Phee Calls Research Articles

Social context affects phee call production by nonreproductive common marmosets (Callithrix jacchus).

Common marmosets produce two variants of their long call (phee call) in different situations. Intergroup calls are produced in territorial situations, and intragroup separation calls are produced by marmosets isolated from group members. Marmoset groups frequently include postpubertal, nonreproductive members; their roles in the spontaneous production of territorial vocalizations is unclear. This study analyzed the production of home cage phee calls by nonreproductive, postpubertal marmosets while they were housed in their natal groups and after pairing with an opposite-sex conspecific. Additionally, the production of the separation phee call variant was assessed in both social conditions. The results indicated that the marmosets rarely produced home cage, or territorial, phee calls while they were natally housed. In contrast, both males and females produced the territorial phee call at a much higher rate as early as 4 days after pairing. Agematched females remaining in their natal groups throughout the study produced home cage phee calls infrequently. Most marmosets produced separation phee calls at a high rate after separation from either their natal group or a partner, suggesting that the makeup of a social group has little effect on an animal's motivation to reunite with conspecifics. These results suggest that the social environment has an important influence on the production of territorial phee calls.

Responses to natural and synthetic phee calls by common marmosets (Callithrix jacchus).

Captive adult common marmosets (Callithrix jacchus) produce whistlelike "phee" calls in two contexts: in the home cage, where phee calls may function as part of territorial marking behavior, and when separated from social companions, where phee calls may function to reunite conspecifics. Natural and synthesized calls representing the acoustic structure of male and female calls in each context were presented to adult marmosets in a playback paradigm. Marmosets demonstrated discriminative abilities according to the context of the call and the caller's sex. Vocal and behavioral responses indicated increased vigilance and territorial behavior, following playbacks of naturally produced calls as well as synthetic calls. All animals scanned more frequently following produced calls as well as synthetic calls. All animals scanned more frequently following natural home cage as well as isolation calls, but only increased contact behavior (trills) in response to home cage calls. The responses were dimorphic according to the sex of the caller, where adult males scanned more following male calls, and adult females were more aggressive following male and female calls. The differential behavioral responses to playbacks of marmoset phee calls suggest a biological relevance to subtle differences found in the acoustic parameters of the phee call. © 1994 Wiley-Liss, Inc. This article is a US Government work and, as such, in the public domain in the United States of America.

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.

The stability of the vocal signature in phee calls of the common marmoset, Callithrix jacchus.

Phee calls were recorded from five captive common marmosets on three occasions. An initial recording session was followed by further sessions 1-12 days later, and finally, 12 months after the initial sample. Sonograms from the first recordings were measured using one duration and five frequency parameters, and significant differences between individuals were found for all six parameters. Discriminant function analysis was then applied to classify each call to a particular individual, witn a resulting classification accuracy of 97.27%. Analysis of the second and third recordings demonstrated accurate classification to the same caller using the measurements obtained from the initial sample. The accuracy remained high despite intra-individual differences in acoustic structure among the three recording periods. Such differences may well reflect proximate changes in the underlying arousal state of the caller. Stability over time in the vocal signature of the phee call supports the view that this vocalization may be important in signalling individual identity over long distances, in a habitat where visual contact is limited. © 1993 Wiley-Liss, Inc.