|
Deepseawaters
Home Deep
Sea BirdsPelagic Cormorant
Pelagic Cormorant
Common Name: Pelagic Cormorant
Scientific Name: Phalacrocorax pelagicus
Description
The
Pelagic Cormorant and the Red-faced
Cormorant are two of the three species of cormorants
that nest in Alaska. They differ from the third cormorant
species, the Double-crested Cormorant, in that they are strictly
marine birds. Cormorants are part of a large family of seabirds
that includes pelicans, boobies, tropicbirds, and frigatebirds.
They are diving birds that use their large webbed feet to
swim underwater in search of food. They like to eat a wide
variety of foods but their favorite is fish that live close
to the ocean floor. Their feathers are different from other
diving birds in that they are not naturally waterproof. In
order to waterproof their feathers, cormorants must spend
a lot of time preening or grooming their feathers with oil
they collect on their bills from a gland at the base of their
tail.
Unlike
many other seabirds, cormorants do not like
to stray far from their nesting colonies on land. There they
build large nests out of whatever plant material they can
find and are not above stealing it from one of their unsuspecting
neighbors. Often one bird of the pair will present a piece
of grass or seaweed to its mate as a way
of strengthening their bond.
Pelagic
Cormorants nest on coastal headlands or islands throughout
Alaska and the Asian North Pacific. Red-faced Cormorants nest
in a much smaller region of the North Pacific that stretches
from northern Japan through the Aleutian Islands. Both species
use their own excrement to cement their nests onto small ledges
of vertical cliff faces.
Pelagic
and Red faced Cormorants are not only similar in habits, but
also in their appearance. During the winter they look nearly
identical except the Red-faced Cormorant is slightly larger.
However, in the spring the birds begin to dress-up for the
breeding season and the two species can be more easily separated
by their appearance. Pelagic Cormorants develop a patch of
dark red skin around their eyes and base of the bill. They
often develop long white plumes on their necks. Red-faced
cormorants develop a patch of reddish-orange skin around their
eyes that extends up onto their foreheads and the base of
their bill turns light blue. Both species have two crests
on their heads but these are much more obvious on Red-faced
Cormorants.
Diet
Fish
and crustaceans
Habitat
Ledges
of cliffs, ground on islands. Nests made of seaweed and
guano.
Identification Tips
Length: 22 inches
Wingspan: 40 inches
Sexes similar
Large, dark
waterbird with a long, hooked bill and long tail
Long, thin
neck
Gular region
red
Often perches
with wings spread to dry them
Adult
Entirely dark
plumage except for white flank patch
Two crests
on head
Thin, white
plumes on neck
Immature
Very dark
plumage
Similar Species
Loons
are similar on the water, but lack hooked bills. Most loons
hold their bills level while swimming while cormorants hold
theirs angled upwards. All adult cormorant species in the
U.S. are separable by the shape and color of the gular areas.
No other species has a small red gular region. The Pelagic
Cormorant shares its Pacific Coast range with the Double-crested
and Brandt's Cormorants. Adult Double-crested Cormorants have
orange gular regions and Brandt's have yellow-bordered blue
ones. Immature Double-cresteds and Brandt's have paler underparts
than the Pelagics. The Pelagic Cormorant is noticeably smaller
and slimmer than the other species. The Red-faced Cormorant
overlaps the range of the Pelagic Cormorant
only in Alaska. In the breeding season, the Red-faced
Cormorant has a red forehead and a pale bill.
|
