GALÁPAGOS ISLANDS, Ecuador (AP) — Warm morning light reflects from the remains of a natural rock arch near Darwin Island, one of the most remote islands in the Galapagos. In clear, deep blue water, thousands of creatures — fish, hammerhead sharks, marine iguanas — move in search of food.
The 2021 collapse of Darwin's Arch, named for the famed British naturalist behind the theory of evolution, came from natural erosion. But its demise underscored the fragility of a far-flung archipelago that's coming under increased pressure both from climate change and invasive species.
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Bigeye trevally fish swim against the current at Wolf Island, Ecuador in the Galapagos on Monday, June 10, 2024. This time of year, the Cromwell current comes from the west and is the coldest and holds most nutrients. (AP Photo/Alie Skowronski)
A pod of dolphins swim off of Wolf Island, Ecuador in the Galapagos on Sunday, June 9, 2024. (AP Photo/Alie Skowronski)
A colony of sea lions rest at Playa Mann on San Cristobal Island, Ecuador in the Galapagos on Sunday, June 16, 2024. As ocean temperatures rise, it reduces the abundance of plants, the sea lions' food source. (AP Photo/Alie Skowronski)
A feral dog wanders the streets of Santa Rosa, Ecuador in the Galapagos, outside the highland grounds where giant tortoises feed on Saturday, June 15, 2024. Feral dogs, cats, and pigs can destroy nesting sites for the tortoises. "It's a shame to see dogs everywhere. We have a big problem right now, I don't know what we're going to do," Cabezas said. (AP Photo/Alie Skowronski)
A flightless cormorant found only in the Galapagos dries its wings on the coast of Isabela Island, Ecuador in the Galapagos on Friday, June 14, 2024. These cormorants lost the use of their wings but gained strong legs for swimming through evolution. According to the Galapagos Conservancy, there are only about 1,600 adults left, found only on Fernandina and Isabela Islands. (AP Photo/Alie Skowronski)
A Nazca booby, right, feeds its young on the cliffs of Wolf Island on Tuesday, June 11, 2024. According to the Galapagos Conservancy, the Nazca boobies lay two eggs and typically only one of them survives. (AP Photo/Alie Skowronski)
Naturalist Natasha Cabezas poses on San Cristobal Island, Ecuador in the Galapagos on Sunday, June 16, 2024. "We have something of everything here – that's why people say the Galapagos is so diverse – but we have a small number of each thing," Cabezas said. (AP Photo/Alie Skowronski)
Natasha Cabezas, a naturalist from San Lorenzo, Ecuador, hikes up a hill formed by volcanic ash on Bartolome Island, Ecuador in the Galapagos on Friday, June 7, 2024. (AP Photo/Alie Skowronski)
Galapagos ringtail damselfish swim near reef in Cabo Marshall at Isabela Island, Ecuador in the Galapagos on Friday, June 14, 2024. (AP Photo/Alie Skowronski)
A Pacific green sea turtle swims near Fernandina Island, Ecuador in the Galapagos on Saturday, June 8, 2024. The turtle feeds mostly on algae and seagrasses, so as microplastics are found in these plants, the turtles will ingest them. (AP Photo/Alie Skowronski)
Two marine iguanas found only in the Galapagos swim on the outskirts of Fernandina Island, Ecuador on Saturday, June 8, 2024. The marine feeds directly from the ocean, making it a good indicator of overall ocean health. (AP Photo/Alie Skowronski)
A Galapagos sea lion swims in front of Galapagos penguins at Bartolome Island, Ecuador in the Galapagos on Friday, June 7, 2024. Naturalists estimate fewer than 2,000 of the penguins are left. (AP Photo/Alie Skowronski)
A Galapagos penguin swims around Bartolome Island, Ecuador in the Galapagos on Friday, June 7, 2024. Naturalists estimate fewer than 2,000 individual penguins are left, putting them on the endangered list. (AP Photo/Alie Skowronski)
A feral cat roams the highland grounds where giant tortoises feed outside a reserve called Rancho Primicias on Saturday, June 15, 2024, on Santa Cruz, Ecuador in the Galapagos. This invasive species, along with others brought by humans like feral dogs, pigs and cattle threaten the endemic species on the islands. (AP Photo/Alie Skowronski)
Untagged and unbranded cattle roam the highland grounds where giant tortoises feed on a reserve called Rancho Primicias on Saturday, June 15, 2024, on Santa Cruz, Ecuador in the Galapagos. This invasive species, along with others brought by humans like feral cats, dogs and pigs, threaten the endemic species on the islands. (AP Photo/Alie Skowronski)
A giant tortoise estimated to be over 100 years old feeds in the highlands on a reserve called Rancho Primicias on Saturday, June 15, 2024, on Santa Cruz, Ecuador in the Galapagos. Galapago in old Spanish meant saddle, so the islands were named after the tortoise's shell shape. (AP Photo/Alie Skowronski)
A Galapagos sea lion swims around the rocky reef off of Isabela Island, Ecuador in the Galapagos on Saturday, June 8, 2024. Colder waters around the western islands provide a refuge for many species like the sea lion. (AP Photo/Alie Skowronski)
A marine iguana found only in the Galapagos Islands feeds on algae and other plants off of Fernandina Island, Ecuador on Saturday, June 8, 2024. The marine iguana feeds directly from the ocean, making it a good indicator of overall ocean health. (AP Photo/Alie Skowronski)
Sally Lightfoot crabs, also known as the red rock crabs, line the volcanic ash on Bartolome Island, Ecuador in the Galapagos on Friday, June 7, 2024. (AP Photo/Alie Skowronski)
Saltwater succulents grow by the water on Bartolome Island, Ecuador in the Galapagos on Friday, June 7, 2024. (AP Photo/Alie Skowronski)
A piece of the edge of Darwin's Arch is visible in the ocean above Pacific creolefish off of Darwin Island, Ecuador in the Galapagos on Thursday, June 13, 2024. (AP Photo/Alie Skowronski)
A type of Pacific green sea turtle swims through the water off of Wolf Island, Ecuador in the Galapagos on Monday, June 10, 2024. (AP Photo/Alie Skowronski)
Natasha Cabezas, a naturalist from San Lorenzo, Ecuador, dives with hammerhead sharks off of Wolf Island, Ecuador, in the Galapagos, on Sunday, June 9, 2024. The hammerheads are present year-round, and schools often come to shallow water to be cleaned by butterfly fish and feed. (AP Photo/Alie Skowronski)
A sea bird dives down to look at fish off of Wolf Island, Ecuador in the Galapagos on Monday, June 10, 2024. (AP Photo/Alie Skowronski)
Hammerhead sharks swim below schools of fish off of Wolf Island, Ecuador in the Galapagos on Monday, June 10, 2024. The hammerheads are present year-round, and schools often come to shallow water to be cleaned by butterfly fish and feed. (AP Photo/Alie Skowronski)
A school of black striped Salema fish, native to the Galapagos Islands, swim together off the coast of Darwin Island, on Thursday, June 13, 2024. (AP Photo/Alie Skowronski)
A whale shark swims through the waters off of Wolf Island, Ecuador, next to Enrique "Quike" Moran, a local naturalist from Santa Cruz Island, Ecuador in the Galapagos on Sunday, June 9, 2024. (AP Photo/Alie Skowronski)
Warming oceans affect the food sources of many of the seagoing animals in the Galapagos. Marine iguanas — one of many species that are endemic, or unique, to the Galapagos — have a harder time finding the red and green algae they prefer. Sea turtles struggle to nest in warmer temperatures. Raising young gets harder as water warms and fewer nutrients are available.
While the Galapagos are known for a great multitude of species, their numbers aren't unlimited.
"We have something of everything here – that’s why people say the Galapagos is so diverse – but we have a small number of each thing,” said Natasha Cabezas, a naturalist guide.
The Galapagos have always been sensitive to changes in ocean temperature. The archipelago itself is located where major ocean currents converge — cool from the south, warm from the north, and a cold upwelling current from the west. Then there's El Nino, the periodic and natural Pacific Ocean warming that affects weather worldwide.
While temperatures vary depending on the season and other naturally-occurring climate events, ocean temperatures have been rising because of human-caused climate change as oceans absorb the vast majority of excess heat in the atmosphere. The ocean experienced its warmest decade since at least the 1800s in the last 10 years, and 2023 was the ocean's warmest year on record.
Early June brings winter in the Southern Hemisphere, and the Cromwell current brings whale sharks, hammerheads, and massive sunfish to the surface. It also provides nutrients for penguins, marine iguanas and sea lions in search of food. As more of those animals make themselves known this season, scientists are tracking how they fared in the warming of the past year's El Nino.
El Nino can bring food shortages for some species like marine iguanas and sea turtles, as the warmer ocean means dwindling food sources. Scientists observing the species have noted a significant decline in population numbers during El Nino events.
Marine iguanas swim like snakes through the water from rock to rock as waves crash against the shore of Fernandina Island. They latch themselves onto the undersea rocks to feed on algae growing there, while sea lions spin around them like puppies looking for someone to play with.
The iguanas were "one of the most affected species from El Niño last year and right now they are still recovering,” said Galapagos Conservancy Director Jorge Carrión.
As rising ocean temperatures threaten aquatic or seagoing life, on land there's a different problem. Feral animals — cats, dogs, pigs, goats and cattle, none of them native — are threatening the unique species of the islands.
After the COVID-19 pandemic, many people are abandoning the dogs and cats they wanted to keep them company, Cabezas said.
“If you don’t take care of them they become a problem and now it’s a shame to see dogs everywhere. We have a big problem right now I don’t know what we’re going to do,” she said.
The non-native animals are a special threat to the giant tortoises closely associated with the Galapagos. The tortoises declined dramatically in the 19th century due to hunting and poaching, and authorities have worked to protect them from humans. It's been illegal to kill a giant tortoise since 1933.
“In one night, a feral pig can destroy all nesting sites in an area,” Carrión said. Park rangers try to visit areas with nesting sites once a day, and kill pigs when they find them. But the pigs are elusive, Carrion said.
Feral cats feed on marine iguana hatchings, and both pigs and cats compete for food with the tortoises.
If invasive species and warming oceans weren't enough, there's the plastic that is a widespread problem in the world's oceans. One recent study reported microplastics in the bellies of Galapagos penguins.
“There are no animals in the Galapagos that do not have microplastics in their food,” Carrión said.
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Bigeye trevally fish swim against the current at Wolf Island, Ecuador in the Galapagos on Monday, June 10, 2024. This time of year, the Cromwell current comes from the west and is the coldest and holds most nutrients. (AP Photo/Alie Skowronski)
A pod of dolphins swim off of Wolf Island, Ecuador in the Galapagos on Sunday, June 9, 2024. (AP Photo/Alie Skowronski)
A colony of sea lions rest at Playa Mann on San Cristobal Island, Ecuador in the Galapagos on Sunday, June 16, 2024. As ocean temperatures rise, it reduces the abundance of plants, the sea lions' food source. (AP Photo/Alie Skowronski)
A feral dog wanders the streets of Santa Rosa, Ecuador in the Galapagos, outside the highland grounds where giant tortoises feed on Saturday, June 15, 2024. Feral dogs, cats, and pigs can destroy nesting sites for the tortoises. "It's a shame to see dogs everywhere. We have a big problem right now, I don't know what we're going to do," Cabezas said. (AP Photo/Alie Skowronski)
A flightless cormorant found only in the Galapagos dries its wings on the coast of Isabela Island, Ecuador in the Galapagos on Friday, June 14, 2024. These cormorants lost the use of their wings but gained strong legs for swimming through evolution. According to the Galapagos Conservancy, there are only about 1,600 adults left, found only on Fernandina and Isabela Islands. (AP Photo/Alie Skowronski)
A Nazca booby, right, feeds its young on the cliffs of Wolf Island on Tuesday, June 11, 2024. According to the Galapagos Conservancy, the Nazca boobies lay two eggs and typically only one of them survives. (AP Photo/Alie Skowronski)
Naturalist Natasha Cabezas poses on San Cristobal Island, Ecuador in the Galapagos on Sunday, June 16, 2024. "We have something of everything here – that's why people say the Galapagos is so diverse – but we have a small number of each thing," Cabezas said. (AP Photo/Alie Skowronski)
Natasha Cabezas, a naturalist from San Lorenzo, Ecuador, hikes up a hill formed by volcanic ash on Bartolome Island, Ecuador in the Galapagos on Friday, June 7, 2024. (AP Photo/Alie Skowronski)
Galapagos ringtail damselfish swim near reef in Cabo Marshall at Isabela Island, Ecuador in the Galapagos on Friday, June 14, 2024. (AP Photo/Alie Skowronski)
A Pacific green sea turtle swims near Fernandina Island, Ecuador in the Galapagos on Saturday, June 8, 2024. The turtle feeds mostly on algae and seagrasses, so as microplastics are found in these plants, the turtles will ingest them. (AP Photo/Alie Skowronski)
Two marine iguanas found only in the Galapagos swim on the outskirts of Fernandina Island, Ecuador on Saturday, June 8, 2024. The marine feeds directly from the ocean, making it a good indicator of overall ocean health. (AP Photo/Alie Skowronski)
A Galapagos sea lion swims in front of Galapagos penguins at Bartolome Island, Ecuador in the Galapagos on Friday, June 7, 2024. Naturalists estimate fewer than 2,000 of the penguins are left. (AP Photo/Alie Skowronski)
A Galapagos penguin swims around Bartolome Island, Ecuador in the Galapagos on Friday, June 7, 2024. Naturalists estimate fewer than 2,000 individual penguins are left, putting them on the endangered list. (AP Photo/Alie Skowronski)
A feral cat roams the highland grounds where giant tortoises feed outside a reserve called Rancho Primicias on Saturday, June 15, 2024, on Santa Cruz, Ecuador in the Galapagos. This invasive species, along with others brought by humans like feral dogs, pigs and cattle threaten the endemic species on the islands. (AP Photo/Alie Skowronski)
Untagged and unbranded cattle roam the highland grounds where giant tortoises feed on a reserve called Rancho Primicias on Saturday, June 15, 2024, on Santa Cruz, Ecuador in the Galapagos. This invasive species, along with others brought by humans like feral cats, dogs and pigs, threaten the endemic species on the islands. (AP Photo/Alie Skowronski)
A giant tortoise estimated to be over 100 years old feeds in the highlands on a reserve called Rancho Primicias on Saturday, June 15, 2024, on Santa Cruz, Ecuador in the Galapagos. Galapago in old Spanish meant saddle, so the islands were named after the tortoise's shell shape. (AP Photo/Alie Skowronski)
A Galapagos sea lion swims around the rocky reef off of Isabela Island, Ecuador in the Galapagos on Saturday, June 8, 2024. Colder waters around the western islands provide a refuge for many species like the sea lion. (AP Photo/Alie Skowronski)
A marine iguana found only in the Galapagos Islands feeds on algae and other plants off of Fernandina Island, Ecuador on Saturday, June 8, 2024. The marine iguana feeds directly from the ocean, making it a good indicator of overall ocean health. (AP Photo/Alie Skowronski)
Sally Lightfoot crabs, also known as the red rock crabs, line the volcanic ash on Bartolome Island, Ecuador in the Galapagos on Friday, June 7, 2024. (AP Photo/Alie Skowronski)
Saltwater succulents grow by the water on Bartolome Island, Ecuador in the Galapagos on Friday, June 7, 2024. (AP Photo/Alie Skowronski)
A piece of the edge of Darwin's Arch is visible in the ocean above Pacific creolefish off of Darwin Island, Ecuador in the Galapagos on Thursday, June 13, 2024. (AP Photo/Alie Skowronski)
A type of Pacific green sea turtle swims through the water off of Wolf Island, Ecuador in the Galapagos on Monday, June 10, 2024. (AP Photo/Alie Skowronski)
Natasha Cabezas, a naturalist from San Lorenzo, Ecuador, dives with hammerhead sharks off of Wolf Island, Ecuador, in the Galapagos, on Sunday, June 9, 2024. The hammerheads are present year-round, and schools often come to shallow water to be cleaned by butterfly fish and feed. (AP Photo/Alie Skowronski)
A sea bird dives down to look at fish off of Wolf Island, Ecuador in the Galapagos on Monday, June 10, 2024. (AP Photo/Alie Skowronski)
Hammerhead sharks swim below schools of fish off of Wolf Island, Ecuador in the Galapagos on Monday, June 10, 2024. The hammerheads are present year-round, and schools often come to shallow water to be cleaned by butterfly fish and feed. (AP Photo/Alie Skowronski)
A school of black striped Salema fish, native to the Galapagos Islands, swim together off the coast of Darwin Island, on Thursday, June 13, 2024. (AP Photo/Alie Skowronski)
A whale shark swims through the waters off of Wolf Island, Ecuador, next to Enrique "Quike" Moran, a local naturalist from Santa Cruz Island, Ecuador in the Galapagos on Sunday, June 9, 2024. (AP Photo/Alie Skowronski)
NEW YORK (AP) — This week's frigid weather has many New York City residents shivering, scurrying into cozy spots and feeling sapped. Including the rats.
The United States' most populous city has been spared the Upper Midwest's extreme wind chills, not to mention the shock of record-breaking snow in the deep South, in this week's Arctic blast. But temperatures peaked Monday around 26 degrees Fahrenheit (-3 Celsius) and roughly 20 degrees (-7 Celsius) Tuesday and Wednesday, well below average.
Such cold has, yes, a chilling effect on the Big Apple's notorious rodents. But it boosts efforts to get rid of them, says city “rat czar” Kathleen Corradi.
“It's stressing out rats. It’s putting them in their burrows,” she says. “So we kind of get to double down now while the rats are ‘feeling the heat’ from this cold snap.”
New York City's wild rat species — Rattus norvegicus, also called the Norway rat or brown rat — doesn't hibernate in winter but does become less active when the weather is freezing for prolonged periods. At the same time, the rodent's food source tends to shrivel because people are out less and therefore discarding few food wrappers and other rat snacks on the streets, Corradi said.
All that makes for stressed rats and suppresses breeding, which “is really their superpower,” Corradi said. Norway rats can reproduce many times a year, essentially any time conditions are suitable, though they tend to be most prolific from spring through fall.
Jason Munshi-South, a Drexel University ecology professor who has researched New York City's rats, said those that are already holed up in subway tunnels, sewers, crawlspaces or other nooks can weather the cold fairly well.
Rats that haven't secured a hideaway might venture to unusual places, such as car engine blocks. Or a tempting basement? Perhaps, if building owners haven't diligently blocked them out.
But Munshi-South said some of the animals likely will freeze to death, especially if they're already sick, malnourished or otherwise weakened.
“Harsh winters like we are having so far will keep the rat population at a lower level if we have sustained cold, freezing periods,” he said in an email.
All of that, Corradi said, allows the city's rat-fighters to make headway ahead of the warmer months.
There's no official count of New York City's rats, but no one disputes that they have long been legion. Successive city administrations have tried various approaches to eliminating or at least reducing them.
Current Mayor Eric Adams, a Democrat who has battled the critters at his own Brooklyn home, created Corradi's position — officially, the director of rodent mitigation — about two years ago. Adams' administration also has focused on requiring trash “containerization,” otherwise known as putting household and business garbage into enclosed bins instead of piling refuse-filled plastic bags on the curb.
FILE - A rat is seen in Central Park in New York, Sunday, March 19, 2017. (AP Photo/Seth Wenig, File)