Fort Collins - A tourist-filled raft slammed into the Class 3 rapid Sarah's Hole on the Cache la Poudre River one morning this week.
Some rafters grimaced, others screamed or laughed as they punched through the waves. Their faces were captured by photographer Charlie Malone.
When Malone was done shooting, he pulled the memory stick out of his Nikon camera and slipped it into a tiny Lycra backpack worn by a gray pigeon named Lucky.
Malone gently released the bird riverside, and Lucky took wing.
Malone and the company he works for, Rocky Mountain Adventures, were relying on the uncanny - and scientifically mysterious - ability of homing pigeons to fly for tens and even hundreds of miles and find their way home.
No one knows how they do it, said pigeon expert Charles Wolcott, a professor of neurobiology and behavior at Cornell University in Ithaca, N.Y.
Wolcott believes pigeons rely on "multiple, redundant systems" to navigate accurately - using vision, smell and even the Earth's magnetic field to orient.
Researchers have covered pigeons' eyes or capped them with magnetically active hats to try to disorient the birds. Still, they locate their home base more often than not.
"It's like wearing belts and suspenders - you can disable any one thing, and they still find their way home," Wolcott said.
Dave Costlow, owner of Rocky Mountain Adventures, estimated that last year, 91 percent of the time, his pigeons delivered film or memory sticks fast enough to print and display rafting pictures before clients, still dripping from their ride, walked back into the store.
They get more and more reliable as the season goes by, Malone said.
"I've had people watch me release the birds, and they still don't believe me," Malone said. "They think it's a stunt."
So while other rafting companies race their film back by car or kayak, Rocky Mountain
Rafters, Fred and Shirley Kremer, from Holland, pick out photos from their white water adventure June 21. (Special to the Post / Nathan W. Armes)takes it on the wing. He is, Costlow said, the only one that does it that way.
"We may not increase our profits because of the attraction of the birds themselves," Costlow said, "but we do increase our profits by having our photos ready."
The pigeons, which fly about 60 mph, make that possible. Most of the time.
This year's rafting and pigeon-training seasons began late, slowed by a chilly spring. Costlow's 16 birds still haven't completely adjusted to their work, he said.
Lucky flew just 15 feet from Malone's hands and landed on a pine branch.
"Go, Lucky! You're the one with the film today," the 27-year-old Malone called.
The bird looked calmly down at the photographer and then gazed across the river.
Three of her nest mates - released with her for company - were soaring in wide, high circles, gaining altitude and their bearings before heading back down the canyon.
Lucky stayed put.
"Come on, Lucky," Malone urged. He needed to get back in his car to shoot pictures of another rafting group on a longer trip upstream.
During homing-pigeon races, birds may fly hundreds of miles in a day, and they almost always make it, Cornell's Wolcott said.
"And then there are these strange occasions - called smashes - where for reasons unknown, you'll let 20,000 go and three appear at the home loft," Wolcott said. "We don't know why."
This day, Lucky wasn't racing - or even in a hurry.
At about noon, back in Fort Collins, the morning's soggy rafters returned to the Rocky Mountain Adventures store.
The photos of the rafters and flailing paddles were there, thanks to a backup driver and car.
Lucky arrived later.
"It's early in the season," Costlow said. "They'll get better."