Other Information
SE
Arizona Rare
Bird Alert
(520) 798-1005
Report
Rare Birds
(520) 798-1005
Email
a report
Nature Shop
(520) 629-0510
Agua Caliente Shop
(520) 760-7881
Mason Audubon
Center
(520) 744-0004
Membership
(520) 629-0757
AZ IBA Program
(520) 628-1730
Education Program
(520) 622-2230
Habitat Restoration
(520) 206-9900
Development
(520) 622-5622
Executive Director
(520) 622-5622
|
Birding home | Access updates | RBA | Dastardly Duos | AZ/NM listserv | Tucson area |
Tucson Audubon Society
Dastardly Duos
by Larry Liese
Golden Eagle and Bald Eagle
by Larry Liese
Illustrations by George C. West
(Article first appeared in the February 2002 Vermilion Flycatcher
newsletter. To receive the newsletter in the mail, become a member of the Friends
of Tucson Audubon.)
There’s something special about gazing up at a soaring raptor, when the
light hits it just right, or another bird ventures near enough, or that
telltale wing shape suddenly jars your brain into realizing – That’s
an eagle! Symbols of our country, majestic patrollers of the skies,
just darn neat-looking birds - eagles are just rare enough to be a great
bird for the day, yet are not that hard to come by.
Wing shape is one of the field marks I trust most in determining that a given raptor is indeed an eagle. Our other birds don’t quite have that really long rectangular wing shape. When shifting direction and gliding they can lose the squared-off appearance, but it will reappear when they begin soaring again.
|
|
In southeastern Arizona, Golden Eagles (Aquila chrysaetos) are listed as uncommon permanent residents, preferring mountain or valley habitat where they prey mostly upon mammals. Bald Eagles (Haliaeetus leucocephalus) are rare here, present in our area only in the cooler months. They prefer fish, so they are generally seen near water, such as at Parker Canyon Lake, but are also seen in both the San Rafael and Sulphur Springs Valley where they feed on carrion, birds, and mammals.
Telling adult eagles apart is straightforward. The adult Golden Eagle appears all-dark, with good views revealing the golden nape for which it is named. Recognizable by anyone who watches TV, the adult Bald Eagle has a gleaming white head and tail along with a bright yellow bill and legs, all of which contrast sharply with its brown body and wings. Balds have a huge head and bill, while Goldens have a much less bulky head and neck. Look to see whether the head and neck appear more than half the tail length (Bald), or less (Golden). Bald Eagles take up to five and one-half years to attain definitive adult plumage, while Golden Eagles attain adult plumage in four or five years.
|
|
|
|
Immature eagles are a little more difficult. For soaring birds, check carefully the white plumaged areas on the bird’s underside. Juvenile Golden Eagles have a white tail with a sharply bordered, very wide, dark terminal band, while the non-adult Balds’ tails are a dirty white with a narrower dark band at the tip and dark outer tail edges. The way that I remember which is which is to remember that juvenile Golden Eagle tail feathers are the ones that make up those long chief’s headdresses for Native American tribes (at least in the movies), and that I never saw a bald Indian in a western. Every one had long, braided, black hair! Yes, this may be bad humor, but it is how I keep the two straight because the Bald Eagles’ tail feathers aren’t as distinctive.
Next try to notice light feathers on the underwing. Juvenile Golden Eagles usually (but not always) have a distinct white patch on the underwing at the base of the primaries. Non-adult Bald Eagles have white underwing feathers that are mottled and blotchy looking. The Golden Eagle will always have a dark body and dark wing coverts, while the Bald will have white feathers there, especially on the belly and axillaries, often-forming noticeable white lines across the wing linings. Golden Eagles’ flight feathers can appear lightish with dark tips yielding a dark trailing edge. At all ages they have wider wings with less parallel edges than Bald Eagles do.
For close up views of perched birds, Golden Eagles always have the golden nape and have three colors to their bill and cere. Bald Eagles have the aforementioned large head and bill, with the bill dark in juveniles and yellow in adults. Third year Bald Eagles take on an "Osprey" look with a dark eyestripe and whitish superciliary.
If this sounds like too much to remember, just concentrate on how sharp the white is patterned and whether the head is gold or
white and you’ll be all set.
Good luck!
Bird questions? Check Birding | General questions? Contact: Tucson Audubon Society | Webmaster: Email
This page was updated on 02/21/06