Winging It

Flightless cormorant (Phalacrocorax harrisi)
From Darwin's Zoology of the voyage of H.M.S. Beagle

© AMNH Library

Though it is related to the 35 other cormorant species around the world, the flightless cormorant lives only the Galápagos Islands. And while all other cormorants can fly, this one cannot. Its wings are, however, perfectly suited to swimming—much more useful than flying when searching for octopus, its favorite food.

Before humans arrived on the Galápagos, the cormorant had no natural predators, so it had no need to fly. It was wonderfully adapted to its isolated environment. But when people came, bringing dogs, cats and pigs with them, the defenseless birds were at their mercy. Their numbers have dropped dramatically, and now they are rare.

A Long Way from the South Pole

Galapágos penguin (Spheniscus mendiculus)
Illustration by John Gould, from Darwin's Zoology of the voyage of H.M.S. Beagle Beagle

© AMNH Library

When most people think of penguins, they think of Antarctica, where these flightless seabirds waddle over the ice and dive for fish and krill. But some penguins live on the coast of South America, thanks to a cold, north-flowing ocean current, and one tiny penguin lives in the tropics. Instead of huddling for warmth, it must battle the blazing heat of the sunbaked Galápagos Islands.

The Galápagos penguin is not only the smallest penguin, and the only one found near the equator, but it is probably the only penguin that has to hold its wings outstretched over its webbed feet to prevent sunburn. Once again, Darwin had found an example of a unique species that lived only in the Galápagos, but which seemed to be a modified version of a species from somewhere else—as if it had somehow become specially adapted to its island environment.