Our associate editor Antonio Nafarrate has brought this paper to my attention.
“Does the Earth’s magnetic Field serve as a reference alignment for the Honeybee waggle dance” (Dec 2014) by Professor Gerhard Gries et al.
This paper is fascinating as it uses the famous waggle dance performed inside the hive by the foragers to show other bees where there is a good food source as the driver for researching if bees are directed by gravity or the magnetic field.
I liked the way that they bothered about the fact that this is conducted in the darkness of the hive on the vertical sides of the combs where the direction of the sun (which is the key director) is the vertical and the angle off is the bearing for the food source. The dance also tells how far off the food source is to be found. They admit we still do not understand how the other bees read the waggle dance in the pitch black of the inside of the hive.
The question for the researcher was whether the reference lines for the bees is the magnetic field or the Earth’s gravitational field. As changing the gravitational field is impossible and would upset the bees it was decided to change the hive magnetic environment with Helmholz coils to manipulate both the declination of the magnetic field and its intensity.
Whatever was done to the Magnetic environment (LGMF = Local ambient geomagnetic field) this had no effect on the waggle dance and its efficiency in recruiting and directing bees to the food source. This led the researchers to conclude that the direction of the Earth’s gravitational field was the obvious alternative reference line.
This is a seminal piece of work as it again questions the belief that animals use the magnetic field to navigate by. Interestingly, the Wiltshcos, whose work on magnetic navigation in animals is legendary, were invited to review this paper.
Summary by Richard Nissen
Editor – July 2015