Animals
Biologists created a unique method to boost numbers of the tropical bird—and it seems to be working.
ByChristine Peterson
Published October 13, 2022
• 6 min read
More than a decade ago, P. Dee Boersma used crowbars and hammers to chisel a small hole out of lava on the Galápagos Islands, hoping to attract one of the world’s rarest penguins.
Five months later, a Galápagos penguin pair moved into one of these hollowed-out recesses and raised their young. The next year, another pair of penguins moved in.
Today, at least 84 of the 120 nests that Boersma, a biologist at the University of Washington in Seattle, and colleagues have scoured from the black rock at the world’s Equator are still usable. And a recent census reveals a quarter of the endangered species are juveniles. That’s significant for an animal that likely numbers somewhere between 1,500 and 4,700, according to Boersma, who is also a National Geographic Explorer.
For the first time in a long while, Boersma says she feels hopeful for the future of these four-pound birds, which already contend with the mercurial climate of the Galápagos—one that flip flops between warm and cold water depending on Earth’s cyclical weather cycles, El Niño and La Niña. (Learn more about the world’s only tropical penguins.)
The latter, which causes colder water—and thus more plentiful fish—along the western coast of South America, is contributing to penguin population’s current increase by providing more food.
“I expected it to be really good,” she says. “But I was just so pleasantly surprised, because it’s the best breeding we’ve seen over the last 12 years.”
A disastrous El Niño
No one knows exactly how a type of animal best known for living in southern, often icy environments set up camp at the Equator.
Since the Galápagos penguin is most closely related to the Humboldt penguin of coastal Peru and Chile, it’s likely some Humboldt penguins caught a ride on an ocean current and stopped at the Galápagos, about 600 miles off Ecuador, millions of years ago. And there they stayed, evolving to raise chicks up to three times a year on rocky islands hot enough to fry an egg.
Galapagos penguins require shade near water to nest, but trees are rare on the islands. So the monogamous black-and-white birds waddle into lava tubes usually about three feet deep and sometimes up to 90 feet long, laying one or two eggs right on the rock. Chicks fledge at eight to nine months old, though will occasionally return to their parents for food.
When people arrived on the islands, they introduced species, such as cats and rats, that prey on eggs, chicks, and even adults. Commercial fishing operations in surrounding waters have overharvested many of the bird’s preferred fish. (Read how penguins are slow to evolve, making them vulnerable to climate change.)
But in 1982, a particularly strong El Niño event swirled around the globe, ushering warm water into the islands and preventing critical nutrients from rising to the surface. No nutrients meant no fish, which meant no food for penguins. Chicks starved first, going to their parents for a meal and finding none. Adults perished next. The Galápagos penguin population dropped by about half, Boersma estimates, from as many as 10,000 to fewer than 5,000.
They never recovered.
Comeback chicks
Because the species doesn’t seem to fare well in captivity, “there are no zoos with Galápagos penguins,” says Paul Salaman, president of the Galápagos Conservancy, a U.S.-based nonprofit which works to conserve the wildlife of the volcanic archipelago. “This is it. We really need to make an effort.”
In 2010, looking for ways to increase the population, Boersma and fellow Galapagos biologist Godfrey Merlin, observed many of the species’ original nesting sites were on islands inhabited by predatory rats and cats.
So the team decided to create new nests on islands less impacted by these predators, work that has been funded by such sources as the National Geographic Society and the David and Lucile Packard Foundation.
It’s too early to say if the recent rise in young penguins means the species is truly rebounding, cautions Boersma, who has been studying the species since 1970.
But “as long as they have a lot of good-quality nests, then the population should build back up.”
The National Geographic Society, committed to illuminating and protecting the wonder of our world, has funded the work of Explorer P. Dee Boersma. Learn more about the Society’s support of Explorers highlighting and protecting critical species.
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