missing_pigeon

168 Flight of the mystery birds www.frontiersinecology.org © The Ecological Society of America In late August 2012, the BBC, along with several respect-ed British newspapers (including the Guardian and the Daily Telegraph), plus a host of smaller and sometimes more sensationalist news sources, reported the mysterious dis- appearance of a flock of racing pigeons. The stories told of how, out of 232 birds released in Thirsk, a small town in northern England, just 13 had made it back to their lofts in southern Scotland. The pigeon fanciers who were inter- viewed added that bird losses over the same area had been high since April. Their describing it as a kind of avian Bermuda Triangle was a journalist’s dream – a dream likely responsible for the press failing to report the full story. “What actually happened was that only 13 birds had returned to their lofts within the designated race time”, explains Linda Brooks, Secretary of the Scottish Homing Union, the body governing pigeon racing in Scotland. “By the next day, 60% of the birds released were home, and within a few days about 80% were back; that’s not a very unusual loss rate.” So, the birds had not dis- appeared into thin air after all. However, something did make all but 13 late, and prevented some from ever coming home. But what? Oddly, there may actually be Bermuda Triangle-like areas for some birds. “There is a place about 90 miles west of Ithaca, New York, called Jersey Hill Fire Tower, and homing pigeons raised at our lofts at Cornell University become totally disoriented there”, explains Charles Walcott, Emeritus Professor of Neurobiology and Behavior at Cornell. “Only about 10% of them ever return home from that location. But birds from other lofts, even as close as 10 miles away, have no trouble at all getting back.” However, the Scottish birds came from many lofts, so while some may have found it harder to fly from Thirsk, all but 13 would hardly be late for that reason. Could the weather, or even space weather, have affected them? Pigeons use the Sun as a primary cue for finding their way home, and on the August 18th race day, north- ern England suffered another dull and rainy day. But no problem; even if the birds in Thirsk got no glimpse of the Sun, they would have relied on their internal magnetic compass system. Were they, then, thrown off course by some interference with their perception of the Earth’s magnetic field, perhaps, as the press hinted, caused by solar flares? Unlikely; the British Geological Society’s data for the area’s K index, a measure of solar- induced disturbances in the magnetic field, show there were no perturbations in the race area at all in August. We know, however, that pigeons, especially inexperienced youngsters like many of those released in Thirsk, often try to fly around bad weath- er or even land to avoid it – perhaps the birds simply took the long way around to avoid heavy showers over northern England, or landed somewhere to sit them out. The dread- ful weather the area had experienced in this, the wettest of all British summers, may also help explain the other losses endured over the racing season. But that may not be the full story. The weather in Scotland on the 18th and 19th of Aug- ust was reasonably sunny and that may have brought the birds new trouble: raptors. The increase in peregrine fal- cons (Falco peregrinus) and sparrowhawks (Accipiter nisus) in the UK is a conservation success story. Rising from once-crashed populations, the country is now home to some 1400 and 40 000 breeding pairs, respectively. Sadly, this has brought conservationists and pigeon racers into conflict – peregrines and sparrow- hawks eat pigeons. The racing fraternity insists attacks are causing huge losses among their flocks and has even lobbied the British Parliament for protection for their often very expensive birds. Conservation groups, in contrast, have quoted different studies to argue that 86% of pigeons that fail to return home do so for reasons other than falling to raptors. Of course, that means that 14% of non-returners are taken by them. “But it’s not just about predated birds”, says Brooks. “Raptors can send panic through a pigeon flock, causing birds to fly off course or crash into buildings or overhead cables. I’ve even heard a report of a whole flock ditching in the sea while being harried by peregrines. And it’s in bright, clear weather when pigeons fly high that peregrines above them have the necessary time and space to dive down and strike.” The rain-delayed birds returning from Thirsk may have encountered more than better weather in southern Scotland. They may have run into raptors and been scattered. Of course, some of the missing birds may have just gone feral, but none slipped into a secret dimension. Ironically, the truths of that race did; they are nestling in the minds of cooing pigeons, forever beyond our reach. Adrian Burton Racing for home. LIFE LINES LIFE LINES LIFE LINES C G eh rig /w ww . iS to ck ph ot o. co m