One of the more heartbreaking moments of the past few years was when we learned that the Spix's macaw, the bright blue bird made popular by the Rio movie franchise, had been declared extinct in the wild.
The good news is that extinctions don't always mean forever. In some cases, it's merely that animals were declared extinct because they hadn't been seen in a long time. In others, dedicated efforts by conservationists have brought species back from the brink.