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NEW ORLEANS (AP) — Louisiana’s small flock of young whooping cranes has already equaled last year’s nest total with four, and there’s a good chance of doubling that number. But if the eggs hatch, will the young adults be good parents?
The question arises because the birds taught to migrate by following ultralight planes from Wisconsin to Florida have had little success raising chicks. Out of hundreds of eggs, 64 have hatched, but only nine chicks lived long enough to fly.
Like those in the flock taught to migrate by following ultralight planes from Wisconsin to Florida, Louisiana’s birds grew up in a crowd that learned to eat and drink by mimicking the pecking of model crane heads held by people in baggy white garments with hoods and black masks. Their caretakers flapped their arms and the birds copied them, ultimately managing liftoff.
That let biologists raise more youngsters than cranes could on their own, and kept the chicks from imprinting on humans as their parents.
But this year, the public-private group overseeing all captive-bred whooping cranes decided to see whether upbringing is the problem with the migratory flock. Perhaps they really need parent cranes to learn how to be crane parents.
So instead of being hatched in incubators and raised by costumed people, eggs for that flock will be hatched and raised by cranes, then, at about 3 months old, released near a wild pair that is still flush with parenting hormones because they recently either lost their own chick or laid eggs that didn’t hatch.
Pete Fasbender, a U.S. Fish and Wildlife Service member of the supervisory Whooping Crane Eastern Partnership, said he’s worried Louisiana’s cranes may have the same problem as the human-created migratory flock.
The next year or two will show one way or the other, said Sara Zimorski, a biologist with the Louisiana Department of Wildlife and Fisheries, adding she’s not worried now.
“I think our birds have shown a lot of promise,” she said.
Whooping cranes, standing at 5 feet tall, are North America’s tallest flying bird and among the world’s rarest with only about 600 alive. About half are in the only natural flock, which migrates between Canada and Texas. Another 137 are captive, nearly 100 are in the eastern migratory flock, and 42 are in southwest Louisiana — where a non-migratory flock once lived.
All are descendants of 15 birds that survived in Texas. If any chicks peck their way out of the shell in Louisiana, they’d be the state’s first wild hatchlings since 1939.
Cranes mate for life, and trade off time incubating their eggs.
Zimorski said one very promising pair laid their first eggs this year.
“They did really good nest switches,” she said of the cranes and their habit of taking turns on the nest keeping the eggs warm. She added they had well-timed changes accompanied by a duet of the calls that give the bird its name.
This pair’s eggs may well be infertile, like those of the first pair to lay this year, Zimorski said. That pair didn’t incubate their eggs to full term last year, but did this year. In addition, their switchovers had become better synchronized by the end of their nesting season.
“That’s a little progress in the right direction,” she said.
If a chick dies or an egg fails, cranes will often lay new eggs, and the pair whose eggs didn’t hatched have time to do so this year, Zimorski said.
In Louisiana, only one pair of last year’s eggs was known to be fertile, but that nest was flooded, ruining the eggs. So far, flyovers haven’t spotted a nest for the definitely fertile couple. Zimorski said another flyover is scheduled next week.
Whooping cranes’ early clutches of eggs often are infertile.
“They’re just starting to practice being adults,” said Sarah Converse, an ecologist at the U.S. Geological Service’s research station in Patuxent, where the largest number of captive whoopers is housed.
“Everyone in the crane community is looking at Louisiana now with their fingers crossed,” Converse said.
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