Rodent Vocalizations: Adaptations to Physical, Social, and Sexual Factors

This chapter introduces representative studies in acoustic communication in rodents. By using rodents as a model in which to study the evolution of vocal communication, researchers are able to utilize their diversity in physical habitats, social complexity, and sexual rituals. The widespread use of rodents as subjects of acoustic communication research is largely because many such species are the most successful mammalian group in terms of speciation. Much attention has been paid to isolation calls, alarm calls, and contact (or signature) calls in several species of rodents, with emphasis on the physical, social, and sexual variables involved in their production. Emergence of song-like vocalizations in both mother-infant contexts and male-female mating contexts are also discussed. Furthermore, the chapter focuses on the degree of plasticity in perception, production, and usage of these vocalizations in relation to the organization of neural structures related to hearing and vocalizations in rodents. Finally, these observations are integrated to suggest a general hypothesis on the evolution of vocal communication in rodents.