MASS strandings of pilot whales may be linked to disruption to their family groups new research has suggested.

Recent genetic analysis in both the northern and southern hemisphere by a team including academics from Aberystwyth University challenges existing thinking as to the role of social behaviours in mass strandings of these animals.

Mass stranding events in cetaceans - a group of marine mammals including the whale, dolphin and porpoise - have been reported since the times of Aristotle and there has been a long drive to understand what causes them.

Long-finned pilot whales - a gregarious species with complex social bonds - are those most often affected.

At sea they form family units known as pods.

Within a pod there are multiple generations of pilot whales that are all related to a single female.

It has therefore long been thought that mass strandings may be caused by family members trying to stay together.

However, the data reveals that in most cases each mass stranding involved multiple unrelated pods, rather than a single pod as was previously thought.

This suggests that family disruption, rather than family cohesion, may be a major cause of these events.

Dr Niall McKeown, a lecturer in Marine Biology at Aberystwyth University, said: “The findings provide further evidence that there may be mixing of family units at some stage during stranding processes.

“It remains to be seen to what extent this is a cause, or a consequence of mass strandings.”