One way to go extinct: Be delicious and clumsy. Or, in the case of the dodo, just be extremely easy to catch, and nest on the ground where newly-introduced dogs and rats can easily eat your eggs. Dodos were not particularly tasty, but they had easy-to-cure meat, and were fat.
Top Left: Great Auk
Top Right: Spectacled Cormorant
Bottom: Dodo Bird
Extinct Birds. Hon. Walter Rothschild, 1907