After a week of constant rain, it was a rare sunny day when we headed out from Loch Craignish into the Sound of Jura. We were searching for White Tailed Eagles but the captain first took us to see a colony of Grey Seals.
On a rocky outcrop rising from the swirling, dark waters was a small seal colony. There was a mix of adults, older juveniles and huddled close to their mothers, this year’s fluffy white pups. And there is a rather sinister reason why they were sticking so close to mum.
This year some of the bull seals have been catching, drowning and cannibalising the pups. Although a rare occurrence, this behaviour has been seen in grey seals before. On the Isle of May, a bull seal has also been documented cannibalising pups that were sired by other males. One explanation might be that by eating the pups he will ‘free up’ previously occupied females for new breeding opportunities. Another theory is that they provide an easy meal without having to leave the harem behind to hunt.
Our boat captain explained that these bull seals have been resorting to infanticide due to a lack of fish. I was unable to find any detailed figures for the state of fish stocks in the area but it is no secret that many of Britain’s fisheries are under immense pressure from overfishing.
Whatever the reason for the occurrence of cannibalism in this group of seals, the pups never strayed far from their mothers and we observed one female aggressively chasing off another seal when it got too close to her pup.