seismic communication

  • How elephants communicate

    Like all highly social mammals elephants have a well-developed system of communication that makes use of all of their senses - hearing, smell, vision and touch - including an exceptional ability to detect vibrations.

    Acoustic communication takes a look at sound production and hearing in elephants; chemical communication explains how elephants use various secretions and their acute sense of smell to communicate; visual communication looks at how elephants make use of postures and displays and their sense of sight in communication; tactile communication describes how elephants make use of their sense of touch to communicate.

    At one end of the spectrum elephants communicate by rubbing their bodies against one another, at the other end they may respond by moving toward the sounds of other elephants calling, perhaps 10 kilometers away. They convey information about their physiological (e.g. sexual/hormonal, body condition, identity) and emotional state (e.g. whether they are fearful, playful, joyful, angry, excited) as well as communicating specific "statements" about their intentions or desires. In this section we look at how elephants use the different pathways of communication and the actual mechanics of communicating.

    You will in the fully searchable database The Elephant Ethogram: A Library of African Elephant Behavior find close to

  • Seismic communication

    References

    Seismic energy transmits most efficiently between 10-40 Hz - in the same range as the fundamental frequency and 2nd harmonic of an elephant rumble. It turns out that when an elephant rumbles a replica of the airborne sound is also transmitted through the ground. Elephant sounds have been measured as traveling at about 309 meters per second through air and at about 248-264 meters per second through the ground.

    Experiments carried out by Caitlin O'Connell and colleagues have shown that elephants are able to pick up these seismic signals, to orient in the direction that the vibrations come from and even to respond to them appropriately.

    Elephants may be able to detect these seismic vibrations, or rayleigh waves, through two possible means: bone conduction and the use of massive ossicles of their middle ears or, possibly, by mechano-receptors in the toes, feet or trunk that are sensitive to vibrations.

    The tip of an elephant's trunk has layers of cells called Pacinian corpuscles that are extremely sensitive to vibrations and are thought to be able to detect movement as subtle as Brownian motion. Pacinian corpuscles have also been found in the elephant foot - concentrated in the front and back (toes and heel