Yellow-Billed Loon

SCIENTIFIC NAME: Gavia adamsii

STATUS: Petitioned for threatened status

HABITAT: Large lakes in the high arctic tundra (spring/summer); coastal waters in bays and inlets and among island groups (winter)

LIFE HISTORY: Pairs are monogamous and share responsibility for rearing the young; nests in mid-June on islands or shallow areas

THREATS: pollution, habitat loss and human disturbances such as oil and gas development

RANGE: Northern Alaska, the northern Northwest Territories and Nunavut (spring/summer), to the marine offshore waters of southern Alaska and British Columbia (fall/winter)

CURRENT POPULATION: 3,000 to 4,000 in Alaska; global population estimated at 17,000

This superb diver can stay underwater for a minute and a half . It's the largest and probably the rarest of all loon species, numbering around 17,000 individuals. Yellow-billed loon nesting sites are scattered across millions of acres of fragile Arctic tundra -- much of which is in prime oil and gas drilling territory. Once displaced from their habitat, the birds are slow to re-colonize. What's more, their fish-based diet makes them particularly vulnerable to mercury pollution and contamination from oil spills and toxic solvents used in oil drilling.

NRDC filed a petition to list the yellow-billed loon under the Endangered Species Act, and the petition is now undergoing a status review.

Photos: Alaska © PhotoDisc; polar bear © Steve Amstrup, Alaska Image Library, USFWS; spectacled eider © Chris Dau, Alaska Image Library, USFWS; steller sea lion © Donna A. Dewhurst, Alaska Image Library, USFWS; beluga whale © Corbis; yellow-billed loon © Getty Images