Life for a baby seal is tough. Within minutes of your birth, gulls want to pluck your eyeballs out (yes, that is a thing that happens), orcas are waiting for your first swim ... oh, and your friend's dad wants to drown and eat you.  

seal cannibal-2016-2-18
Image: Dr Sean Twiss/Durham University

Seals and other pinnipeds are notoriously territorial, and sometimes that means trouble in the rookery.

On Scotland's Isle of May, Durham University biologist Amy Bishop and her colleagues have been observing a rogue male grey seal with a knack for infanticide (video here, for those who can stomach it). The team suspects the bull has killed over 11 pups in the past two years – but just why is still up for debate. 

It's possible, they explain, that the male seal is simply taking advantage of an easy food source, one that doesn't require leaving the harem to hunt. But the more likely explanation is that this is a grimly strategic manoeuvre. 

"[We witnessed him] attempting to copulate, unsuccessfully, with a female to the northeast of the pool," the team explains. "The female had an estimated seven-day-old nursing pup and displayed aggression during the mounting."

"Removing" any pups that get in the way would solve this coitus conundrum by freeing up the female's attention, and in the end, would mean more of the male's own descendants in the rookery. 

On that note, there is another clue here that suggests this is more than an attempt at a free meal: the infanticidal male seems to be avoiding eating his own young. Grey seals return to the same spot each year to breed, and the male has moved beyond the territory in each instance of infanticide. 

Interestingly, it's not just the males who are guilty of this gruesome practice. Just last year, our cameramen witnessed a female Cape fur seal snatching a newborn pup from its mother's clutches, just seconds after birth.


Top header image: George Paterson/Flickr