Art Lander’s Outdoors: The eagle has landed — survived and flourished — back from the brink

This is the last of a two-part series on the comeback of America’s national symbol.

On July 12, 1995 federal biologists believed that populations had recovered enough so that the bald eagle could be taken off the endangered species list, and designated as a threatened species.

That designation lasted just 12 years. Secretary of the Interior Dirk Kempthorne announced the delisting of the bald eagle at a ceremony on Thursday, June 28, 2007, on the steps of the Jefferson Memorial in Washington, D.C.

In 2007 the U.S. Fish and Wildlife Service (USFWS) estimated there were 9,789 breeding pairs in the Lower 48 states. Minnesota topped the list of nesting pairs with 1,312, followed by Florida with 1,133, and Wisconsin with 1,065.

The Lower 48 states had been divided into five recovery regions. Kentucky was placed in the Southeastern Bald Eagle Recovery Region, where the delisting goal was 1,500 nesting pairs. There were an estimated 980 breeding pairs in the region in 1993, up from about 400 in 1981. By delisting in 2007, the estimate of breeding pairs in the region was 2,227, and Kentucky’s count had surpassed 35.

Bald eagles are protected under the Migratory Bird Treaty Act and the Bald and Golden Eagle Protection Act, which prevents them from being harassed, or taken for their feathers or talons.

Continued Population Expansion

By 2010, the number of nesting pairs of bald eagles in Kentucky had more than tripled over the previous decade.

“In 2000, there were 23 nesting pairs, by 2010 the number have grown to 80,” said Kate Slankard, an avian biologist with the Kentucky Department of Fish and Wildlife Resources. “We have documented more eagles nesting in the state than ever before and we expect to see more in the future,” said Slankard in 2010.

During the winter, the number of eagles in Kentucky increases dramatically when birds migrate down from the Great Lakes region to escape the ice and snow, to find open water.

“From band recoveries, we found that many of these eagles are coming from Wisconsin and Michigan,” said Slankard. “The number of birds we count each winter depends on the severity of the weather up north.”

Wintering Bald Eagles Create Tourism Opportunities

The comeback of the bald eagle created a tourism opportunity, where visitors go on eagle viewing tours, to see birds wintering on Lake Barkley, Kentucky Lake and Dale Hollow Lake.

The first tours were held in the late 1970s. The tours on Kentucky Lake and Lake Barkley are hosted by Kentucky State Parks and Land Between the Lakes.

Two eagle viewing weekends are also held each January on Dale Hollow Lake, hosted by the U.S. Army Corps of Engineers Nashville District rangers and staff at the Dale Hollow Lake. Visitors ride a barge to view the wintering eagles.

The Corps of Engineers partnered with the Tennessee Technological University in Cookeville, and the Tennessee Wildlife Resource Agency, to hack eagles at the lake beginning in 1987. Forty-four bald eagles were released into the wild during the five year project. The immature eagles came from Minnesota, Wisconsin, and Alaska.

Today, Dale Hollow Lake is the winter home to 60 to 100 bald eagles. The wintering eagles usually arrive starting in November and stay as late as March. The lake also has at least six year-round resident eagles.

Resident Bald Eagles and Geographic Range

The eagles that nest in Kentucky typically do not migrate. After they establish a territory, they seldom leave it for very long throughout their lives.

The geographic range of the bald eagles includes most of North America, from Alaska southward through Canada and the Lower 48 states into northern Mexico. About half of the continent’s population of bald eagles live in Alaska.

Food Habits

Bald eagles often dive from a perch to snatch unsuspecting prey but they can also take prey in mid-air. Their diet consists mostly of fish, that’s why they nest close to water, but they also consume rodents, rabbits, songbirds, waterfowl, turtles and feed on carrion, mostly waterfowl and mammals, sometimes as large as a deer.

They are big, powerful birds, weighing 10 to 14 pounds with wingspans of six to eight feet, so they need to eat about one to two pounds a day. Eagles may “steal” prey from smaller raptors, especially ospreys, who feed primarily on fish.

Nesting

Adult eagles are typically paired up, and already working on their nest by late fall/early winter. Pairs mate for life, but will find a new mate if their partner dies. In the wild, eagles have a 15 to 25-year life span.

Females lay their eggs at the end of January through February. Eagle eggs hatch anytime from mid-March to mid-April. Eaglets start out white and downy, but leave the nest with dark feathers and a dark bill.

Young usually leave the nest in May or June.

“Parents continue to feed and protect their young even after they have fledged,” said Slankard. Young eagles usually “disperse” by August or September.

“Young eagles are constantly moving around,” said Slankard. “They do not defend territories until they are adults, and until they reach maturity, they tend to wander.”

Researchers found that a nesting eagle’s home range depends on habitat and prey density. Nests are spaced apart to ensure sufficient food resources for nestlings and to raise young with minimal disturbance from other eagles.

In Kentucky, an eagle’s home range is rather large. A transmitter was put on male bird at Ballard WMA, and his home range was about 16 miles by 10 miles.

“He went inland (away from the Ohio River) to farm ponds and creeks to catch fish and turtles to bring back to the nest,” said Slankard. “We were quite surprised.”

Eagle pairs often build more than one nest, which allows them to move to an alternate nest while remaining in their territory. “On Ballard WMA and at LBL, where eagle density is highest, nests may be as close as a mile apart,” Slankard.

Most of the time eagles reuse their nests. It can take younger pairs a few years to settle into a territory and successfully raise young. Eagle nests are large, typically five to six feet in diameter, two to four feet high, and can weigh more than 1,000 pounds. Nests are a mound of sticks and limbs, lined with grasses, leaves and moss.

Identification

It’s not surprising that in the excitement of seeing an eagle in the wild, it’s easy to misidentify the big birds.

That’s because golden eagles look very similar to immature bald eagles, which don’t grow their characteristic white head and tail until adulthood.

Golden eagles don’t nest in Kentucky, but migrate here from eastern Canada during the winter months. They have feathers all the way down their legs, while bald eagles have bright yellow, featherless lower legs, and a large, bright yellow bill.

Juvenile golden eagles are dark brown with white patches under the wings and at the base of the tail. Adult golden eagles are dark brown with a golden crown and neck, and a gray bill.

Some bald eagles exhibit leucism, a genetic mutation that affects feather pigment. They may have patches of white feathers on their body and wings, or have faded or pale feathers. Bald eagles and golden eagles are nearly identical in size. As with most birds of prey, females are typically larger than males.

For years it was thought that there are two subspecies of bald eagles, a northern and southern bird. The northern bird was thought to be larger, with slight coloration variations, but many biologist now believe that introductions of wild birds through hacking, and the migrations of bald eagles on the continent, have blurred these differences.

Vision and Vocalizations

The eyes of the bald eagles are large, nearly the size of human eyes, but the big bird’s vision is at least four times that of a person with 20/20 vision. The eagle’s voice is shrill, high pitched, and its vocalization include squeaky cackling, squeals and twittering.

Eagles do not have vocal cords. Sound is produced in the syrinx, a bony chamber located where the trachea divides to go to the lungs. Bald eagle calls may be a way of reinforcing the bond between the male and female, and to warn other eagles and predators that an area is defended.

Lakes Create Eagle Habitat

Bald eagles are now nesting on most of Kentucky’s major rivers, including the Mississippi, Ohio, Cumberland, Tennessee, Green, Kentucky, and Rolling Fork Rivers, but they have also taken advantage of the state’s large number of manmade reservoirs.

“Although we have lost some habitat to development and deforestation, we’ve also gained some habitat through the creation of reservoirs throughout the state,” said Slankard.

The first major reservoirs in Kentucky to have nesting eagles were Lake Barkley, Kentucky Lake, Cave Run Lake, Laurel River Lake, Yatesville Lake, Grayson Lake, Martins Fork Lake, and Taylorsville Lake. But today Slankard said “almost all major reservoirs in the state have at least one eagle nest.”

LBL, which was the site of Kentucky’s first eagle hackings in the 1980s, is cranking out birds now. In 2016, there were 27 active nests (highest number ever), and 31 young eaglets fledged at the 170,000-acre national recreation area.

Another high density population is on Ballard WMA, and Ohio River river bottoms just downstream.

“It’s nothing out of the ordinary to see eagles,” said Robert Colvis, Ballard WMA’s area manager. “In 2016 we had eight active eagle nests here.”

The waterfowl management area fills up with eagles in the winter.

“The most I’ve seen roosting here is 95,” said Colvis. “They follow the ducks and geese down the flyway.”

In all, there are about 15 eagles nests in Ballard County, a sparsely-populated county bordered by McCracken County on the east, and Carlisle County to the south, at the confluence of the Ohio and Mississippi Rivers.

Eagle Populations Today in Kentucky

Biologists in Kentucky have counted as many as 400 Bald Eagles while on their mid-winter survey routes. The number of year-round residents can only be estimated, but in 2016, KDFWR officials confirmed 151 active eagle nests in Kentucky.

“The number of nesting pairs has grown even more than we expected,” said Slankard.

The eagle has landed — survived and flourished — back from the brink of extinction.

Art Lander Jr. is outdoors editor for NKyTribune and KyForward. He is a native Kentuckian, a graduate of Western Kentucky University and a life-long hunter, angler, gardener and nature enthusiast. He has worked as a newspaper columnist, magazine journalist and author and is a former staff writer for Kentucky Afield Magazine, editor of the annual Kentucky Hunting & Trapping Guide and Kentucky Spring Hunting Guide, and co-writer of the Kentucky Afield Outdoors newspaper column.