Dear MARMAM subscribers, My co-authors and I are pleased to announce a new publication on the neuropeptide hormone oxytocin's relationship with maternal behaviour in grey seals: Robinson, K.J., Twiss, S.D., Hazon, N. & Pomeroy, P.P. (2015). Maternal Oxytocin is Linked to Close Mother-Infant Proximity in Grey Seals (Halichoerus grypus) PLOS ONE, DOI: 10.1371/journal.pone.0144577 Abstract: Maternal behaviour is a crucial component of reproduction in all mammals; however the quality of care that mothers give to infants can vary greatly. It is vital to document variation in maternal behaviour caused by the physiological processes controlling its expression. This underlying physiology should be conserved throughout reproductive events and should be replicated across all individuals of a species; therefore, any correlates to maternal care quality may be present across many individuals or contexts. Oxytocin modulates the initiation and expression of maternal behaviour in mammals; therefore we tested whether maternal plasma oxytocin concentrations correlated to key maternal behaviours in wild grey seals (Halichoerus grypus). Plasma oxytocin concentrations in non-breeding individuals (4.3 ±0.5 pg/ml) were significantly lower than those in mothers with dependent pups in both early (8.2 ±0.8 pg/ml) and late (6.9 ±0.7 pg/ml) lactation. Maternal plasma oxytocin concentrations were not correlated to the amount of nursing prior to sampling, or a mother's nursing intensity throughout the dependant period. Mothers with high plasma oxytocin concentrations stayed closer to their pups, reducing the likelihood of mother-pup separation during lactation which is credited with causing starvation, the largest cause of pup mortality in grey seals. This is the first study to link endogenous oxytocin concentrations in wild mammalian mothers with any type of maternal behaviour. Oxytocin's structure and function is widely conserved across mammalian mothers, including humans. Defining the impact the oxytocin system has on maternal behaviour highlights relationships that may occur across many individuals or species, and such behaviours heavily influence infant development and an individual's lifetime reproductive success. The article can be found at: http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0144577 The article is open access; so anyone who is interested in the manuscript should be able to download a pdf of it. However if you have any problems getting a copy please email kjr33@st-andrews.ac.uk<mailto:kjr33@st-andrews.ac.uk>. Kind regards, Kelly Robinson Sea Mammal Research Unit University of St Andrews