As climate change disrupts many species, sub-Antarctic penguin thriving as it adapts

Editor’s note: “Behind the News” is the product of Sun staff assisted by the Sun’s AI lab, which includes a variety of tools such as Anthropic’s Claude, Perplexity AI, Google Gemini and ChatGPT.

When scientists look at the effects of a warming planet on wildlife, the news is almost universally grim. Animals and plants are falling out of sync with each other. Ecosystems are fraying. Coral reefs are dying. Ice is vanishing.

But in a sub-Antarctic archipelago, a tuxedo-clad bird is doing something remarkable: thriving.

A new study published Wednesday in the journal Science Advances found that king penguins are breeding 19 days earlier than they were in 2000 — and that the shift has boosted their breeding success rate by 40%. Researchers tracked roughly 19,000 birds in the Crozet Archipelago, a remote French-administered island chain in the southern Indian Ocean. [1]

It is, scientists say, a genuinely rare piece of good news from the world of climate and wildlife science.

What is a king penguin?

The king penguin (Aptenodytes patagonicus) is the second-largest penguin species in the world, surpassed only by its close relative the emperor penguin. Adults stand roughly 35 inches tall and weigh between 20 and 40 pounds, with males slightly heavier than females. They are striking animals: sleek black-and-white bodies, long curved bills and vivid orange-yellow ear patches that fade into a golden blush across the chest.

Early explorers who encountered their chicks — which are covered in fluffy brown down so thick they were once believed to be a different species entirely — nicknamed them “woolly penguins.” [2]

King penguins are not Antarctic animals, strictly speaking. Unlike their emperor penguin cousins, who breed on the Antarctic continent itself, king penguins inhabit the sub-Antarctic islands that ring the Southern Ocean, at latitudes between 45 and 55 degrees south. Their range includes South Georgia, the Crozet Islands, the Kerguelen Islands, the Prince Edward Islands, Macquarie Island, the Falkland Islands and the southern tip of South America. [8]

The largest single colony in the world is at St. Andrews Bay in South Georgia, where more than 450,000 breeding pairs occupy a stretch of coastline that can, by some accounts, stretch as far as the eye can see. The Crozet Islands — where the new breeding study was conducted — hold about 455,000 breeding pairs. [2]

The total world population is estimated at approximately 2.23 million breeding pairs, and the population trend is increasing. The International Union for Conservation of Nature lists the species as “Least Concern” on its Red List of Threatened Species. [9]

How do king penguins differ from other penguins?

There are 18 recognized species of penguins in the world, ranging from the tiny little blue penguin of New Zealand and Australia to the massive emperor. King penguins sit near the top of the size chart but are distinguished from the emperor by several features: their bill is longer and more slender; their orange cheek patches are more vivid and solid, compared with the emperor’s paler yellow-white coloring; and, crucially, they live at very different latitudes. The two species rarely, if ever, encounter each other in the wild.

King penguins also have the longest and most complex breeding cycle of any penguin. A single chick takes 14 to 16 months from egg to independence — so long that parents cannot complete two full breeding cycles in a calendar year. This means that, in any given colony, there are always birds at some stage of the process: incubating, brooding, guarding juveniles, or molting. [2]

Their diet consists primarily of lanternfish — small, bioluminescent deep-water fish — as well as squid and crustaceans. To hunt, they dive repeatedly to depths of 100 to 300 meters and have been recorded as deep as 343 meters off the Falkland Islands. [2]

Unlike many penguin species, king penguins have a remarkably flexible breeding window — from late October through March — a trait that, researchers now believe, may be a significant advantage in a changing world. [1]

Why is warming helping king penguins?

The study of how the timing of natural events — flowering, migration, hatching — is shifting with climate is called phenology. It has become a major preoccupation in biology because the problem is almost always the same: Species that depend on each other are adapting to warming temperatures at different rates, creating dangerous mismatches. A plant blooms too early. The bee that pollinates it hasn’t emerged yet. The insect a migratory bird depends on for chick-rearing peaks before the bird arrives. [10]

Most birds, especially in North America, are not keeping pace with these phenological shifts, according to Casey Youngflesh, a biological sciences professor at Clemson University who was not part of the king penguin study. [1]

The king penguin, it turns out, is different.

Having a species like the king penguin adapt so well to seasonal shifts and timing changes “is unprecedented,” said Celine Le Bohec, a seabird ecologist at the French science agency CNRS and co-author of the study. [1]

Lead author Gaël Bardon, a seabird ecologist at the Scientific Centre of Monaco, said the birds have shown a remarkable ability to adjust where they forage as ocean conditions change. Some birds are pushing further south toward the polar front, others are ranging north and still others are staying closer to the colony — a behavioral flexibility that allows the colony as a whole to keep pace with shifting prey. [1]

Unlike other penguin species that have narrow diets and limited flexibility, king penguins are not strictly dependent on a single food source. While lanternfish makes up roughly 80% of their diet, they supplement with other sources when conditions change. [1]

Their broad breeding window — spanning several months — also means a warming shift in the season’s start doesn’t strand them outside a viable reproductive window. For other penguin species, breeding is tightly tied to ice conditions and very narrow seasonal windows. A shift in timing breaks the system. For king penguins, it opens earlier, and they simply move into it. [1]

A word of caution

The researchers and outside scientists are careful not to declare a wholesale victory.

“So that’s why for the moment the species is able to cope with this change, but till when? This, we don’t know, because it’s going very, very fast,” Le Bohec said. [1]

Michelle LaRue, a professor of Antarctic marine science at the University of Canterbury in New Zealand, noted that king penguins live 20 or more years in the wild and that the study covers only a portion of their lifespan. Questions about the species’ long-term survival beyond the breeding season remain unanswered. [1]

Youngflesh offered another caution: gains for one species often mean losses for another. [1]

And Ignacio Juarez Martinez, a biologist at Oxford University who has studied other penguin species with earlier breeding, put the findings in the starkest terms: “This study shows that king penguins might be a winner for now, which is excellent news, but climate change is ongoing and future changes to currents, precipitation or temperatures can undo these gains.” [1]

What warming is doing to the rest of the natural world

The king penguin’s good fortune throws into stark relief the catastrophe unfolding for so many other species, including some of their closest relatives.

Emperor penguins: The emperor penguin — the king’s larger cousin — faces a fundamentally different situation. Unlike king penguins, emperors breed exclusively on Antarctic sea ice, laying eggs in winter and raising chicks through the spring. That ice is now vanishing at a rate and scale scientists had not anticipated.

In 2022, 4 out of 5 emperor penguin colonies in the Bellingshausen Sea, off the western Antarctic Peninsula, experienced total breeding failure after sea ice disappeared weeks before their chicks could develop the waterproof feathers needed to survive open water, according to a study in the journal Nature Communications Earth & Environment. It was the first recorded incident of a widespread breeding failure of this kind, and one the researchers described as a direct consequence of historically low sea ice extent. [3]

Researchers from the British Antarctic Survey said between 2018 and 2022, 30% of the 62 known emperor penguin colonies in Antarctica were affected by partial or total sea ice loss. If warming trends continue unchecked, more than 90% of colonies could be quasi-extinct by 2100. [3]

The U.S. Fish and Wildlife Service listed the emperor penguin as a threatened species under the Endangered Species Act in October 2022, citing climate change as the primary driver. [4]

Polar bears: The polar bear, listed as a threatened species in 2008, faces a similarly existential problem. As Arctic sea ice melts earlier in spring and forms later in the fall, polar bears have less time to hunt ringed seals — their primary prey — and more time stranded on land where food is scarce. The Arctic is warming roughly twice as fast as the global average, and sea ice extent has declined by more than 13% per decade since satellite records began in 1979. [5]

Coral reefs: Coral reefs — sometimes called the rainforests of the sea because they shelter an estimated 25% of all marine species — are among the most dramatically affected ecosystems. As ocean temperatures rise, corals expel the symbiotic algae that give them their color and provide their nutrients, a stress response known as bleaching. Repeated or sustained bleaching can kill entire reefs. [12]

More than half of coral reefs worldwide are being affected by bleaching events. Global coverage of living coral has declined by roughly half since the 1950s. Scientists warn that without dramatic reductions in greenhouse gas emissions, up to 90% of all coral reefs could disappear by 2050. On the other hand, scientists say deep water reefs are thriving and other marine life along with it. [6, 12, 13]

Birds and pollinators: For birds and pollinating insects, the problem is the mismatch described at the heart of the king penguin study. Climate change is shifting the timing of flowering and the emergence of insects at different rates, with potentially cascading consequences. When flowers bloom before their pollinators arrive, both may suffer: Plants go unpollenated, and bees arrive to find their food source already gone.

Research published in the Proceedings of the National Academy of Sciences found that climate change is intensifying this plant-pollinator mismatch and raising the risk of what scientists call secondary extinction — the loss of a plant species not because of direct harm to the plant, but because its pollinator has disappeared or fallen out of sync with it. [7]

Most birds, particularly migratory species, are not adapting their timing quickly enough to track these changes, according to Youngflesh and other researchers. [1]

The king penguin is a remarkable exception in a story that is otherwise deeply troubling. Its flexibility — in diet, in behavior, in breeding timing — has allowed it to absorb a shock that is breaking other species. But even that flexibility has limits, and the planet is not done warming.

“The king penguin may have a bit of flexibility as a trick up its sleeve, and may be in a good position to adapt as their environment changes,” LaRue said. But she and others are quick to add that the same forces producing that rare silver lining are the ones bearing down, hard, on species that don’t have such a trick available. [1]