Wading Birds and New World Vultures: Ciconiiformes
WADING BIRDS AND NEW WORLD VULTURES: Ciconiiformes
Most of the birds in the order Ciconiiformes (including the heron, hammerhead, stork, New World vulture, shoebill, and ibis families) are wading birds. Recently, the New World vultures (including condors) were switched into this order from a birds of prey family. (The New World vultures live in North and South America. Old World vultures live in the rest of the world and are still considered birds of prey.) The New World vultures were moved into this group with the wading birds because they are more closely related to storks than they are to hawks and eagles, but many people still think of all vultures as birds of prey.
All of the ciconiiforms (birds in the order Ciconiiformes) have big bills and long necks, bulky bodies with short tails, long legs and toes, and large, broad wings. They are all medium to very large birds, and males and females look alike. Very few of these birds have colorful feathers—most are combinations of gray, brown, black, or white. But many of the wading birds and vultures have bare parts on their heads, necks, and legs that are very colorful.
Birds in the heron family (including egrets and bitterns) have some other special features in common. They have a have a comblike claw on each of their middle toes. At breeding time, both males and females grow long, showy feathers on their heads, necks, and backs. They also have powder downs, which are feathers that are not shed. Instead, these feathers turn to powder that the birds use to keep their other feathers in good shape.
Members of the order Ciconiiformes are found almost everywhere in the world, except for areas far to the north and south. Most of them prefer warm areas, and those that nest in the coldest places migrate in fall and spring.
Most of the wading birds in this group live in wetlands, from tidal areas (where saltwater and freshwater mix), to swamps, marshes, damp meadows, and forest streams. Some live in grasslands near the wetlands. Just a small percent of the wading birds are able to live in drier areas.
The other birds in this group, the New World vultures, can live wherever they are able to soar on warm air currents and search for carrion (dead and decaying animals). They do not have to depend on wetlands for their food, so they can live practically anywhere, including deserts, mountains, tropical forests, and cities.
The Ciconiiformes are carnivorous birds. Wading birds catch many different kinds of animals in or near water, including shrimp and other crustaceans, fish, frogs, insects, and snails. Some also feed on small mammals, birds, and reptiles. Very few of them also eat carrion and fruit. The New World vultures feed almost entirely on carrion.
Ibises, spoonbills, and some of the storks have very sensitive bills. They hunt for prey by touch, either by probing in the water and mud with their bills slightly open or by swinging their bills from side to side in the water. The other birds in the order Ciconiiformes search for prey by sight. Most herons and storks stand still or wade slowly through shallow water to stalk their prey. Some of the vultures do not have to see carrion in order to find it—in addition to having good eyesight, they also have a strong sense of smell.
Goliath herons and some other wading birds feed by themselves. These birds protect a feeding territory as large as 3.7 square miles (9.6 square kilometers). Many other wading birds feed in huge flocks. As feeding areas dry out or get flooded, the flocks move around to find the best places to eat.
BEHAVIOR AND REPRODUCTION
Most of the Ciconiiformes birds gather in big groups called colonies when they roost at night and when they breed. If they migrate, they usually fly in huge flocks—when birds gather in colonies, they are usually safer from predators that might harm them. Colonies may include many different kinds of herons, storks, and ibises, for example, or they may be made up of all the same species. A few kinds of wading bird pairs stay by themselves when they breed.
For the most part, these birds are not noisy. The vultures do not have a voice box, so the only sounds they can make are soft wheezes and whistles. Storks, shoebills, ibises, and spoonbills also have very little to say most of the year, but some of them squeal, croak, and clap their bills when greeting a mate. The herons are noisier year round, and the loudest birds in the group are the bitterns. They make booming calls to attract mates or proclaim their territories.
ON THE MOVE
Since most birds can fly, it is easy for them to move to new places. They usually move in order to find more food, water, or space. When food becomes too hard to find in winter, for example, many wading birds migrate long distances to warmer places. Then, in spring, the birds fly back to the places they left and get ready to raise a new family.
Wading birds often move shorter distances, too. This kind of movement is called dispersal. Most wading birds depend on shallow pools of water for their food, and many of them live in areas that have rainy seasons and dry seasons. As the pools of water shrink and grow, the birds disperse to areas where the water is just the way they like it.
The wading birds' champion mover is the cattle egret. These egrets used to live just in Africa and Asia. Then some of them flew across the ocean to South America. The first cattle egrets appeared in Florida in 1940, and by now they have spread all across North and South America.
Depending on where wading birds live, they nest at different times of the year. The best time to nest is when the most food is available so there is plenty to feed the young. Spring and summer is nesting time in the cool weather of the temperate areas. In the warmer subtropical areas, the birds tend to nest during the dry season to avoid the threat of flooding. The birds that live in the tropics near the equator usually nest in the wet season when food is most plentiful.
When wading birds are ready to nest, the males arrive at the nest site first. They defend their territories by stretching and flapping their wings. When the females arrive, the birds often greet each other with a courtship display. This may include bill snapping and tapping, and smoothing each other's feathers. The females usually build the nests with sticks brought by the males. After the eggs are laid, the parents take turns sitting on the eggs and feeding the young. The chicks are blind and almost naked when they hatch. The parents feed them by regurgitating (spitting up) food on the nest floor or by letting the chicks eat it from their open bills.
The New World vultures do not build nests. They lay their eggs on the ground in caves, under bushes, in large tree holes, or even in abandoned buildings. Vulture chicks depend on their parents for a long time.
Young condors do not learn to fly until they are six months old.
WADING BIRDS, NEW WORLD VULTURES, AND PEOPLE
Myths and superstitions have kept many wading birds and New World vultures safe from harm. Native peoples have honored vultures and sacred ibises as gods. White storks were thought to bring babies and considered lucky by Europeans. Some of the wading birds that migrate arrived just as the rains came, and people treated them kindly as "rain-bringers." Hammerheads and bitterns were thought to bring bad luck and even death, so people often stayed away from them.
BILLS THAT "FILL THE BILL"
At first glance, the bills of the birds in this group might look very similar. But although the birds all have large bills, they come in many interesting shapes. The storks' bills are thick and exceptionally long. Most herons have thinner, dagger-shaped bills. New World vultures have beaks with hooked tips and sharp edges that are used for tearing meat. A hammerhead's bill is shaped like some of the storks' bills, but it has a hook on the end, which storks don't have. The bills of ibises turn downward, and shoebills have wide, hooked bills. Spoonbills have the most unusual bills of all. They are long and flat, with a "spoon" on the tip. Whether the bills are used to probe, swish, stab, or tear, they are just what the birds need in order to feed.
Other birds are not so lucky. Herons were killed in North America and Europe because some people thought the birds ate too many fish and were harmful to the fishing industry. Vultures were shot because some farmers thought they killed calves. And millions of egrets, ibises, and spoonbills were killed so their feathers could be put on fancy hats. Laws now stop people from killing birds for their feathers, but many of the birds in this group are still in trouble.
More than one-fifth of the wading birds and New World vultures are listed as Threatened or Endangered. Many of their problems come from loss of habitat. As the Earth's population grows, people take more and more of the wetlands where the wading birds once lived. They turn the wetlands into farms and cities. Wading birds also suffer greatly from polluted water, and in some parts of the world, they are still shot for food.
Many people, however, are doing what they can to help the birds. The last of the California condors were taken from the wild and bred in captivity—now they are gradually being released into the wild again. Although many birds are still in serious trouble, pollution and hunting laws now protect some of the threatened wading birds. Governments and conservation groups are also working to set aside protected areas for wading birds and New World vultures in many parts of the world.
FOR MORE INFORMATION
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.
Eckert, Allan W. The Wading Birds of North America. Garden City, NY: Doubleday & Company, 1981.
Erlich, Paul R., David S. Dobkin, and Darryl Wheye. The Birder's Handbook. New York: Simon & Schuster, 1988.
Hancock, J.A., J.A. Kushlan, and M.P. Kahl. Storks, Ibises and Spoonbills of the World. London: Academic Press, 1992.
Hancock, James, and Hugh Elliott. The Herons of the World. New York: Harper & Row, 1978.
Houston, David. Condors and Vultures. Stillwater, MN: Voyageur Press, 2002.
Perrins, Christopher, ed. Firefly Encyclopedia of Birds. Buffalo, NY: Firefly Books, 2003.
Berger, Joseph. "In City Bustle, Herons, Egrets and Ibises Find a Sanctuary." The New York Times (Dec. 4, 2003): B1.
Montgomery, Sy. "Heavenly Scavengers: Turkey Vultures." Animals (March 2000): 26.
Regis, Necee. "The Shy Beauty of the Everglades." Boston Globe (February 16, 2003): M1.
Williams, Ted. "Lessons from Lake Apopka: Fish-Eating Birds Dying from Pesticide Poisoning in Florida." Audubon (July 1999): 64.
American Ornithologists' Union. http://www.aou.org (accessed on March 30, 2004).
Bird Life International. http://www.birdlife.net (accessed on March 30, 2004).
Birdnet. "Avian Orders: Ciconiiformes." Smithsonian National Museum of Natural History. http://www.nmnh.si.edu/BIRDNET/splists/Ciconiiformescl.html#Ciconiidae (accessed March 31, 2004).
Cornell Lab of Ornithology. http://www.birds.cornell.edu (accessed on March 30, 2004).
Georgia Museum of Natural History. http://naturalhistory.uga.edu (accessed on March 30, 2004).
Georgia Wildlife Web Site. "Order; Ciconiiformes." The Georgia Museum of Natural History. http://museum.nhm.uga.edu/gawildlife/birds/ciconiiformes/ciconiiformes.html (accessed March 30, 2004).
Ornithology Laboratory. "Order Ciconiiformes, Herons and Allies." University of Illinois. http://cm27personal.fal.buffalo.edu/birds/bow/bow_1/ciconiiformes.html (accessed March 20, 2004).
Wetlands International. http://www.wetlands.org (accessed March 30, 2004).