Kisling’s Corner: Eagles
Welcome to Kisling’s Corner: This week’s topic is eagle identification.
Eagle identification is not always easy. If all bald eagles looked as they do when they reach adulthood, identifying eagles would be much simpler, unfortunately, that is not the case. All raptors go through a time when their plumage differs from their adult plumage. This does have the benefit of saving young birds from adults of the same species who might look upon them as sexual rivals, but it presents some problems for those of us who are trying to identify them.
Both golden and bald eagles require at least four years to attain adult plumage, with five years being the norm. Any good field guide can point out the subtle plumage difference between these two species, but there are a few things that field guides rarely cover. If I see a brownish eagle, I first look at the size of the head. On occasion, a golden eagle may appear to have a normal sized head for a bird its size, but most often, it appears that the head is a bit small for such a large bird. If you see a small group of eagles and there is an adult bald eagle among them, check the head size of the brown eagles near it. If they all appear to have a head about the same size of the adult bald, they are all young bald eagles.
Since bald eagles have a larger head and beak than do golden eagles, they also have a different head to tail ratio then goldens. When seen in flight, bald eagles have a tail projection that is about one and a half times the head projection whereas golden eagles have a tail projection that is two to two and a half times longer than the head projection. If this seem a bit hard for you to absorb, I can make remembering it easier. It is the bald eagle that has the big head and who wouldn’t get a big head if they were the national bird? That may sound a bit silly, but it does make it easy to remember.
There are a few other differences between the species that may be of help when the lighting is not good. Bald eagles hold their wings fairly flat when soaring while golden eagles fly with their wings held up in a shallow V that resembles the way turkey vultures fly, except that vultures are always tilting side to side and eagles only do so when it is very windy. One other difference between the two eagle species is something I have never seen in print, but it works. If you see an eagle fly a long distance and it flaps continuously, it is certainly a bald eagle. Golden eagles may flap for a bit, but a large part of their flight consists of soaring. A bald may also flap a while and then soar, so be careful, since both species flap and soar. It’s only when the flapping goes on for long while that you may be confident it is a bald eagle.
Questions, comments? Kiss@cot.net
Charlotte, Thanks for the insight that only comes from years of experience. I would add that Charlotte’s neck of the woods – the Dorris and Tulelake area – is a hot spot for eagle sightings, especially in the winter and early spring. You can learn more by visiting the Klamath Basin National Wildlife Refuge website. The website provides a seasonal list of birds you expect to see, no matter when you’re planning a visit. Summer time means waterfowl and marsh birds, early morning expeditions on the driving tours and spending the hot afternoons in the cool caves at Lava Beds National Monument, which borders the Tule Lake Refuge.
Thanks again,
Renee
Tags: Birding, Dorris, eagles, klamath basin, Klamath Basin Wildlife Refuges, Lava Beds National Monument, Tulelake
Birding | Visit Siskiyou June 25, 2009