A new video, captured by researchers from Durham University, UK, shows the disturbing cannibalism of grey seals.
An adult male grey seal was caught drowning, killing, and partially eating a seal pup after unsuccessfully mating with an unrelated female grey seal.
The cannibalism was videotaped at the seal breeding grounds in the Isle of May, Scotland. The grey seal was taped eating the pup on Dec. 2nd, 2014. He killed and ate four more pups in the following week, using the same method of dragging them into a pool of freshwater with his jaw, drowning them, then eating them.
An autopsy of the seal pups found that the adult grey seal did not consume all of the carcass, just a chunk of blubber from each of the bodies.
The researchers also found the half-eaten bodies of other pups, presumably killed by other adult seals.
“One potential explanation is that the male is tapping into a handy food reserve right next door to him,” team member Sean Twiss told the New Scientist. “It may be some new strategy to maximize reproductive success.”
Finding food elsewhere would mean leaving the breeding colony to hunt for prey, which would risk the loss of his territory in the colony.
“The chance of the male then regaining its territory would be close to zero,” Twiss said.
Grey seals return to the same spot to breed every year, and there’s a chance that the pups surrounding the grey seal are his own pups. That’s why Twiss believes the adult grey seal was moving outside its territory and passing up on fatter pups before settling on a pup that was less likely to be his own, according to New Scientist.