avian pilotage

"Dan Luke" wrote in message
...
"Gary Drescher" wrote:
pigeons ... follow roads.

That doesn't mean they're using pilotage. The pigeons are carried along
the roads in cars to the release points. How would they recognize a
route from the air they had traveled (and probably not seen) only on the
ground?

Birds are capable of magnetic navigation.
http://www.gi.alaska.edu/ScienceForum/ASF3/345.html
Most likely the pigeons are able to sense and store the route they
travel to the release point, and then retrace it home.

You raise a good question. It's conceivable that the pigeons identify
landmarks from the ground that they can recognize from the air. But not
having read the road-following study itself, I can't really discuss it
intelligently. Offhand, though, I'd be skeptical that a stored magnetic
route (fly heading 053 for 220 meters, then 072 for 570 meters...) could be
precise enough that the pigeons would stay above a road and turn at
intersections, even following rotaries. (And the pigeons would need a
source of distance information, as well as heading information--perhaps
derived from timers and accelerometers, or visual cues.) A system
incorporating both pilotage and magnetic tracks is certainly a possibility.

--Gary

--
Dan
C172RG at BFM
(remove pants to reply by email)

Pigeons have been put on trains/boats/planes and carried for
hundreds/thousands of miles, including overwater... When released thay
usually find their way home...

I personally, not due to any published articles feel that their magnetic
field sensing is far more sophisticated than simply saying, "North is
thattaway"... I suspect that they sense magnetic patterns analogous to the
way that our eyes do with reflected light - pattern recognition that allows
you to walk to the front door and put your hand on the knob - and our ears
do, in that we can track the sound of the dripping faucet... They live in a
world of rippling, flowing, magnetic currents that they sense and track,
like following the echoes of the faucet through the house at night...

denny

"Dan Luke" wrote in Most likely the pigeons
are able to sense and store the route they
travel to the release point, and then retrace it home.

"Dan Luke" wrote in message ...
"Gary Drescher" wrote:
pigeons ... follow roads.

That doesn't mean they're using pilotage. The pigeons are carried along
the roads in cars to the release points. How would they recognize a
route from the air they had traveled (and probably not seen) only on the
ground?

The article I read said they basically fly like us. When they cross
the ocean or fly home after being driven somewhere they use a
combination of things (their brains are sensitive to magnetic field
and they seem to know where the sun is and should be). However, if you
ask them to fly the same path over and over they get lazy and shut off
the "GPS" and just follow the roads. That makes sense, that's how I
fly. I don't use the GPS to fly around the local area.

It also makes sense because other animals work that way. A dog finds
his way home by following the roads he's familiar with. There is no
reason to believe birds who fly the same path all the time don't do
the same.

-Robert