Wood Stork Fact Sheet

An Introduction

Wood storks are the largest wading birds that breed in North America; they nest 60 feet off the ground in cypress trees in wetland areas of Georgia, South Carolina and Florida. Only three other species in the world are similar to wood storks; two live in Southeast Asia and one in Africa.

Wood storks almost became extinct before being listed on the U.S. Fish and Wildlife Service's Endangered Species List in 1984. In the 1930s, more than 60,000 wood storks inhabitated the United States. But development, destruction of habitat and other factors reduced their population to about 4,500 breeding pairs by 1980.

Prompted by this decline, a 12-year research project initiated by the University of Georgia's Savannah River Ecology Laboratory has produced previously unknown information about wood storks and served as a model for similar projects throughout the world. That information has helped in the recovery of this endangered species.

The Biology of a Wood Stork

Adult wood storks stand about three feet tall, are bald and make no noise except to clatter their heavy, dark bills. The birds are white with a purplish sheen to some of their wing feathers and a purple-greenish sheen to their small tail. Their long, stilt like legs are black, but their feet are pink. Their bodies can weigh almost 7 pounds, which limits the distance they can fly.

The adults raise their young in treetop nest 3 to 4 feet wide. Their eggs are bigger than tennis balls. Baby wood storks have white feathers all over their heads, yellow bills and the ability to call very loudly for their parents.

The adult birds propel themselves as high as 6,000 feet into the air on broad wings, sometimes spanning almost 6 feet. Wood storks will fly as many as 50 miles to search for food. They are tactile feeders – they wander around in shallow water with their mouths open and catch whatever they come across. They depend on high densities of fish to feed efficiently. While wood storks spend the winters in south Georgia and Florida, they depend on rainfall in their summer feeding areas because it sets the conditions for the reproduction of fish. Also, it is important that water remains underneath their treetop nests. If the water dries up, then raccoons can come in and eliminate a wood stork colony in a week or two. When water is present, alligators keep out the raccoons.

Wood Stork Research

A colony of wood storks was discovered in 1980 in Big Dukes Swamp near Millen, Ga., in Jenkins County. It is located near a small crossroads town once known as Birdsville. Researchers from the Savannah River Ecology Laboratory began studying the wood storks in Birdsville and followed the storks to the Savannah River Site. There, they found the birds foraging for food in the delta of Steel Creek, a stream once used for cooling waters from the site's L-reactor. The reactor was inactive then.

When the U.S. Department of Energy decided to restart L-reactor a few years later, that meant the water used to cool the reactor would be discharged into Steel Creek, as had been done previously. Those discharges would make the water in the delta too deep for the wood storks, so the U.S. Fish and Wildlife Service required the Department of Energy to create and alternative feeding site for the birds.

The cooperation of six groups – SREL, DOE, the National Audubon Society, the U.S. Fish and Wildlife Service and SRS contractors Du Pont and Westinghouse – led to the development of Kathwood Ponds in Aiken County near Jackson, S.C., in 1985. The four ponds – developed from Kathwood Lake which emptied when an old grist mill dam broke in 1977 – have since attracted as many as 250 wood storks annually to feed there in June and July. The ponds are stocked with fish, and the water level is lowered during the summer so the storks can feed there.

The Savannah River Ecology Laboratory today continues its study of the biology of wood storks, looking at both breeding and foraging ecology of the birds as they hope to support the alternate foraging habitat at Kathwood Ponds.