By ALEX LEARY, Times Staff Writer
CHASSAHOWITZKA -- It was about to get very noisy, so the guide in floppy brown hip waders paused to remind her passengers one more time.
"Once we get there," she cautioned, "we need to keep our voices low." And with that said, Sara Zimorski eased into the accelerator.
For the next eight minutes, the airboat skimmed over the reflection of the early morning sun, between vast islands of needlerush, past the occasional crab trap and oyster bar.
The motor dropped to a lull, and Zimorski inched the airboat toward shore. There was a signpost in the deep, black mud: Government property. No trespassing.
In the distance stood 17 of the rarest birds in the world -- whooping cranes. They were not visible from the shore, but their faint warbling carried on the salty breeze.
Along with three other researchers, Zimorski, a biologist with the International Crane Foundation in Wisconsin, has spent the past two months studying these revered creatures with unmatched intimacy.
That would become evident soon, but first Zimorski, 26, had to run through the more academic part of her daily routine.
On a bright morning recently, a small group of visitors were allowed a glimpse of her tightly guarded work. The tour was part of an effort to raise public awareness about the whooping crane recovery project.
Nothing is ordinary about these birds.
Hatched in a laboratory, and trained in and above the vast wetlands of central Wisconsin, they were guided to Chassahowitzka National Wildlife Refuge by ultralight aircraft, unwitting participants in an ambitious experiment to save their species.
The hope is the cranes will establish their own migratory pattern between Wisconsin and Florida, and thus help bring the species back from the margin of obscurity.
The peculiar human-led migration, dramatized in the movie Fly Away Home, has proven successful so far. One of the 17 cranes is part of the flock that made the inaugural 1,200-mile journey in fall 2001. Along with four others, it flew back on its own to Wisconsin in the spring, then returned to Chassahowitzka. The four others continued on to explore other parts of Florida.
Going to great lengths to observe
Zimorski bent over the front of the airboat and dipped an eyedropper into the dark water, then squeezed a drop onto a device called a refactometer.
The refactometer indicated the salt level was 18 parts per 1,000. Anything more than 21 parts per 1,000 is considered unsuitable for the birds to drink, so fresh water is provided.
Every few weeks, 50-gallon barrels are hoisted on the airboat and taken to the site. The water is pumped through garden hoses to storage tanks at a blind, an elevated plywood building shrouded in camouflage about 50 yards from the crane pen.
As Zimorski noted the salt level, her passengers stepped onto the gooey shore. Dick Blewett of the Friends of Chassahowitzka National Wildlife Refuge was the first victim. He laughed nervously as his rubber boots sank in the mud.
"Now I can see why you wear waders," he said in a tone that seemed a bit too loud for Zimorski, though she did not say anything. It took two people to free Blewett.
Fortunately, wooden planks were nearby. Zimorski and assistant refuge manager Ted Ondler led the way down a narrow path worn in the salt grass and then through a stand of palms.
Only whispers were allowed this close to the pen. To ensure the birds remain wild, researchers have gone to great lengths. The cranes have not heard a human voice or seen a human form (if you discount the hundreds of people who watched them fly over Crystal River Mall on Nov. 30), only people in crane costumes.
Inside the blind, Zimorski cleaned her mud-caked hands with a towel, then scanned the marsh with binoculars.
Fourteen whooping cranes were inside the pen, which is on a large pool and provides protection against predators. Three cranes were outside, foraging for crabs, snails and algae in a narrow channel of water.
"We need to try and keep track how much they are exploring the area," Zimorski explained, taking careful notes in a small notebook.
The birds' movements could indicate they are looking for more freshwater, food or more suitable roosting locations.
So far, most cranes seem to prefer the comfort and safety of the pen, which was greatly enlarged from the first year.
In preparation for their arrival, 95 tons of natural shell material was dropped by helicopter to create a gradual slope in the pool. When the tide is out, the cranes can go to low areas; when it is in, they can move to higher ground.
Water provides a natural protection for the cranes, since they can hear the splashing of a predator. This migration, the young cranes were exposed to water earlier and more often. At Chassahowitzka, decoys have also been placed in the water, standing on one leg, just like the real thing.
Zimorski switched on a radio receiver and cycled through its channels. It chirped and beeped back at her. The leg of each bird is fitted with a transmitter. Though marginally useful now, transmitters will be vital when the cranes begin to migrate in the spring.
Still more observations. Zimorski noted the depth of the pool and looked for signs of life in a trio of traps along the perimeter of the pen.
Two cranes were killed by bobcats last winter -- a disappointing setback, though researchers said nature is bound to run its course. There has been little sign of predators this winter, but the threat remains.
"Hey look," Ondler said, breaking the silence. "They just took off. Three of them. Isn't that cool." The cranes' white wings, tipped with black, flapped gracefully in the cloudless sky. Blewett's eyes widened.
Standing her ground amid the hierarchy
It is 9:30 a.m. and Zimorski is pulling on her crane costume, a baggy white sack that extends past her knees. She looks like a beekeeper, or Halloween ghost.
With a crane head puppet in one hand and a bucket of feed in the other, Zimorski walks toward the pen. She pauses at the entrance to disable the electric fence, then slips inside.
The whoopers follow her, equally curious and hungry.
"Mama is here, huh," Blewett chuckles from back behind the blind.
Zimorski is doing more than refilling food dispensers. She visually inspects the birds for injuries or other problems.
She also notes physical changes. The birds' voices are starting to mature, changing from a high-pitched peep to a stronger, deeper, more complicated sound, and their brown feathers are being replaced by white.
Whooping cranes quickly establish a hierarchy, so dominant birds will assert themselves in the presence of a newcomer. They stand taller, stomp the ground and flatten their head feathers, which will one day be red.
"The biggest thing we can do is stand our ground," Zimorski said. "If they actually start to peck at me, I'll chase them a bit or poke them back with the puppet head."
Though less important now as human contact is being reduced, early on it is important for the handlers to maintain control so the cranes see them -- and the ultralight aircraft -- as the leader.
Back in the blind, Zimorski pulls off the costume and gathers her things. Her work is done, for now, and she heads for the airboat.
It all seems so ordinary to her.
"I don't think about it all that much because it's my day to day routine," she said. "But there are moments that catch you."
She is fond of her recent encounter in a grocery store parking lot. As she carried bags to her truck, a couple approached her, explaining that they had noticed the whooping crane partnership logo on her truck.
"They were going on and on, very complimentary," Zimorski recalled. "Hearing it from other people who have this outside perspective, it's like, oh yeah, it is sort of cool what I get to do."
-- For information about the whooping crane migration, visit www.operationmigration.org or www.bringbackthecranes.org. Alex Leary can be reached at 564-3623 or firstname.lastname@example.org .
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