laying in Alaska would probably start in May, so that the chicks would be hatching in June so they can capitalize on the bountiful food supply in July and August because once you get past that, then food supply diminishes very quickly.

“With eagles, both the female and the male will assist in incubation. And they will share the duties. And usually then you get a call when one eagle flies in to replace the other on the nest, they greet each other with one of these greeting calls, and then they switch places. One goes out to hunt to find food and the other incubates the eggs.”

In Alaska, many eagle chicks will be hatching next month.

Additional funding for Pulse of the Planet has been provided by the National Science Foundation. I’m Jim Metzner.

Bald Eagles: Nesting

Now is the time of year when bald eagles build their nests, some of which have been in construction and use for up to 30 years.
Air Date:05/25/1998
Scientist:
Transcript:

Right now in Alaska, it's the season for bald eagles to be building their nests, and laying and incubating their eggs. I'm Jim Metzner, and this is the Pulse of the Planet, presented by the American Museum of Natural History. We're listening to the sounds of nesting eagles.

Don Bruning is Chairman and Curator of the Department of Ornithology for the Wildlife Conservation Society.

"Bald Eagles are interesting in that they continue building frequently on the same nest. So that you may have a nest that may have been in the same location for 20 or 30 years. And the nest may weigh several ton because the eagles will carry new twigs and sticks up to the nest every year. So when they're putting it on top of the old structure, it just gets bigger and bigger. Frequently what happens it eventually reaches a size in which the tree that it's in can no longer support it and the whole thing crashes to the ground. But there are records of nests that have been occupied by eagles for over thirty years.

"Eagles will normally lay between one and four or maybe five eggs. Two or three is the normal number of chicks for an eagle. Egg laying in Alaska would probably start in May, so that the chicks would be hatching in June so they can capitalize on the bountiful food supply in July and August because once you get past that, then food supply diminishes very quickly.

"With eagles, both the female and the male will assist in incubation. And they will share the duties. And usually then you get a call when one eagle flies in to replace the other on the nest, they greet each other with one of these greeting calls, and then they switch places. One goes out to hunt to find food and the other incubates the eggs."

In Alaska, many eagle chicks will be hatching next month.

Additional funding for Pulse of the Planet has been provided by the National Science Foundation. I'm Jim Metzner.