EASTERN EGG ROCK, Maine — On a recent balmy afternoon, at the extreme southern end of their range, a steady stream of Atlantic puffins, with their unmistakable tuxedo plumage and orange webbed feet, swooped in from the sea, alighting on the granite rocks surrounding this remote island off midcoast Maine.
Many carried in their multicolored beaks the small fish their chicks depend on for survival, and that have been increasingly difficult for puffins to find as waters warm.
Biologists are watching intently to gauge the future of this beloved, bellwether species. Maine’s population, long stressed, took an alarming hit last summer as water temperatures in the Gulf of Maine surged to record highs. As the chunky seabirds struggled to find enough to eat, the number of surviving chicks plummeted to about a quarter, down from about two-thirds in a typical year.
“There are real red flags — warning signs — right now for these puffins,” said Donald Lyons, director of conservation science at the National Audubon Society’s Seabird Institute in Bremen, Maine. “They’re the proverbial canary in the coal mines for our oceans.”
Temperatures in the gulf have cooled slightly, and though a full picture of chick survival this year will only emerge when data become available in coming months, the seabirds so far appear to be faring better.
“This summer is going much better than last summer,” said Keara Nelson, 29, a biologist who monitors the puffins here.
Atlantic puffins, a cold-weather species that weighs about 1 pound and ranges as far north as the Arctic, have been listed as “vulnerable” by the International Union for Conservation of Nature, which maintains the world’s most comprehensive list of threatened species. While their population has been estimated to exceed 10 million birds, the IUCN describes their numbers as “declining rapidly,” the result of predation by invasive species, pollution, and food shortages.
In Maine, where puffins are designated as “threatened” on the state’s list of endangered species, scientists estimate there are only several thousand of the tourist-attracting birds left. Maine has never had a large number of the seabirds. But their population has been decimated over the years by people harvesting their eggs and feathers; entanglements in fishing nets; and predation by everything from rats to herring gulls.
Climate change has only increased the threat. As temperatures rise, their prey — small fish, such as herring and hake — tend to move into colder, deeper waters or farther offshore, beyond the reach of the seabirds. They’re also vulnerable to the heavy storms that are becoming more frequent in the region.
Nearly killed off in the 19th century, the region’s puffins rebounded in recent decades after Stephen Kress of the National Audubon Society established a puffin restoration project here in the 1970s, transferring hundreds of chicks from Newfoundland.
Since the seabirds began returning on their own to Eastern Egg Rock, a 7-acre island in the cobalt waters between Boothbay Harbor and Rockland, their numbers have climbed steadily. Biologists counted a record 188 nesting pairs in 2019, the last year for which there’s an official count.
Even as the climate worsens for the region’s puffins, their overall numbers have remained stable.
Still, Kress worries about their future in the Gulf of Maine.
“I am concerned about the pattern that is developing,” he said. “If this resilient species cannot survive in the Gulf of Maine, they are telling us that the gulf has changed so much that human life will also be greatly impacted, given our own reliance on productive oceans.”
On Petit Manan, a national wildlife refuge off Down East Maine, scientists last year estimated that just 10 percent of chicks from the island’s estimated 87 puffin pairs survived long enough to take flight. The seabirds on Matinicus Rock and Seal Island, also national wildlife refuges, had more success, successfully raising an estimated 34 percent and 53 percent, respectively.
Linda Welch, a wildlife biologist for the US Fish and Wildlife Service who oversees the puffin-monitoring program on Petit Manan, said the seabirds had “very low productivity” during four years over the past decade, all of which had unusually high sea temperatures. As the planet warms, those temperatures are only likely to increase.
“I had really hoped that I would feel a lot more comfortable with seabird recovery efforts at this point in my career,” said Welch, who has been monitoring puffins for 25 years. “Instead, each spring I now find myself wondering if this will be the year the birds finally give up and decide not to nest on a particular island.”
Further to the north on Machias Seal Island, a disputed territory between the United States and Canada, just 10 percent of last summer’s chicks took flight.
Scientists there and elsewhere have observed other effects of climate change on the puffins.
With less availability of their traditional food, the seabirds have been forced to feed their chicks butterfish, which can be too large to fit in their tiny mouths. Moreover, increasing numbers of adults have been arriving from their winter at sea with less girth, likely because of eating less. That has resulted in puffins laying their eggs some two weeks later than usual, leaving the chicks less time to grow and amass the strength to fly.
“I do think we will start to see population-level effects, but I hope I’m wrong about that,” said Heather Major, an associate professor of biological sciences at the University of New Brunswick, who oversees the puffin-monitoring program on Machias Seal Island.
On a recent morning, as a shroud of fog lifted over Eastern Egg Rock, Lyons arrived at the island with Derrick Jackson, an author and former Boston Globe columnist who has written two books about puffins and adores them so much he wears a puffin earring.
Nelson and her colleagues guided them to one of the few structures on the island, a solar-powered hovel that doubles as office and kitchen, which they’ve dubbed the Eastern Egg Rock Hilton. There, they keep charts they use to track the feeding and other behavior of the seabirds.
“Each have different personalities,” said Nelson, who pulls the furry, pint-sized chicks from their burrows to measure their weight and wingspan, keeping them in milk cartons so they don’t waddle off.
Afterward, carrying long rods with small flags to ward off the aggressive terns shrieking overhead, Lyons and Jackson walked to a blind on the southern edge of the island, where they watched scores of the clown-like puffins landing on the granite rocks with meals for their chicks. Some had as many as a half-dozen tiny, shiny hake hanging from their sharp beaks.
Jackson was relieved to see that the colony appeared to be doing better than last summer, which he described as the “most distressing thing I’ve seen in all my time observing puffins.”
“It looked like a battlefield of climate change, with carcasses of terns and puffins strewn along the island, as if they got hit by a wave,” he said.
Lyons said it was good to see so much high-calorie food coming in for the chicks. But if the bad years continue to accumulate, and fewer chicks survive, it’s unclear how long the Gulf of Maine will be able to sustain the region’s puffins.
“There’s certainly reason for concern,” Lyons said. “But I choose to be hopeful. They have the capacity to adapt. If we give them a chance, they can get through this.”