Sophont
Sunday, February 22, 2004
 
Pigeon Navigation
femail.co.uk: They are known as the great natural navigators of the sky, using an in-built compass to find their way home across hundreds of miles.

Taking their bearings from the sun and stars, pigeons have become famous as messengers with an unerring sense of direction.

But a ten-year study has found a rather more down-to-earth explanation for their astonishing skill.

They are simply following roads and major junctions.

Researchers at Oxford University were taken aback to find that the pigeons ignored their in-built compass wherever possible, choosing instead to follow the main roads beneath them.

Using tiny transmitters strapped to the birds' backs, they were repeatedly tracked flying down motorways before circling round city ring roads and even turning right and left at main junctions - often adding miles to their journey.

Pigeons 'like humans'

Tim Guilford, a professor of zoology at Oxford, said pigeons are rather like humans when it comes to finding their way: they prefer to follow main roads rather than go cross-country, simply because it is easier.

"It really has knocked our research team sideways to find that, after a decade-long international study, pigeons appear to ignore their in-built directional instincts and follow the road system," said Professor Guilford.

"For long-distance navigation and for birds doing a journey for the first time, they will use their in-built compasses and take sun and star bearings.

"But once homing pigeons have flown a journey more than once, they appear to ignore the traditional forms of navigation and depend more and more on the roads that they remember being on the route the first time they flew it.

"Our interpretation is that they do this simply because it is easier.

Making journey simple

"Research has found that for birds, even a small area of landscape has a phenomenally large amount of information.

"But by ignoring all this excess information and remembering the road system, pigeons are just simplifying things. They are making their journey as simple as possible.

"So, as strange as it sounds, pigeons really do end up following the AA-suggested routes."

The research follows the development of a global positioning tracking device weighing only two-thirds of an ounce, and small enough for a pigeon to carry one on its back.

Professor Guilford's team carried out dozens of tests with pigeons in Oxfordshire, releasing the birds ten to 20 miles away from their "home" destination.

He said: "The transmitter we are using gives out directional bearings every second so we can track the bird's journey almost exactly.

"By matching their routes to detailed maps of the country it is striking to see the pigeons fly straight down the A34 Oxford bypass, and then sharply curve off at the traffic lights before curving off again at the roundabout.

"It was almost comical watching one group of birds that we released near a major A-road.

"They followed the road to the first junction where they all turned right and, a couple of junctions on, they all turned left."

Navigate by eye

He said birds find it easier to navigate by eye when they are not flying over oceans or on long-distance journeys.

"Like us, birds prefer to follow the AA-suggested main routes, even if it means they are taken miles out of their way, rather than try to be really clever by taking all the country roads."

Peter Brian, general manager of the Royal Pigeon Racing Association, said he believed Professor Guilford's research was "spot on".

He said: "The Royal Pigeon Racing Association is based in Cheltenham and every Saturday you can see whole flocks of pigeons flying up the M5.

"Professor Guilford's research in animal behaviour and migration is renowned and there is a lot of credence to what he is saying."

AA spokesman Rebecca Rees said: "We devise 30million routes for motorists every year - but we didn't realise thousands of pigeons were among our customers."

Professor Guilford's research features in an BBC documentary, Animal Camera, to be screened later this month.

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