Ecological Constraints for Sound Communication: From Grasshoppers to Elephants

Abstract

Sensory ecology is mainly concerned with the mechanisms that enable an animal to produce or utilize signals within its specific environment, and how the information about identity or location of the sender is transmitted to the receiver(s). Biotic and abiotic factors constrain the transmission of an acoustic signal and the performance of receivers in detection and location. Since animals use acoustic signals in a wide range of carrier frequencies — from infrasound to high ultrasound — with corresponding wavelengths spanning a range from tens of meters to a few millimeters, the rate of attenuation and degradation of sound signals varies largely in different communication systems. As a result, the active range of a sound signal covers probably hundreds of kilometers for marine mammals, several kilometers for elephants, to less than 1 m in some grasshoppers. This chapter examines some mechanisms by which these different animals achieve a maximum range of communication. In particular, I will show how sound interference in stratified environments can dramatically influence communication distance, and how animals adapt their timing and location of the site of their signaling to these environmental conditions.