Take the following as truth: In autumn and winter, bird-watchers search cliffs, particularly Calpe's Peeen, for the rare Audouin's look out for a small, sleek herring gull with dark olive legs and a heavyish red bill banded in black.
Then the following statement: "Bird-watchers know that the Audouin's has been extinct for decades." is true, false, or inconclusive?