Evolution of Infrasound Communication

How did elephants come to evolve this behavior?

        Until the Miocene Period (~ 24 mya), the areas inhabited by elephants were heavily forested. In such a low-visibility environment, it would have been evolutionarily advantageous to develop other forms of more long-range communication [1].


            Studies of the hyoid apparatus in ancestors to modern elephants reveal that specific parts of the hyoid apparatus (the ceratohyals and epihyals) were lost at one point, creating the structure of hyoid found in modern elephants.  This modern structure of hyoid is connected by muscles to the elephants tongue, and is used to manoevre the tongue forward and backward [8].

            Today, both Asian (
Elephas maximus) and African elephants (Loxodonta africana, Loxodonta cyclotis) are capable of sending and receiving ultrasound signals [7]

Co-evolution of seismic signalling

            Many animals use  seismic stimuli for communication, including some reptiles, amphibians, insects and some small mammals [6].  These animals use seismic signals to communicate  spacing, warning, resource assessing, group cohesion (this is what elephants use seismic signals for), and to find mates [4].   Some examples of other mammals that use seismic signals are African lions and rhinoceroses.