The drought that has forced Okefenokee Swamp's wildlife to gather near deeper pools and its alligators to engage in cannibalism is necessary for the survival of the swamp, a parks official says.

"The swamp has tolerated drought for thousands of years. Drought is a part of the biological process that creates open water areas and marsh areas," said John Schroer, manager of the Okefenokee National Wildlife Refuge.Swamp vegetation dries out during a drought, increasing the chance of wildfire ignited by lightning. But, Schroer said, wildfires are necessary because they burn off floating islands of peat, which eventually can turn into dry land. Indians dubbed the swamp "the land of the trembling earth" because of the undulating peat.

In 1954 and 1955, fires raged for 12 months, burning 80 percent of the swamp, and fires in the 1840s created some of the Okefenokee's lakes by burning large holes in the peat.

"If it weren't for the natural wildfires that have occurred throughout history, the swamp would not be a swamp," said Schroer. "It would be a forest."

The peat floats to the surface of the swamp's reflective tea-colored water, forming islands that support vegetation. Eventually trees begin growing in the peat, sinking their roots into the swamp's sandy bottom. The islands get larger and larger, and without fires, they could be transformed into forests.

The 700-square-mile swamp in southeastern Georgia and northeastern Florida is home to many types of animals, including rare birds, fish, poisonous snakes and alligators. Many exotic plants also thrive, including orchids, lilies, cypress trees and carnivorous pitcher plants. President Franklin D. Roosevelt designated most of the swamp a national wildlife refuge in 1937.

The drought has caused wildlife to congregate near water holes, Schroer said. Game officials recently counted nearly 1,000 alligators along a 5-mile spillway on the swamp's western side.

"When they get concentrated, predators have more prey," he said. "Alligators start eating other alligators. We've seen some cannibalistic activity, but this is nature's way of keeping populations in check. The big males typically try to keep other males out of their territory."

Schroer said water levels are 8 to 10 inches below normal on the east side of the swamp, near the Suwannee Canal. Levels are about a foot below normal near the 80-acre Stephen C. Foster State Park on the swamp's western edge near Fargo.

Visitors can still take two-day canoe trips into the swamp from the Suwannee Canal, but the longer trips of up to five days have been canceled because boats have trouble navigating some of the shallow trails, Schroer said.

Barbara Metts, assistant superintendent at Georgia's Foster State Park, said anglers can still reach Billy's Lake, a popular fishing spot, but canoe trails to Minnie's and Big Water lakes are closed because of low water.