Galapagos Flightless Cormorant
The Perfect Study of Species Adaptation
What a wondrous creature — the Galapagos Flightless Cormorant (Phalacrocorax harrisi). There is nothing like it anywhere else in the world. It epitomizes the meaning of species adaptation and is one of the most unique and interesting birds anywhere on Earth. With its long neck, grace and gentle demeanor, it’s a favorite attraction for all Galapagos visitors. Look at those piercing blue eyes.
There are cormorants found all over the world and all species of cormorant are marine birds that source their food from the sea. With one exception — our distinctive and remarkable cormorant — cormorants fly above the ocean and dive down to catch the fish on which they survive. Once, our cormorant too flew, just like the other 27 species of cormorants found around our planet. Yet, over time, our special and beautiful creature evolved and adapted to the rugged and arid volcanic terrain surrounded by salt water that defines the Galapagos Islands.
Over the millennia, our cormorant stopped flying and started swimming for its sustenance. When flying became a skill it did not need for survival, it adapted. When it could successfully hunt for food and avoid predators without flying, it preserved its energy and its wings atrophied into complete disuse. Instead, waddling and swimming became its means of locomotion. It became the world’s only flightless cormorant. There are two likely causes for its adaptation: First, the cormorant does not need to go far for its food, preferrably squid, octopus, eel and small fish, all found within about 100 meters of the shoreline. Second, it has no natural large land-based predators from which it has to take to the sky.
It makes perfect sense when you think about it. Ask yourself this: “Why use all that energy to fly when you can stand around and take a short swim before returning for a little rest, a little breeding and more standing around in the sunshine?” Maybe you’d choose to adapt too!
Of great interest to me is the fact that no flying cormorants remain anywhere in Galapagos. Every single one of them became extinct, to be replaced by this bird that cannot fly, an anomaly in itself. And now, the flightless cormorant is at risk and considered “vulnerable” by the International Union for Conservation of Nature. This classification means that the flightless cormorant is likely to become endangered unless the circumstances threatening its survival and reproduction improve. Consequently, though not at this time labeled as endangered, the flightless cormorant is the object of a thorough conservation effort here to regenerate the species.
The species is so rare that there are only about 1500–1600 birds remaining throughout the archipelago, and those few live only on the shores of Fernandina and Isabela. They swim in the colder Cromwell and Humboldt Currents.
The physical adaptations to the bird’s body have occurred to make the cormorant an excellent swimmer and forager in the water. If you have read my post about the Penguins on the Equator, you will recall that a penguin propels itself by using its front wings (fins) as paddles. The cormorant, instead, uses powerful kicks of its legs, but its wings do little work at all. Most avians have a strong keel on their breastbone to support the relatively heavy muscles that birds need to fly and to support their wings. Unlike them, the flightless cormorant doesn’t need this heavy musculature because its wings are stunted — just about 1/3 the span and weight of typical bird wings. Instead, a flightless cormorant has substituted a heavy and powerful lower body for a strong upper body. With this power, the cormorant quite literally propels itself through the water by kicking its legs through the current. It’s particularly impressive to see a cormorant under water. It is very fast and appears to dart around searching for its prey.
Even though Galapagos cormorants cannot fly, they have a quirky behavior that remains as a vestige of its past. This particular behavior has not changed as the cormorant adapted to its peculiar Galapagos environment. All other species of cormorants dive under water for their food. But, their wings are not waterproof and do get heavy. As a result, when any “typical” cormorant emerges from the water, before it takes off to fly again, it takes a break, opens its wings and air dries them, reduces weight and adding heft and lift. That makes sense if for a bird that is about to undertake another flight across the ocean and needs to maximize its wing potential.
But, wing-drying behavior doesn’t really doesn’t make evolutionary sense for an avian that is going to jump right back in the water. While there is no good reason for it, Galapagos flightless cormorants have never given up the act of stretching out their stunted wings into the sun to dry. Often, you will see these guys, like the one in the photo above, with their scrawny wings outstretched drying in the air, a vestige of their earlier days of flight.
On the other hand, the flightless cormorant’s body feathers have evolved to accommodate their time in the water. Their feathers are downy and far more luxurious than those of the non-flying cormorant types. The Galapagos cormorants have thick, soft and dense body feathers to protect their bodies from the water and to give them buoyancy. When air gets trapped in their dense feathers, it helps them float, like a protective vest.
I’ve observed the complex and unique courtship ritual between a male and female flightless cormorant — rare behavior to catch in progress, but equally fascinating and spell binding. Here is one of my favorite videos made available on You Tube by Galapagos Expeditions. It is beautiful and very special footage of two flightless cormorants preparing a nest for their eggs.
Occurring July though October, the cormorant’s courtship ritual and behavior appears to humans as tender and gentle, even dance-like. Necks bob up and down in unison; a male brings gifts like sticks and grass to a female until she responds to his advances. The pattern begins in the water and then continues on the land.
As you can see from the photographs, the birds have long graceful necks to help them reach their food source. In the course of the mating ritual, they bend their necks in a snake-like “S” shape and swim around each other until the male leads the female onto the shore. The male will lead, and can be seen looking back at the female to assure that she is following him; all the time he is displaying his long neck.
Together, the pair selects a spot on which to construct a nest, generally in a breeding colony consisting of about 12 cormorant pairs. They really are an industrious couple. The nest building project is undertaken by the male and female together. The male forages and brings back items to the female. She, in turn, incorporates the male’s offerings or “gifts” into the nest. Ultimately, the nest will consist of many types of natural materials such as sea weed, sea urchins, starfish, sticks and dead fish; sometimes unnatural elements such as bits of rope or other human garbage unfortunately get to be a part of a nest as well.
Once the nest is built, the female lays three eggs. Then, together, the pair protects and incubates the eggs, often taking turns and sometimes staying together. Incubation takes about one month; typically only one of the three eggs will survive. It takes about 6 weeks of feeding, again shared by male and female, before the chick is able to fly. As soon as the chick is sufficiently independent, the female takes off to find another male with whom to breed, leaving the first male in charge of the chick. It is because of the female’s ability to breed about three times a year that the flightless cormorant has recovered from natural occurrences such as El Nino and unnatural interference such as introduced species (goats, cats, etc.)
The flightless cormorant, like so much here in the Galapagos Islands, is unique and awe inspiring.
Harry Jiménez, Owner and General Manager
Galapagos Eco Friendly
Av. 12 de Febrero y Av. J Roldo
San Cristobal Island
Galapagos, Ecuador SCY
Reservations: 593 052 520 124
Email: info@galapagosecolodge.net
A version of this article was published previously at blog.galapagoslodge.net.
