A pine marten, a member of the weasel family, is seen high in a tree, looking away from the photographer. The elegant creature's posture highlights its agility and preference for forested habitats. Pine martens are small, agile mammals that live in forested regions of the Northern Hemisphere—including much of Alaska and Canada. They have slender bodies, bushy tails, and rich brown fur with a lighter patch on the throat. Skilled climbers, pine martens spend much of their time in trees, where they hunt small animals, forage for berries, and use cavities for shelter. Photographer: Sean Neilson