Flightless Cormorant
 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. One year I was snorkeling
off of Fernandina and turned back to check on my snorkeling partner
when I saw a cormorant dart past. Its speed was impressive. The
birds feed no more than 100 m offshore, feeding near the bottom
on squid, octopus, eel, and fish. The loss of flight is probably
related to both an absence of natural predators in the Galapagos,
and to a restricted feeding area. They are only found on the coastline
of Fernandina and the northwestern shore
of Isabela, where there are upwellings
of the cold Cromwell and Humboldt currents. The flightless cormorant
is among the rarest of the Galapagos sea birds with a population
size of only around 800 pairs. Nevertheless, it is not considered
to be endangered.
Although all cormorants feed underwater, their
feathers are not completely waterproof. Thus, upon emerging from
the water, they typically stand for some time with their wings
outstetched to dry. Flightless cormorants preserve this behavior,
and it is not uncommon to see them standing with their stunted,
scruffy-looking wings held out. The flight and contour feathers
are much like those of other cormorants, but the body feathers
are much thicker, softer, denser, and more hairlike. They produce
very little oil from their preen gland, and it is the air trapped
in their dense plumage that prevents them from becoming waterlogged.
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. They have
been known to incorporate bits of flotsam such as rope, bottle
caps, and plastic six-pack holders. In 1998, I saw a nest in which
the pair had incorporated a dead marine iguana! The female lays
three eggs, though usually only one chick survives. Both male
and female share in incubation. I observed the owners of the marine
iguana nest trade places. The male had been sitting patiently
on the nest when his mate emerged from the water. She slowly ambled
over to the nest and stood in front for about 15 minutes with
her wings outstretched. She then stepped on to the nest and they
exchanged some coarse grunts, the only vocalization these birds
make. The male got off the nest, walked over to the water and
dove in.
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.
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