Paradox of the Arctic Fox
This cunning animal's appetites are a powerful force in Far North ecosystems, and once human beings get into the act, the fragility of those ecosystems becomes all too clear
Out on the flower-spangled tundra, the fox hesitated; and in the indecision of that raised forepaw, researcher Alice Stickney felt that she could read the small predator's thought: Two eggs, one mouth; there must be a way!
It was an arctic fox — a male Alopex lagopus. By November, he would skitter across the polar ice like a ball of pure white fluff. But now, in his brown-blotched summer coat, he looked rangy—even haggard. And with those circles of dark fur under his eyes, he appeared to Stickney more the villain in character with what he was doing: stealing eggs from wild sea goose nests on Alaska's Yukon River Delta. "His problem," the biologist recalls, "was that he had stolen one black brant egg and was trotting off to cache it somewhere, when he passed a second egg. He paused, moved on, then stopped and went back. You could see him teetering on the horns of dilemma. Here was an animal genetically programmed not to pass up an egg." The fox finally made its call with what seemed to Stickney — a biologist for ABR, Inc., of Fairbanks, which has conducted fox behavioral studies for oil companies — to be perfectly foxy logic. He simply dropped the cream-colored egg he carried, picked up the second and sallied resolutely on across the wet Arctic green.
In Native lore, the white fox is neither clever nor cunning. It is a harmless sprite of the long northern night, a cheery escort with a saucy bark that announces the arrivals of polar bears. And with lightsome feet, the fox escorts the souls of children to the swirling, heavenward dance of the aurora borealis. But poignancies aside, the creature's appetite for eggs and birds is a powerful force in Far North ecosystems. And once human beings get into the act, whether by fox farming on islands or by overhunting waterfowl, the fragility of those ecosystems becomes all too clear.
Says Vernon Byrd, supervisory wildlife biologist for the Alaska National Maritime Wildlife Refuge, "We know that foxes take thousands of eggs and birds from refuge islands each year. And it's millions we're talking about over the years." Byrd and coworkers have spent two decades working—with considerable success—to restore bird colonies wiped out by fox populations established for fur farming between 1750 and 1950 on more than 450 islands. All concerned agree that removing introduced foxes from the islands is a biologically sound correction of human mismanagement.
On the mainland, however, foxes are indigenous, their relationship to bird colonies snore complex and human intercession far less easy to justify — much less pull off. In the late 1970s and the 1980s, after decades of slow declines, four nesting goose species on the Yukon-Kuskokwim Delta reached unprecedented lows. The reason was largely overhunting by people, which took place at both ends of the birds' migratory paths. And the hunting, says Tom Rothe, waterfowl coordinator for the Alaska Department of Fish and Game, "pushed the populations down to the level where other factors kicked in."
One of those factors was the arctic fox, which was going through a population boom. "In no way do we want to suggest arctic foxes caused the decline in geese," Rothe says. "But it's fair to say they suppressed the recovery." The hunting is now limited by more restrictive regulations and the Yukon-Kuskokwim Delta Goose Management Plan formulated with rural hunters in Alaska, and the goose populations have largely recovered. Says Rothe, "Eventually, the geese outnumbered the ability of foxes to hold them back. The bottom line is that normally arctic foxes don't control bird populations. Only if the foxes are on an island or if goose populations get very low do foxes have an impact."
But it appears that people can alter the fox-bird equilibrium in other unintended ways too. Take the growing number of landfills and dumpsters in some Far North areas. "Because of the steady food supply from the accessible garbage, more foxes survive the winter and have more pups, and come summer they eat more birds," says Robert Burgess, senior research biologist and coworker with Stickney at ABR.
Foxes have been known to sit up begging for food when oilfield workers leave their pickup trucks. One snow goose colony that sprang up on Howe Island near Prudhoe Bay in the early 1970s now numbers about 500 pairs, but the birds and their young have suffered the consequences of living near an Arctic human enclave. Garbage draws the wide-ranging foxes, which then scout for more food, crossing the ice to the island in spring for newly laid eggs, ambushing families moving to mainland rearing areas and taking flightless adults during the molt.
Arctic foxes are dimorphic, in that the same species can occur with winter coats of either white or blue. Most are white, with various censuses estimating the blue fox phase at 2 to 7 percent of the total. Populations of the white variety are concentrated on the coastal plains of circumpolar regions. The blue fox phase exists mainly near bird colonies, probably because the dusky color is a better camouflage among the cliffs and rocks.
More typically, an arctic fox is tundra brown in summer, ice white in winter, and its waking life is a restless foxtrot punctuated by quick pounces. White foxes will steal eggs from tundra-nesting waterfowl and shorebirds, but for the most part, they depend on lemmings, voles and scavenged carcasses of sea mammals.
If the Arctic's four-year lemming cycle is low, only one or two pups might survive the average whelping of seven. But if the cycle is high, as many as 15 pups are born, and most will survive. Their 8-pound parents spend the summer with legs a-blur, snatching rodents they then deliver to the pups or to caches. In winter, hungry foxes may gather at the heels of wolves or polar bears, traveling many hundreds of miles to scavenge the leavings of the larger predators' kills. Biologist Byrd reports seeing as many as 50 foxes at a walrus carcass. Canadian researcher Fred Bruemmer reports arctic foxes "eating tunnels into the corpse of a 60-foot whale, until the colossal carcass resembled a Swiss cheese."
Ed West, a biology professor at the University of Alaska in Anchorage, can chuckle now at the memory of himself chasing arctic foxes across the tundra of an Aleutian island a few years back. "I had spent weeks setting up this field research project," he says. "I had packed in and set up a Weatherport base, installed an oil stove and tables, stocked it neatly with food, and then gone back to the mainland to get my wife." He came back to find the foxes had gotten to it all. "Food, clothing, candles—it didn't matter. They had everything in the place ripped open and ripped apart and had spread a healthy layer of defecation over the whole mess. When we walked in, I remember there was this one little fox in particular sitting in the mess on my bed, and he just cocked his head and said with a look as plain as English: 'Oh. And just what are you?"
The bird-predating blue phase foxes, however, don't have to be so opportunistic. Each spring, seabirds come, lay eggs, rear their young and leave. Colonies of gulls, cormorants, murres, auklets, guillemots and puffins in all circumpolar regions draw resident blue foxes that systematically collect eggs, fledglings and adults.
Both types of arctic fox cache food for retrieval during the bitter winter. The white tundra foxes are known as "scatter cachers," often burying their summer surplus where they find it. Their blue-phase kin, on the other hand, store their harvests in centrally located and often impressively stocked "larder" caches.
Prior to their introduction by fur farmers—by Russians as early as 1750, and by Americans as late as the middle of this century—no foxes existed on the Aleutian Islands, nor on most of the other Alaskan islands to which they were introduced. The foxes were transplanted to the islands simply because the vast avian colonies were a natural smorgasbord. Then barrels of "fox fodder"—voles and ground squirrels that later caused severe erosion problems—were introduced to supplement the bird diet.
The results, says Edgar Bailey, a U.S. Fish and Wildlife Service (USFWS) biologist who has spent decades monitoring fox and bird activity, were "devastating." By the mid-1920s, with fox prices soaring to up to $2,800 a pelt and harvests from the Alaskan farms totaling tens of thousands of pelts per year, foxes were killing 40,000 or more seabirds per island per year. Entire colonies of burrow-nesting seabirds like storm-petrels, Cassin's auklets and tufted puffins were wiped out. Mobs of gulls and auklets, murrelets, storm-petrels, terns, puffins, loons, black oystercatchers and others disappeared. Sky-clouding flocks of common eiders faded to wisps.
In the 1970s, USFWS biologists began the fox-eradication program. "It's going to take awhile," says Byrd. "But with the exceptions of some populations that were completely wiped out, there's no reason to think that the rookeries won't rebuild to their old levels." Though the Aleutian Canada goose, for example, is now federally listed as threatened, its recovery is nearly assured.
On the Yukon Delta, however, if waterfowl populations were to drop precipitously again, solutions would not be so easy. "It's easy to know what to do with artificially introduced foxes on islands," says researcher Stickney. "It's another matter entirely to deal with a species in an established ecosystem." Especially ecosystems as delicate as those of the Far North's wetlands and a species as far-ranging as the arctic fox. As long as people insist on being in the tundra, they're going to have neighbors that are a bit cheeky and a bit sneaky—but also are fluffy, yappy celebrations of life in what can be such brutal country.
For More On Alaska
When predation by arctic foxes slowed the recovery of overhunted geese populations on the YukonKuskokwim Delta in the 1980s, that relationship helped illustrate the fragile balance of the ecosystem, as well as the vital importance of the state's 175 million acres of wetlands to both the birds and the foxes. One of NWF's primary issues in Alaska is protection of wetland habitats. If you would like to stay informed on Alaska wildlife and environmental issues, write: Alaska Natural Resource Center, NWF-NW, 750 West Second Avenue, Suite 200, Anchorage, Alaska 99501.
Author of Leaving Alaska (Grove Atlantic, 1994), Grant Sims freelances in Corvallis, Oregon.
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