Wineka column: Dan Nicholas bald eagles strike out with infertile eggs, but maybe they’ll try again

  • Posted: Thursday, February 28, 2013 10:45 p.m.
    UPDATED: Friday, March 1, 2013 1:18 a.m.
Bob Pendergrass holds up one of the two Bald Eagle eggs that was collected from a nest in the Bald Eagle habitat at Dan Nicholas Park. Park officials were hopeful for the two eggs to hatch after they were discovered in early January. Hope dwindled as no baby birds hatched out after nearly two weeks after the normal incubation period ended. A test indicated the eggs were not fertile. Photo by Jon C. Lakey, Salisbury Post.
Bob Pendergrass holds up one of the two Bald Eagle eggs that was collected from a nest in the Bald Eagle habitat at Dan Nicholas Park. Park officials were hopeful for the two eggs to hatch after they were discovered in early January. Hope dwindled as no baby birds hatched out after nearly two weeks after the normal incubation period ended. A test indicated the eggs were not fertile. Photo by Jon C. Lakey, Salisbury Post.

SALISBURY — These things take time.

Fact Box

More about eagles

Here’s some background information on bald eagles:

• Bald eagles sit on their nests for about 35 days.

• They learn to fly in 11 to 12 weeks, after which they leave the nest.

• Liberty and Justice, the bald eagles at Dan Nicholas Park, were hurt when they were young. They are considered disabled and could not survive in the wild.

• Liberty and Justice both were rehabilitated at the Audubon Center for Birds of Prey in Maitland, Fla., before being transferred to Dan Nicholas Park in 2006. They’ve been part of a permanent wildlife exhibit ever since.

• A bald eagle eats from a half-pound to 1.5 pounds of food a day.

• Favorite food: fish.

• A bald eagle in the wild typically lives 20 to 30 years. Some eagles in captivity have lived up to 50 years.

• Female and male bald eagles look identical, but the female is larger, which helps distinguish between the sexes.

• Bald eagles usually have one mate for life.

• Bald eagle eggs are dull white with some pale brown splotches.

• The eagles reach their sexual maturity at 5 years old, but can breed as early as 4.

• The eagle’s full white head and tail is not obtained until it’s 5 or 6 years old.

• Bald eagles are becoming more plentiful in North Carolina. Biologists monitor more than 100 active nests in places such as Badin Lake and Lake Norman.

• Bald eagles tend to build big nests and keep adding to them through the years.

• Bald eagles were taken off the endangered species list in 1995.

• The bald eagle was selected as the national bird by the Continental Congress in 1782. Ben Franklin had lobbied for the wild turkey.


For the past month and a half, bald eagles Liberty and Justice did everything by the book. Liberty laid two eggs. She and Justice, her mate, dutifully kept those eggs warm through the incubation period.


They did plenty of protective squawking whenever people came close to the nest, which was built in the crook of large limbs at the Robert Lee Honbarrier Bald Eagle Habitat of Dan Nicholas Park.

But the eggs’ due date for hatching came and went without any signs of life.

Bob Pendergrass, Nature Center supervisor at Dan Nicholas Park, gave the would-be parents 10 extra days with the nest, just in case, but each day meant the American bald eagles and park staff were closer to a sobering truth.

The eggs were not fertile.
 
 
Pendergrass made the purposeful climb toward the eagles’ nest Thursday morning to collect the eggs, so Liberty and Justice could stop their futile efforts toward ever seeing eaglets poke through the shells.

“They won’t try to incubate anything that’s not here,” Pendergrass said.

As he reached the nest, Pendergrass found two perfectly shaped eggs, mostly a dull white in color.

“I think they are both formed fine,” he said. “It’s just a matter that they were never fertilized.”

Liberty and Justice, while a bit perturbed, gave Pendergrass plenty of room around the nest. He knew they wouldn’t be aggressive, he said, because nature dictates that animals with the ability to reproduce go with their instinct to survive first.

They wanted to be sure they were around for another try.

The nest had a thin top layer of pine needles and evergreen twigs, which provide a chemical aroma to deter insects, such as mosquitoes.

“We’re going to try and get out of here as soon as we can,” Pendergrass said, dropping the eggs into a soft tote bag.

Later, in the environmental center, Pendergrass conducted a test to make sure the eggs were not fertile.

He has considerable experience in breeding birds of prey such as cooper hawks, barn owls and falcons. But bald eagles were new for him.

Pendergrass fashioned a slide projector so that the light came through only a pinhole in the bottom of an aluminum can. With the thin beam of intense light, he examined each egg for any sign of a blood vessel network or embryo.

A uniform darkness was all he could see.

“My opinion is,” Pendergrass said, “there’s never been any development of the eggs.”

Pendergrass’ contacts with the Carolina Raptor Center in Huntersville said the center’s bald eagles laid eggs for five years before any eaglets were hatched (in 2006).

Pendergrass believes with high certainty Liberty and Justice, who are each 10 years old, will keep trying. Expect more eggs in late December or next January, he predicts.

“I’m disappointed — I guess that’s a selfish sort of thing,” Pendergrass says. “(But) I think they’ll work it out. They’ve come a long way from my saying they’ll never breed.”

Liberty and Justice came to Dan Nicholas Park in 2006 from a rehabilitation center in Florida. They are both disabled and could not survive in the wild.

Pendergrass thought for years they would never breed, given their disabilities — Justice essentially has only one wing that works — and the limited room for flying in the habitat.

It severely tests any instincts they might have for aerial courting.

But the eagles showed a new kind of industriousness in building a nest last summer, and the first egg showed up in the nest Jan. 12, followed by another egg Jan. 15.

Pendergrass knew from the start the chances of the eggs being fertilized were iffy, but he had even persuaded himself they were going to hatch.

“In my mind, I was giving this 100 percent (chance of happening),” he said. “Laying them is one thing, but their dedication to the eggs was another.”

Eagles in captivity are highly regulated. Pendergrass will contact the U.S. Fish and Wildlife Service to see if he’ll be permitted to void the inside of both eggs and put them on display for educational purposes at the Nature Center.

Pendergrass remains optimistic. He expects Liberty and Justice to keep adding bulk to their nest this summer and mate again.

It’s nature’s way.
 
 
 
 
Contact Mark Wineka at 704-797-4263,or mwineka@salisburypost.com.

Notice about comments:

Salisburypost.com is pleased to offer readers the ability to comment on stories. We expect our readers to engage in lively, yet civil discourse. Salisburypost.com cannot promise that readers will not occasionally find offensive or inaccurate comments posted in the comments area. Responsibility for the statements posted lies with the person submitting the comment, not Salisburypost.com. If you find a comment that is objectionable, please click "report abuse" and we will review it for possible removal. Please be reminded, however, that in accordance with our Terms of Use and federal law, we are under no obligation to remove any third party comments posted on our website. Full terms and conditions can be read here.

Do not post the following:

  • Potentially libelous statements or damaging innuendo.
  • Obscene, explicit, or racist language.
  • Personal attacks, insults or threats.
  • The use of another person's real name to disguise your identity.
  • Comments unrelated to the story.