Abstract
In some non-human primates, infants function as a social tool that can bridge relationships among group members. Infants are a desired commodity for group members, and mothers control access to them. The biological market theory suggests that grooming is widespread and represents a commodity that can be exchanged for infant handling. As a limited resource, however, the extent to which infants are interchanged between mothers (females with an infant) and non-mothers (potential handlers, females without an infant) remains unclear. In this study, we collected behavioral data to investigate the relationship between grooming and infant handling in free-ranging Tibetan macaques (Macaca thibetana) at Mt. Huangshan, China. Our results showed that females with infants received more grooming than females without infants. After her infant was handled, mother females received more grooming than they did during daily grooming interactions. However, with the increasing number of infants within the social group, both the grooming that mothers received and the grooming that non-mothers invested for handling infants decreased. We also found that non-mothers invested more time in grooming to gain access to younger infants than older infants. Our results provide evidence that infants are social commodities for both mother and non-mother females. Mothers use infants for obtain grooming and non-mothers use grooming to gain access to infants. The current study implies a bidirectional and complex interchange pattern between grooming and infant handling to compensate for the dyadic grooming disparity in non-human primates.
Highlights
While female attraction to infants represents a common feature in non-human primate species, maternal responses to infant handling show a certain degree of variability (Maestripieri, 1994; Nicolson, 1987)
The extent to which individuals groom in exchange for infant handling or offer infant handling in exchange for grooming among females remains unclear
We found that mothers received more grooming from non-mothers after birth than before birth, and that mothers groomed non-mothers less after birth than before birth
Summary
While female attraction to infants represents a common feature in non-human primate species, maternal responses to infant handling show a certain degree of variability (Maestripieri, 1994; Nicolson, 1987). In some species, such as Asian colobines, females allow their newborn infants to be held frequently and carried for long durations by other group members (infant caretaking) (Nicolson, 1987; Stanford, 1992). Biological market theory proposes that the infant can be considered as a social commodity, Received: 01 November 2017; Accepted: 26 April 2018; Online: 28
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
