In the 1940s the short-tailed albatross population plummeted from tens of millions to such a small number that they were believed to be extinct. Their decline was due to hunting for their feathers and damage to their breeding islands from volcanic activity. Keeping track of these migratory birds can be difficult. They nest and breed on islands off of Japan and then fly to the west coast of the United States. Today they aren't hunted, but they are often caught mistakenly by longline fishing gear. In 2008, it was estimated that only 2,000 of the birds remained. See more endangered ocean species in our slideshow.