Sharp-eyed birders might spot brown boobies, a tropical species once rare even in the Southern states. A flock of Canada geese might just include a pink-footed goose, too.
Birds that were once rare in New York City have been making more frequent appearances in recent years, to the thrill of local bird-watchers. But that excitement is tempered by the knowledge of what may be causing these changes: warming ocean temperatures, melting snowpacks and wildfires.
“It raises awareness of what’s happening on the planet and that this is a concern, and it causes more people to care about what is happening with climate change,” said Heather Wolf, a birder and application programmer with the Cornell Lab of Ornithology. That excitement causes people to get involved with conservation efforts, she added.
Birders have also noticed a reduction in the number of birds passing through New York City, said Marshall Iliff, the project leader for the Cornell Lab of Ornithology’s eBird project. Many birders love to watch warblers on their southward migration in mid-August, but Mr. Iliff noted that the wildfires in Canada caused many birds to leave earlier than expected.
“It’s those kind of things that sort of raise the question of whether birds are going to be able to adapt to these changing environments,” Mr. Iliff said. He said that as the forests dry out and as fires increase, birds that are expected to be seen passing through Central Park in spring could become “these really rare, rare events.”
People who subscribe to Cornell’s E-Bird alert can receive updates on when a rare bird is in the area. Here are some of the rare birds that have been spotted in New York recently.
The brown booby, a tropical species often found in the Caribbean, was once difficult to see in this country, even in Florida. But since 2010 or so, that bird has been seen “all up and down the East Coast, multiple times per year,” Mr. Iliff said. One was spotted on Coney Island on June 27.
The brown booby is a large warm-water species with brown plumage and a white belly. It has been seen farther north because of warming ocean temperatures, scientists say. It has also been seen inland, including in lakes in western Massachusetts, which birders find confounding because it is generally a saltwater bird.
Ms. Wolf suggested looking for brown boobies around New York Harbor or the Hudson River area. She recommended taking the NYC Ferry because “you’re going to see things that you couldn’t see just walking around the parks.”
It’s unclear whether the species will become a truly regular bird to encounter in the North.
The brown pelican is another southern bird that has been expanding its range northward because of warming ocean temperatures. The species has become a regular sight off western Long Island beaches over the past decade. Several were spotted on Aug. 6 at Manhattan Beach Park, and one was seen at Coney Island in July, Ms. Wolf said.
The species, which has a long white neck and yellow feathers on its head, has become common in northeastern New Jersey and the mouth of the harbor in western Long Island. “People that go out and sort of watch the ocean for the better part of the day have a really good chance of seeing a pelican now,” Mr. Iliff said.
Birders who want to see this species should keep their eyes directed at the horizon. The brown pelican, similar to the brown booby, is a large bird and should not be too hard to spot, Ms. Wolf said.
The brown pelican may start nesting in New York state in the next decade, Mr. Iliff said. That could lead to territorial disputes between the new birds and the existing ones, but seabirds tend to be tolerant of each other.
The white ibis, a coastal marsh bird, is common in Florida, Texas and South America. It has been gradually expanding northward. In recent years, the ibis, which has a long pink beak and pink feet, has started nesting in Cape May, N.J. The species tends to breed in May through early July.
“It’s sort of exciting because it’s this bird that didn’t really regularly reach the New York area previously, and now people have a decent chance of finding them if they go out to salt marshes in — basically right now — August and September,” Mr. Iliff said.
At least two have been seen in recent years in Brooklyn: One was spotted last year in Calvert Vaux Park, and one was spotted in 2015 flying over Green-Wood Cemetery and Prospect Park. Looking up in open spaces is a great way to spot rare birds, Ms. Wolf said.
The species hasn’t been spotted recently at Jamaica Bay yet, Mr. Iliff said, but the big salt marshes there would be a great place for people to look for them.
Arctic geese largely nest in the high Arctic, but as the snowpack has melted, the geese have more space to nest and breed. That is allowing their population to expand.
Pink-footed geese and greater white-fronted geese, which are primarily brown with orange feet, typically nest in Greenland. But they have also begun to turn up regularly in the Northeast and the New York City area. Greater white-fronted geese have been spotted in Central Park and Van Cortlandt Park.
A pink-footed goose was seen in Van Cortlandt Park in the Bronx within the past decade. The species has yet to be spotted in Manhattan but could turn up in Central Park in the coming years, Mr. Iliff said, adding that “a lot of bird-watchers are watching for that bird to appear.”
When an Arctic goose is spotted, it is usually an individual traveling with a flock of Canada geese.
“If you looked at like all the sightings ever of pink-footed goose 20 years ago, there would be two for the whole northeastern region,” Mr. Iliff said. But it is now a bird that people have “a really good chance of finding” if they are “diligently, checking big, big flocks of Canada geese.”