Portrait of a 'sea parrot'

The puffin is nicknamed the 'sea parrot,' but the brightly colored bill that lends it that title is only present for part of the year. A puffin's beak will become awash with reds and oranges just before breeding season, when puffins form nesting colonies of hundreds, thousands, or even millions of individuals. The beak's size and the depth of its hues signal whether a bird is a healthy mate. Once the year's young are raised, the beak's outer layer is shed to reveal duller colors. Each pair of new puffin parents then part ways—but these monogamous creatures usually return to each other season after season.