Bone conduction and seismic sensitivity in golden moles (Chrysochloridae)

Abstract

Some genera of golden moles are known to possess enormously hypertrophied auditory ossicles. These structures have been implicated as potentially mediating a form of inertial bone conduction, used by the golden mole to detect seismic vibrations. A simple model of ossicular inertial bone conduction, based on an existing model of the human middle ear from the literature, was used in an attempt to examine vibrational sensitivity in these animals. Those golden moles with hypertrophied ossicles are predicted to possess a sensitive inertial bone conduction response at frequencies below a few hundred hertz, whereas species lacking these middle ear adaptations are predicted to have a far less sensitive response in this ecologically important frequency range. An alternative mode of inertial bone conduction in golden moles, potentially conferring sensitivity to vertically-polarized seismic vibrations such as Rayleigh waves, is proposed. Certain behaviours of golden moles described in the literature are interpreted as augmenting seismic sensitivity.