Authorities were alerted to the incident on Sunday morning around 0600 GMT, and subsequent attempts to refloat more than a dozen whales alive were unsuccessful.
Rescuers later decided to euthanize the stranded whales for welfare reasons. In total, 55 whales died and one is believed to have survived.
The British Divers Charity Marine Life Rescue (BDMLR) said a female had been found with a vaginal prolapse and suspected the whole whale was stranded after one of the whales suffered complications from childbirth.
“Pilot whales are known for their strong social bonds, so often when one whale has difficulty and moves on, the rest follow,” BDMLR said.
The Scottish Marine Animal Stranding Scheme (SMASS) said it would begin scanning the bodies of mammals to determine the cause of the stranding.
“Over the next several days we will be conducting sampling and necropsy of pilot whales to gather as much data as possible to better understand the health of these animals and why they are stranded,” Smas said in a statement on Instagram.
(Reporting by Farouk Suleiman; Editing by William James).
