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| Mature eagle patrols for cormorants on the Smith Cove side of South Ferry. Cliff Clark photo |
By Nick Hamblet
For those of you who don't already know, Shelter Island seems to be hosting an increasing number of bald eagles (or at least the increasing visits of certain individuals). As I mentioned in a previous article, this species was seen eight months out of the year in 2004. Most of the reports have concerned immature birds yet I am happy to say that we are now being graced with sightings of the beautiful and spectacular adults.
The first bald eagle sighting this year was by Mike Scheibel (natural resources manager at Mashomack Preserve) at South Ferry on January 9. That was yet another young bird. Shortly after that, however, an adult bird begun to show up and frequent the South Ferry and Mashomack Preserve areas.
South Ferry crew members and I last saw this bird at South Ferry on February 6. It had been hanging around the area for about two weeks and was seen almost every day.
The bird is putting on quite a show and has been observed by Mashomack Preserve personnel and the customers of South Ferry. We have seen it soaring, targeting ducks for prey, feeding, riding ice floes, perching in trees and even resting in the South Ferry osprey nest!
Quite a few times it could be watched at rest for hours at a time. Thanks to Clifford Clark's quick action, he was able to take an amazing photo of the bird.
I am sure many of you know that Congress chose the bald eagle (over Ben Franklin's suggestion of the wild turkey) as the national bird of the United States due to its majestic form and many other qualities that it represents. Here are some other facts (some provided by Mike Scheibel) about our national bird that you may not know.
The bald eagle is a bird of prey characterized by the fact that it has toes that are equipped with sharp, curved talons designed for grasping and dispatching prey. It is a member of the hawk family, Accipitridae, which includes the well known red-tailed hawk (but not vultures, the osprey and falcons). Eagles are specially adapted hawks usually classified by a very large bill. They are the largest of all birds of prey.
There are two eagle species in the United States. Besides the bald eagle, there is also the golden eagle. This bird is more restricted to the western U.S. although it migrates throughout the eastern part of the country. Sightings along the East Coast are very rare.
Bald eagles belong to a group of eagles known as fish eagles. They are not closely related to the golden eagle. As the name suggests, fish eagles usually feed on fish, although not chiefly. They are found wherever there is water (especially along coasts and rivers) and abundant prey.
Bald eagles are mostly scavengers. They prefer to feed on dead or dying fish yet they will also snatch live fish from the surface of the water (never diving like an osprey). Water-based prey is not the bald eagle's only food, however. They will feed on land-based mammal carcasses when the opportunity arises. The golden eagle, on the other hand, is more of a live mammal specialist.
Where prey is abundant, so are bald eagles. Many hundreds of the birds can gather in one small area. It is much less costly energy-wise for one eagle to take advantage of food that another bird has found so they will attempt to "steal" another bird's meal. With so many of the birds in one area, this may seem to be an intense competition but bald eagles have evolved a ritualistic way of "sharing."
One eagle will watch another feed and then swoop down toward it. Talons are presented to the feeding bird and a quick skirmish ensues. This is mostly for show and rarely leads to true violence. Another eagle will then replace this one and so on. This way, they allow each other to feed equally on the easier meals so they can spend more time resting.
Bald eagles are not so accommodating with other species. They have been known to harass ospreys and make them drop their fish.
Fish eagles are huge birds (the Steller's sea eagle of Asia is one of the largest birds of prey in the world) and the bald eagle is no exception. From bill to tail, they measure nearly three feet and have a wingspan of six and a half to seven feet. The females are slightly larger than the males but both sexes weigh in at about nine and a half pounds. That is very heavy for a flying bird.
The bald eagle is well known for its white head, white tail, brown wings and body and a huge yellow bill. The birds do not attain this plumage pattern until they are four years old. The young are all brown but with white mottling on the underside of the wings, body and tail.
Both bald and golden eagles are nearly the same size and they are not easy to tell apart in flight. Since the golden eagle is mostly all brown, it can look like a young bald eagle. The young golden eagle usually has clear white (not mottled) patches on the wings and a large area of white at the base of the tail. Bald eagles soar with their wings flat ("like a board nailed to its back," to quote Mike Scheibel) while the golden eagle soars with a slight dihedral (like a squashed "V").
The bald eagle is primarily a winter visitor in our area. They breed mostly in northern U.S. and Canada (with a smaller nesting area in central U.S. and Florida). One of the largest concentrations of these birds in summer is along the Chillcat River in Alaska. They favor the large rivers in the interior U.S. in winter.
These birds build a huge nest of sticks in a tree or sometimes on a cliff. The nest can weigh into the tons and is added to every year, sometimes to the point of collapse. Three white eggs are laid yet only one of those chicks will survive long enough to breed in most cases.
Such a survival rate worked fine for bald eagles before mankind intervened. After World War II, however, the situation turned very grim. Habitat loss and the widespread use of pesticides such as DDT began to take a toll on the birds. Many birds of prey suffered the same fate, including the osprey. Both bald eagles and ospreys were considered endangered with extinction.
It was up to mankind to intervene yet again, this time in a positive way. Young birds were taken from Alaska (then one of the last remaining nesting areas for bald eagles) and then "hacked" or reared in the wild. This was done in outside enclosures that allowed the birds to get used to their surroundings yet were screened from any contact or views of human beings (hand puppets of adult eagles were used to feed the eaglets).
Once the young were able to fly, they were released in other areas of the U.S. besides Alaska. The effort proved to be successful as the species began to rebound in the 1980s. Only one nest was known in New York State in 1976. However the bald eagle population has made a comeback in New York. Last year alone their numbers surged 12 percent to 84 breeding pairs across the state, according to Robert Paxton of North American Bird magazine and Peter Nye of the State Department of Environmental Conservation. Successful pairs increased 20 percent to 66 while the number of eagles fledged increased 28 percent to 111.
The bald eagle is now regaining its former breeding range throughout the United States. They are still considered a protected bird but they are showing much promise for the future. The national symbol of the United States proudly soars once again.
We don't know why the bald eagles have come to Shelter Island. They have been seen mostly in Mashomack Preserve and it is possible they may be inspecting it for breeding territory. It is also possible that the adults that have not had success with breeding are merely wintering over here. Hugh McGuinness (a teacher at the Ross School who is also a knowledgeable birder) has noted a definite increase in both immature and adult bald eagles this winter across the East End of Long Island.
Whatever the reason for their presence on Shelter Island, we should enjoy them while they are here. If you want to see them, just spend a little time down at South Ferry (particularly in the morning) and you may get lucky. After all, it isn't every day that people can see our national bird on a ferry commute to work.
