Nesting wood storks return to Corkscrew Swamp for first time since 2014

Wood storks have been spotted nesting in the tops of the bald cypress trees at Corkscrew Swamp Sanctuary for the first time since 2014, a hopeful sign for the declining Southwest Florida population, scientists say.

Corkscrew has been in the middle of its longest nesting drought since record-keeping began in 1958. Back then, storks would build as many as 6,000 nests each year.

But they have nested at Corkscrew only two other times in the past 11 years. This week, a crew in a survey plane counted 40, maybe 50, active nests.

“It gives me hope that they haven’t given up on Corkscrew,” said the sanctuary’s research manager, Shawn Clem.

Wood storks, which were moved off the endangered species list in 2014 but retain their status as threatened, have shifted their range to other Southern states such as Georgia and South Carolina.

Southwest Florida advocates opposed the downgrading of their status on the grounds it amounted to writing off a Southwest Florida population struggling with wetland loss.

Wood storks popular roadside attraction in Southwest Florida

The number of wood stork chicks leaving Corkscrew nests has fallen from an average of 5,400 chicks per year between 1956 and 1967 to an average of fewer than 300 chicks per year since 2007, sanctuary figures show.

In 2014, the last time wood storks nested at Corkscrew, they fledged about 300 chicks.

“It’s been more than disappointing,” said Audubon of the Western Everglades advocate Brad Cornell. “It’s been devastating.”

Wood stork nesting is all about water levels. The tall, bald birds find food by touching it with their beaks. That means the more crayfish and fish, and the more concentrated they are, the more likely wood storks will build up the stores of energy they need to build a nest, care for eggs and fledge young.

Conditions were just right this year for them to find food, after an unusually wet year last year allowed crayfish and fish populations to explode.

A slow dry-down since October concentrated prey, said Clem, the research manager.

Wood stork nesting once was an annual event at Corkscrew, much anticipated by Southwest Florida birders each winter, even attracting visitors from around the world to witness the celebrated nesting colony.

Storks may be starving due to high water

A loss of the shallow wetlands that wood storks rely on for food early in the nesting season has been blamed for falling nesting numbers. Researchers have estimated that wet prairies within the Corkscrew colony’s foraging area have been reduced by 82 percent.

In 2014, heavy rains in late January dispersed the storks’ prey and put an early end to the nesting season, Clem said. It could happen again this year, but the early start to nesting this year is in their favor, she said.

Monitors think the storks might have started nesting as early as December, which would mean more of their chicks will be leaving the nest before the rainy season arrives and makes food harder to find.

Clem expects, if all goes right, nesting numbers to continue to climb at Corkscrew in coming weeks. Besides too much rain, strong winds or cold weather could trigger an end to the nesting season, she said.

Clem said the return of wood stork nesting this year shows that land managers still have time to restore the types of wetlands that storks need for successful nesting and for policymakers to enact better rules for building new wetlands in return for destroying them.

“I think there are things we can do with what we have left,” she said.

Cornell said the return of nesting this year amounts to a quirk of rain patterns, not any proactive step that was taken to improve the storks’ chances of nesting at Corkscrew.

“It’s not where we should be, but we’ll take every success we can get,” he said.