Alloparental behaviour of an adult male Rhesus Macaque (Macaca mulatta)

We report an unusual case of caregiving by an adult male rhesus macaque (Macaca mulatta) at Sur Sarovar Bird Sanctuary, India. Observations from 7th June to 15th July, 2024 followed the adult male engaged in behaviors typically associated with female macaques, such as carrying, grooming, and protecting an infant male. Despite his aggressive interactions with other macaques, the adult male exhibited significant nurturing behaviors, including allowing the infant to suck from his nipple and maintaining close physical proximity for protection. These findings expand on previous research by demonstrating that male rhesus macaques can exhibit rare but impactful caregiving behaviors, underscoring the need for further investigation into such atypical male-infant interactions.