Bald Eagle Facts
Q&A with Peter Nye in 2003
New York Department of Environmental Conservation

Characteristics

Q: How long are a bald eagle's talons?

A: Eagles have 4 talons (and toes) on each foot, a hallux talon at the back of the foot that faces front, and 3 toes on the front of the foot where the talons face toward the back. The hallux talon is always longer than the other regular talons. And in females, this talon is longer than in males. As a matter of fact, that is one way we tell the gender of bald eagles, by measuring the hallux talon, as the females is longer than the males. These hallux talons are almost 2 inches long on large, female eagles, and only about an inch and a quarter on small males.

Q: Are talons made of the same thing as human fingernails?

A: Yes, and they are very similar to a dog's nails.

Q: Are the talons strong?

A:
The real strength comes from the muscles in the legs, that when contracted clamp the tendons in the lower legs and toes down, closing all the talons together in a vice-like grip. I remember this grip well, once getting fully footed by an eagle we captured; it took two of us to pry the toes apart and extract the talons.


Ecology

Q: What specific type of fish do bald eagles prefer?

A: The easiest to catch! Usually this means fish that spend more time near the surface or in the shallows; ones that make themselves available to bald eagles, which hunt and capture fish near the surface of water. The species involved are not as important as the niche they occupy, and vary with the region. Here in New York, along our Hudson River, as just one example, breeding eagles take a lot of American eels, which can often be found near the surface and in shallow waters, especially when the tide is low in the river.

Q: What are the bald eagles' enemies besides people?

A: Not many. Humans and our activities are definitely the biggest problem for eagles. But, occasionally other bald eagles will be a problem, fighting each other, especially over prime breeding territories. Raccoons can also be a problem to nesting eagles. Attracted by fish scraps and smells at the base of nest trees, raccoons have no problem scaling trees 80 feet high or higher to investigate, sometimes killing the young eaglets in the nest. This has happened in many places, including here in New York and in Massachusetts.

Q: Are there bald eagles west of the Rockies?

A: Absolutely! Bald eagles are found in all 48 continental states as well as Alaska. Only Hawaii doesn't have bald eagles. The Pacific Northwest has a very large bald eagle poplulation, with hundreds of pairs breeding in Oregon and Washington. If you go back in the Journey North archives, you'll find some wintering eagles from Washington State that were tracked to their breeding grounds, just like we are doing here in New York. What major difference can you find in west coast versus east coast movement patterns?

Q: What is the bald eagles' migration path?

A: That's exactly one thing we are trying to find out!
The answer to this varies due to many factors:

  • where the birds are from
  • where they are wintering
  • their age
  • the season

Some eagles don't migrate at all. If they live in an area where they can survive all winter (one with plenty of open water and food), they will stay close to their nesting area and not move far at all. If they do have to move to find open water and food, generally they will only move as far as they need to find a suitable over-wintering area that meets their needs. Young eagles, not yet adults, may move in more random directions than adults who have developed strong habits, returning along the same routes to the same wintering and nesting areas year after year. Movement pathways also depend on the season. In the spring, adult eagles departing their wintering area usually follow a pretty direct route to their nesting area, wanting to get back quickly to reestablish their territory and initiate breeding. In the fall, these eagles are in no such hurry to get back to the wintering area, and take a more leisurely route, not as direct and taking longer.

Go to the Journey North archives and investigate these things for yourself. See how different birds routes differ, and compare the spring and fall routes of the same bird. Also, take a look at the route followed by the same bird in different years and see what you can discover: this is what we biologists do!

Q: We like the maps showing where the Bald Eagles travel. We were curious if you have noticed any patterns in all of the years you have been showing the bald eagles' travels.

A: Absolutely! The most important finding we've had, especially with adult eagles, is that they exhibit nearly perfect fidelity to their wintering sites. That is, they return to their same wintering site, over and over again, winter after winter. That obviously tells us these areas are extremely important to them, and must be protected if we are to ensure they continue to use these areas for many years to come. Such use of research findings is called applied management, and is very important to keeping these populations around.

We've also seen differences in routes and timing, in spring vs fall migration. We are constantly learning, and using that knowledge to help this species. We will be preparing a scientific paper with our results as soon as we have enough eagles tracked to make meaningful assumptions.


Peter E. Nye
New York State Dept. Environmental Conservation
Division of Fish, Wildlife and Marine Resources
Albany, NY
Spring, 2003