If Rover Can Make It Here, Perhaps Bald Eagles Can Make It Anywhere

Visitors to Central Park’s reservoir in New York are taking in a drama filled with feathers. Its star performer, thrilling parkgoers and terrorizing gulls, is Rover, a bald eagle.

The city’s birders have been tracking Rover for two years, and some point to his ongoing story as demonstrating the conservation benefits of attaching aluminum bands to the legacy of threatened bird species when they are young. Rover’s arrival in the five boroughs also adds to mounting evidence of a return to urban areas by birds of prey. If Rover can make a home in and around Central Park, perhaps even more eagles will fill the city’s skies in the years ahead.

Rover’s story begins in New Haven, Conn. In 2016, the town’s birders were surprised to see a pair of bald eagles set up a nest near a busy intersection. The male wore a band around his leg reading “P2,” while the female was unbanded. Birders christened the pair Walter and Rachel — W and R after the West River, which flows through the city, said Martin Torresquintero, the outdoor adventure coordinator for the city’s government.

Walter and Rachel failed to raise any young that year and then relocated to a nearby cemetery. They succeeded the next year, and again in 2018 when they laid three eggs.

Biologists with the Connecticut Department of Energy and Environmental Protection monitored the nest until the eggs hatched. On May 11, 2018, Brian Hess, a state wildlife biologist, rode a New Haven city cherry picker up to the nest and removed the chicks. He weighed and measured them, placed a metal ring around each of their legs, and returned them. One ring contained a long number assigned by the United States Geological Survey’s Bird Banding Laboratory, while the other contained two large characters visible through spotting telescopes or zoom lenses. The female sibling’s band read P7, while one male’s read R7 and the other, S7.

Two years later, a young bald eagle began keeping vigil in the tall pine trees of Brooklyn’s Green-Wood Cemetery. “I couldn’t believe that a bald eagle was hanging out at Green-Wood Cemetery in the middle of Brooklyn,” said Angela Panetta, a birder in the borough who said the eagle got her interested in birding.

Birders in Green-Wood caught sight of a ring around his left leg, R over 7 — earning him the nickname Rover, and they’ve been tracking him ever since.

Then, just a few weeks ago, a banded bald eagle dramatically appeared in Central Park, perching low over the reservoir and snatching a gull out of the air in front of onlookers.

Mr. Hess had seen a video of the Central Park bald eagle on the hunt. “I thought, wow, that’s the coolest thing,” he said. Shortly after, he was contacted with a report that a bald eagle with the black band reading R7 had been hanging around New York City. He recognized the combination instantly — it was one of the siblings he’d banded in 2018.

Rover represents part of an ongoing trend of birds of prey moving into urban areas. Raptor populations plummeted in the first half of the 20th century because of widespread hunting and use of the insecticide DDT. These chemicals traveled up the food web and accumulated in predators such as bald eagles, making their eggs’ shells too thin to support the parent’s weight, said Jen Cruz, a population ecologist at Boise State University.

Bans on DDT, as well as laws forbidding harming or disturbing bald eagles, have led to the species’ recovery. The US bald eagle population has quadrupled since 2009, and these large, white-headed raptors are now a regular sight even in New York City; bald eagles breed on Staten Island, for example. The birds are adaptable, and can feed on fish, roadkill, other birds and more — even in Central Park.

“I’ve been birding Central Park now for at least five years,” said Ursula Mitra of Manhattan. “And frankly I have never seen an eagle hunting on the reservoir except for the past four or five weeks.”

Birds of prey still face threats in New York City. Just last year, Central Park’s celebrity barred owl Barry died after colliding with a maintenance vehicle. An autopsy found that she had eaten poisoned prey.

Rover’s family has endured drama, too. There have been no reported resightings of P7, and S7 was killed in September 2018 by a truck in West Virginia. Rover’s mother, Rachel, was hit by a truck on I-95 in 2020 and survived. But during his rehabilitation, Walter found a new mate who fought off Rachel when she tried to return to him, Mr. Torresquintero said.

Mr. Hess is optimistic about Rover’s future. Bald eagles begin breeding around 5 years old, and Rover is 4. Perhaps he will find a mate and choose to breed in New York City, too.

“Clearly this bird has figured out how to catch gulls, and probably ducks as well,” Mr. Hess said. “They really are smart and adaptable birds who have figured out how to survive in lots of different places.”