There are certain areas on Earth where homing pigeons seemingly become lost, unable to return home, and simply go missing.
I wrote about such an incident last August, when pigeon racers began calling an area of the UK the “Bermuda Triangle of Pigeons.” Hundreds of pigeons just kept vanishing during the racing season of April 2012, never to return. “When they fly down to the Thirsk, Wetherby, and Consett area…something always seems to happen,” remarked Scottish pigeon racer Austin Lindores at the time.
Explanations ranged from a high number of rain showers to solar flares, something that could force the pigeons off course, but the problem of vanishing pigeons isn’t a new phenomenon. Scientists have long known that certain areas, for whatever reason, interfere with a pigeon’s ability to locate their home.
“The way birds navigate is that they use a compass and they use a map. The compass is usually the position of the Sun or the Earth’s magnetic field, but the map has been unknown for decades,” says Dr. Jonathan Hagstrum. He and his team recently published a study in the Journal of Experimental Biology that suggests pigeons “home in” by sensing infrasound waves, which create an “acoustic map” of their route back.
An infrasound wave is a low-frequency sound, lower than 20 Hz, below the limit of human hearing. However, birds hear much lower than that.
These infrasound waves, originating from deep within the ocean, provide the pigeons with a “map,” which can occasionally become distorted. This may explain why pigeons sometimes get lost – if the infrasound waves in their current location don’t make it to their home, their “acoustic map” is incomplete. They don’t know the way.
Even more confusing for the pigeons is if these waves are carried by the wind, or affected by the temperature, leading them somewhere else entirely. Experiments must, of course, be performed to confirm this idea.