Male parenting and response to infant stimuli in the common marmoset (Callithrix jacchus)

Abstract

Callithrix jacchus infants are raised in complex family environments where most members participate in rearing the young. Many studies examining male parental behavior have focused on the carrying of infants with observations made within the family context. However, interference from family members can make it difficult to assess the father's motivation to care for infants. Our goals were to develop a testing paradigm for determining an individual's response to infant stimuli separate from family influences, compare a male's motivation to respond to an infant stimulus outside the family with his paternal behavior within the family, to compare responses to infant stimuli of parentally experienced versus inexperienced males and finally to develop a reproducible and standardized method of testing male responsiveness to infant stimulus that could serve to evaluate hormonal manipulations. Fifteen experienced common marmoset fathers were evaluated using three different measures of parental behavior: (1) instantaneous scan sampling, (2) continuous focal sampling in the family, and (3) continuous focal sampling of males presented with four infant stimuli: familiar and unfamiliar infants, familiar and unfamiliar infant vocalizations. Six parentally inexperienced males (non-fathers) served as controls. Males that carried the most in the family were typically the same males that responded most to the infant vocalization tests. Experienced fathers did not differ in their latency to enter the stimulus cage for any of the four infant stimuli response tests while inexperienced males took significantly longer to enter the stimulus cage. In addition, fathers expressed a greater frequency of infant-directed behavior than did the inexperienced males during the unfamiliar infant and unfamiliar vocalization tests. These studies show that experienced male marmosets are highly motivated to interact with infant stimuli and that there is interindividual variability in response to infant vocalizations. Testing males outside of the family allows for a clear assessment of male's interest in infant stimuli in both parentally experienced fathers and inexperienced males.

Cooperative breeding and human cognitive evolution

“…2). 32,35 Zahed and coworkers 36 demonstrated that adult male marmosets in general possess a spontaneous motivation to care for any infant, related or not. Helpers often provision offspring by giving food calls and actively offering high-value food items rather than in response to infant begging.…”

A molecular blueprint of gene expression in hippocampal subregions CA1, CA3, and DG is conserved in the brain of the common marmoset

“…Many studies have therefore used the marmoset for comparative morphology to investigate neurocircuitry or neuroanatomy (Roberts and Wallis, 2000;Bourne et al, 2007;Karasawa et al, 2007;Pinato et al, 2007). The marmoset has been used to study behavior, ranging from the psychobiological features of anxiety and fear (Barros and Tomaz, 2002) to sexual behavior (Dixson, 2001), social interactions (Ziegler and Sousa, 2002;Caldwell and Whiten, 2004;Schiel and Huber, 2006), and parental care (Da Silva Mota et al, 2006;Dettling et al, 2007;Zahed et al, 2008). Behavioral testing in marmosets can be also used to test higher-order processing of cortical functions using more complex cognitive tasks than in rodents.…”

Targeted helping by a wild adolescent male chimpanzee (Pan troglodytes verus): evidence for empathy?

“…Evidence in primates suggests that males will care for unrelated as well as related infants in some cases. Experiments with common marmosets (Callithrix jacchus) showed that males removed from the context of other adults exhibited similar interest in caring for related and unrelated infants (Zahed et al 2008). In a 12-month study of alloparental behavior in Mahale chimpanzees, Nishida (1983) reported such behavior performed by an adolescent male that was not maternally related to the infants he carried and groomed with, similar to what is normally seen in young female chimpanzees.…”