Vocalizations of Australian hopping mice (Rodentia: Notomys )

The sounds produced in the laboratory by four species of Australian hopping mice ( Notomys alexis, N. cervinus, N. mitchellii and N. fuscus ) were investigated using a tape recorder and Kay Sound Spectrograph. All four species had the same basic repertoire of eight more or less discrete vocalizations. No vocalizations were associated with threat, or fighting. Calls given in the nest by suckling young are well developed and the intensity of such calls appears to mirror the general motivational state of the caller. It is suggested that these calls may act to maintain maternal behaviour in the mother. Summary The four species of hopping mouse studied, N. alexis, N. cervinus, N. fuscus and N. mitchellii , were found to have a basic repertoire of eight more or less discrete vocalizations: three in the young—the calls produced in the nest, ultrasonic pipping given when removed from the nest and a high intensity (pain) squeal—and five in the adult—a low intensity pip given during mutual grooming, a high intensity (pain) squeal, a medium intensity squeak given when “annoyed”, twittering given during aggressive chases and ultrasonic pipping given during non‐aggressive encounters. The calls of the different species varied in structure and in pitch. No vocalizations were associated with threat or fighting. Calls given in the nest by suckling young are well developed and the intensity of such calls appears to mirror the general motivational state of the caller. It is suggested that these calls may act to maintain maternal behaviour in the mother.