And then there were two?
A severely malnourished female eaglet found on the ground at Connetquot River State Park has died, possibly outcompeted for food by two stronger and probably older siblings.
Only about one in 10 bald eagles reaches adulthood, so the loss weighs heavily on a population slowly making headway after all but vanishing from New York.
“It’s the brutality of nature,” said Ellen Leonhardt, medical director of Animal General of East Norwich. Referring to the parents, she added: “And from my standpoint, they did great. They raised two — if it is the same pair.”
Whether the eaglet hatched at Connetquot can never be proved. Biologists believe its parents were a pair that had taken up residence in a remote spot of the park, where two fledglings have been observed.
But eagles build such gigantic and deep nests high up in the trees that biologists say this doomed bird, which died in a veterinarian’s office the day she was discovered, might never have been seen by any of the park workers who had guarded the parents’ privacy until the chicks learned to fly.
“There’s a good potential it probably came from Connetquot,” said Chip Hamilton, a senior wildlife biologist with the New York State Department of Environmental Conservation. “A little bird down in the bottom (of the nest) could easily be missed by observers.”
'It was in real trouble'
Patricia Manzi, a stewardship specialist at the park who has studied wild birds for two decades, knew as soon as she saw the eaglet that it was a juvenile — and one that was critically ill.
“Eagles typically take five years to get adult plumage, a white tail and head,” she said. “This bird was pretty brown. There was little white on it, which basically indicated to me it was a young bird.”
Other small birds were “mobbing,” or launching divebomb attacks, when she first saw it.
“The fact that I was able to walk up to it told me it was in real trouble,” said Manzi, who was able to cover it with a blanket before picking it up. A healthy bird would have run or flown away — or tried to.
“Part of you is filled with such awe to see such a big, beautiful animal up close,” Manzi said. “And then, the other part of you — for me, just feels tremendously sad, when you see a beautiful animal like that on the ground, you know it’s in a lot of trouble.”
The eaglet died that same evening on July 5, about an hour after it was brought to Leonhardt, one of a few select Long Island vets who treat injured or ailing wildlife.
“It was amazingly skinny … there were bugs all over it,” Leonhardt said. A necropsy confirmed it starved to death.
Biologists concluded that sometime after the bird fledged, the parents couldn't feed it, or stopped feeding it, and it was unable to feed on its own, the DEC said.
“Eagles are new to Long Island,” Leonhardt said. “It’s really rare for eagles to be able to successfully raise one or two. Three would be extremely rare, they would have to stretch themselves to provide an enormous amount of food for themselves and the chicks.”
And siblicide, experts said, is not uncommon among raptors and many other bird species. Eaglets typically hatch in a series, with the first at least a day ahead. As a result, older eaglets are stronger and can push younger ones out of the way when their parents arrive with food.
Had this female lived long enough to breed, she might have lived for three decades and easily surpassed any lifelong mate in both height and weight.
The wingspan of an adult female can reach 84 inches, nearly three times their height, though they might only weigh 14 pounds, experts said. Males may have a six-foot wingspan and weigh eight pounds.
Though full-size, the female eaglet found at Connetquot weighed just 2,500 grams, or just around five pounds, according to the DEC.
Bald eagles were chosen to symbolize the United States for their strength and independence, the DEC says. They have amply demonstrated these attributes, experts say, citing their remarkable comeback from over-hunting, development and the shell-weakening pesticide DDT, which was banned in 1972.
As with so many other species, the new roads, homes and buildings taking over their age-old habitat increasingly threatens their survival, scientists say. There have also been a few recent cases of hunting upstate and poisonings by Chesapeake Bay, where many winter, noted Kevin J. McGowan, an ornithologist at the Cornell Laboratory of Ornithology, a nonprofit that is part of the Ithaca-based university.
“People are still the main threats to eagles,” McGowan said.
But successful efforts to boost the population have led the DEC to reclassify bald eagles from endangered, a species that faces an "imminent" threat of extinction, to “threatened.” The second, less dire category, means the eagles are “likely to become an endangered species within the foreseeable future in New York State,” the DEC said.
In 1970, New York had only one active nest and it was unproductive. But by 2017, the state had 323 nesting pairs, eight of which were on Long Island.
Still, the death of even one fledgling saddens those who hope to keep seeing them soaring aloft.
"We are very disappointed at the park," Manzi said.
DID YOU KNOW?
- Bald eagles are the only eagles found solely in North America
- They can fly about 30 mph but dive as fast as 100 mph
- Eagles can see using both their eyes together — like humans — or independently, focusing one eye in front and the other to the side
- They can spot small prey running at a distance of 3 miles
- Their nests can be 9 feet wide, nearly twice as deep, and weigh as much as 2 tons
- Pairs mate for life
- Bald eagles’ calls are surprisingly high and weak-sounding. Listen at: https://www.allaboutbirds.org/guide/Bald_Eagle/id
- Mainly fish-eaters, they sometimes steal prey and nests from rivals, including ospreys
Sources: U.S. Fish & Wildlife Services; Cornell Lab of Ornithology; the New York State Department of Environmental Conservation