Eagle on the Edge
Living in the forbidding terrain of Russia's Far East, Steller's sea eagle may be the most impressive raptor you've never heard of
- Lucille Craft
- Sep 01, 2000
With the Moon Still High over Kuril Lake on the Kamchatka Peninsula of Russia’s Far East, Alexander Ladyguin rises in the subzero darkness to light his log cabin’s iron stove and prepare porridge. Ladyguin and his wife, Olga, eat quickly, then set off on skis over billowing snowdrifts to a tiny igloo next to a creek a few miles away.
Ladyguin (rhymes with paraffin) pulls a salmon from the creek, splits it open and arranges the morsel invitingly on a gravel bar beside the igloo. Then he and his wife shovel snow from the igloo´s entrance and wriggle inside. Near a small opening, the lanky Moscow State University ornithologist arrays his camera, tripod, scope and notebook, and he and Olga swaddle themselves in sleeping bags and wait.
Shortly after dawn, a group of massive, white¬-shouldered birds glides over the lake in search of breakfast. Brushing snow from his notebook, Ladyguin watches as they descend to the gravel and begin feeding on the salmon. The birds are Steller´s sea eagles, and although Ladyguin has been studying the species for more than a decade, the boyish¬ looking 33¬ year ¬old scientist still gapes in awe.
"Every bird is a mystery," says Ladyguin. "But to observe such a large, impressive bird very close and very often¬¬ - that´s amazing!"
Ladyguin is one of the few scientists to get such an intimate view of this striking raptor in its Russian habitat. Until recently, the forbidding and remote terrain of Russia’s Far East, where Steller´s eagles dwell, has kept scientists at bay. (A key military outpost during the Soviet era, Kamchatka was off-limits to scientists until the mid-1980s.) As a result, relatively little was known about this bird of prey. But Ladyguin´s work - ¬¬together with that of researchers in other areas of Russia and in northern Japan, where some of the birds winter - ¬¬has allowed scientists to sketch a clearer portrait of Steller´s sea eagle. As the bird comes into focus, disturbing facts emerge: Pollution, overfishing and even tourism are decimating eagles and could wipe out the species in the next 50 years.
One of eight varieties of sea and fish eagles, Steller´s was named after German biologist Georg Steller, who explored Kamchatka and Alaska in the eighteenth century. Weighing as much as 20 pounds and with wings stretching 7 feet, the Steller´s is among the largest of eagles ¬¬out weighing even its sizeable cousin the American bald eagle. Its imposing dimensions are matched by a strikingly patterned plumage, brown¬ black except for white tail, shoulders and crown.
But its prime anatomical advantage over other fis h¬eating birds is a large and deeply arched beak. Placing a Steller´s beak beside that of a falcon, kite or osprey is like setting a hatchet beside a penknife. This lethal tool is ideal for feeding in Russia’s Far East, where the hide of an adult sockeye salmon is so tough that native people use it for shoes and clothing. White¬ tailed eagles, which inhabit the same territory, may struggle for hours merely to pry an opening around a fish’s gills or front fin. Only the Steller´s eagle, with its stiletto talons and fearsome yellow beak, has the hardware to make quick work of leathery salmon skin.
Being a heavyweight in the bird kingdom has its disadvantages, however. A Steller´s eagle can burn off an entire day´s calories by flying for just 45 minutes. To husband their energy, eagles nest within easy striking distance of their prey in lakes, oceans and rivers. They also tend to glide, rather than flap, exploiting updrafts of warm air for lift. Steller´s eagles also resort to "kleptoparasitism"¬¬ - swiping fish from each other. "To steal a caught and opened fish is less ´expensive´ in terms of energy," explains Ladyguin.
Scientists estimate there are a total of between 3,200 and 4,200 breeding pairs, distributed along the Sea of Okhotsk and Bering Sea coasts and the basin of the Amur River. Kamchatka is the most eagle friendly of all these areas and about a quarter of all Steller´s eagles breed and winter here. Buffeted by blizzards from October through May, Kamchatka seems hostile and barren, but it is actually a teeming oasis of wildlife supported by its vast fishery. Kuril Lake at the southern tip of the peninsula alone is the destination for as many as 8 million salmon during the spawning season, from July to March. This bounty sustains thousands of birds of various species through the long winter, including great groups of Steller´s eagles.
Ladyguin first heard about gatherings of Steller´s eagles at Kamchatka while he was a student in Moscow. But only a handful of scientific articles on the species had been published when he decided to make the eagles his thesis subject in 1986. In 1987, he and his wife moved to Kamchatka to undertake the first in¬ depth studies of the eagles there. He lived on the frosty peninsula until 1994, following the birds from their wintering feeding grounds at Kuril Lake to their summer breeding grounds 250 miles north at the Kronotskiy Biosphere Reserve. Since then, he has continued to observe the birds each summer.
From December to March, Ladyguin and his wife watched from their igloo as sea eagles fed at Kuril Lake. The birds roost communally in stands of birch and large rocks near the shore, flying out to the water to dive for fish. As spawning winds down and fish become scarce, the communal roost serves as a communications center. "Eagles flapping in a particular direction will soon catch the attention of the birds still in the roost, and the ´word´ will spread," Ladyguin says.
In mid¬-March, Ladyguin followed the migrating eagles to their summer range at the Kronotskiy reserve, a 3,721 ¬square ¬mile sanctuary that contains the Valley of the Geysers, a popular stop for American cruise ship tourists. There, Ladyguin set up blinds to watch the previously unrecorded nesting behavior of the sea eagles on Kamchatka.
Built in the crowns of trees as high as 70 feet, the nests have a nasty tendency to topple. And the only thing between a fragile egg and gale¬ force blizzards is its mother, which is probably why female eagles weigh as much as about 7 pounds more than males. Leaving the white or bluish eggs uncovered even briefly during the often frigid 36¬ day incubation period spells doom for the young. Of the eggs produced each year on Kamchatka only one ¬third to one ¬half will survive to fledging, not only because of exposure, but also because of predation by sable and collapsing nests.
Eagles supplement their favorite food, salmon, with edibles that wash onto the beach¬¬ - sea cucumbers, octopuses and dead fish. By July, after the young have hatched, the salmon schools have moved inland, in such numbers that sometimes Ladyguin can´t avoid hitting them with his canoe paddle. The scientist watches as eagles dive into the river, emerging laboriously moments later with silver salmon firmly in their talons. The birds fly to the nearest shallows, pin the fish to the ground and tear off and swallow several large chunks of flesh. Once sated, the eagles take the leftovers to their nests, where their offspring wait impatiently.
This gourmet diet of pure salmon is like a magic growth hormone. Ladyguin found that the downy 5¬ ounce nestlings multiply in weight 40 times in less than two months. This prepares them for the long flight to Kuril Lake and other points south, when the lakes in northern Kamchatka freeze over and lock up their food supply.
While Ladyguin was sketching in the details of the raptor’s life in Kamchatka, other researchers were beginning to trace the route of the bird’s travels to and from Russia. For years bird-watchers in Hokkaido, Japan’s northernmost island, had witnessed the arrival of Steller´s eagles each November. But it wasn’t until 1995, when Mutsuyuki Ueta, a researcher with the Wild Bird Society of Japan, and other scientists began attaching small transmitters to chicks at Russian nesting sites around the Sea of Okhotsk, that their migration was fully understood. Ueta and others were surprised to learn that few Kamchatka eagles end up in Japan. Many of the nearly 2,000 wintering eagles in Hokkaido hailed from the Amur River area, with some traveling from as far north as Magadan, on the Russian mainland. In recent years, Japan has become merely a way station in the fall, as the eagles continue east to the fish ¬rich southern Kuril Islands off the coast of Hokkaido. But as snow and ice put the Kuril fish out of reach, the eagles fly back to Hokkaido for the remainder of the winter.
The few months before spring thaw are a struggle for the sea eagles. Most rivers on Hokkaido are fishless because of weirs placed downstream to collect salmon. Eagles in the 1980s survived for a few years by consuming turbot, cod and walleye pol lack either lost from fishing nets or discarded by fishermen. But as fisheries have declined in recent years, the eagles were left without a food source. Their response surprised bird experts.
Researchers downloading satellite data at Wild Bird Society of Japan headquarters in Tokyo were baffled one spring day in 1995 by the signals coming from one of the sea eagles. "We thought all Steller´s eagles stayed near the ocean," recalls Ueta, "but we noticed one had moved inland and had stopped moving." The researcher dispatched a local colleague to investigate. He discovered the eagle consuming the remains of an Ezo deer, which scientists surmised had become the best option in the absence of fish. Later that year, scientists found the carcass of a Steller´s eagle, poisoned by lead shot ingested from a deer abandoned by hunters. Since 1995, more than 50 poisoned Steller´s eagles have turned up on Hokkaido. "The actual number of these eagles dying and going undiscovered are likely many times the number recovered," writes Keisuke Saito, a Hokkaido¬based ornithologist. "We suggest that this level of additional mortality would have a severe impact on the population size of the species and could lead to a serious decline."
Prodded by concerned citizens, Japan´s Environment Agency announced a ban on lead shot starting in November 2001. Hokkaido hunters have been asked to switch to copper bullets voluntarily before the law takes effect. But because the ban is so limited in scope¬¬ - on the island of Hokkaido it covers only deer, not bear, ducks or other game - ¬¬and because there are no rangers to enforce it, Saito is skeptical that the action will help the eagle.
Interested in learning more about Steller´s sea eagles and what is being done to protect them? Check out the Web site for the International Working Group for the Steller´s Eagle Conservation.
Ueta is more sanguine about the lead shot ban, but points out that other threats could wipe out Steller´s eagle in just a few decades. He believes the eagle’s natural food source should be restored, to reduce its dependence on unreliable and often contaminated human food sources. Scientists and outdoors enthusiasts are now urging Hokkaido authorities to remove river fish-catching devices and restore the salmon runs. In response, some of these weirs have been dismantled.
Threats to Steller´s eagles lurk outside of Japan, too. Autopsies on eagles in Hokkaido show PCB and DDT levels similar to those in raptors in North America and Europe, says Hajime Nakagawa of the Shiretoko Museum. Nakagawa found high levels of toxic chemicals in the industrial cities of Khabarovsk and Magadan, implicating those areas in the poisoning of the eagles. This contamination may be connected to increased sightings of dead chicks under nests in recent years, experts say.
Back on Kamchatka, the threat to eagles is more subtle, yet no less worrisome. A surge in tourists, hunters and fishermen has Ladyguin and other experts scrambling to come up with a management plan. Ladyguin says eagles require about 11 minutes of undisturbed feeding time in winter and four times that in summer (when food must also be obtained for eaglets) to meet their daily caloric needs. Merely the sight of people, however, often sends eagles fleeing from their feeding sites and thus poses a threat to survival. Trappers attack the eagles, which steal fur¬bearing animals from traps. These and other human intrusions can prompt eagles to desert their nests, giving predators a chance to grab eggs or eaglets. The only solution, Ladyguin says, is to keep nesting and feeding areas off¬ limits to visitors.
The scientist recalls dusk on Kuril Lake, when the wintry winds had subsided and the lake´s resident symphony began its overture: the cawing of ravens and eagles, the trumpeting of swans and the gentle splashing of salmon. For a few sublime moments, Ladyguin felt he and Olga were a modern ¬day Adam and Eve. Unlike his Biblical counterparts, however, Ladyguin is painfully aware that for the sake of its larger¬ than¬ life eagles, this Garden of Eden must be defended.
Lucille Craft is a Tokyo-based correspondent for U.S. public radio and television.