Comparative studies of the ultrasonic calls of infant murid rodents.

The ultrasonic calls of 10 species of murid rodents including 3 strains of house mice are described and the significance of interspecific similarities and differences is discussed. The calls of newborn murid rodents may be characterized by their gradual onset and cessation, their comparative lack of amplitude and frequency modulation, and, often, by the presence of only 1 frequency component. These common acoustic characteristics may be important in eliciting and/or maintaining various aspects of maternal behavior, both in and out of the nest.