The mass stranding and death of 55 pilot whales on the Isle of Lewis in 2023 was caused by the whales’ loyalty to their pod, a new report has found.
The unusually large landing on Tràigh Mhòr beach on the island’s west coast could have been driven by the pod staying close to a distressed member during birth.
One of the female whales was shown to have had a difficult birth, which may have been due to a large or poorly positioned calf. Pilot whales are known for their strong social cohesion, and the entire group may have followed the distressed female into shallow waters.
The topography of this beach in the Outer Hebrides may have played a role in the stranding, as the steep shelf of the shallow bay may have combined with onshore winds, hindering the pod’s navigation. Once stranded, the whales will have been unable to refloat themselves due to the onshore winds and soft sands.
The whales were shown to have good overall health, with no significant underlying diseases.
This stranding in July 2023 was followed by an even larger stranding on Sanday, one of the inhabited islands of Orkney in Scotland, in July 2024. The 77-strong pod was believed to be the subject of one of the biggest mass strandings in decades.
Find out more about the increased number of whale strandings in Scotland here.
