Vibrational Communication in Subterranean Rodents: The Possible Origin of Different Strategies

Here we discuss different factors that could influence the development of vocal and/or seismic communicative channels in subterranean rodents. We suggest that: 1) Highly social subterranean rodents that do not leave their burrows use essentially vocal signals in the vibrational channel; 2) Solitary and almost permanently fossorial species use vocal signals in short range and seismic signals in long range communication; 3) Other solitary species that leave the burrow system more frequently and that retain good visual capabilities are constrained to use vocal communication only. Also we suggest that seismic communication probably derives from digging activities and, consequently, developed after the acquisition of the subterranean way of life. The first three statements are based on a previously proposed relationship between visual capabilities, hearing capabilities, time spent outside the burrows, social organization and type of vibrational signals used by the species. The fourth statement is based in the correlation found between digging and transporting tools and thumping tools, that are the same across the literature on pertinent genera. Some thumping techniques unique to subterranean animals lead us to propose an evolutionary sequence leading from digging to thumping.