Wood Stork Fact Sheet
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