At the same time, boreal animals from farther south have been moving in, including an influx of predatory cetaceans. Humpbacks, pilot and minke whales, orcas, and dolphins used to be a rare sight, and now they’re commonly seen. They hunt for capelin and mackerel, yet more fish species that are migrating north. Fin whales, the second biggest animals on earth, are also now swimming through these seas, feasting on krill. In all, the new predators are eating around two million tons of food a year, most of it compressed into a few months, triggering changes that are cascading all through the food web.
Eastern Greenland remains incredibly remote, and very few people live there or visit, besides scientists and tourists on cruise ships. Nevertheless, the transformation of the region matters far beyond the borders of these melting seas. It warns of just how swiftly—and sometimes irreversibly—ocean ecosystems can switch into an alternate state. The changes involve not just a species here and there arriving or disappearing but entire ecosystems operating in completely new ways. This could happen elsewhere in the ocean, away from the melting polar seas, if currents drastically alter, or if key habitats like coral reefs find the ocean unbearably warm and acidic and they finally disappear.
Greenland is also a forerunner for the rest of the Arctic Ocean, which is expected to become entirely ice-free in the summertime. Across the North Pole, there are no landmasses, just a vast area of frozen sea, which expands in the winter and shrinks each summer. Since 1978, when scientists began monitoring the polar seas from satellites, the extent of sea ice in the Arctic has shrunk by 13 per cent every decade. This incessant melting is one of the clearest signs of the climate crisis in progress. Experts now think we’ve passed the point where the Arctic’s summer sea ice can be saved—it’s just a question of when the entire region will be open ocean for the first time in thousands of years, from Canada and Alaska to Russia. This could be in the 2030s, or as late as the 2050s, depending on how quickly and deeply carbon emissions are reduced.
Already, consequences of the warming Arctic Ocean are being felt by people all around the world. There’s increasing evidence that rising temperatures in the Arctic are weakening the jet streams (strong winds that flow high above the earth’s surface) and leading to extreme weather events, from flooding to droughts and heatwaves.
The changing Arctic seas are also showing that life will continue and ecosystems will still function in the newly mixing Anthropocene ocean. But some species, such as the narwhal and cold-loving polar cod, although they can migrate and adjust their ranges, will be able to move only so far, and the time will come when they run out of cooler ocean and have nowhere else to go.
a If Wally had shown up in North America, he probably would have been named Waldo.
b Yes, unihorn, not unicorn.
c Pterois miles and Pterois volitans.
d Named after Ferdinand de Lesseps, the French diplomat in charge of building the Suez Canal.
PART TWO
VANISHING GLORIES
Chapter 3
Ice Walkers
Antarctica is the coldest, windiest, and brightest continent on earth. It’s colder than its northern counterpart, chiefly because, while the Arctic is surrounded by land, Antarctica is bathed in the freezing Southern Ocean, which keeps it cut off from the warmth of the rest of the planet. Here, life is dominated by two seasons. The long summer begins in October, when the midnight sun hangs low on the horizon, and temperatures in some places rise above freezing. Then around March, the sun sets, and winter comes. The switch from light to dark happens because the earth’s tilt brings the polar regions into the shade and farther from the sun, the north and south taking turns. Wintertime temperatures in Antarctica plunge to—76 degrees Fahrenheit. The lowest temperature ever recorded on the earth’s surface,—128.6 degrees Fahrenheit, was made in the heart of winter in July 1983 at a research base roughly halfway between Antarctica’s coast and the South Pole. Cold, dense air pours off Antarctica’s high plateau towards the coasts, driving katabatic winds of more than one hundred miles an hour that whip up blizzards and can roar constantly for days on end. Most living organisms simply could not exist in Antarctica’s winter, especially out of the sea and on the exposed ice. But this is where one species comes each year to spend a key part of its life cycle, a feat made possible by its supreme survival skills.
An emperor penguin in peak condition is encased in a life-sustaining suit of feathers. Outermost is a rigid layer, windproof and waterproof, made from long, stiff-vaned plumes called contour feathers; black on the back and head, with characteristic yellow smudges around the cheeks and chin, and white at the front, as if the penguins picked up the colour of snow while tobogganing along on their bellies.
Many scientific reports recount the fact that emperor penguins have the highest density of contour feathers per square inch of skin of any birds. In fact, until recently, nobody had properly checked; instead, it was assumed this must be the case for these birds to be able to survive the extreme conditions of Antarctica. However, the white-throated dipper, a small, plump passerine with a largely European distribution, which dips into near-freezing streams in search of food, beats the emperor penguin in contour-feather density six times over. But the emperors win on the density of downy feathers that lie beneath their outer cocoon.
Fixed near the base of the penguin’s contour feathers are fluffy plumes, called after-feathers, and fixed directly to the skin are separate feathery puffs called plumules. In all, an adult emperor penguin has at least 150,000 after-feathers and plumules, which together trap an insulating blanket of air that helps maintain the bird’s core body temperature at around one hundred degrees Fahrenheit, no matter the external conditions.
All this fluff also helps penguins to swim and, briefly, to fly. Emperor penguins prowl the Southern Ocean for squid, fish, and krill, swimming at a steady pace of four to five miles per hour and diving for over half an hour, the longest dives of any penguin species, and to depths of at least fifteen hundred feet, deeper than any other animals that rely on fur or feathers for warmth. When it’s time to get out, especially if they’re being chased by a predatory leopard seal, the penguins’ stubby legs are no use for quickly scrambling onto the ice. Instead, emperors shoot towards the sea surface, doubling their speed, then leap clear of the water. Key to their acceleration is the stream of bubbles they leave behind in the sea, like smoke trails. When a penguin dives down, air trapped between its feathers gets compressed as the water pressure pushes in; it then locks its contour feathers in place, trapping the compressed air until the critical moment when it needs a boost. As it races upwards, the air quickly expands as the pressure drops, and the penguin finely adjusts its plumage to let go of bubbles, which fizz out through its fine, downy feathers. The tiny bubbles cloak the body and reduce its drag in the water, helping the penguin swim fast enough to burst into the air, a trick scientists call air lubrication. An especially thick covering of contour feathers across an emperor penguin’s chest helps to cushion it as it lands on the ice.
Emperor penguins also have even tinier feathers right next to the contour feathers, known as filoplumes. In birds that fly, these act as sensory devices, which fire when nearby flight feathers are knocked out of alignment, alerting the bird that it needs to preen its plumage back into shape to keep itself efficiently in flight. Penguin experts generally assumed these swimming birds had no need for filoplumes, until 2015, when some keen-eyed researchers spotted the tiny wisps within an emperor penguin’s plumage. It’s likely the filoplumes signal to the emperors when their contour feathers need preening to ensure their bodies stay hydrodynamic and well insulated.
Ultimately, their exceptional plumage makes emperor penguins’ lives possible, and it’s what ties them intimately to the frozen edges of Antarctica. There, the surface of the sea forms an icy skin, doubling the continent’s size each winter and growing thick enough to support the world’s biggest penguins, which can weigh as much as ninety pounds. Feathers keep male and female emperors warm as they march over white expanses of sea ice in March and April to congregate in their colonies. Out on the land-fast sea ice, the stable parts that are frozen to the edges of the continent, the adult penguins perform courtship rituals, bowing and swinging their heads from side to side. Females select a male, usually a different one each year, and the pair gracefully moves in synchrony, mirroring each other’s gestures, which reinforces their bonds. Each female produces a single egg, one of fifteen or so she’ll lay in her twenty-year lifetime. She quickly transfers it to her partner, and he balances it on his feet to keep it off the ice, pressing it against a bare patch of skin on the underside of his belly and swaddling it in his softest downy feathers. The females return to sea to feed and leave the males to stand for two months through Antarctica’s long, dark, perishing night. During storms, the males huddle together to preserve body heat, and their feathers are so good at keeping them warm that now and then they break apart and steam, as if they’d just stepped out of a sauna. While the fasting males wait out the winter with nothing to eat on the empty ice, they run down their fat reserves, and their feathers pack more densely around their shrinking bodies, making their insulation even more effective.
Eventually, the sun rises, the chicks hatch, and the female emperors come back and find their partners. Then parents take turns to fetch food from the ocean, busily to-ing and fro-ing across the ice for several months to nourish their fluff-covered chicks, which grow to be as tall as they are.
Sometime in December or January, the fledgling chicks will shed their fuzz and get their first ocean-ready contour feathers. Later, the adult penguins will catastrophically moult. They drop all their old feathers and grow a whole new set. The rigours of Antarctic life are such that a cloak of feathers can be worn for only a single year before it needs replacing. It’s another reason ice matters so very much to emperor penguins. They need a stable platform to perch on for the several weeks it takes for their new feathers to sprout. Only when they have regrown a full coat can they safely go back in the water.
But what happens if the sea ice breaks up too early, before the penguins’ feathers are ready? And what will happen when the ice is gone for good?
Emperor penguins are some of the toughest birds on the planet, but with their hardiness comes a paradoxical vulnerability. The ice walkers utterly depend on their frozen sea, a habitat that will soon become harder and harder to find.
For a long time, humans and emperor penguins kept well out of each other’s way. Emperors live only around Antarctica, a continent that Europeans only dreamt of for centuries, imagining it as a necessary balance to the known continents in the north. Despite earlier dangerous and expensive efforts to find it, Antarctica was officially sighted by explorers from the Northern Hemisphere only in 1820. Russians were the first of them to see the edges of the ice sheet that covers the continent, a frozen white layer that’s between one and three miles thick and contains more than half of all the fresh water in the world. The ice sheet forms from layer upon layer of compacted snow and constantly flows towards the sea, forming glaciers and floating ice shelves like towering white cliffs, which periodically calve off drifting icebergs.
Officers on that Russian naval expedition of 1819–21 navigated their ships through the sea ice, where they were the first people in documented history to lay eyes on emperor penguins. But without a naturalist on board, the explorers assumed these to be the same species as the king penguins already known from South Georgia, a subantarctic island nearly two thousand miles north.
Twenty years later, a British expedition went to Antarctica and brought back several dead, preserved emperor penguins, delivering them to the Natural History Museum in London, where they were officially named as the closest, and slightly taller, relatives of king penguins. The duo was assigned the genus Aptenodytes, from Ancient Greek words meaning “diver without wings.”
And so, Western scientists became aware of the emperor penguins’ existence, but that was really all that was known of them. The extreme conditions these birds evolved to survive keep most other large-bodied life forms away, humans included. Decades passed before more details of their lives were discovered by people who were prepared to venture into their icy world.
“It is extraordinary how often angels and fools do the same thing in this life, and I have never been able to settle which we were on this journey.”
So wrote the British explorer and fledgling zoologist Apsley Cherry-Garrard, known as Cherry, who trekked across the unforgiving Antarctic ice in the winter of 1911. Together with two companions, Edward “Bill” Wilson and Henry “Birdie” Bowers, Cherry was attempting to make a scientific breakthrough. The men hoped to become the first people to find a colony of emperor penguins during the breeding season and to bring back several fertilised and growing emperor penguin eggs. The hope that kept them going as they dragged their sleds towards Cape Crozier was the possibility of uncovering a missing link between birds and dinosaurs.
At around that time, some scientists were keen to test out the theory of recapitulation, which proposed that developing embryos replay the evolutionary stages of their ancestors. Emperor penguins were thought to be the most primitive of living birds (in fact, they are not), and so, the theory went, their embryos could act as virtual time machines, transporting scientists back to when birds first evolved from their reptilian forebears. The only way to get hold of an emperor penguin embryo was to pluck a warm egg from the feet of a brooding male, deep within the cold and dark of the Antarctic winter.
It took the men five weeks to walk around 125 miles from base camp to the emperor colony and back. Cherry, Birdie, and Bill clambered over huge pressure ridges of ice, braved temperatures of minus seventy Fahrenheit, and kept falling down crevasses in the dark. A terrible storm was stirring when they finally arrived at the site of the brooding emperor penguins. The explorers scrambled to grab five eggs and retreated as quickly as they could to the igloo they had built, intending to use it as a base while they made more visits to the penguins. For days, they stayed inside the igloo waiting out the blizzard, huddled around the stove, burning fat from several adult penguins they had also snatched. “The earth was torn in pieces: the indescribable fury and roar of it all cannot be imagined,” wrote Cherry of the storm. Eventually they made it back to base camp with three emperor penguin eggs intact, each around four inches long, the size of a Fabergé egg, with its embryonic contents frozen and preserved.
The following year, during the same Antarctic expedition, Bill and Birdie both died, alongside Robert Falcon Scott, during an even worse journey as they endeavoured to become the first men to walk to the geographic South Pole;a they were beaten to it five weeks earlier by Roald Amundsen and four other Norwegians. Cherry had not taken part in the push for the pole and later found his companions’ tent with their frozen bodies inside. He returned to London as the sole egg bearer, but at the Natural History Museum he did not get the welcome he anticipated. While the three men were toiling across the Antarctic ice, scientific thinking had moved on, and the theory of recapitulation was slipping out of fashion. The museum’s curators showed little interest in the emperor penguin eggs, although in the end they were sent to Cambridge University, where scientist Dorothy Thursby-Pelham drew intricate pencil sketches of a tiny, unborn penguin; it looks as if it’s still floating inside its egg, muffled from the cold by its father’s feathers. The hard-won eggs didn’t lead to great new insights into the origins of birds, but the first emperor penguin eggs brought into the human world do still bear witness to the extraordinary lengths three men went to in the name of science. One of the eggs has recently been put on display at London’s Natural History Museum among other treasures, including the skull of a royal lion, some of Charles Darwin’s pigeons, and a moon rock.
Today, it’s not such a life-threatening business to watch and study emperor penguins in the wild throughout their entire life cycle. Scientists now have equipment, clothing, and communications that are much better at keeping them alive, and they can retreat to well-insulated base stations that look like giant metal caterpillars standing on the ice.
Many details of emperor penguins’ lives have been revealed by scientists who have never actually visited Antarctica and instead are watching the birds from above. Satellites passing overhead take photographs of such high resolution that they reveal guano stains on the ice showing where adult emperors meet, mate, rear their chicks, and defecate. If light conditions are favourable, it’s even possible to make out the shadows cast by clusters of these four-foot-tall penguins. Of course, the imagery doesn’t have much to show when the sun goes down, while the males overwinter with their eggs on the dark ice. But before and after, on days when there are no clouds in the way, scientists get a clear view of where emperor penguin colonies are—and where they are not.
A map of Antarctica with its present-day covering of the world’s largest ice sheet looks something like a human brain. Emperor penguin colonies are dotted around the entire circumference at remarkably regular intervals. By the latest count from satellite images, there are sixty-six breeding colonies spaced roughly 250 miles apart, with a few larger gaps where the biggest ice shelves get in the way.
Since the 1950s, scientists have known of an emperor colony located on the northeast side of the Weddell Sea, at the back of the neck, roughly where the brain’s cerebellum would be. Close to one in ten of all the world’s emperor penguins had been gathering here, near to where the Brunt Ice Shelf flows off Antarctica’s ice sheet at a spot known as Halley Bay. Sheltered spots at the base of the ice shelf had been a good place for them to rear their young, where the sea would freeze and usually stay firm and intact until January, giving enough time for the chicks to fledge. Throughout the sixty-plus years that scientists knew about the Halley Bay colony, the sea ice remained stable and reliable throughout the breeding seasons, and the emperors were doing well. It was one of the largest colonies in Antarctica, with numbers varying each year between around fourteen thousand and twenty-three thousand pairs of adult penguins. Then, in 2016, disaster struck.
In October that year, the weather was unusually stormy. Strong winds whipped along the edges of the ice shelf and broke apart the sea ice. It happened during the emperor penguins’ crèche period, when parents begin to leave their young chicks in groups together on the ice while they go to gather food. That year the ice collapsed beneath the chicks’ feet, long before they had a chance to grow their waterproof feather coats. All the chicks drowned.
The following year, the sea ice froze over again, and the adult penguins returned. But the ice wasn’t strong enough to last, and once again all the chicks perished. In 2018, satellite images showed that only a few hundred adults gathered at the breeding site at Halley Bay, while thousands lingered at the edges of the sea ice, perhaps wondering what to do. Penguins stood among refrozen fragments of brash ice and the slushy soup of grease ice, an early stage in the formation of solid sea ice, which would never have supported their chicks had they produced any. By November, all the sea ice on the northern side of the Brunt Ice Shelf was once again completely gone. After three years of total failure to breed, emperor penguins stopped coming, and the Halley Bay colony was abandoned.
For the adult penguins it was a tragic setback, but more photographs taken from space hint that at least some of them survived. At around the same time that the Halley Bay colony collapsed, a nearby colony got much bigger. Between 2015 and 2018, the number of emperors at the Dawson-Lambton colony, thirty-five miles to the south, increased from twelve hundred to almost fifteen thousand. It’s likely that many of them were adults relocating from Halley Bay after the sea ice disappeared. At first, a lot of them stood scattered in loose groups and were probably not breeding. But by 2018, guano stains showed they were huddled more closely together in two main groups and most likely had settled once again into their breeding rhythm. Some of the missing adults could still be out there somewhere, skipping their breeding and waiting for conditions to improve at Halley Bay (emperor penguins can typically live for around twenty years). Some may have moved away, and maybe one day a new emperor colony will show up on a satellite image.
It’s not possible at this stage to blame the climate crisis directly for what happened at Halley Bay, but the year it happened, 2016, was a turning point for Antarctica in the Anthropocene. For quite some time, sea ice surrounding the southern continent seemed to be defying human-driven climate change. While in the Arctic, the sea has steadily become less icy over the past few decades since satellite monitoring began, Antarctic sea ice had been highly variable and in some places had been increasing. Scientists studying this phenomenon identified changing wind patterns as a major cause. Then, in 2016, there was a sudden decline in sea ice all around Antarctica, the beginning of a relentless downward trend. New record lows in sea ice extent were set in the summer of 2021–22. The following year, even more ice was gone by summer’s end, so much that it left polar scientists deeply shocked and desperate to understand the complex mix of rising temperatures and shifting winds, ocean currents and salinity that could explain the rapid changes.
Meanwhile, late in 2022, the impact of shrinking sea ice on Antarctica’s wildlife became more obvious and tragic than ever. The region suffering worst from loss of ice was to the west of the Antarctic Peninsula, in the Bellingshausen Sea. Five emperor penguin breeding sites had been discovered there from satellite images, all of them smaller than the former Halley Bay colony, and only one of them visited by scientists. Satellite imagery from 2022 showed the usual springtime arrival of adult penguins, but then, one by one, the penguin gatherings disappeared. At the Verdi Inlet colony, the sea ice usually stayed fast until the New Year, but in 2022 it had broken apart by November fourth. At other sites, the breakup happened later in November and into December, coinciding with the end of the emperor penguins’ crèche and fledgling periods. Rothschild Island was the only colony where the sea ice lasted almost to the end of the year, giving some of the chicks a chance to safely swim off with their new feathers fully grown.
