Nicknamed "the seabird crossroads of the Atlantic," Newfoundland's Grand Banks teem with marine life that attracts 35 million seabirds each year.

In early spring, before breeding season, eiders gorge on mussels, crabs, sea urchins and starfish, storing fat for the month they will spend nesting. Loons swallow fish and crustaceans—as well as small pebbles, which help to grind up the bones and shells. Shore-hugging surf scoters dive through waves to snatch small animals and plants, while razorbills and puffins swim after fish and crustaceans that live near shore, close to the land where these birds will soon lay their eggs.

Birds of the auk family, including puffins, power their underwater dives by flapping their stiff, flipperlike wings. © AMNH

Different Strokes
Diving birds share many adaptations, including webbed feet and bones that withstand crushing water pressure. But these pursuit divers have evolved two different strategies for descending to the depths.

Birds of the auk family, including puffins and razorbills, power their underwater dives by flapping their stiff, flipperlike wings. Using wing power alone, these birds pursue fish and other prey to great depths; some auks dive to more than 150 meters (500 feet). An extinct relative of these birds, the great auk, could not fly, but the wings of these modern auks propel them through air as well as water.

The common loon is an excellent swimmer and diver. Its webbed feet and powerful legs propel it underwater to depths of 60 meters (200 feet). © AMNH

Common loons, too, can plummet deep beneath the surface—but it's their large, webbed feet that provide all of the propulsion. Loons' bodies are streamlined to slice through water with their wings held tight at their sides.

CONSERVATION: Fowl play
For centuries, Newfoundland's Grand Banks were renowned as one of the world's most prolific fishing areas. But starting around 1950, giant trawlers hauled up ton after ton of cod; within decades, the population collapsed. Today these fish remain alarmingly rare despite a 1992 cod fishing moratorium. Some scientists thought that such a dramatic change to the ecosystem was bound to affect the Grand Banks' other inhabitants, but it appears that diving birds—and the smaller fish and animals that make up most of their meals—are still plentiful.

Other threats to the region's birds are clear. Isolated nesting spots, undisturbed by people or mammalian predators, are becoming scarce. Laws limiting hunting are hard to enforce. And perhaps the biggest threat today comes from oil spills, which can kill thousands at a time by poisoning the birds or coating their feathers so that they lose their insulation against the icy waters.