The 2023 mass whale stranding at North Tolsta may have been caused by a member of the pod experiencing a difficult birth.
A study into the deaths of 55 long-finned pilot whales in July 2023 by the Scottish Marine Animal Stranding Scheme (SMASS) found that whales were generally in good health before they beached.
But their investigation uncovered that one of their number had suffered a prolapse, leading to a prolonged and difficult birth.
SMASS concludes the female’s distress vocalisations may have been the “possible social trigger” for the mass stranding due to the pod’s strong social bonds compelling them to follow the distressed female into shallow water.
Once beached at Tolsta’s Tràigh Mhòr, the whales were unable to refloat and return to sea. Only one whale refloated successfully; the rest died or were euthanised on welfare grounds.
SMASS cites no evidence of disease, trauma, or sonar-related disturbance as primary causes of the stranding.