Drivers and consequences of male care for young in a promiscuous primate

• Applicant: Professorin Julia Ostner, Ph.D.
• Subject Area: Sensory and Behavioural Biology
• Term: since 2022
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 515982111

Evolutionary modelling and empirical evidence predict male care for young to be restricted to species with a high degree of paternity certainty, i.e. pair-bonded or monogamous species, as costs of care for males are alleviated in these situations. Consequently, the majority of studies on the evolution of male care focused on pair-living and monogamously mating species. Natural selection, however, will favour the evolution of male care even in promiscuous systems with low paternity certainty under specific circumstances. Male care may be selected if it functions as mating effort via mate attraction if caring males enjoy mating benefits when females base their mate choice on a male’s propensity to care, or as parenting effort if males channel care into their genetic progeny and male care enhances offspring quality and fitness. In the proposed project, we will in a promiscuous species of nonhuman primates (1) test the benefits in terms of increased mating and reproductive success that a male can reap from investing in young either via mating effort and mate attraction or via true paternal care for related young. Next, we will (2) investigate a potential tradeoff between male parenting and mating effort and a potential switch in the tactics as the relative payoffs from either effort may change across a male’s life span or with status changes. Finally, we will (3) crucially add to the research on male care by assessing the fitness consequence of care for the offspring in a promiscuous system. We address these aims by leveraging a large long-term data set on male care and sexual behavior, short- and long-term benefits of care for young (e.g. age at maturation, survival), and genetic data on relatedness collected since 2006 on our study populations of Assamese macaques living in their natural habitat in northeastern Thailand and characterized by a promiscuous mating system with low level of paternity certainty.

• DFG Programme: Research Grants
• Co-Investigators: Professor Dr. Christian Roos; Privatdozent Dr. Oliver Schülke, Ph.D.