How Stranger Encounters of Common Marmosets (Callithrix jacchus jacchus) Are Influenced by Family Members: the Quality of Behavior

Abstract

The initial confrontations of 33 previously unfamiliar pairs of common marmosets were observed. Four types of pairs were used (alpha males/alpha females; alpha males/subdominant females; alpha females/subdominant males; subdominant males/sub-dominant females). Each dyad was tested in five different experimental conditions: (1) isolation of both individuals from their families, unilateral encounters in which either the (2) male’s or the (3) female’s family was visible to the dyad through a one-way screen, and interactive encounters in which either the (4) male’s or the (5) female’s family was present behind a wire screen. Pairs which included alpha females exhibited no affiliative, practically no sexual, but high levels of aggressive behaviors. Pairs which included subdominant females exhibited affiliative, high levels of sexual, and practically no aggressive behaviors. Behavior was reduced qualitatively as well as quantitatively with increasing presence of the families. Possible functional aspects of the results are discussed.

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

“…The observations of intrasexual aggression, combined with the finding that paired animals show more aggressive behaviors towards oppositesexed stranger when the familiar pairmate is present, suggest that common marmosets are considerably more aggressive in the presence of the familiar pairmate than they are individually (Evans 1983). However, in the absence of the pairmate, common marmoset females are indifferent to novel males, whereas males actively solicit contact and even sexual interactions with novel females (Anzenberger 1985;Evans 1983).…”

“…From several previous studies, it is known that common marmosets often behave aggressively towards opposite-sexed strangers when their own mate is present (Anzenberger 1985(Anzenberger , 1993Evans 1983;Sutcliffe 1980;Sutcliffe and Poole 1984). Furthermore, common marmosets show a high level of intrasexual aggression (Evans 1983).…”

“…Several experimental studies investigating the pair bond have yielded a sound body of knowledge about bonding and social dynamics in different primate species [titi monkey, Callicebus moloch (Anzenberger 1988;Anzenberger et al 1986;Mason 1975, 1978;Fernandez-Duque et al 1997;Mason 1975;Mendoza and Mason 1986); common marmoset, Callithrix jacchus (Anzenberger 1985(Anzenberger , 1993Epple 1970;Evans 1983;Evans and Poole 1983;Harrison and Tardif 1989); black tufted-ear marmoset, C. kuhli (Smith et al 1998); cottontop tamarin, Saguinus oedipus (French and Snowdon 1981;Harrison and Tardif 1989); saddleback tamarin, S. fuscicollis (Epple 1990); red-bellied tamarin, S. labiatus (Buchanan-Smith and Jordan 1992); golden lion tamarin, Leontopithecus rosalia (French and Inglett 1989;Inglett et al 1990)]. However, almost nothing is known about the physiological correlates of the pair bond.…”

Fecal androgen levels in common marmoset (Callithrix jacchus) males living in captive family groups

“…On the other hand, few studies have addressed the role of sex hormones in male behavior among captive marmosets, with only a few papers examining the sexual strategies used by males to maintain social rank and reproductive position within the social group (7,(13)(14)(15).…”

“…This investigator also reported that the dominants in other captive groups of unrelated adult males had significantly higher plasma luteinizing hormone and testosterone levels, indicating that reproductive failure in males seems to depend, at least in part, on hormonal differences (16). Despite this reproductive inhibition, subordinate males may show the mounting behavior and even ejaculate (7,13). Baker et al (15), investigating a mechanism to explain the reproductive collapse of sons living in their natal groups, found that avoidance of mating with familiar and related females and possibly behavioral mechanisms of competition were involved in the inhibition since testosterone levels were similar for fathers and sons.…”