High oxytocin infants gain more mass with no additional maternal energetic costs in wild grey seals (Halichoerus grypus)

Maximising infant survival requires secure attachments and appropriate behaviours between parents and offspring. Oxytocin is vital for parent-offspring bonding and behaviour. It also modulates energetic balance and neural pathways regulating feeding. However, to date the connections between these two areas of the hormone’s functionality are poorly defined. We demonstrate that grey seal (Halichoerus grypus) mothers with high oxytocin levels...