The BBC reports that an entire pod of 55 pilot whales died after a mass stranding on a beach in the Outer Hebrides. Only 15 were alive after they washed onto Traigh Mhor beach at North Tolsta on the Isle of Lewis at about 07:00 on Sunday morning.

The marine charity British Divers Marine Life Rescue (BDMLR) attempted to refloat one of the more active whales but it was later found restranded farther down the beach.

A further three whales then died, leaving 12 still alive – eight adults and four calves.
A statement said: “At about 15:30, the local vet along with the Coastguard, Fire and Rescue, and a forensics vet came to the conclusion that the shallow beach and rough wave conditions made it too unsafe to refloat the remaining animals.
 
“Considering how long the pilot whales had been out of the water in addition to the poor conditions, it was decided that they should be euthanized on welfare grounds.”

The BDMLR released an update on Sunday evening which said that one of the dead whales appeared to have had a vaginal prolapse.
 
This led them to suspect that the whole pod stranded due to one female giving birth.
Pilot whales are known for their strong social bonds, so often when one whale gets into difficulty and strands, the rest follow.

The Scottish Marine Animal Stranding Scheme (SMASS) will now carry out post-mortem examinations of the bodies to conclude the cause of the stranding.

Thanks to Alaric Bond for contributing to this post.