Aleutian Cackling Geese, which have a slighter build and shorter beak than Canada Geese, build their nests on a chain of islands off the western coast of Alaska. In the 1700s, fur traders introduced foxes to the islands, nearly wiping out the geese. For decades, they were believed to be extinct. But in the 1960s, a biologist discovered about 300 birds nesting on Buldir Island. Habitat protections have allowed their populations to recover. Learn more at BirdNote.org.