Species are declared extinct when there have been no verifiable sightings for 50 years. Declaring a species extinct has implications for conservation efforts and policies.
There are no more ivory-billed woodpeckers or Bachman’s Warblers on Earth, but they’ve left an echo behind.
It’s been 80 years since the last undisputed sighting of the striking black-and-white bird. The U.S. government believes the ivory-billed woodpecker is extinct — but many will keep searching for it.