Structure, functions, and mechanisms of Rodentia vocalizations across the lifespan

Vocalizations are an integral way that rodents and many other mammals communicate. Historically, research on rodent vocalizations focused on laboratory-derived strains of two species, house mice (Mus musculus), and brown rats (Rattus norvegicus). However, with over 2000 species, Rodentia is one of the largest vertebrate orders with many species available for communication research. In this review, we synthesize recent findings on lesser-studied species spanning five Rodentia families: Muridae, Caviidae, Cricetidae, Bathyergidae (including Heterocephalidae), and Sciuridae. First, we take an evolutionary perspective to compare adult vocalizations within and across these five Rodentia families. Then, we take a developmental perspective to characterize immature vocalizations and how they transition into mature vocalizations. Next, we explore the potential functions of rodent vocalizations by surveying the behavioural contexts in which they occur. Finally, we summarize recent work on the physiological mechanisms that underpin rodent vocalizations, from biomechanics to neuromodulator systems and neural circuitry. Together, this research shows that Rodentia is an excellent taxonomic group for exploring the diversity and evolution of vertebrate acoustic communication.