Charles Darwin spent a mere five weeks in the Galapagos and during that time was more interested in the volcanic nature of the islands than its wildlife. But one of his assistants gathered specimen birds. Only later, as Darwin looked at these, did he realize that there were 14-15 different species of finches (actually today they are classified as tanagers, but the ones in the Galapagos are still called finches). Each island, with differing rain fall, vegetation, insects, seeds, etc had evolved a different "finch." The notable difference in these birds is the beak, each different to handle the different diet.
A number of sub-species of birds are found only in the Galapagos Islands. Some of the birds are slight variations on birds we know in North America, others from the southern hemisphere. A few take on characteristics which make them markedly different from the rest of their species.
The cormorants of the Galapagos are flightless. They feed in the waters bordering their islands and have no need to fly. Here one preens its feathers.
Below are photos of Galapagos Brown Pelicans. Although avid birders will note the differences from other Brown Pelicans, the bird is easily recognizeable as a pelican like the ones I knew growing up along the west coast. These days I am more accustomed to Yellowstone's White Pelicans.
We usually associate penquins with Antartica and very southern South America. The Galapagos Penquin, one of the smaller penquins, is the most northerly of all penquins. Like their cousins to the south, they do not fly, except that their speed underwater resembles flying. The cold Humboldt Current which reaches the Galapagos is the reason they can survive so close to the equator.
I loved watching Frigate Birds....one above on the rocks and another in the air. The forked tail is an easy way to identify them in the air.
Blue-footed Boobies are one of the favorites of the Galapagos. I am not sure how the blue feet and bill figure into the natural selection scenario and how it helps the bird in its adaptation, but the feet are a blue color seldom seen in the animal kingdom