Bald Eagle Facts
Q&A with Peter Nye in 2000
New York Department of Environmental Conservation
Characteristics
Q. What is the difference between the life of a male and female eagle?
A. A very interesting question! Very little is known about this,
or even conclusively about how long bald eagles live in the wild. This
depends, of course, on the type of life they live (how difficult it is,
or if they run into problems). Some captive eagles have been recorded
to live 47 years; many others in the 30-year range. Wild eagles on the
other hand, are believed to live 20-30 years, and we have no idea if males
live longer than females. Just some speculation on my part, I might guess
males live longer, since females live a harder life (biologically), laying
eggs, doing the bulk of the incubation and chick-rearing, and having larger/heavier
body mass to contend with and feed. From several observations here in
NY, they are also the ones that are attacked and displaced when other
females want to come in and take over a territory; I've never seen this
in males. Further, females seem to be the more aggressive ones when feeding
on carrion, making them more vulnerable to injury and life-shortening
situations. I think male eagles have it easier!
Life Cycle
Q: Do eagles push their young out of the nest to encourage them to fly?
A: No! The adults may withhold food as the eaglets get near fledging, and encourage them to fly to a nearby perch to get their meal, but that's about it. Usually, no coaxing is necessary and the eaglets are all too anxious to test their wings!
Q. If an eaglet falls, will a parent fly below the nest to catch it and carry it back to the nest?
A: No!
Ecology
Q. Who do Eagles migrate with?
A. Eagles are believed to migrate alone, not in groups as some
other birds (and even some raptors do), and not even with their mate necessarily,
although as we learn more, that might change. For now, we've found male
and female eagles tend to travel separately to (and from?) their breeding
areas. This could be adaptive, so if something were to happen along the
journey (an accident or just harsh conditions that might make it difficult
for a bird to survive), both of the pair wouldn't be lost, since they
are travelling separately and at separate times. We tracked one male to
his nest in Ontario years ago, and know from that that he travelled alone
and arrived their first; his female mate showed up a few days later.
Q. When do Eagles migrate?
A.This depends on where they are going (where they are from) !
They will generally begin migration when certain environmental cues tell
them it is time to initiate the breeding cycle and move back toward their
nesting areas. Cues such as day-length (amount of daylight) and hormones
within the birds likely are at work. Of course, their timing for this
move is critical; they mustn't move north until conditions (ie open water
and food) will allow them to survive back on their breeding grounds.
Peter
E. Nye
New York State Dept. Environmental
Conservation
Division of Fish, Wildlife and Marine Resources
Delmar, NY
Spring, 2000
© 1997 – 2019 Journey North. All rights reserved.
