Cormorants and Anhingas: Phalacrocoracidae

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CORMORANTS AND ANHINGAS: Phalacrocoracidae

GREAT CORMORANT (Phalacrocorax carbo): SPECIES ACCOUNTS
AMERICAN ANHINGA (Anhinga anhinga): SPECIES ACCOUNTS

PHYSICAL CHARACTERISTICS

The thirty-six species of cormorants are sleek, long-necked, dark waterbirds. They are good at flying and swimming, but they are clumsy when walking. Their length is between 19 and 40 inches (48 and 102 centimeters) from their bills to the end of their tails. Some weigh just 1.5 pounds (0.7 kilograms) and others weigh up to five times as much: 7.7 pounds (3.5 kilograms). Their long, thin, hooked bills have a saw-tooth edge. The Galápagos cormorant is unusual because it has stubby wings and cannot fly.

The four species of anhingas (pronounced an-HING-guz) are similar to the cormorants, but they have even longer necks. In some parts of the world, they are called darters. Their bills are sharply pointed (not hooked) and bright yellow. Their length from their bills to the end of the tails is between 34 and 36 inches (86 and 92 centimeters). They do not have oil glands for waterproofing their feathers.

GEOGRAPHIC RANGE

Cormorants are spread widely across the worlds' continents, except for desert areas and the very coldest regions. The birds that nest in the coldest regions migrate to warmer places in winter. Anhingas live in the warm, tropical and subtropical areas of North and South America, Africa, Asia, and Australia.

HABITAT

Cormorants and anhingas live in freshwater wetlands, swamps, lakes, rivers, and estuaries (wet areas near the ocean where freshwater and saltwater mix). Ahingas that live near the ocean stay close to shore, cormorants fly out over the coastal waters.


DIET

Besides fish, these birds also eat other water animals such as frogs and crayfish. Cormorants snatch their prey with their bills, and anhingas usually spear their food. After swimming, the birds sit on perches and spread their wings in the sunshine.


BEHAVIOR AND REPRODUCTION

Usually cormorants and anhingas breed in colonies. They build rather messy nests on tree limbs or on cliff ledges. Both parents sit on the eggs and care for the young. When they are not breeding, they often flock together for feeding and for roosting at night.


CORMORANTS, ANHINGAS AND PEOPLE

Big flocks of cormorants are considered pests by some people because the birds can be messy and they eat fish. In South America, farmers gather the cormorants' droppings for fertilizer. In Japan and China, some people use cormorants to help them fish. Bird watchers sometimes travel long distances to see rare cormorants and anhingas.

FISHING WITH BIRDS

Some people in Asian countries use cormorants to help them catch fish. The birds are trained to behave like fishing machines. The fisher ties a piece of grass around a trained cormorant's neck to keep it from swallowing the fish it catches. After the bird jumps into the water and catches a fish, the fisher puts a pole in the water for the bird to grab with its feet. The fisher lifts the bird out and removes the fish. After a while, the fisher unties the grass from the bird's neck and lets it catch and eat all the fish it wants.

CONSERVATION STATUS

One species of anhinga and fourteen species of cormorants are at risk. The Pallas's cormorant has recently become Extinct (died out). Of the fourteen cormorant species, two are listed as Endangered.

GREAT CORMORANT (Phalacrocorax carbo): SPECIES ACCOUNTS

Physical characteristics: The great cormorant is the largest of all thirty-six species of cormorants. Its average length is about 37 inches (93 centimeters) and it weighs as much as 8 pounds (3.6 kilograms). Male and female birds look alike. Adult birds have glossy black feathers and a yellow throat pouch. In breeding season, the adults grow some white feathers on their necks and at the top of their legs.


Geographic range: Great cormorants are the most widely spread of all cormorant species. They are found on the east coast of North America, and in temperate areas in Africa, Asia, and Australia where the climate is moderate or cool. They usually spend the winter near their breeding places.

Habitat: In North America, great cormorants nest mostly along the shore of the Atlantic Ocean and feed in coastal waters. But in other parts of the world, they are also an inland bird. They breed in many kinds of wetlands, including marshes and mangrove swamps, lakes, rivers, and reservoirs.


Diet: Great cormorants eat mostly small fish, but they occasionally catch other water creatures such as crayfish, squid, frogs, salamanders, snakes, and insects. They catch most of their prey underwater.

A cormorant usually swims along the surface and dips its head in and out of the water, looking for prey. If it spots something to eat, it dives in with its wings held firmly against its body. It pushes itself along with its webbed feet, and its heavy feathers help it sink down quickly. When the bird grabs a fish, it swims to the surface and swallows it headfirst. Later, it will regurgitate (spit up) the bones and scales. It leaves the water as soon as it has finished eating.

Behavior and reproduction: Cormorant feathers are not fully waterproof and become very heavy when wet. Colonies of cormorants can often be seen standing around with their wings spread as they dry their feathers.

Great cormorants nest in colonies on rocky cliffs along seacoasts or in trees near lakes and rivers. The male chooses the site and waves his wings. When a female approaches, the birds greet each other with courtship displays. The male brings nesting materials to the female, and she builds a big nest. She lays three or four eggs, and the adults both sit on them and care for the chicks. By the time the young birds are eight weeks old, they can fly as well as adults and take care of themselves.


Great cormorants and people: In most places, they are not of great importance to humans. In Asia, some great cormorants are trained to help people catch fish.


Conservation status: Great cormorants are widespread and plentiful. They are not in danger of extinction. ∎

AMERICAN ANHINGA (Anhinga anhinga): SPECIES ACCOUNTS

Physical characteristics: With its long, snakelike neck, yellow pointed bill, and a tail that can be fanned out like a turkey's tail, the American anhinga is easy to recognize. Its average length is about 34 inches (85 centimeters) from bill to tail, and it weighs about 2.7 pounds (1.2 kilograms). The male is an overall black color with silvery-white markings on the upper wings. The female has a brown head, neck, and upper chest.


Geographic range: American anhingas live in the southeastern part of the United States and in Mexico, Central America, and the northern two-thirds of South America.


Habitat: American anhingas usually live in warm wetlands, especially cypress swamps, and along the edges of wooded ponds, lakes, and slow-moving rivers. They need to have logs or tree branches nearby where they can sit in the sun to dry their feathers.

Diet: An anhinga usually catches fish, crayfish, and frogs by waiting for them to swim nearby underwater and spearing them with a lightning-fast jab of its sharp bill. Then, with the flick of its head, it tosses the prey into the air, catches it, and swallows it headfirst.


Behavior and reproduction: Unlike cormorants, anhingas soar high on outstretched wings. They often feed alone, but at night they roost with other birds in a colony. American anhingas sometimes nest in trees and bushes along with herons and cormorants. The male chooses a nest site and performs a variety of courtship displays, including wing waving and bowing. When a female joins him, she builds the nest with sticks brought by the male. She lays between one and five eggs, and both parents sit on the eggs and care for the young.


American anhingas and people: People are fond of watching this bird, especially the way it tosses fish into the air and catches them. Some call it the "water turkey" because of its tail. It is also called the "snakebird" because of the way it swims with just its neck and head above water. Bird-watching tourists spend money on boat tours, food, and hotels, which helps the local people who live near the birds.


Conservation status: American anhingas are not in danger of extinction. ∎


FOR MORE INFORMATION

Books:

Alsop, Fred J. III. Smithsonian Birds of North America. London and New York: DK Publishing, 2001.

del Hoyo, Josep, A. Elliott, and J. Sargatal, eds. Handbook of the Birds of the World. Vol. 1, Ostrich to Ducks. Barcelona: Lynx Edicions, 1992.

Harrison, Peter. Seabirds, An Identification Guide. Boston: Houghton Mifflin Company, 1983.

Johnsgard, Paul. Cormorants, Darters, and Pelicans of the World. Washington, DC and London: Smithsonian Institution Press, 1993.

Kaufman, Kenn. Lives of North American Birds. New York: Houghton Mifflin Company, 1996.

Sibley, David Allen. National Audubon Society: The Sibley Guide to Birds. New York: Alfred A. Knopf, 2000.

Soper, Tony. Oceans of Seabirds. London: David and Charles Publishers, 1989.

Swan, Erin Pembrey. Pelicans, Cormorants, and Their Kin (Animals in Order). Danbury, CT: Franklin Watts, 2002.

Periodicals:

Frederick, Peter C., and Douglas Siegel-Causey. "The Birds of North America, Anhinga, No. 522." Cornell Laboratory of Ornithology and The Academy of Natural Sciences (2002): 1–24.

Hatch, Jeremy J., Kevin M. Brown, Geoffrey G. Hogan, and Ralph
D. Morris. "The Birds of North America, Great Cormorant, No. 553." Cornell Laboratory of Ornithology and The Academy of Natural Sciences (2000): 1–24.

McGrath, Susan. "Shoot-out at Little Galloo: Angry Fishermen Accuse the Cormorant of Ruining Their Livelihood." Smithsonian (February 2003): 72–78.

Sharp, Eric. "Controversy Surrounds Cormorants." Outdoor Life (August 2000): 119.


Web sites:

"Anhinga anhinga." Animal Diversity Web. http://animaldiversity.ummz.umich.edu/site/accounts/information/Anhinga_anhinga.html (accessed on April 12, 2004).

"Anhinga." Museum of Science, Miami, Florida. http://www.miamisci.org/ecolinks/everglades/anhingainfo.html (accessed on July 12, 2004).

"Anhinga anhinga." FloridaNature.org. http://www.floridanature.org/species.asp?species=Anhinga_anhinga (accessed on April 12, 2004).

"Anhingas and Darters of the World." WorldBirdInfo.net. http://worldbirdinfo.net/search_results.asp?gillfamilyname=ANHINGIDAE:Darters,Anhingas (accessed on April 12, 2004).

"Cormorant." The Royal Society for Protection of Birds. http://www.rspb.org.uk/birds/guide/c/cormorant/index.asp (accessed on April 12, 2004).

"Double-Crested Cormorant." United States Geological Survey. http://www.mbr-pwrc.usgs.gov/id/framlst/i1200id.html (accessed on April 12, 2004).

"Great Cormorant." United Stated Geological Survey. http://www.mbr-pwrc.usgs.gov/Infocenter/i1190id.html (accessed on April 12, 2004).

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