Alaska’s Bald Eagles; 2nd of 2 blogs

Please consider all images as copyrighted – thank you. Contact me for use… DEClapp

The Bald Eagle is a notorious thief and bully. Benjamin Franklin was quite outspoken about the negative qualities that the eagle harbored and he was not happy with it being made the national bird and state emblem of the new United States of America. Franklin would have favored the canny, and tasty, Wild Turkey. Be that as it may our nation has been represented by the majestic eagle since 1782.                                            Actually, Franklin wrote to his daughter well after the eagle was made the symbol of the United States, regarding the use of the eagle on the logo for an organization called the Society of the Cincinnati, a group of revolutionary war veterans. In that letter he speaks disparagingly of the eagle and rather glowingly of the Eastern Kingbird, Osprey, and (Wild) Turkey. But Mr. Franklin may have understated the case. The eagle is quite a builder with nests often ten feet deep and nine feet across weighing more than 2000 pounds. Nests are almost always within a couple hundred yards of open water. They are good parents and do, in fact, hunt their own food most of the time. The use of the eagle by the 1782 congress was really a carry-over from their admiration of the eagle-festooned Roman Empire. It copied the Romans use of the Golden Eagle rather than specifically glorifying the American Bald Eagle.

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The images above and below show an adult Bald Eagle swimming ashore from the water of Kachemak Bay off the Homer Spit at the end of the Kenai Peninsula. Despite Mr. Franklin’s admonition that the eagle is a thief and rarely hunts its own meals this eagle had just grabbed a very large salmon and either had to drag it ashore, let it go, or drown making up its mind. It swam at least two hundreds yards dragging what we figured was a fifteen pound salmon. I had many questions go through my mind: how often might they do this? how large a fish could he handle? does the fish fight and struggle? could the eagle let go if it wanted to? would there be a bear on shore watching this and waiting for the fish to be delivered to it? and so on….

DSC_3056The Bald Eagle sexes look the same in their plumage but the female is up to one-quarter again the size of a male. That is true in most birds of prey – the female is generally larger. Bald Eagles are widespread over North America. They are in general a fish eagle; with almost 60% of their food being fish. They do eat ducks and geese when they are available and easy to obtain and fish are not readily available.  If fish are available they will make up to 90% of the eagles diet. They will collect fish from waterfalls, turbine outflows, shallow waters, and those that swam (too slowly and casually) near the surface – they also collect dead fish anywhere they find them. As fish populations have declined in many coastal areas the opportunity to feed on fish has diminished, especially in areas where there are kelp beds. The eagles have begun to eat cliff and island nesting sea birds in many of these locations. Sea birds, generally pelagic/oceanic birds, such as puffins, guillemots, and especially murres have become a usual prey item now that their standard fish fare has declined. Adults can be taken in the air at the jam-packed nesting sites, tunnel nesters like puffins and shearwaters can be dug out, and fat and oily youngsters can be plucked off the cliff edges with ease. An attack by an eagle at a nesting cliff can cause many young to plummet from the cliffs to the water or rocks below. In many areas this is a new and significant threat to the sea birds.

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As the eagle reached the shore it was seen to have caught the fish with one foot. Eagles, like Osprey, have spicules on their talons to create a better grip and this bird did just fine with that right leg. Birds maintain their feathers by preening with an oil that, in general, keeps the feathers waterproof. It looks like this bird has feathers that have not become waterlogged. A very helpful procedure isn’t it?
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The eagle headed for the nearest bit of land which was this small bar that reached out into the water. 
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Once on shore the fisherman had a few bites before the female came down and took her share. An eagle can store about two pounds of food in its crop, an expandable part of the throat, to be swallowed and digested later. They can fly with prey items that equal their own weight*. Once prey items get as heavy as the bird they need a head wind to get into the air. A heavy prey animal needs to be broken down into smaller pieces. Gorging and crop storage are two methods for getting as much food as possible in a short time. Eagles will return to a fish later in the day or the next day if nothing else has scavenged it.                                        *The weight of an eagle will vary throughout the year. It depends on the age and sex of the individual, with females being heavier. The time of the year and the availability of food is another factor, as is the place in the breeding cycle in which they find themselves. A large female in times of the salmon run might weigh as much as 17 pounds and a male in lean times could be as light as 9.5 pounds.
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He dried off, shook his feathers free of water, and then they seemed to chat over their meal. It’s all in a days work for this eagle pair.

 

 

 

 

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