The Great White Bear (29 page)

Little wonder that Derocher was quoted in the
Anchorage Daily News
as doubting that most of the article's authors "had ever seen a polar bear."
^*
(Despite its clear shortcomings, however, the article was quoted often by then-governor of Alaska Sarah Palin in opposition to the notion of granting polar bears greater federal protection.)

Still, small but vocal groups of contrarians remained. One particularly persistent assertion was that, far from showing signs of decline or endangerment, the global polar bear population has grown over the past several decades—the factor most frequently expressed was quadrupled. The contention's origin was not in the peer-reviewed literature, but in the conservative blogosphere it became received wisdom. Bjorn Lomborg, a serial skeptic on environmental matters, wrote that there were "probably 5,000" polar bears in the 1960s, citing a
New York Times
article that read, in part: "Other experts see a healthier population. They note that there are more than 20,000 polar bears roaming the Arctic, compared to as few as 5,000 40 years ago." When Peter Dykstra, then executive producer for science, tech, and weather for CNN, asked the author of the
Times
article for the source of his figures, the latter said that he could not remember but that he understood the numbers to be "widely accepted." Certainly, Dykstra found, in a review for the Society of Environmental Journalists, that they were widely repeated, albeit with variations:

In a May 20
Los Angeles Times
opinion piece, Jonah Goldberg took a whack at what he sees as quasi-religious overtones to conservation. Part of his backup? "Never mind that polar bears are in fact thriving—their numbers have quadrupled in the last 50 years."...James Taylor of the Heartland Institute cited a London
Daily Telegraph
article that "confirmed the ongoing polar bear population explosion" in a September 11, 2007, blog ... Taylor adds a new number into the mix from a March 26, 2008, posting at the Heartland site: "The global polar bear population has doubled since 1970, despite legal polar bear hunting"...From James Delingpole, a
Times
of London blogger, similar numbers, but different dates. And no source: "In 1950, let us not forget, there were about 5,000 polar bears. Now there are 25,000."

A clue to the likely origin of the much-repeated 5,000 could be found in a URL that Lomberg e-mailed to Dykstra, which linked to a paper tabled by Soviet scientist Savva Uspenski at the First Scientific Meeting on the Polar Bear in Fairbanks, Alaska, in 1965. Extrapolating from his own studies of denning sites, Uspenski proposed a global figure of 5,000 to 8,000. But, to repeat some text from two chapters previously, his view was by no means the consensus:

Five thousand, said some. More than 10,000, reckoned Canada's Richard Harington. Between 10,000 and 19,000, according to official U.S. estimates. As high as 25,000, according to others.

Thor Larsen, who was present at both that first Fairbanks meeting and the subsequent inaugural meeting of the Polar Bear Specialist Group, told Dykstra, "Most data on numbers from the late 1960s and early 1970s were indeed anecdotal, simply because proper research was lacking. As far as I can remember, we did stick to a worldwide 'guesstimate' of 20—25,000 bears in these years." Ian Stirling ventured that any estimate of 5,000 bears "was almost certainly much too low." And Steven Amstrup commented that, at the time of the 1965 meeting, "people were just beginning to figure out how we might study animals scattered over the whole Arctic in difficult logistical situations. Some estimated that world population might have been as small as 5,000 bears, but this was nothing more than a WAG."

WAG, Dykstra points out, is scientific jargon for "wild-ass guess."

Since those early days, Amstrup argued, "the scientific ability to estimate the sizes of polar bear populations has increased dramatically." Even so, many uncertainties remain. While the Polar Bear Specialist Group agrees that the species' worldwide population is indeed somewhere within the range of 20,000 to 25,000, there are no reliable estimates at all for the Kara Sea region or the Arctic Ocean basin. Of the nineteen recognized subpopulations, the PBSG was unable, as of its 2009 meeting, to determine status or trends for seven. For those where the data are sufficiently robust, however, the picture is not bright. Three of the remaining twelve are reckoned to be stable, and one, in the Canadian Archipelago, even increasing slightly—albeit from much-reduced numbers as a result of previous overhunting. But fully nine are considered to be in decline, among them western Hudson Bay, the polar bears of Churchill, where additional years of study and number crunching have allowed researchers to calculate with some confidence that these most iconic of all polar bears have decreased in number from approximately 1,200 in 1987 to a little over 900 by 2004.

Some Inuit hunters, noting increases in polar bear sightings near settlements during the time when the ice has melted and the bay is open water, have argued that polar bear numbers are growing, not diminishing. Researchers, in contrast, remain equally convinced by data showing a lack of increase at best, and future or even current declines at worst. Those declines, they fear, will be made only worse by increases in quotas for subsistence hunts, increases made on the basis of the more frequent sightings, sightings that scientists assert are the result of hungrier, more desperate bears coming inshore in search of food.

Such encounters are not restricted to Canada. In northern Alaska, too, polar bears have begun to encroach more on human settlements, sometimes out of apparent desperation, sometimes seemingly because sheer exhaustion robs them of their normal caution and determination to avoid potential danger.

Alaska journalist Charles Wohlforth relays one particularly evocative instance of the latter, as told to him by Barrow biologist Craig George. Summer was reaching its end, and the sea ice of the southern Beaufort Sea had retreated fully 200 miles, by George's reckoning, from the coast. And yet, as if from nowhere, a mother and two cubs swam ashore on the beach near the town. Twice residents used cracker shells to drive the bears back into the ocean; twice they returned. Continued George, in Wohlforth's telling:

Dodging cracker shells, she came ashore a third time and walked right through our crowd of dissuaders, crossed the beach road, and lay down with her cubs, barely 100 yards from the beach and only 10 yards from the road. She seemed to say, 'Shoot me if you must, but I ain't moving. If I go back to sea, I'm dead anyway...' So there she lay with her cubs for two days, barely moving a muscle ... and finally, after two days of comatose rest, she slowly got up and ambled to the coast with her cubs to spend the rest of the fall on the tundra. We never saw her again.

In the waters north of Alaska and Siberia, the Beaufort Gyre has long circled endlessly, a closed loop that gathers ice floes into its embrace and pushes them into and onto each other, creating pressure ridges that rise from the surface of the floes and enormous islands of ice that grow ever thicker, the entire assemblage the perfect combination of stability and volatility, the ice thick enough to provide platforms for seals and bears but active enough to provide multiple openings where seals may breathe and bears may feed.

Since the beginning of the twenty-first century, however, the Beaufort Gyre has been weakening, and warming coastal waters have eaten away at the ice it contains. The thick, stable floes that used to reach all the way to the coast now retreat from it, changing the nature of northern Siberia and Alaska perhaps forever and bringing into question their future as polar bear residences.

"Places like northern Alaska and the northern coast of Russia, the sea ice has historically been close to the shoreline in summer; now it's way offshore and by mid-century it will probably be totally absent," says Steven Amstrup. "If the bears stay with the ice like they have been doing, and the ice retreats farther and farther to the north, is there any sense in them coming back for just a few months in the wintertime when the ice refreezes? Would you migrate a couple of thousand miles for just a short stay and return?"

Yet therein, especially for pregnant females, lies a dilemma. Those that choose to continue denning on the sea ice, as more than half of Beaufort Sea females traditionally have done, will do so on a platform that is thinner, more chaotic, and less reliable than before, that may transport them even farther than previously while they rest in their dens, that could conceivably break apart beneath them. It seems that, as the ice thins and retreats, a greater number of bears than before are now making dens ashore, but this, too, poses its risks. A growing distance between shoreline and ice edge exposes newly emergent cubs to the considerable dangers of being forced to take a plunge before reaching the sanctuary of the sea ice; and while their mother is likely to carry them on her back, her stamina is not limitless. Polar bears are excellent swimmers, it is true, but in swimming too great a distance without respite they risk exhaustion, as in the case of the family described by Craig George, or worse.

Between 1987 and 2003, biologists Charles Monnett and Jeffrey Gleason saw a total of 351 polar bears during aerial surveys off Alaska's Beaufort Sea coast, 12 of which were swimming at the time the aircraft passed over them. In 2004, they saw 55 bears, 51 of them alive, and 10 of those living bears in the water. The 4 dead bears were all floating in the water, and while it cannot be certain that they drowned, it can reasonably be surmised that they did. It is, suggest Monnett and Gleason, a fate that is likely to befall an ever greater number of polar bears as the ice retreats and disappears.

Our story began in what seemed on the surface the most fragile of environments, and it is where we shall end. A layer of snow covering a hole in a drift scarcely seemed adequate protection for a mother to raise her cubs, and yet, in the dark and the warmth, that is what she does. It is, in fact, in many ways the most peaceful and secure experience of a polar bear's life. But that security, too, may no longer be a guarantee.

As temperatures climb in western Hudson Bay, so too does the likelihood of fires in the areas of the Wapusk National Park where forest yields to tundra and, in the other direction, tundra vegetation is slowly subsumed by a forest of spruce and larch. It is here, in the shade and relative cool, that the polar bears of Churchill spend their summer months, curled up in dens dug into the permafrost, dens in which expectant mothers remain in wintertime, digging outward into the snowbanks that cover them up with the onset of fall. But fires caused by lightning strikes sometimes damage those earthen shelters, causing their collapse, and while polar bears returning from the sea ice will investigate dens in burned areas, they rarely decide to remain there, forcing them to keep searching or, possibly, to dig new ones instead of being able to take advantage of those that have existed for generations. It is yet another expenditure of energy that a pregnant female in particular can ill afford to undergo, but one that may prove increasingly difficult to avoid.

Far to Churchill's northwest, researcher Doug Irish was traveling along the coast of the Yukon in June 1989 when, sticking out of a snowdrift, he saw the head of a dead polar bear. Digging into the snow, he realized that he had stumbled across a den that had collapsed; buried in what remained of the dwelling were two small cubs. Given the extreme care and exactitude with which polar bear mothers choose den locations, such collapses are likely exceedingly rare; but in a world where snow is more prone to melt, or heavy rains take the place of some snowfall, they may become less so.

Yet even the most ideal den location, even the most perfect winter conditions, will be to no avail if, as the ice retreats, as seals diminish and become harder to find, as polar bears become hungrier and ever more desperate, a den is no longer a sanctuary but a target.

In January 2004, researchers flying over denning habitat along the Beaufort Sea coast came across a den that had been broken open. From the den's opening, a trail of blood led to the carcass of a bear. Landing to investigate further, they documented a scene without known precedent. Arterial blood was sprayed along the back wall of the den, into which a great deal of snow and ice rubble had been pushed. Two hundred feet away, the carcass was of a female, the den's occupant. Surrounded by large paw prints, it had been partly devoured.

Examination of a single set of paw tracks shone light in the shadows and completed the picture. An adult male—wandering, meandering, directionless—had suddenly stopped and made straight for the den. Using his massive forepaws, he had smashed through the roof as if it were the lair of a ringed seal. When the roof caved in, the snow buried two young cubs, but the male was after larger prey. His massive limbs held the mother down as he bit at her head and neck, severing her artery and penetrating her skull. Then he dragged her into the open and began to eat her.

Cannibalism in polar bears is not without precedent. It is to avoid this prospect that females keep cubs close by and build their dens far away from areas where male bears are likely to roam. But such incidents as do occur are almost always the result of accidental encounters; when females are killed and sometimes eaten, it is likely in defense of their young. Never before had any of the researchers involved seen anything quite like this, never before had there been any record of a male actively breaking into a den and killing a female.

Three months later, the same researchers followed the tracks of a female which, having lain undisturbed during her denning period, had emerged with one cub in tow. The tracks led to a pressure ridge, where she had lain down in the snow and nursed her cub. It would be the last meal she offered, and the last the cub consumed. Just beyond the ridge, she lay dead, overwhelmed, killed, and eaten by a much larger bear. The tracks of the fleeing cub continued for a short while but then were lost.