Water-oriented birds from every continent flock here in spectacular numbers when brief Arctic summer transforms frozen tundra of the vast Lena River delta into fertile wetlands. Of some 109 bird species in this 9,584-square-mile (24,830-km2) preserve, at least 60 nest on its tens of thousands of islands, lakes, and channels.
Big orange-legged bean geese arrive while snow still covers the 12,352 square-mile (32,000-km2) delta. Then come greater white-fronted geese, black brant and two subspecies of brent (aka brant) geese from Vietnam and Europe. Wild cries of some 7,000 red-throated and 25,000 black-throated loons echo across tundra lakes. Not long after, Sabine’s and pink-plumaged Ross’ gull colonies settle down noisily with green-winged teals, northern pintails, king and Steller’s eiders, and long-tailed and tufted ducks, spotted redshanks, and big, graceful whooper swans. Peregrine falcons swoop from cliffside aeries. Willow warblers with bright blue throats flit through lower vegetation, along with Siberian accentors and Pallas’ reed and little buntings.
Pink and purple carnations blanket river terraces. Reindeer come for rich grasses, followed by wolves. Bighorn sheep and black-capped marmots graze high meadows. More than 6,500 river channels and bypasses offer plankton-rich forage for 36 kinds of fish. Belugas and occasionally narwhals swim in outer reaches—once, a herd of 120 belugas in one channel.
By September it’s all over. In winter, only such hardy species as polar bears, arctic foxes, musk oxen, mountain hares, snowy owls, and willow and rock ptarmigans remain—and Ust- Lensky once again is frozen to a depth of more than 3,000 feet (1,000 m).