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Cormorants are pelican-like water birds with fully webbed feet and a throat pouch that can expand to accommodate large fish for swallowing. The flightless cormorant is a peculiar species that only inhabits the Galápagos Islands. This species is the only cormorant in the world that cannot fly. Flightless cormorants are also the heaviest of the cormorants, measuring around 35 to 39 in (89 to 100 cm) in length and weighing 5.5-11.0 lbs (2.5-5.0 kg). Males are about 35% heavier than females. Their limited habitat is tied to a few places where cold currents provide a sufficient
food supply. Within the Galapagos Islands, they are only found on Fernandina Island (primarily the east coast) and the northern and western coasts of Isabela Island. Scientists believe that over the years, this cormorant species gradually lost the ability to fly because of having abundant food sources nearshore and lacking terrestrial predators. Individuals that were better suited to swimming were more successful in passing on their genes. Their wings are about one-third the size needed for flight. Their bill is long and strong. Adults are black on top and dark brown underneath
with bright turquoise eyes. Like other cormorants, their feathers are not waterproof, so they can often be seen holding out their small wings to dry after diving. Their feathers are denser and softer than those of other cormorants. They are excellent swimmers and divers, using their powerful webbed feet to propel themselves underwater. Their wings are too small to be used as flippers. When they wish to dive they make a small leap up and out of the water before diving straight down. Their diet consists of octopuses and fish. Their flexible neck helps them to nab prey from crevices
in reefs and rocks. Since males are heavier, they can dive deeper and catch bigger prey. Even when hunting, flightless cormorants stay close to the shoreline. The are nonmigratory. They are known to be quarrelsome and territorial. They can be aggressive towards humans that are in the water. They can breed year-round, but most eggs are laid between May and October, during the colder months when marine food is most abundant. They have an elaborate courtship ritual which usually starts in the water with an aquatic dance, in which couples swim back and forth past each other,
with their necks bent into a snakelike form, making low growling sounds. The dance is then continued on land. They then build a nest near the sea, usually in a sheltered area among the rocks. Snake-necking is also used as a greeting ceremony between a pair with eggs or young. They nest in small colonies. Their nests are exotic collections of seaweed, twigs, fish bones, starfish, and whatever else the male offers to the female. Females typically lay two or three whitish eggs per clutch, but only one chick usually survives to maturity. Some eggs are sterile,
some are preyed on by Galapagos hawks, and in most cases, the smaller of the nestlings dies of starvation. Egg incubation takes about 35 days. Juveniles have dark, rather than turquoise, eyes. Initially both parents feed the young regurgitated food. A unique breeding behavior is that the female may desert the male about two to three months after the eggs hatch to find another mate and attempt to breed again. This only happens when food is plentiful. The male is then left to care for the young alone for five to nine months until they fledge. This "staggered brood"
approach is a solution to the unpredictable food environment. The current population of flightless cormorants is roughly estimated to be around 2,000 individuals. Due to their limited range, they are highly vulnerable to environmental changes like El Niño events, which have caused significant population reductions in the past. On land, they face threats from natural predators like snakes, owls, and hawks, as well as introduced species such as cats and rats. In the sea, they may be preyed upon by sharks or become entangled in fishing gear. Conservation efforts, including controlling invasive species and monitoring populations,
have helped to keep their numbers stable. For more marine facts, click the SUBSCRIBE button!
