Drought in South Georgia and a warmer winter in southern Florida likely contributed to a downturn in wood stork nesting this spring in Georgia.
Still, a Georgia Department of Natural Resources biologist said the estimate of 2,136 nests is the state’s third-highest total on record and does not reverse a general trend of increases in wood stork nesting.
The DNR-led survey of the endangered birds found nests in 10 South Georgia counties. While the count is less than last year’s 2,696, the most since surveys by air began in the 1990s, the number highlights the annual fluctuations in wood stork nesting. There were 1,676 nests in 2009 and 2,292 in 2008.
Fewer nests this year is not seen as cause for alarm, suggested Tim Keyes, a natural resources biologist with the DNR’s Nongame Conservation Section. “Over 2,000 is still a strong nesting year in Georgia,” Keyes said. “This bird in Georgia is still doing just fine.”
Wood storks were listed as endangered in the U.S. 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 8,000 pairs of these large wading birds, America’s only true stork, now nest in Florida, Georgia and South Carolina. Georgia supports about 20 percent of the U.S. nesting population.
The drought gripping most of the state has sapped many of the small, natural wetlands where wood storks nest. The majority of this year’s nests are in deep-water artificial impoundments. The birds build the stick nests in trees over water, a setting in which alligators unwittingly help protect the eggs and chicks above from raccoons and other predators.
When the water dries up, storks sometimes either do not nest or abandon nests, Keyes explained. Eggs and chicks become more vulnerable to predators, and the loss of important shallow-water foraging wetlands can undercut the parents’ ability to feed their young – even at sites that maintain some water.
“A lot of the smaller natural wetland sites were not active this year,” said Keyes, noting that the number of wood stork colonies fell from 28 in 2010 to 18.
Also this year, southern Florida did not repeat the unusually cold late-winter that in 2010 caused nesting failures at wood stork colonies there and pushed some pairs north to Georgia, presumably to nest again.
With water levels still falling, there is concern that storks may abandon nests in large Georgia colonies such as at Big Dukes Pond Wildlife Management Area near Millen. Keyes said biologists with the U.S. Fish and Wildlife Service, St. Catherines Island Foundation and DNR, including the agency’s State Parks and Historic Sites Division, will monitor nests and young at a number of Georgia colonies to determine how many young are fledged and average nest productivity. Follow-up surveys also will help document whether any colonies collapse before the young fledge.
WONDER OF WOOD STORKS
• 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 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.
• Standing about 3 feet tall, these lanky, bald-headed birds feed by wading with their opened beak partially submerged, snapping it shut when it touches a small fish or other prey. They often shuffle their feet and flash their wings to startle potential prey, which are then captured.
• 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 by purchasing or renewing wildlife license plates featuring a bald eagle or a ruby-throated hummingbird. Also, contribute to the Georgia Wildlife Conservation Fund state income tax checkoff or directly by mail. These programs support the agency and conservation of wildlife not legally hunted, fished for or trapped.
Details: www.georgiawildlife.com or (478) 994-1438.