Boom in wood stork numbers sparks debate over endangered status
The wood stork, an ungainly duckling among the Everglades' elegant wading birds, has been breeding in numbers unseen in decades.
Rain in the last crucial month of nesting season took a toll, leaving half the weakened fledglings prey for waiting gators. But even with that loss, preliminary surveys estimate some 3,500 will leave South Florida nests this year.
Contrast that to the survivors last year: Zero.
"We haven't seen this kind of nesting efforts and eggs laid since the 1930s," said Dean Powell, director of watershed management for the South Florida Water Management District, which compiles an annual population assessment of wading birds.
The sex surge isn't completely understood -- ironically, it may be a ripple effect of a drought that largely turned off their libidos the previous year -- but it's clearly an encouraging sign for the only Florida wading bird on the federal list of endangered species.
It's also more fuel for developers and a property rights advocacy group who argue it is long past time to ease regulations that protect the big birds, sometimes at the expense of builders.
In May, before the nesting numbers were known, the Pacific Legal Foundation and Florida Homebuilders Association petitioned federal wildlife managers to reclassify the birds to the less severe "threatened."
Steven Gieseler, an attorney who leads the foundation's regional office in Stuart, Fla., said the groups are only asking the U.S. Fish and Wildlife Service to sign off on its own science. A federal review two years ago, prompted by a lawsuit by the foundation and builders association, recommended downlisting the wood stork, but the service has not started the process.
"I don't pretend to be a scientist, but I can read," Gieseler said. "We're simply looking at the work the government itself did. You need to follow your own recommendations."
Environmentalists don't dispute that the stork has rebounded from a low of about 2,500 pairs in 1978. But they also point out the bird's range and habits have been radically altered. Most notably, the stork largely abandoned the Everglades, once home to more than 20,000 pairs, as bulldozers and flood control policies destroyed marsh or altered seasonal wet and dry cycles.
Because of its feeding method, the stork is particularly vulnerable to water conditions. It hunts in pools no more than 18 inches deep, feeding by feel as it wades, its long beak snapping shut on fish, frogs and other prey with lightning speed.
"They're fast with those beaks," said Powell. "They feel something and grab it."
One of the largest colonies -- more than 1,000 pairs -- still lives on the fringe of the Glades in the Corkscrew Swamp Sanctuary east of Naples, but more are now in smaller, scattered groups from North Florida to Georgia and South Carolina, two states where the birds were never found before the 1980s.
They've also adapted their foraging to suburban surroundings, hunting in golf courses, retention ponds and farm fields often laced with pesticides and fertilizers.
Julie Wraithmell, wildlife policy coordinator for Audubon of Florida, said such changes raise concerns about the bird's long-term stability.
"We're seeing these birds do things they haven't historically," she said. "We want to celebrate success stories, but at the same time you want to make sure the recovery is true and lasting."
Bill Brooks, a wildlife service biologist, said the agency is reviewing the Florida Homebuilders Association petition and has 90 days to issue a preliminary decision.
Overall, recent population trends have been positive -- with an estimate of 11,000 in 2006, 5,000 from a partial count in 2007, 7,000 last year and perhaps 8,000 to 10,000 this year. Those numbers would meet the "threatened" target -- an average of at least 6,000 breeding pairs for three years running -- but might fall short on other measures, including the number of fledglings per nest.
The location of many nests this year is just as exciting as the number of them. Nearly half, Powell said, were south of Alligator Alley in the historic Everglades. Some birds even nested in coastal mangrove rookeries that had been nearly silent for decades.
Stork breeding rises and falls seasonally, with the birds depending on the dry season to concentrate prey in receding pools, making for easier hunting to feed hungry chicks. One theory for why this year was so good, Powell said, is that the previous drought knocked back stocks of bass and other larger predator fish.
Then, after Tropical Storm Fay replenished South Florida last year, this year's dry season produced more small prey, and less competition, for the birds. More food equals more breeding.
Heavy rains in June, however, ended the easy pickings. With food in short supply, adults only feed the oldest fledglings, likely dooming second or even third birds that might otherwise have made it.
"If the rainy season would not have started early, it would have been spectacular," he said.
Whether the boom will lift the stork off the endangered list is uncertain. In the past, the service has pointed to budget shortages for not moving forward on the lengthy, expensive process of formally reclassifying species.
Developers contend they're paying a high price for federal inaction, particularly in Southwest Florida, where several large housing projects in bird habitats have been blocked or shrunk. U.S. District Judge William Hoeveler also cited impacts on the bird in halting rock-mining plans in Southwest Miami-Dade County.
Gieseler, the Pacific Legal Foundation attorney, believes politics will play a major role in whether wildlife managers pursue the downlisting, putting the Obama administration's "science-first" pledge to a serious test.
"My guess is that as one of the first actions, endangered species-wise, they probably are not too keen to have it go in this direction," he said.
Wraithmell of Audubon said changing the stork's status to "threatened" would do little to change regulations or revive a building industry in a state already sick with unsold housing stock.
"Scapegoating particular endangered species or environmental protections is not going to improve economic conditions," she said.
(c) 2009, The Miami Herald.
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