Behavioral and cardiophysiological responses of common marmosets (Callithrix jacchus) to social and environmental changes

Abstract

Under captive conditions common marmosets (Callithrix jacchus) show socially monogamous propensities. Male and female form a social bond as characterized by signs of behavioral arousal during separation of the pairmates, high levels of affiliative interactions between pairmates and agonistic responses towards strange conspecifics. In the present study behavioral and cardiophysiological responses of mated individuals of common marmosets were recorded while the animals were in an unfamiliar environment (1) alone, (2) with the pairmate, or (3) with an opposite-sexed stranger. Pairmates of 6 established pairs were tested in 3 replicates yielding a total of 36 trials per experiment. A trial was divided into three 10-min segments (baseline; unfamiliar environment; reunion). Behavioral responses were videotaped with a remote controlled camera system installed within the cage. Systolic (SBP) and diastolic blood pressure (DBP), and heart rate (HR) as well as locomotor activity (ACT) were recorded telemetrically through peritoneally implanted transmitters. The individuals' responses measured while in an unfamiliar environment was only reduced by the pairmate, but not by an opposite-sexed stranger. No affiliative behaviors occurred between strange conspecifics, whereas aggressive and sexual behaviors were observed. During reunion with the pairmate individuals recovered physiologically. The present study shows that an individualized pair bond exists between pairmates of common marmosets. Further, it becomes evident that establishing a social bond with the pairmate is important for maintaining physiological homeostasis.

Physiological and behavioral responses to routine procedures in captive common marmosets (Callithrix jacchus)

“…In Callithrix geoffroyi, males and females, isolated or living in family groups, exhibited increased cortisol levels when paired with a sexual partner. Therefore, previous research and this study suggest that the efficacy of social support during the stress response is not a generalized event, but rather depends on certain factors such as species, gender, pairing duration, partner familiarity, and previous living condition (Gerber et al 2002;Galvão-Coelho et al 2012). Thus, pair-formation demands an extended temporal period to attain stability and achieve baseline levels of physiological and behavioral functioning.…”

Behavioral and cardiophysiological responses of common marmosets (Callithrix jacchus) to confrontations with opposite-sexed strangers

“…When both conditions are imposed immediately one after the other, any behaviors withheld by the confrontees (during the pairmate's presence) should become visible (during the pairmate's absence). In an earlier study (Gerber et al 2002), the first mounting between unfamiliar animals occurred within two and a half minutes and this finding determined the 5-min test duration applied here. During reunion, data were collected when the test-individual had been returned to its pairmate in the home cage.…”

“…Behaviors were classified in four different categories: aggressive behaviors (vocal threat, cuffing, attacking, fighting), courtship behaviors [nuzzling, lip-smacking (males), lip-smacking with tongue-flick (females)], sexual behaviors (genital inspection, mounting, thrusting, penis-licking) and affiliative behaviors (sitting in body contact, grooming invitation, grooming). The behavioral elements used, followed the descriptions of several authors (see Gerber et al 2002). Phee calls were also recorded which are used both in intra-as well as intergroup communication and have sex-specific characteristics (Norcross et al 1999).…”

“…From the strange conspecific cardiophysiological data were not collected. For further information see Gerber et al (2002).…”

“…Urine collection and hormone analyses are fully described elsewhere (Gerber et al 2002). The day of ovulation was visually inferred from the hormone profiles of the female individuals as described by Hodges and Eastman (1984).…”