Posted on 02/04/2004 6:21:47 PM PST by blam
How do homing pigeons navigate? They follow roads
By Caroline Davies
(Filed: 05/02/2004)
Researchers have cracked the puzzle of how pigeons find their way home: they just follow the main roads.
Zoologists now believe the phrase "as the crow flies" no longer means the shortest most direct route between two points. They say it is likely that crows and other diurnal birds also choose AA-suggested routes, even though it makes their journeys longer.
Some pigeons stick so rigidly to the roads that they even fly round roundabouts before choosing the exit to lead them back to their lofts.
Animal behaviouralists at Oxford University are stunned by their findings, which follow 10 years of research into homing pigeons. For the last 18 months they have used the latest global-positioning technology, allowing them to track the ground the birds covered to within one to four metres.
"It really has knocked our research team sideways to find that after a decade-long international study, pigeons appear to ignore their inbuilt directional instincts and follow the road system," said Prof Tim Guilford, reader in animal behaviour at Oxford University's Department of Zoology.
"For long-distance navigation and for birds doing a journey for the first time, they will use their inbuilt compasses and take sun and star bearings.
"But once homing pigeons have flown a journey more than once, they home in on a habitual route home, much as we do when we are driving or walking home from work.
"In short, it looks like it is mentally easier for a bird to fly down a road and then turn right. They are just making their journey as simple as possible".
His team carried out dozens of tests with pigeons in Oxfordshire, releasing them between 10 and 20 miles from their lofts, each with a tiny GPS tracking device attached to their backs. Matching their routes, they found most flew straight down the A34 Oxford bypass.
"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".
Not all of the pigeons did it all of the time, but there were enough occasions when they did for the researchers to build up a pattern.
"We even had one bird flying down the road, going round the roundabout, taking one of the turnings down that to another roundabout then leaving the road.
"Up until now, we have always thought about the way that birds go in terms of the energetics of the flight efficiency, which is the most direct route home . . . as in the phrase 'as the crow flies'.
"But the answer is, they don't go as the crow flies, and neither, it is my hunch, do crows. As they get familiar with the environment, they just follow the obvious features which often don't take them directly home.
"That may sound trivial to some people, but to us that is quite important because it is starting to get at the structure of a birds' memories, and what the map looks like to a bird.
"We are genuinely surprised. It makes you think what did pigeons and other birds do before we cluttered the landscape with all these linear features. And it makes you think hard about how flexible animals are amid what we have done to their landscape.
"Lots of animals have invaded and made use of the changes we have provided for them. You only have to look at Trafalgar Square and how it has become a fantastic three-dimensional cliff environment for pigeons to live in. It's evolution in action.
"Maybe they were using rivers and coastlines before. But when we got our first tracks of birds flying up the dual carriageway and then turning off the road to the village where their home loft was, we thought, 'This shouldn't happen, but it's very exciting'.
"Roads and important things like roundabouts do appear to be very attractive to birds. If they have made the journey before, the pigeons are more likely to say, 'Well, I know this is south - the way I want to be going - but rather than fiddle around with my inbuilt compass I'm going to follow the A34, which will take me home nicely'."
Peter Brian, general manager of the Royal Pigeon Racing Association, based in Cheltenham, said: "Every Saturday you can see whole flocks of pigeons flying up the M5. Prof Guilford's research in animal behaviour and migration is renowned and there is a lot of credence to what he is saying. I think his findings are spot-on".
Very probably, in this experiment, the pigeons were taken from their homes to their launch points by vehicles using roads. Even if the birds couldn't see the highways, they probably (on an instictive level if nothing more) figured out that their outward trip involved roads, and once aloft they used the nearest road to find their way back.
There is also the possibility that roads, being clear of grass and trees and mountains, provide different air movement than natural landscape and the birds follow the more regular air flow that would be above roads because it's easier than flying over natural (and uneven) landscapes.
Normal pigeons do it by instict.
I would be very concerned if they became that small...
How did they do this job/survey? (sitting down, legs crossed)
Pigeons have iron related minerals in their inner ear that will align to the magnetic field. Some humans have that also, as I was remember from that initial research.
My father and I could always detect North, even when blind-folded and often made a game of it with our family.
That is why the pigeon research has stuck with me all of these year.
Is that how we do it? If I need to seek North, I just close my eyes and turn until it "feels" right.
OMG, at five pounds apiece, even the crack of dawn wouldn't be safe.
I've read this also. Humans too.
Yup, it's a very ancient gene.
Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.