Oxytocin level in seals key to understanding maternal behaviour in humans

The level of oxytocin hormone is responsible for mother-pup bonding in seals, reveals a study that holds the key to understanding the differences in maternal behaviour in humans.

Scientist Dr Kelly Robinson studied the grey seals of north Atlantic island of North Rona in Scotland and found 'love hormone' - oxytocin - plays a key role in keeping the mothers in close proximity to their pups.

"Some grey seal mothers are much better at raising pups than others, even when allowing for differences in the mother's age and size and, as a result, some pups in a breeding colony die while others thrive, Dr Robinson, a research fellow at St. Andrews University's Sea Mammal Research Unit in Scotland, said.

"Studying the role of oxytocin, a hormone that regulates maternal behaviour, offers some insights into why such differences in individual behaviour occur," she noted in the study published in the journal Plos One.

During the two-year study, she recorded the maternal care behaviour the grey seals showed towards their pups during the rearing period on the island, situated in the most north-westerly point in mainland Britain.

"Oxytocin has been linked to optimal maternal behaviour in humans and many captive animal species; this is the first time such a link has been shown in completely wild animals in their natural habitat," she added.

A study on the blood samples from the mothers showed that the higher the level of the hormone in a nursing mother seal, the closer she stayed to her new pups. As the amount of oxytocin in a mother's blood decreased, her distance from the pup increased.

"The link between oxytocin and maternal behaviour not only has important consequences for pup survival in the grey seals, but helps us understand why some individuals, including humans, are better mothers than others," Dr Robinson said.