Narins, P.M.*; Lewis, E.R.: Good Vibrations: Seismic Signal Use by Fossorial Mammals

Low-frequency seismic vibrations are known to travel across the surface of the earth, a medium relatively free from background noise. In recent years, seismic sensitivity has been recognized as an important sensory modality in fossorial mammals. Consistent with this idea, it has been experimentally demonstrated that seismic signals are propagated at least an order of magnitude better than airborne signals between the natural tunnels of the South African Cape mole-rat, Georychus capensis. Indeed, low-frequency seismic signals are generated by foot- and head-drumming in many fossorial rodents. It has been proposed that the “seismic communication modality may be the major long-distance communication channel in the evolution of�[the mole-rat Spalax]�and possibly in subterranean mammals generally”. Evidence is accumulating to indicate that certain fossorial mammals, as in the case of frogs, may use the auditory system to detect seismic signals. Geophone and microphone measurements in the sand suggest that the Namib Desert golden mole (Eremitalpa granti namibensis) is able to detect termite colonies and other prey items using seismic cues from distances up to 20 m, presumably aided by its hypertrophied malleus and the low substrate background noise level. We here review the evidence for the use of seismic signals by subterranean mammals and discuss putative mechanisms underlying their detection.