A question was asked about the article in Nature and reports of using
harmonic radar to track bees.

Joe Riley in England pioneered this system, and Elizabeth went to England
to use his setup.

Others in CA got recent coverage by National Geographic concerning a hand
held unit and tracking of butterflies (Riley uses a trailer based set of
transmitters, etc.

The principal is simple.  The hand held units were developed to find skiers
buried under snow.  The "target" (bee, skier, etc.) wears a diode.  The
transmitter signal triggers or activates the diode.  The diode bounces back
the signal (it doubles the frequency of the source signal).  A receiver
picks up the signal and translates it to a visual (radar type screen) or
audible (ping) signal.

We tried the hand held systems and got 400 yds range - but the sticking
point is the length of the antennae (seen in the picture under the URL
listed below).  No bee could ever return to a hive wearing that, and I'm
skeptical about how realistic any flights are wearing that much hardware.
We decided that the bees could fly, but remained unconvinced about the
relevance of the data.  Also, this system does not I.D. individual bees.
You get a ping from the diode.  Diodes in your cell phone, computer, radio,
etc. will also produce a ping.

Having said all of that, congrats to Joe and Elizabeth for the first steps
along this path.  We may find that the bee does ignore the load.  In the
meantime, we keep searching for the technology that makes the breakthrough
- range, individual bee I.D., unrestricted movement (in or outside the hive).

No small task, and lots of hard work has been done by Joe and the gang.
Someone had to start the ball, and these articles will get the idea out on
the land.

Cheers

Jerry


>http://www.enn.com/news/enn-stories/2000/02/02042000/bee_9704.asp