Re: Do any organisms utilize radio waves for sensing or conmmunicating?

Dear Aaron,

Your question gets at a fundamental problem in animal behavior and cognition: with so many types of information present in the environment, what cues do animals actually use? We know that many animals can detect signals we cannot, for example: migrating birds utilize the earth’s magnetic field for navigation, some insects can detect ultraviolet patterns on flowers, and elephants can use inaudible (to humans) vibrations for communication. With regard to radio waves, I have found little solid evidence that animals communicate using this source of information. However, a large literature on the effects of radio waves on animal tissues and brain activity suggests that, at least on a physiological level, animals may be sensitive to these waves. While I share your skepticism towards the article you sent on bats by Koemel (1996), I think the author is quite serious. Near the beginning, Koemel references an article he coauthored with Dr. Philip Callahan, who has written a number of works about insect and animal communication. That article (Koemel and Callahan, 1994) suggests that ELF (a type of radio wave) emissions from insect wings may enhance chemical communication signals between the insects. If this is true, some animals may well have "figured out" a way to use radio waves in communication, though in an indirect way. The conclusions Koemel draws in his paper on bats, however, are radical interpretations of the data. What he actually showed were radio wave pulses near several flying bats. While this may be consistent with a role for this type of radio frequency in bat communication, it does not prove so by a long shot.

I did not find much more on animals communicating using radio frequencies.

Articles on sensitivity of animal tissues to ELF and VLF radio waves, on the other hand, are numerous and I’ll give a couple regarding the brain. Recently, Cook and colleagues (2004) showed that ELF pulses affect the resting brain activity in humans. Other workers have looked at ELF effects on snails, showing that neurons fire in closer synchronization in an ELF field (Azanza et al 2002). Such sensitivity is interesting from a couple of perspectives. First, many researchers are interested in side effects on our tissues (brain in particular) from using electronic devices that create such fields. From the perspective of your question, it means that at a physiological level, some animals are sensitive to radio waves, but whether they can make any behavioral use of this remains largely unclear.

This was a really neat question; in my opinion, one we don’t fully understand yet.

All the best,

Jim

References:
Azanza, MJ, Calvo, AC, and A. del Moral. 2002. Evidence of synchronization of neuronal activity of molluscan brain ganglia induced by alternating 50 Hz applied magnetic field. Electromagnetic biology and medicine 21 (3): 209-220.
Cook, CM, Thomas, AW, and FS Prato. 2004. Resting EEG is affected by exposure to a pulsed ELF magnetic field. Bioelectromagnetics 25 (3): 196-203.
Koemel, W.C. 1996. Extremely Low Frequency Radio Emissions in Bat Caves. Journal of Caves and Karst Studies 58(1): 35-37.
Koemel, WC. and PS Callahan. 1994. Relationship of Extremely Low Frequency Radio Emission from Flying Insects to Semiochemical Communications. Annals of the Entomological Society of America, 87: 491-497.