Bald Eagle –– An opportunistic and resourceful raptor increasing in the region
In December when Rhoda Nanouk of Unalakleet posted photos on eBird of two bald eagles perched on a stump along the icy shoreline of eastern Norton Sound, it grabbed my attention. Then in mid-January she documented a mature bald eagle atop a power pole in Unalakleet.
Bald eagles in the region in winter seemed unusual, so I asked Nanouk about her experience with them around Unalakleet. She told me she was very surprised to see them, and that she had never seen a bald eagle there before during the winter season.
Nanouk also mentioned seeing noticeably more bald eagles in summer in recent years, which is something I too had happily noted along Nome’s road system.
In 1989, Brina Kessel published “Birds of the Seward Peninsula, Alaska,” which summarizes extensive ornithological field research and observations of birds by knowledgeable residents of Seward Peninsula villages. At that time, Kessel noted that bald eagles were known to breed in the upper Unalakleet drainage but were rare summer visitors and occasional breeders on the Seward Peninsula. She noted a single nest site reported at Bald Head west of Koyuk.
That assessment has certainly changed in subsequent years. Sightings are no longer rare, and nesting occurs along the main rivers in forested portions of the peninsula and on the Kuzitrin River.
I contacted raptor specialist Steve Lewis, with the U.S. Fish and Wildlife Service, to get his thoughts about the increasing presence of bald eagles in the region and to learn about their normal winter distribution in Alaska.
Lewis suspects that a combination of factors have led to more frequent sightings and nesting opportunities for bald eagles in the region. He said bald eagles have been thriving along Alaska’s Pacific coast, which could fuel an expansion into this area as conditions improve for them here.
Bald eagles have long nested throughout most of Alaska including along salmon streams in Alaska’s interior as far north as the southern Brooks Range. Lewis says the species has been slower to occupy northwestern and northern Alaska where food and nest sites may be limiting. As the changing climate enhances tree growth for nesting and fishing perches and salmon explore new rivers in the far north, bald eagles are likely to follow.
Good nesting sites are limited, so bald eagles stay on their breeding territories to defend them year-round, if food permits. According to Lewis, lack of food after freeze-up rather than cold temperatures generally drives bald eagles in northern parts of the state to southern Alaska or the Alaska Peninsula for the winter.
However, he said “bald eagles are very good at exploiting human subsidies. If Unalakleet has an open landfill, and there are eagles staying around in the winter, I’d bet that is where they are getting food. That does not surprise me one bit as they use landfills all up and down the coast in winter.”
In a bald eagle tagging study along the Pacific coast of Alaska, Lewis said most of his marked birds visited landfills in winter. After mentioning this to Nanouk, she checked out the Unalakleet dump and found the eagle perched among the ravens.
Bald eagles are resourceful and opportunistic in their food habits and make use of the most readily available food items. In Alaska, fat-rich salmon are their main food source, especially pink salmon that spawn in shallow water and are easy to catch. But other fish close to the surface are targeted too, such as spawning herring, smelt or tomcod.
These large fish eagles also scavenge on spawned out salmon carcasses and any other food they can find, and readily steal food from other eagles, birds and mammals. Bald eagles will hunt on the wing, but aerial hunting that demands tight maneuvering is not usually their forte.
They regularly hunt waterfowl but tend to wait for opportunities to pick off injured or compromised birds. Bald eagles can catch hares and mammalian prey, but, according to Lewis, they probably couldn’t sustain themselves over the winter on that diet alone.
Bald eagle stick nests are among the largest nests in the bird world, so they need a substantial tree to support it. The nest site is usually along a forested shoreline or close to water where the eagles fish, with unobstructed access for landing and takeoffs. In this region large cottonwoods and spruce are options, but availability of suitable trees may limit nesting opportunities here. Nests are typically refurbished and used year after year.
Bald eagles form lifelong pair bonds. The pair shares incubation, brooding, hunting and feeding of young, but the female does most of the incubation.
One to three (most often two) eggs are laid, and incubation begins when the first egg is laid. The chick from the first egg hatches first and has a better chance of survival, especially if food is limited. Often only one chick fledges.
After leaving the nest, fledglings follow their parents who feed them for up to six weeks. Then the young birds become nomadic for four to five years as they mature, covering vast distances in search of food and eventually a suitable nesting area.
In addition to the immature wanderers, a portion of the adult population is also nomadic. They are referred to as “floaters” and are on a more targeted search for a nesting area. Many of the adult bald eagle sightings along the Nome roads are likely “floaters.”
I asked Council/Nome resident Dan Stang when he first became aware of bald eagles in the Council area. He had a memorable first sighting around the spring of 2004 when beaver hunting in American Creek, a Niukluk tributary north of Council. He and his sons were astonished to find a huge, occupied bald eagle nest in a large cottonwood tree. The nest was eight to ten feet high, with layers of sticks apparently added over a number of years.
Each spring as the Stangs headed to American Creek, they wondered if the eagles would still be there. And for the next four years they were, until they returned to find the tree and nest on the ground, toppled by beavers.
Since that time Stang has seen increasing numbers of bald eagles in the Niukluk and Fish River drainages. He knows of three active nest sites between Council and White Mountain alone.
Since 2011 Stang has kept his eye on a pair of bald eagles that nests several miles below Council on the Niukluk. This year initially two chicks were seen in the nest, but only one fledged. Stang suspected poor salmon runs and high water last summer made it more difficult than usual for them to find food last summer. Stang’s eagle neighbors stay until freeze-up in October or November.
If the presence of bald eagles continues to increase in the region, I hope more of us will have the exciting opportunity to get better acquainted with these magnificent raptors.