Seismic Signal Use by Fossorial Mammals

Abstract

The subterranean environment is not favorable for the use of vision or the audition of airborne sounds as means of long-distance sensory perception. However, seismic vibrations have been shown to propagate at least an order of magnitude better than airborne sound between the burrow systems of the mole-rat Georychus capensis. The use of the seismic channel for communication underground is well documented for other species of bathyergids, as well as the spalacine mole-rat Nannospalax. It has recently been suggested that the golden mole Eremitalpa granti namibensis may also be sensitive to ground vibrations, in this case used in foraging in its desert habitat. In this paper, the use of seismic signals among these and other fossorial mammals is reviewed from theoretical, behavioral and anatomical standpoints. The question of whether auditory or somatosensory means are used to detect vibratory signals is examined. Attempts to explain the distribution of seismic sensitivity and communication mechanisms among fossorial mammals are considered. The potential influences of different soil type and digging methods are discussed, and it is proposed that digging mechanisms involving the head might preadapt a fossorial mammal towards the development of seismic sensitivity.