All of the studies referenced by Adrian and Jim use the same technology --
pioneered by Joe Riley in England.   None are true radar in the strictest
sense.  They all use a diode on the back of the bee, an antenna, and a
radio transmitter/receiver, usually mounted on a trailer.  The transmitter
sends out an RF signal.  That supplies the 'power' to the diode.  The diode
'wakes up' and sends back a beep at twice the original RF frequency.  The
'radar' dish on top of a trailer plots the beeps.

Joe has a couple of versions - the larger one seen on the TV clip, that was
also used in an earlier paper on honey bee orientation - again in
Nature.  Joe has a smaller version for honey bees. Its fragile, so
investigators working with honey bees have tended to opt for the larger
one.  The weight of that unit is close to the maximum weight that a bee can
carry.

Joe's units use a vertical antenna on the insect (the range of the harmonic
system is affected by the orientation of the antenna relative to the
receiver dish).

At least one honey bee investigator chose the 'bumblebee' version of his
transponder because the long antenna served as a 'handy' handle.

Several years ago, we worked with Battelle Pacific Labs on a similar
system.  We gave it up after deciding the size and weight of our device too
severely impacted the bee's behavior -- it could barely fly.

I brought Joe to the states a few years ago, saw lots of his data.  His
bumblebee data was interesting, and it seemed that bumblebees managed to go
about foraging without too much trouble.

To date, most of the honey bee work talks about linear flights.  You might
fly in straight lines too, if you had the equivalent of the telephone pole
sticking up from your back.  I'm surprised that the bee can turn without
falling over and out of the sky.

Despite popular press claims, we (at UM) do not have a usable RF system for
tracking bees. We've got pin point sized chips -- but haven't resolved the
antenna problem.  However, one of our collaborators used a laser to plate a
foil antenna on the back of a living bee.

We do have RF chips for marking hive equipment.

Hope this helps explain the technology.

Jerry

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