BRUNSWICK — A see-saw cycle of drought in early spring and heavy rains in late spring and the start of summer resulted in fewer wood stork nests and young in south Georgia this year.
Georgia Department of Natural Resources surveys of the endangered birds counted 1,903 nests across 19 counties in May. That’s down from 2,136 nests last year and 2,696 in 2010, the highest estimate since surveys by air began in the 1990s.
Recent follow-up checks did not help this year’s outlook. Some nesting colonies, or rookeries, have been abandoned, said Nongame Conservation Section biologist Tim Keyes of DNR’s Wildlife Resources Division.
Keyes estimated that average production will be well below one chick per nest. The federal recovery plan for wood storks targets an average of 1.5 chicks per nest.
“Of the colonies we marked, we had about 50 percent of nests abandoned,” Keyes said. “So it has not been a great year. … But there are still a lot of big chicks that should be fledging soon.”
Wood storks are tall, bald-headed wading birds that nest over water and depend on wetlands for food. Too little rain can dry wetlands and leave nests vulnerable to predators like raccoons. Yet too much rain disperses fish, making them harder for wood storks to catch. The birds feed by running their opened beak through the water and snapping it shut when it touches prey, a technique known as tacto-location.
Wood storks, America’s only true stork, were listed as endangered when the number of breeding pairs in the Southeast slid to about 5,000 in the late 1970s, down from as many as 20,000 in the 1930s. The decline was blamed on wetland habitat loss and alteration due largely to ditch building in Florida.
About 12,000 pairs nest in Florida, Georgia and South Carolina. Georgia supports about 20 percent of the U.S. nesting population.
Annual nest fluctuations are normal. Georgia had an estimated 1,676 wood stork nests in 2009 and 2,292 in 2008. Considering the lack of rain in late winter and early spring, this year’s low numbers are no surprise, Keyes said. However, the long-term trend for wood storks in the state remains positive.
“Still a lot of wood storks will be produced in Georgia this year,” he said.
Wood stork facts
• Wood storks use freshwater and estuarine wetlands for breeding, feeding and roosting.
• They are colonial nesters, and several nests are often located in the same tree.
• The stick nests are built in trees over water, a setting in which alligators unwittingly help protect the eggs and chicks above from raccoons and other predators.
• The first record of wood storks nesting in Georgia was in 1965 on Blackbeard Island.
• Colony size in the state has ranged from fewer than 12 to more than 500 nests.
• Colonies in the state this year ranged in size from four nests at a Grady County rookery to 464 at Harris Neck National Wildlife Refuge in McIntosh County. Colonies in southwest Georgia are usually less stable than those in coastal counties, where many wetlands used by storks are influenced by tides — more reliable than rainfall.
• Wood storks also may be spotted soaring on thermal updrafts or gliding to feeding sites.
• More than 75 percent of the stork rookeries in Georgia are on private land. The success of conservation efforts for this species depends on landowners’ willingness to ensure the protection of viable freshwater wetland nesting sites.
• Regionally, populations must reach the recovery goal — three-year average of 6,000 pairs and 1.5 chicks per nest — to down-list the species to threatened.
• More on wood storks in Georgia at www.georgiawildlife.com/node/2620
How to help
Georgia DNR’s Nongame Conservation Section works to conserve wood storks and Georgia’s other rare and endangered animals and native plants. Yet the agency receives no state general funds, depending instead on fundraisers, grants and donations.
Help can be given by purchasing or renewing wildlife license plates featuring a bald eagle or a ruby-throated hummingbird and by contributing directly to the Georgia Wildlife Conservation Fund. These programs support the agency and conservation of wildlife not legally fished for, hunted or collected.
For details, go to www.georgiawildlife.org/conservation or 478-994-1438