Post by cjm on May 30, 2016 18:13:26 GMT
Curiously Krulwich
A Blog by Robert Krulwich
After Tens of Thousands of Pigeons Vanish, One Comes Back
Posted Thu, 05/26/2016
At first the whole thing seemed preposterous. No way this could happen. Tom Roden, 66 at the time, was standing at the door of his home near Manchester, England. “I was just setting out on a walk with my dog when I saw him,” he told a reporter. “I recognized him straight away because of his white tail feathers.”
It was a pigeon. His pigeon. It had been missing for five years. Suddenly it was back. Why? And where were the tens of thousands of pigeons that vanished with him?
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It had a name: Champion Whitetail. In 1997, Roden had sent Whitetail and a bunch of other racing birds to France, 430 miles south, to compete in the Royal Pigeon Association’s centenary cross-Channel competition, a major long-distance pigeon race with cash prizes that attracted 60,000 bird entries. The contestants, quietly cooing, were brought to a field near Nantes and released at 6:30 in the morning—that was the race’s motto: “At dawn we go.”
Picture of the logo of the Central Southern Classic Flying Club with a pigeon flying through a sunrise
At the signal the birds took flight and, following a deep pigeon instinct, dashed at speeds as high as 50 miles an hour straight back toward their roosts, or “lofts,” all across England. This is something pigeons do. It’s called a homing instinct, and even though many of these animals had never been to France before, didn’t recognize the land below them, and had to cross a wide channel of ocean water before finding the house or roof or backyard from which they came, normally most of these racers would have find their way home.
Whitetail was expected to arrive early, because he was a champion. He’d already won 13 races in his lifetime, had flown across the English Channel 15 times, and had finished the Central Southern Classic from Lessay in northern France against a field of 3,026 birds with the winning time. He was a bird to watch.
So on Sunday, June 29, 1997, Roden was doing just that—waiting at home and watching for Whitetail, who could be expected to land at, well, Roden was hoping for a 2 p.m. or so arrival. Maybe earlier. He waited. And waited.
But Whitetail didn’t show.
A few of Roden’s birds did arrive later that day—but not Whitetail. The same thing was happening all over England. Tens of thousands of birds belonging to hundreds of English pigeon racers never made it home. They simply disappeared. There’d been no storm on the Channel, no ferocious headwinds, no giant gusts, nothing that would explain why so many birds would suddenly vanish. Where did they go?
The newspapers dubbed this “The Great Pigeon Race Disaster.” And for the next five years nobody could say what happened until Roden, standing at his front door, saw Whitetail calmly land right there in front of him. Could it be, he wondered? So he went and checked the ring attached to one of the pigeon’s legs, “and his ring number confirmed I was right.”
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Picture of pigeon fancier Tom Roden holding his pigeon, Champion Whitetail, who disappeared during a race and was missing for five years
Photograph by PA, TopFoto, The Image Works
Whitetail was back. “I was absolutely amazed,” Roden told the Manchester papers. “He must have a phenomenal memory to recognize his way home after all this time.” For a 16-year-old pigeon, he looked spry and healthy. Pigeons tell no tales, of course, but his reappearance meant whatever it was that pushed tens of thousands of pigeons off course hadn’t killed them all. More than a few scientists were curious.
When they checked, not only was the weather on that day in 1997 largely clear—with no sudden changes in barometric pressure, no unusual fogs, no interference in the magnetic field (which pigeons use to navigate)—but nothing obvious seemed amiss.
That’s when a geophysicist at the U.S. Geological Survey, John Hagstrum, had an idea. What if birds navigate by hearing sounds we humans can’t? Earlier experiments had shown that pigeons can hear tones 11 octaves below middle C—that’s way, way below our human range. What might they be hearing?
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Here’s a hint: Jennifer Ackerman, in her new book The Genius of Birds, describes another bird mystery. This one took place in eastern Tennessee.
It was April 2014, and researchers at the University of California, Berkeley, were testing whether a population of tiny golden-winged warblers … could carry geolocators on their backs. The birds had arrived only in the past day or two after a 3,000-mile journey north from their wintering grounds in Columbia. The team had just attached the gizmos to the tiny warblers when all the birds suddenly flew the coop, spontaneously evacuating their nesting grounds.
Where’d they go? Why would so many birds all scatter at the same time? Ackerman says that later scientists learned [H.M. Streby et al, “Tornadic storm avoidance behavior in breeding songbirds,” Curr Biol (2014) doi:10.1016/j.cub.2014.10.079.] that a gigantic spring storm, a supercell, was heading toward Tennessee at that very moment—one that “would spawn eighty-four tornadoes and kill thirty-five people.” When it was still 250 to 500 miles away, the warblers seemed to hear it coming—the deep rumble of storm reached them, and so the birds scattered, flying every which way, even as far as Cuba. When the storm passed, they all returned and began to breed.
Can birds hear subtle changes wafting long distance through the air? John Hagstrum thinks they can. Not just warblers, but, in our case, pigeons may be able to sense soft, low background noises—the sounds of swells in the ocean, the swishswash of waves, changes in air pressure—and can read those sounds as they bounce, wavelike, off hillsides, cliffs and other steep terrain. “Similar to the way we see a landscape,” Hagstrum told Ackerman, “I think birds are hearing it.” These low, low natural sounds are carried on “infrasound waves.” Those waves exist. That we know. They may help birds read the map below them and teach them how to find their way home.
Thinking about the Great Pigeon Race Disaster, Hagstrum noted that our 60,000 pigeons were heading north from Nantes in France at speeds varying from 20 to 50 miles per hour. The fastest birds, he figures, might have reached the Channel Crossing on or about 11 a.m. that day as they headed to their various homes in England.
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Could something have interfered with their ability to “hear” and “read” the terrain below? Something unexpected? Violent? Different?
Hagstrum cast about and noticed that on the day of the race, the fastest commercial airliner in the world, a Concorde supersonic transport (SST) just happened—at 11:20 to 11:30 that morning—to be flying across the birds’ flight path along the English Channel. The Concorde SST in its day was an impressive piece of engineering. It flew so high that passengers could look out the window and see the sky above darkening, glimpsing the edge of space. It traveled at twice the speed of sound (1,354 miles per hour) and so could make the trip from Paris to New York in just three and a half hours. It was also beautiful …
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… but a Concorde in flight leaves its mark—in sound. As the plane gathered speed once it broke the sound barrier at 750 miles per hour, it would have created a shock wave that would have traveled quickly and widely back toward the ground—and back toward those pigeons. The pigeons would have noticed.
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Any jet moving through the air faster than the speed of sound creates a shock, laying down, says Hagstrum, “a sonic boom carpet” almost a hundred miles wide that would certainly have, as Ackerman writes, obliterated “the pigeons’ navigational, acoustic map, completely disorienting them.”
If Hagstrum’s idea proves true, we can imagine what happened on that day. The birds took off, heading north toward England. The Concorde took off, heading west toward America. When the birds and plane crossed paths, the sonic boom trailing off the Concorde so discombobulated the pigeons that, like the Tennessee warblers, they scattered in every direction, flying east, west, north, and maybe even south again, back to Nantes.
Which brings us back to Whitetail. We now know where our champion pigeon spent at least the beginning of his missing five years.
To Monsieur Tom, ‘Interested in Pigeons’
A few weeks after Whitetail’s return, a letter arrived at Roden’s house, addressed to “Monsieur Tom Roden, Interested in Pigeons, Hattersley, England.” It came from Jean Bouchard, resident of Nantes, who wrote that sometime on the day of the cross-Channel race in 1997, he walked into his small garden and found, sitting there, exhausted, a pigeon.
The pigeon had a ring with a number on it. Bouchard wrote down the number and decided to keep the bird for a while, until it “built up its strength.” He built him a birdcage “to protect him from neighbour’s cats” and then, several weeks later, took him to the local natural history museum, where he presumes the pigeon was released.
When, years later, Whitetail’s return to Manchester hit the Internet, Bouchard saw the story, compared ring numbers, and wrote Roden: I’m the guy who found your champion. Your bird was my bird.
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Which leaves me wondering: How come this pigeon, which had outpaced thousands of competitors and crossed the Channel 15 times without a hitch, ended up dazed and exhausted a few miles from the start of his race? Had he gotten sick? Or had he gone hundreds of miles north, hit a shock wave, lost his bearings, reversed direction, and ended back where he started?
We can’t ask him. Even if pigeons could talk, Whitetail was 16 when he returned to England. That’s extremely old for a homing pigeon, even a domesticated one. I imagine Whitetail is beyond talk now. Concordes aren’t flying any more. Tens of thousands of pigeons remain missing. Were they sonic-boomed? Maybe. Where did they go? Nobody really knows, but closing my eyes, here’s what I see …
… An old pair of pigeons, long past their racing days, are hobbling along a busy Polish sidewalk. They have a strange fondness for fish and chips, and when I listen very closely (at 11 octaves below middle C), I sometimes catch them humming snatches from “God Save the Queen.” They seem a little confused.
But that’s just me.
John Hagstrum’s infrasound theory has its critics. A Danish biologist, Henrik Mouritsen, wonders if birds can even hear infrasound. There’s no experiment that proves they can. For the moment, the evidence is based on correlation. Birds behave as if they hear something, but cause and effect are still untested. It’s also possible, Mouritsen thinks, that the reason those warblers left Tennessee was not because they heard wisps of a distant superstorm but because of changes in atmospheric pressure. We just don’t know. Much of what I write here can be found in Jennifer Ackerman’s wonderful new book, The Genius of Birds.