Ultrasonic vocalizations in a South American subterranean rodent: the social tuco-tuco (Ctenomys sociabilis)

AMAYA J P; EILEEN A. LACEY; BENITEZ JULIANA; ARETA, JUAN I

Congreso; 13th International Mammalogical Congress; 2023

Vocalizations produced by subterranean rodents typically emphasize low- and middle-frequency audible sounds, presumably due to convergent evolution to maximize the propagation of acoustic signals in underground burrows. Tuco-tucos (genus Ctenomys) are subterranean rodents that occur in sub-Amazonian South America. Studies of more than a dozen species of tuco-tucos indicate that these animals produce audible vocalizations as an integral part of their behavior. Here, we provide the first evidence of ultrasonic and high frequency communication among members of this genus. Specifically, using recordings made from eight social groups of captive colonial tuco-tucos (Ctenomys sociabilis), we demonstrate the use of harmonic and tonal notes (peak frequencies of 10-45 kHz) by members of this species. Typically, these sounds were produced when two or more members of this group-living species were in close contact during non-aggressive interactions. To date, the only other subterranean rodent for which ultrasonic vocalizations have been reported is the group-living mole-vole, Ellobius talpinus. Regular interactions among members of social species may facilitate the evolution of short distance vocalizations, thereby allowing use of a wider range of signal frequencies, including use of ultrasonic signals. We suggest that considering how sociality mediates the selective pressures imposed on sound transmission in subterranean environments will generate new insights into the evolution of acoustic communication in subterranean and other burrow-dwelling rodents.