Galapagos Islands birdwatching - flightless cormorant

The Galapagos flightless cormorant evolved in an isolated island environment that was free of predators.The birds had no need to fly and eventually became flightless.

This unique variety of cormorant lives in the westernmost islands, Fernandina and Isabela, where there is plenty of food and nesting habitat for this unusual seabird. In islands with plenty of food and safety, the cormorants had no practical use for their wings and, simply, by means of natural selection, became flightless. Most of the predators being at sea the cormorant with smaller wings became a better swimmer. 

The flightless cormorant (Nannopterum harrisi) is the only cormorant (family Phalacrocoracidae) found in the Galapagos, and of the 27-28 cormorant species world-wide, it is the only one that has lost the ability to fly. So unusual is the flightless cormorant by comparison to other cormorants, that most authors place it in a separate genus - all other cormorants belong to the genus Phalacrocorax. Like other flightless birds, the keel on the breast bone, which supports the large flight muscles, is drastically reduced. Instead, the legs are heavier and more powerful than in other cormorants. Unlike the penguin, whose wings are used as paddles to literally fly through the water, the flightless cormorant propels itself by powerful kicks. The birds feed no more than 100 m offshore, feeding near the bottom on squid, octopus, eel, and fish.

However, the Galapagos Islands have not remained free of predators, and, consequently, this cormorant is now one of the world’s rarest birds. 

Through the years, dogs, cats, and pigs were introduced to the Islands and have had a drastic effect on the cormorant population. As well, these birds had no fear of man and could be easily approached and picked up. There are now only about 1,000 flightless cormorants left and the species is listed as rare.  Nevertheless, it is not considered to be endangered.

Flightless cormorants have a complex courtship behavior which begins in the water and then continues on shore. The pair swims around each other, their long necks bent into a snake-like figure. The male then leads the female ashore, turning back towards the female, and assuming the snake-neck posture. The pair builds a nest composed of sea weed, sea urchins, starfish, and dead fish, and the male continually brings "gifts" to the female, which she incorporates into the nest. The female lays three eggs, though usually only one chick survives. Both male and female share in incubation.

Once the eggs have hatched, both parents continue to share responsibilities of feeding and brooding (protecting the chicks from exposure to heat and cold), but once the chicks are old enough to be independent, and if food supplies are plentiful, the female will leave the male to carry out further parenting, and she will leave to find a new mate. Females can breed three times in a single year. Thus, although their population size is small, flightless cormorants can recover fairly quickly from envirnomental disasters like el Nino.