Although extremely odd to us, flightlessness was actually quite common among birds inhabiting isolated oceanic islands. Several famous examples, unfortunately now extinct, are the flightless goose of Hawaii, the dodo of Mauritius and the moas (and many other flightless birds) of New Zealand. As a matter of fact, unless a bird needs flight to feed, the loss of flight is extremely beneficial if there is a lack of predators and no need to commute, as flying requires so much energy.
Once a mutation in the wings occurred, this gene spread easily among the small population of cormorants, to whom it conveyed a definite advantage. A curious thing, however, is that even though they cannot fly anymore, they display what is termed "relic" behavior, in that once out of the water they stretch their wings out to dry just like cormorants the world over.
While all other oceanic islands have sadly lost these strange and wonderful examples of adaptation because of invasion by humans and their domesticated animals, the Galapagos still retains every one of its original inhabitants. This is because of the inhospitable nature of the archipelago, which over the centuries has luckily preserved its pristine state.
