Context and gender-specific differences in the acoustic structure of common marmoset (Callithrix jacchus) phee calls.

Captive adult common marmosets (Callithrix jacchus) produce whistle-like "phee" calls in two contexts; in the home cage environment, phee calls may function as part of territorial marking behavior, and when animals are separated from social companions, phee calls may serve to reunite the group. Isolation phee calls tend to have more syllables than calls produced in the home cage by the same animals, and as a result, are longer in duration. The durations of isolation call syllables are shorter than in home cage calls, and isolation calls have lower start and end frequencies, higher peak frequencies, and increased frequency range compared to phee calls produced by the same animals in their home cages. The modifications made to the general structure of the phee call by isolated animals result in more information that may indicate context or location of an isolated caller. When the vocalizations were analyzed by sex, between-sex differences in call structure appeared consistently in both contexts. Males tended to exhibit higher call frequencies and greater variability between syllables than females. Published 1993 Wiley-Liss, Inc.