Like college graduates who move back in with mom and dad, three adolescent whooping cranes are steadfastly declining to fly the coup.
For the past three years, human-piloted ultralight aircraft have led new whooping crane hatchlings into an isolated, protected pen at the Chassahowitzka National Wildlife Refuge, where the cranes spend their first winter.
Nearly all the birds from the inaugural flight in 2001 and the second flight in 2002 have spread their wings in subsequent years, finding their own suitable spots to roost.
But three cranes _ a 2-year-old male and two 1-year-old females _ aren't going anywhere, even though they no longer are constrained.
They have formed an ornery gang of marshland bullies that sometimes terrorize the younger birds. They have been spotted chasing this year's flock of 16 hatchlings away from the food and intimidating them with something bird biologists call a "threat walk."
"They're trying to say, "Hey, we're the head of the pecking order,' " said Shawn Gillette of the U.S. Fish & Wildlife Service. "No pun intended."
Program organizers haven't tried to move the older birds along. In fact, sometimes Marianne Wellington, an aviculturist who monitors the birds for the International Crane Foundation, believes the wayward adolescents can be a help. She has spotted them herding the younger birds into the pen, a safe roosting spot for the night.
"They do this bullying stuff, chasing them away from the feeders," Wellington said, "but at times you'll see them acting more like guardians."
When perturbed, the older cranes go after the young ones with their threat walk, described by Wellington as a "rocking-horse gait." They flash the red bird skin on top of their heads at the chicks _ red skin the young birds haven't yet developed.
Then, Wellington believes, they emit a sort of growl.
Like a rebellious teenager, the only male crane in the gang also stands up to "the costume," the term wildlife officials use for crane-outfitted humans who help with the young cranes. The cranes were introduced to the costume as soon as they were hatched and relate to it as a mother.
Costumed pilots fly the cranes south in ultralight aircraft, teaching them a migratory path. The young cranes are expected to fly unaided on their return trip to Necedah, Wis., this spring, and will also return unaided next fall, as the previous two classes of cranes have done.
"No. 5 does not like the costume too much anymore," said Wellington, referring to the 2-year-old male crane still hanging around with the youngsters. "I think he thinks he's grown up and doesn't need the adults around."
To deal with the adolescent whoopers' poor manners toward the young cranes, wildlife officials have added more feeding sites to the pen. Wellington said she thinks the subtle change has done the trick.
Yet she's still not giving up on the idea that the older cranes sometimes act as a troop of helpful role models.
Said Wellington: "I think with the adults coming in, the chicks have . . . become much better fliers."