The dovekie, the kittiwake, the thick-billed murre (Brunnich’s guillemot), and the ivory gull all rely heavily on the ice and ice-edge zone for food. They also need to nest where they are safe from their two big predators, the Arctic fox and the glaucous gull. Kittiwakes and murre seek out steep cliffs with ledges close to the sea, dovekie (little auk) search out inaccessible rocky mountainsides where they nest among boulders, while the ivory gull prefers isolated mountain tops surrounded by snow. Even so, during the breeding season, the pickings are rich for fox and gull.
Around the great kittiwake colony at Diskobukta, on the west side of Svalbard’s Edgeøya Island, I have watched Arctic foxes poised, waiting for a young kittiwake’s first flight. If it does not go smoothly and the kittiwake makes a nearby crash landing, it rarely takes off again. Its broken body ends up flapping helplessly in the mouth of a contented Arctic fox, which will carry it away, perhaps with plans to bury it against leaner winter times. Not far north, the gigantic sea cliffs of Alkefjellet on Spitsbergen are the breeding place for 300,000 thick-billed murre. They face the same threat to their chicks. This time it is the large glaucous gulls that are waiting for an easy meal, their own fat chicks sitting alongside them. A baby murre cannot really fly: it must make a tumbling glide from its nest on the high cliff and try to hit the water. Its father waits down there, calling desperately, and if they are reunited, they will paddle away together on a journey to their southerly wintering grounds. If the baby murre fails to find its father quickly, there will always be a gull ready to snatch it up as a meal for its own young. Sitting by those cliffs I’ve seen the lucky chicks that tumble from the sky and make it safely to their fathers and the unlucky ones that don’t. Just occasionally a chick is snatched away by a glaucous gull but manages to struggle free from its grip in midair and escape to the sea.
For the kittiwake, murre, and many other Arctic breeding birds to survive, they need those inaccessible places where their predators can only pick off the unlucky. But these rare places cannot be too far from the ice edge where parents fly to fetch food for their young. As the ice retreats, we are beginning to see the first evidence of the strain being placed on Arctic breeding birds.
In Svalbard, Berge is studying colonies of dovekie. The dovekie is a tiny black-and-white bird living in enormous numbers across the High Arctic and nesting in colonies which may contain several million birds. Despite its numbers it is as vulnerable as the polar bear and ringed seal. Dovekie feed almost exclusively on crustaceans, especially those fat copepods that are abundant in the seasonal ice zone. When they have a chick in the nest, they must feed within the range from which they can carry back food.
Already Berge has seen that in a couple of warmer years, when the ice was farther away and it was harder to reach the copepods, the dovekie’s breeding success fell. But he is not drawing any big conclusions yet because “the window of knowledge is too narrow.” Dovekie might breed for twenty years and they must have some good and some bad years or “they would dominate the globe,” he says.
The Arctic researcher’s curse is that decades of patient study and intimate knowledge of a population are needed to spot a developing trend among the enormous natural ups and downs of the Arctic. There are still far too few “baseline studies” to monitor Arctic change quickly and effectively. That’s not too surprising. It takes a rare individual who is willing to take on a study that might last a lifetime, especially as long-term research grants are always a terrible struggle to come by and recognition may have to wait for decades.
George Divoky is one such individual and to him we owe some of the few long-term records we have of the impact of the retreating ice on Arctic birds. For the past thirty years, Divoky has spent his summers on an isolated, low-lying island thirty-five miles northeast of Barrow in Alaska, closely following the good and bad times of a colony of black guillemot, a starling-sized sea bird that comes here to breed. There have been obstacles to Divoky’s research at every step. It has been hard to find funding, and Cooper Island is not easy to reach. For many years, Divoky just lived in a tent. More recently friends helped him build a small hut.
For his first twenty-five years no one beyond a small circle of ornithologists much appreciated what he was up to. Then, in 2002, a reporter from the New York Times spent two months on Cooper Island with him and published a 12,500-word article about his work.8 Suddenly he was famous. And rightly so, as his patient studies have allowed him to see the first impacts of climate change in a way that no one else can.
Divoky’s black guillemots should not really be there. Black guillemots nest in clefts amid boulders while Cooper Island is flat and featureless. But as Divoky discovered back in 1972, the U.S. Navy had dumped old ammunition cases on the island and the guillemots had found that they made perfect places to nest.
That was a big advantage, Divoky told me. He could lift the lids of the boxes and see how the birds and chicks were getting along. “If they weren’t breeding in such a strange area I would never have gone up there,” he said. “I have complete access to every nest site and that really makes it for me. I have been to those boulder colonies, too, and getting to the nests is really tough.”
I first talked to Divoky when I called him in Seattle, his home when he is not up on his island.9 Webcasts of him out on Cooper Island show a man in his early sixties with a graying beard, wrapped in multiple layers of baggy clothes, some stained with what look like guillemot droppings, talking intensely to the camera.10 Sometimes he wears a purple-and-mauve wooly hat pulled down over a pair of round spectacles, and other times a complicated white sunhat with visor, ear flaps, and neck guard. His online image is of an eccentric ornithologist, but when I eventually met him a few months later at a conference in Quebec, he turned out to be a lean, clean-shaven, well-dressed, and urbane storyteller with a droll sense of humor and a profound feel for nature. Seattle and Cooper Island are perhaps two sides of his personality.
Divoky has been ringing the birds that nest at Cooper Island (now around 160 pairs) for so long that he has grown to know them and their individual struggles well. Guillemot male and female couples normally reunite when they return to the nesting ground. If one member of the pair shows up late, however, he or she may find his or her partner has grown impatient and paired with another bird. Divoky can tell tales of bloody battles when an aggrieved male arrives to find his partner already taken.
Sometimes disaster strikes and it is personal. A polar bear comes along and kills a bird that Divoky first ringed seventeen years earlier. Another time, a group of horned puffins kills all the guillemot chicks in a part of the colony. “It is very disheartening when you are measuring those guillemot chicks,” he says, “and also just because you get connected to them.”
Now his intimate knowledge of the birds is telling him that when the edge of the sea ice retreats far away from the Alaskan shore, it rapidly affects the birds’ efforts to raise their young. Parent guillemots fly back to their nest with their catch held crosswise in their bills, making it easy to see what they have caught. Their two chicks stay in the nest for thirty-five days and pile on weight, growing from 35 grams to an almost adult 350 grams. That keeps the parents busy as each chick eats its own weight in fish every day and needs to be fed once an hour.
From 1975, when Divoky started his work, through 1990 there was always pack ice close by and no shortage of fat Arctic cod living just under and around the ice. The chicks kept growing fast. Then the ice began to move around. In the bad years that ran from 2002 to 2004, the ice was so far away that the parents began bringing back other inferior fish that lived in the sea nearer by, including the four-horned sculpin, which contains little nutrition and which chicks hate to eat as its head is covered with sharp horns.
In 2006, the ice came close in again and provided a good year; then in 2007, the summer of the great collapse arrived, and the ice edge pulled 200 miles offshore. That was way beyond the fifteen- to twenty-mile foraging range of a guillemot. By closely watching his birds as the
y flew back to their ammunition boxes, Divoky was able to compare what happened in the good and bad years. In August 2006, 75 to 80 percent of the fish brought back were the nutritious Arctic cod; the next year it was only 20 percent. When food grows scarce, there is mayhem in the colony. Hungry firstborn alpha chicks start to attack and kill their younger beta siblings. “It is a very straightforward story,” Divoky says. “The ice retreats, the prey species changes, and we go from two chicks surviving to just one.” In 2003 and 2004 every beta chick died. In the earlier, good, years they all lived.
Divoky is looking out for the next and more troubling change. Early in the summer, he waits for his birds to return to the island. In the winter, they live out among the pack ice north of Barrow. “Every year close to 85 percent of the adults have survived,” he explains. “That hasn’t changed, which means that the winter pack ice conditions haven’t really been impacted by the summer changes. The ice is obviously there all winter and there are also enough Arctic cod under the ice.” Now he is looking out for any change in the trend in overwinter survival. That would indicate that the Arctic cod living under the ice are beginning to disappear. “That is a major measure of the Arctic that really isn’t easily obtained in any other way,” he says. “No one is sampling the underice environment except my guillemots. They are sampling it all winter long.”
Knowing that something was going wrong with the Arctic cod beneath the ice would be an important warning that the Arctic ecosystem was breaking down. It reminded me of something that Berge told me: “People tend to talk about the Arctic as very fragile. In one way it is the opposite. The ecosystem is extremely robust because the Arctic species are adapted to cope with very high variability from year to year and extreme conditions. But it is fragile in terms of having relatively few important species. If they disappear they will have immense effects on the rest of the system.” The Arctic cod is one of those species. For now, it is still there, although increasingly out of range of Divoky’s birds when they need it most.
With so many summers spent on Cooper Island, often alone, Divoky seems to me to have gone far beyond the usual ornithologist’s fondness for his birds, to develop a deeper feeling for the vanishing Arctic. More and more polar bears are showing up on his island in late summer, and Divoky explains that he is torn by his concern for himself, for his birds, and for the bears. A polar bear walked up to the back of his cabin where he was sleeping in 2008, he told me. “I heard a snort. I got my shotgun and opened the door and the bear was right in front of me. I shot over the bear’s head and it ran off. But it wasn’t until later that day that I saw where a bear had come out of the ocean. Suddenly these other prints showed up right next to it. A cub had been hanging on to its mother’s neck. I could see where the cub had been waiting down next to some driftwood while the mother came to the cabin to look for food. Of course there wasn’t any food and I scared her away. The worst thing about scaring bears away now, is there is no place for them to go. They set off swimming but the ice is too far offshore. A number of times, I’ve walked down this beach, and I see a totally exhausted bear sleeping; it has come out of the ocean and it is totally sacked out. They stay that way for twelve hours or so. I don’t want to wake that bear up to scare it away. But if I don’t try to scare them away from the cabin I take risks. I also feel awful when I do it.”
At the end of this story Divoky pauses for a moment. Then he says, “You know, there are people who say that if you go out to look for the signs of climate change that’s what you’ll find, because that’s what you want to find. But I would give anything for the ice to come back.” That is how I feel too, but we both know that it is too late.
Chapter Eleven
INVADERS FROM THE SOUTH
Keep going for another fifty miles or so past the top of Scotland, and you reach the Shetland Islands, the very northernmost part of Britain. At a little over 60° north the islands are at the same latitude as Anchorage, Alaska, and well to the north of Churchill, home to Hudson Bay’s famous polar bears. We are still quite a way from the Arctic, but the great sea cliff breeding colonies are packed with thousands of Arctic birds—skua, tern, murre, kittiwake, puffin, and fulmar—and many other animals pass by on their seasonal migrations to and from the north.
I’ve been visiting these colonies every year for more than a decade, and I’ve started to notice a host of small changes that might be the signs of a shifting climate. The most dramatic is the much more regular sighting of killer whales close to Shetland shores. Killer whales were rarely heard of here a decade ago. As there is no name for the killer whales in the local dialect—which is much influenced by Norse—but a name for everything else, the killer whales may never have come here in earlier times. Now there are five or so pods of whales up here every year.
At first, each sighting produced a report in the local newspaper and people rushed off to see them. The paper was sternly critical of boats that went so close that they might scare away what could be a big tourist attraction. Then the killer whales’ image began to change. Seal colonies around the island seemed to be vanishing, although the wildlife biologists demanded hard evidence before pronouncing the whales guilty. A full-grown killer whale needs to eat a seal, or its equivalent, every day or two so a few missing seals would not have been too surprising.
Then the whales were seen massacring a flock of dunter (as the elegant black-and-white eider duck is known in the local dialect) along with their newborn chicks in 2007. They ate forty of them in a few minutes. The following year the whales showed up at a popular bay and, in plain view of tourists, began not only killing seals but tossing a bleeding, half-dead seal pup back and forth out of the water. Seal tossing is a well-known sport of killer whales that live in the Antarctic but it was not entirely what tourists had been expecting.
Killer whales are spreading through the Atlantic and traveling deeper into the Arctic earlier in the year. Their conspicuous presence farther north is a powerful sign of another kind of change in the Arctic. We’ve seen how the disappearing ice may harm the polar bear, the ringed seal, and other creatures dependent on ice, and how changes at the bottom of the food chain may transform the structure of Arctic ecosystems. Now we encounter a third kind of change: invasion. As the seas warm and the ice melts, the open seas provide new opportunities for highly competitive invaders from the south.
For the residents of the Arctic seas, an invasion by killer whales is about as welcome as the Vikings were when they first showed up in the Shetland Islands, slaughtering and enslaving the Celtic population. Up in Svalbard, 1,200 miles north of Shetland, Kit Kovacs of the Norwegian Polar Institute has been seeing killer whales swim right up to the edge of the ice in summer. They are arriving earlier and earlier. “This year [2008], we were up at 80° north [latitude] in March and April, and we had killer whales,” she explains. “That was really surprising to us because normally you expect them in maybe the months of June and July, when the minke whales are active. It seems that it is part of the new Arctic that these big predators are here very early.”
On the other side of the Arctic, killer whales are on the move north too, says Steven Ferguson at the University of Manitoba. He has looked back at old whalers’ records and sea-ice data and found that early in the last century, there was ice in Hudson Strait, leading into Hudson Bay.1 When the ice went, around 1940, more killer whales began to appear. The pattern seems to be continuing. “We think that this probably is going to cascade across the Arctic as you start to lose sea ice. New areas will open up to temperate invasive species like killer whales,” says Ferguson.
The new Arctic is looking a little scary. Killer whales up in Svalbard don’t just eat seals but will hunt minke whales in a pack. Over in Canada, Inuit hunters report that the killer whales they have seen are after big mammals, not fish.
I’ve followed killer whales hunting a minke whale in Antarctica’s Weddell Sea, weaving around ice floes and flat-topped tabular icebergs in a fast inflatable boat. The hunt was an a
we-inspiring and terrifying sight.
The tall, swept-back triangular fins of the killer whales break surface together. In the center of the pack of ten or so of the killer whales was one animal with a smaller, sweptback fin. That was the minke whale, already bleeding where chunks of blubber had been torn from it. Crowds of noisy seabirds followed the hunt, feasting on bits of whale floating in the sea. A decapitated seal—killed by the whales in passing—rose to the surface. Every time the desperate minke came up for air, the killer whales pressed around it to force it back down. They must tire it out for the final kill. On a sprint, the killer can outrun the minke. In a really long distance swim, the minke can outlast the killer.
The killer pack had to make sure the minke couldn’t break away. This was a contest among leviathans. The male killer whales are thirty feet long and weigh six tons, while the minke is slightly bigger and heavier. Every animal is the size of a bus and they are going at twenty knots under the water. Again and again the minke desperately surfaced but was never able to shake off the pack that surrounded it. Eventually the chase headed farther out to sea, leaving us behind. We’d already run for more than eleven miles in our little boat and it was dangerous to go farther. I will never know how that particular minke whale fared. From the size of the pack surrounding it, I don’t think it had much chance.
Up in the new Arctic, the appearance of killer whales has already terrified beluga. In Svalbard, Kovacs tells me that she has been trying to record their underwater sounds. Beluga whales are very social and are known as “the canaries of the sea,” she says, constantly chirping to one another. In her part of the Arctic they are “phenomenally silent.” Here, she says, “they only seem to make noise in two conditions, when mother and calf get separated or are in some way stressed. Then they are highly vocal. That’s not too surprising. The other time is when a big group forms, not a little traveling group of twenty or even a hundred, but a group of many hundreds. When they get together like that, they are vocal.”
After the Ice Page 18
