A beautiful bird
Bald eagles are not really bald. They are so called because of their snowy white head feathers, which they attain at sexual maturity between 4 and 5 years of age. Their tail feathers also turn white, and their beaks and feet change from gray to yellow. Juveniles are brown with mottled white feathers, and closely resemble the smaller golden eagle.
Adopted as our national symbol in 1782, the bald eagle is a true American – it is only found on this continent. It can live up to 40 years in the wild and longer in captivity. Golden eagles, which are native to Europe, are circumpolar and are found in Canada and some western states. A few inhabit the Adirondacks.
Standing 30 inches tall, the bald eagle has a wingspan exceeding 7 feet and can soar for hours in search of prey, ascending to altitudes of 10,000 feet or more on thermal air currents. Five of the 24-inch primary feathers on each wingtip are notched, enabling the eagle to change its aerodynamics like an aircraft while gliding on shifting thermals. Its vision is seven times keener than ours, allowing the bird to easily spot its quarry from high altitudes. And it can dive at the speed of 65 miles per hour to snatch an unsuspecting victim with its powerful talons. Weighing between 8 and 12 pounds, females are 25 to 50 percent larger than males, which is true for most birds of prey.
Bald eagles nest in early spring but not as early as the great horned owl, which may hijack an eagle’s nest if it gets there first. Eagles are equally skilled at commandeering heron and osprey nests and enlarging them to suit their own needs. They will use the same nest year after year. The nest, or aerie, is built in the crown of a tall conifer or hardwood tree and is remodeled annually. Some become enormous, weighing a ton or more, and can collapse from their own weight. If that happens, the pair will quickly build another. The hickory tree containing the nest at Hemlock Lake was toppled by Hurricane Agnes in 1972. The pair constructed eight different aeries there over the years.
Bald eagles have struggled to survive. They mate for life and females lay one to three eggs in March or early April. The natural mortality rate among eaglets and fledglings is near 50 percent. For a century, beginning in the mid-1800s, the raptors were shot as predators or poached for their feathers, a practice that occurs on occasion yet today. In 1940, Congress passed the Bald and Golden Eagle Protection Act, making the capture or killing of any eagle unlawful. But by the 1950s, they faced a new and more serious threat: chemical contamination, principally from the pesticide DDT.
After World War II, DDT was liberally sprayed everywhere to kill blackflies, mosquitoes and a variety of agricultural and forest insect pests. It trickled into waterways and became absorbed by waterborne organisms, insects, amphibians and fish. The bald eagle is primarily a fish eater, but also devours rodents, snakes, waterfowl and carrion. In its position at the top of the aquatic food chain, the eagle accumulated heavy concentrations of DDT with disastrous results –the pesticide weakened its eggshells. Most eggs were broken by parents during incubation, causing the great bird’s reproduction rate to plummet. The Environmental Protection Agency banned DDT in 1972, and bald eagles were placed under the protection of the Endangered Species Act in 1973. The population began a slow turnaround.
Tom Rauber and the experts
When Rauber reported his discovery to the U.S. Fish and Wildlife Service (USFWS) in Albany, federal game agent John Waters asked him to monitor the nest and document his findings. By this time, Rauber had established a close friendship with bald eagle expert Dr. Dean Amadon, curator of ornithology at the American Museum of Natural History in New York. He has since died, but the two men spent several years observing the remnant pair of eagles as it tried in vain to reproduce. They suspected DDT poisoning.
In 1972, at the request of USFWS, Rauber used his lineman’s climbing gear to remove an addled egg from the nest for testing. DDT was confirmed. Amadon hatched a plan to substitute untainted eagle eggs from Minnesota for the contaminated eggs in the nest. The ruse had worked with peregrine falcons. He also helped Rauber secure the federal permit required to handle the birds. Amadon is credited with conceiving the first effective bald eagle recovery plan in the United States, using egg transplants.
In 1974, Rauber received a letter from Gene McCaffrey, the chief of wildlife for the New York State Department of Environmental Conservation (DEC). It expressed his intent to initiate a bald eagle recovery program and asked if Tom would help set it up. With the agency’s superior resources, equipment and staff, Rauber agreed that the state would indeed be a more effective steward. In 1976, the year of the U.S. bicentennial, New York became the first state in the nation to implement a comprehensive bald eagle recovery program under the voluntary guidance of amateur naturalist, Tom Rauber.
Eagle recovery techniques have positive results
One of Rauber’s first assignments was to show DEC wildlife technician Mike Allen the ropes. He did exactly that by teaching him how to climb with lineman’s gear. The two men built an elevated blind from which they spent many hours observing and photographing the two birds. Allen, who still works out of Region 8 headquarters in Avon, has been with the Endangered Species Unit for more than 30 years. “I have been truly blessed to work with bald eagles for all those years,” he said. “Even now, when I see one in flight, I get just as excited as I did back then.”
He credits Rauber with teaching him much of what he knows. “Tom is a good man and we had many good times together,” he added.
Albany-based Endangered Species Unit biologist Peter Nye is one of the nation’s foremost bald eagle specialists. He pioneered the DEC’s eagle recovery program using three techniques: egg transplants, fostering and hacking. In fostering, an artificial egg – one that won’t break – is substituted for a contaminated egg. Remote video observation of the birds at Hemlock Lake showed that they were attentive and would make good parents. The eagles accepted and incubated a synthetic egg as their own, while a newly hatched eaglet was obtained from a captive breeding facility out of state. Two weeks later, the artificial egg was replaced with the live foster chick, which they accepted and reared. For three more years the pair cared for and fledged captive-bred chicks. After the male was illegally shot in 1981, the old female mated again and fostered five more chicks, even after she stopped producing eggs herself.
A 1976 hacking experiment by DEC’s Nye at Montezuma National Wildlife Refuge became the most successful technique. It was the first program of its kind on the North American continent. Under the guidance of Cornell University ornithologist Dr. Tom Cade, young eagles were placed in an artificial nest on an elevated caged platform several weeks before they could fly. To ensure that their instinctive fear of humans would not be compromised, they were discretely fed by hidden caretakers.
When the eagles were 12 weeks old, the cage was opened to allow the birds to test their flight capabilities. Over the next nine years, 175 young birds obtained from Alaska were hacked and released from towers at several locations across the state. By 1989, New York’s bald eagle restoration program put itself out of business by achieving its goal of establishing 10 breeding pairs in the state.
Regional wildlife manager Larry Myers, retired after 32 years with the DEC, said, “Nobody could have hoped for the success that has happened. You can’t expect not to see an eagle almost anyplace in the state today. It’s the most interesting and successful project that I’ve ever worked on.”
Last fall, I had lunch at the home of Jay and Hannah Zukowski in Webster, overlooking Irondequoit Bay. I spotted a bald eagle perched in a tree in their backyard, and when I pointed it out, Jay nonchalantly responded, “Actually, there are two of them.” Right on cue, the second bird joined the first.
The population continues to rebound. In 1963, there were 417 mating pairs of bald eagles in the lower 48 states. Today there are nearly 10,000. The number in New York has grown from a single pair in 1965 to 158 pairs today. The bald eagle was removed from the Endangered Species List in 2007, but is still protected by other state and federal laws. DEC’s Allen is currently monitoring 27 bald eagle territories in the Finger Lakes Region.
An award-winning article by Tom Rauber, published in 1976 in The Kingbird magazine, described his research on the last known pair of bald eagles in the state. In much the same manner as the man who discovered those majestic birds, New York state was generous in sharing its experience in eagle recovery with other states and the Province of Ontario. Now 84, Tom Rauber is modestly proud of his involvement in helping to bring the bald eagle back from the brink of extinction, but is quick to credit DEC’s Pete Nye, Mike Allen and Larry Myers. They all say it couldn’t have happened without Tom.
by John Adamski
John Adamski is a wildlife photographer, nature writer, sportsman and general fan of the outdoors. He grew up in Irondequoit, and began taking pictures when he was the director of fish and wildlife management at Whitney Park in the Adirondacks. Today he lives in Dansville.