Alaska has over 430 species of birds, the largest population of bald eagles in the nation, and the largest land mammal in the world (the brown bear; the polar bear is considered a marine mammal). From pygmy shrews that weigh much less than a penny to gray whales that weigh 16-45 tons, Alaska is the Last Frontier for animals as well as people. Species endangered elsewhere are abundant in Alaska. And that's not all... Alaska has the longest salmon run in the world (2,000 miles up the Yukon), arctic terns that fly 24,000 miles from Antarctica and back, and caribouthat migrate 2,000 miles from Canada to their calving grounds in the Alaskan Arctic. Although Alaska has an abundant variety of wildlife, the land itself is both harsh and fragile. It takes 100 square miles to support one grizzly bear living on the North Slope, and a willow in the Brooks Range may only have a trunk five inches in diameter although it is over 3,000 years old. Alaskan animals are incredibly interdependent with their environment and each other; some hang just a thread from extinction. So who makes up the wildlife in Alaska? Let's check it out