A pod of more than 50 pilot whales became stranded on a Scottish beach on Sunday and died. After reports at about 7am on Sunday that dozens of the mammals were in difficulty at Traigh Mhor in North Tolsta, on the Isle of Lewis, marine rescuers were called to the scene. Rescuers initially thought there were about 55 animals, adults and calves, but it was soon discovered that only 15 were still alive. British Divers Marine Life Rescue tried to refloat two of the more active whales that were still low in the water on the outgoing tide and one got away. But the other later stranded itself again and died, as did three others. At around 3.30pm it was decided that the remaining whales should be put down on welfare grounds. The cause of the stranding is not known but it is thought the pod may have followed one of the females. “One of the dead whales appeared to have had a vaginal prolapse – so it’s currently suspected that the whole pod stranded due to one female giving birth," a statement from the rescue charity, said. “Pilot whales are notorious for their strong social bonds, so often when one whale gets into difficulty and strands, the rest follow.” The coastguard, Scottish Fire and Rescue Service, police and Scottish Marine Animal Stranding Scheme were at the scene on Sunday. Western Isles Council said it also had officers there. “At about 3.30pm, 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," the rescue divers group said. “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 euthanised on welfare grounds. “We’d like to extend our thanks to the Lewis community, Stornoway Coastguard, police, Stornoway and Shawbost Fire and Rescue, SMASS, SSPCA, Civil Air Support, CalMac and of course our dedicated team of medics who all came together in their efforts to rescue these whales. “A sad outcome for this pod and obviously not the outcome we were all hoping for.” The marine group stranding group will now carry out post-mortem examinations on the whales. Pilot whales are classified as part of the dolphin family. “HM Coastguard assisted British Divers Marine Life Rescue this morning following reports of around 50 stranded mammals on Traigh Mhor, Isle of Lewis," a coastguard spokesman said. “Alerted at around 7.40am, Stornoway, Bragar and Ness Coastguard rescue teams were sent to the scene to provide safety cover. "Police Scotland and the Scottish Fire and Rescue Service were also in attendance.”