Big bird revival: Storks, other waders rebound
Endangered avians get assist from Mother Nature — and humans.
Bellwethers of Everglades health balance on long skinny legs the color of driftwood at the Wakodahatchee Wetlands west of Delray Beach.
Perched in tangles of branches woven into treetops, fuzzy heads of white down and muted-orange beaks indicate the wobbly aviators are fledgling wood storks old enough to stretch their wings, but too awkward to leave the nest just yet.
Wood stork nests are a key clue in the progress of restoring Florida’s iconic river of grass, and in the past year, success rates have been something to crow about.
Buoyed by “Goldilocks” conditions of rain and drought, wood storks have turned formerly green canopied tree islands white with nests that totaled 3,894 during an annual count through summer 2017. That’s nearly double the 10-year average and the largest showing by wood storks since a banner year in 2009, according to the South Florida Water Management District.
Wood storks, which will grow to more than 3 feet tall, are the only storks
breeding in the United States and are on the federal list of threatened species.
The birds once flocked to Florida’s southern fringes, dining on bounties of freshwater fish fattened during the rainy season, then corralled for easy hunting as waters receded during dry months.
Man has damaged the unique habitat balance needed by the storks, carving canals to drain South Florida for homes and agriculture. Driven farther north, the birds have suffered, nearly disappearing in the 1980s.
The recent turnaround is mostly attributable to an obliging Mother Nature, but restoration efforts that allow water managers to increase water levels in some areas have also contributed.
“I think there is definitely hope and the birds are showing us that everything is not lost,” said Celeste DePalma, Everglades policy associate for Audubon Florida. “We can still bring it back.”
Wood storks are not the only species that saw improvements since 2016.
White ibis, great egret and little blue heron — all wading birds — also experienced increases in nesting rates.
In the district’s 2017 wading bird seasonal report, released last month, researchers counted 46,248 new wading bird nests between December 2016 and July 2017. That’s nearly 20 percent higher than the 10-year average.
A more recent tally in early January of Everglades National Park and water conservation areas showed the nesting bonanza has spilled into 2018 with more than double the number of wood stork nests compared to the 10-year average. White ibis nests in the same January tally totaled 28,000, compared to the 10-year average of 18,228.
“The chicks are really healthy, and there are just thousands of birds this year,” said Mark Cook, the water management district’s wading bird expert. “My sense is the birds are doing much better. Not only do we have much bigger numbers of birds but they seem to be eating well this year and producing many chicks.”
The bodyguards
Some birds, including the snowy egret and tri-colored heron, showed declines in nesting rates for unclear reasons, DePalma said.
Historically, hundreds of thousands of wading birds nested in the Everglades, flourishing in coastal areas where Florida Bay meets the Gulf of Mexico.
It was a time when Lake Okeechobee’s overflow would naturally trickle south, sending fresh water to wading bird populations that need a fine-tuned ecosystem for exuberant breeding.
A prolonged or unusually wet rainy season encourages higher fish populations that spread with rising waters over the corrugated ridges and sloughs of the Everglades. As the waters dry up during winter months, fish are consolidated into smaller areas.
The high densities of fish are needed by wading birds who hunt by touch, groping with their bills in shallow water then snapping them shut when they touch prey.
A wood stork’s bill closes with a 25-millisecond reflex action — the fastest known for vertebrates.
For nesting, healthy tree islands are required so birds can stay off the predator-rich ground, but enough water is needed for patrolling alligators. Alligators eat the raccoons that want to eat the birds’ eggs.
“Alligators really are the birds’ bodyguards,” said Jason Lauritsen, director of the Corkscrew Swamp Sanctuary northwest of Naples. “All the pieces have to connect so we can have a well-functioning system that supports a population of wading birds that were once known to be here.”
One of the main goals of the Comprehensive Everglades Restoration Plan, or CERP, is to attract wading birds back to their historic nesting areas.
The sanctuary supported up to 7,000 wood stork nests in the 1960s, but had no nests during eight of the past 10 years. About 250 nests were recorded in the 2017 report.
“When we say this is a great year, it’s great for the past decade, but it’s nothing like the historic productivity,” Lauritsen said.
Helping the kites
What happened the past few years was a fortuitous mix of weather with a dose of human help.
Beginning in 2015, an El Niño climate pattern shifted to neutral and then became La Niña. That meant an unusually wet winter in 2016 became a drought-stricken winter of 2017, which was followed by a banner year for tropical systems.
Hurricane Irma and Tropical Storm Phillipe contributed to a rainy season that was the second wettest on record for the 16-county region overseen by the water management district.
As of mid-April, South Florida was running at a rain deficit of about 4.2 inches for the dry season.
Cook said when areas where birds are nesting and foraging get too wet or too dry, the district can redirect water flows to improve the habitat.
That happened in the Rotenberger Wildlife Management Area in western Palm Beach County when endangered snail kite habitat began to dry out. Snail kites, which are raptors, feed on snails that burrow into the ground when water levels drop, making them unreachable to the birds.
The district opened a pump station on the north side of Rotenberger to bring water in from the Miami Canal.
“It’s a combination of good wet conditions, and working with the district and Army Corps to control water levels that are favorable for all wildlife,” said Tyler Beck, snail kite conservation coordinator for the Florida Fish and Wildlife Conservation Commission.
Still, restoration efforts have a long way to go, Lauritsen said.
“If we can restore habitat, if we can continue to do the right things, the birds will come, that’s the big warm fuzzy message,” Lauritsen said. “I’m an optimist; I haven’t lost hope.”