Guadalupe-Blanco River Trust Preservation Matters

News

Love, and cranes, are in the air

March 30, 2005
Greg Bowen
Victoria Advocate

ARANSAS NATIONAL WILDIFE REFUGE - The whooping cranes are gorging on blue crab and dancing their raucous high-stepping, neck-craning, wing-flapping mating dance - a sure sign that their spring migration to nesting grounds 2,400 miles away in Canada's remote Northwest Territories is beginning.

Biologist Tom Stehn, the national whooping crane coordinator for the U.S. Fish and Wildlife Service, which operates the Aransas National Wildlife Refuge, confirmed Tuesday that the migration has begun.

Stehn said a juvenile whooper who got split off from the main refuge flock and wintered by himself in Matagorda County, has flown north.

The Matagorda crane was seen Monday on the Platte River in Nebraska.

"So that's the first whooping crane to start the migration," Stehn said.

As of the most recent aerial count last Wednesday, the other 214 members of the flock of endangered cranes were still on the 35-mile stretch of Texas coast near Tivoli, which serves as their wintering grounds, Stehn said.

But they shouldn't be there much longer.

"Right now there are excellent migration conditions," Stehn said Monday during a boat tour of the cranes' marshy habitat along Blackjack Peninsula and the Gulf Intracoastal Waterway.

"Tuesday is supposed to be even better. We're supposed to have sunshine and southeast winds 20 to 30 mph. So any crane ready to leave could very well go."

"They're anxious to get up there to nest," Stehn said. "They've got business to take care of."

Tour-boat captain Tommy Moore of Rockport explained it this way: "They're feeling amorous. They're doing their dances. It's time to go."

It takes about three weeks for the big cranes to fly the migration route north.

In Canada, nest building begins immediately and within a week or two, the first eggs will appear. The gestation period is about 30 days.

Stehn said he hopes the upcoming breeding season will result in another jump in the flock's population, which has been growing by about 4 percent per year since the 1940s.

The whooping crane, the tallest bird in North America, stood on the precipice of extinction just 60-some years ago, when numbers drooped to just 15.

But in what has become one of the great success stories of wildlife conservation in action, the cranes' numbers, thanks to efforts of conservationists like Stehn, have rebounded.

The population of the Aransas flock, the largest and only naturally occurring migrating flock of whooping cranes on the planet, reached a modern-day high of 217 this year.

Stehn said the wintering season at the Aransas refuge was "an absolute record year - an increase of 22 birds from last spring and the most chicks that we've ever had down here, 34."

The crane's most important food source, the blue crab, was abundant this winter, he said.

"Each adult crane eats about 80 crabs per day," he said, adding that crab numbers remain strong and, as a result, the cranes "are getting a good boost of energy right before the migration."

Out of the 217 cranes, only two - one adult and one chick - died over the winter.

Stehn found one of the carcasses.

"It was just a pile of feathers. If I had to guess, it could have been a bobcat" that killed it, he said.

But it is the migration that is the most hazardous time of year for the whoopers.

They've been known to fly into power lines, get shot by hunters, become meals for predators.

Stehn said citizens can help the cranes along the way.

Anyone who sees a migrating whooper is asked to call Stehn at the refuge at 361-286-3559, ext. 221, or e-mail him at .

The Fish and Wildlife Service receives about 50 sighting reports from citizens every migration period, he said.

If the birds are spotted on the ground, Fish and Wildlife will try to dispatch a trained ornithologist to take a look at them and determine if they're in any kind of trouble.

Stehn said the cranes leave their refuge wintering grounds in small groups.

An adult male and female and their chick might take to the air first. Their next-door neighbors at the refuge, where each crane family group claims about a square mile of marsh territory, might see them go and then follow, Stehn said.

"So you might have five cranes going all at once," he said.

Most of the cranes will be gone by mid-April. Some of the cranes wait around until late April or early May, when the last stragglers will spread their 7-foot wingspan and begin the long flight.

The Skimmer, a 39-foot, double-decker tour boat captained by Rockport's Tommy Moore, shoves off from a refuge dock.

Aboard are about 40 officials of the Guadalupe-Blanco River Trust, the Guadalupe-Blanco River Authority and the Fish and Wildlife Service, as well as members of their families.

GBRA and the Wildlife Service had earlier in the day signed an agreement, brokered by the River Trust, under which the Myrtle Foester Whitmire portion of the refuge, located near Indianola, will receive from GBRA its first-ever guaranteed supply of water, needed to ensure that the Whitmire unit, an important home for wintering waterfowl, remains a strong and healthy habitat during droughts.

The tour group's aim is to take a gander at the whooping cranes, the most celebrated and beloved of all the wild inhabitants of the refuge, before the cranes take wing for their spring migration.

It isn't long before the first cranes are spotted: two parents and a juvenile feeding calmly in the flat, green marshes, which are decorated here and there with yellow wildflowers.

The observers use spotting scopes and binoculars to peer at the birds. Someone notes that the juvenile wears a reddish brown coloration on the top of its head, a flourish not seen in the older birds.

A few minutes later and about a mile farther down the Gulf Intracoastal Waterway, another family group of three is spied.

Another mile and another pair of the big cranes is seen.

Stehn identifies the area as Sundown Bay, which he calls "the real heart" of the whooper's wintering grounds. When the population dropped to just 15, he said, this is where that 15 wintered.

Another pair is seen, feeding calmly like the others.

But it is a single young female seen a few minutes later that really grabs the tour-goers attention.

She is combing the edges of a small brown pond, just 45 yards or so from the rails of the Skimmer. Something at her feet in the marsh spooks her and she jumps, flapping her black-tipped wings and hopping away.

The spotting scopes and binoculars and cameras are focused on her as she continues working the edges of the pond. Now she's got something.

Captain Moore explains: "She's eating a crab, breaking it up. She'll eat the legs first and then the rest of it."

The Skimmer moves on, then Moore cries out: "Three whooping cranes on the wing in front of us at 11 o'clock. Going across left to right."

We watch the three endangered creatures fly in a graceful single-file formation deeper into the marsh.

Just ahead, another family of three cranes is feeding. "This adult pair had twins last year and both chicks survived. That's something that happens very rarely," said Moore.

Two more cranes are seen in open water. Moore tells us they have special goggles built into their eyelids that allow them to see under water to hunt.

Farther on, we see the crane known as the "lobstick male." Moore says the crane is 27 years old and is the oldest wild whooping crane in the world.

Despite his age, the lobstick male fathered twins last year and another chick this year. "He's some good stock," Moore says admiringly.

The Skimmer makes its way, passing bottle-nosed dolphin, an alligator, more whoopers, whose record numbers on this day have been very apparent.

Tom Stehn puts it into perspective.

"The flock is interacting with its habitat the same way it's been doing since the Ice Age," he said. "We're trying to keep man from them and let them be natural."

Conservationists are also working on establishing two other flocks: one a non-migratory population in Florida, the second a flock that is being taught to migrate between Wisconsin and Florida.

But despite their rising numbers, Stehn said the birds remain vulnerable.

Disasters such as oil spills or red tides could decimate the Aransas flock's habitat. A rise in sea level could make the Texas coastal marshes too deep to be suitable as whooping crane habitat.

Diseases such as West Nile Virus could impact the birds. Power lines and hunters and natural predators are a constant threat.

In Florida, one of the cranes strayed too close to a golf course and was struck by a golf ball and killed.

"There are a lot of threats," Stehn said. "It's going to take a lot of people keeping watchdog on the cranes in order for them to survive."