Rescued New Zealand pilot whales die after second stranding 6 November 2014 Last updated at 04:28 Volunteers managed to refloat many of the whales on Wednesday A pod of 22 pilot whales rescued from a stranding in New Zealand on Wednesday have died after beaching themselves for a second time. About 60 whales in two pods had swum into Ohiwa harbour in the Bay of Plenty of Monday and stranded themselves, with 36 dying by Tuesday. Conservationists had refloated the 22, but said 14 were found dead on Thursday and the rest were put to death. The reasons for mass strandings are not fully understood. Pilot whales are particularly prone to such behaviour. The largest known pilot whale stranding involved an estimated 1,000 whales at the Chatham Islands in 1918, according to the Department of Conservation (DOC). Project Jonah, the wildlife group involved in the rescue, said on its Facebook page on Thursday that the discovery of the 22 whales in the Whakatane region of the bay was "a sad outcome after the successes of yesterday's efforts." "Six whales had died overnight, upon arrival it was discovered a further six had died and within moments two more whales had passed," it said. The remaining whales were showing physical signs of distress and the difficult decision was made to euthanise. The organisation added that it was "worth remembering that any time the whales spend out of their natural environment is a highly stressful time for these beautiful animals." New Zealand on average has more whales stranding themselves than any other country in the world, Daren Grover, general manager of Project Jonah told the BBC on Wednesday. Another theory is that as one whale becomes stranded the other members of the highly sociable pods try to help and become stranded themselves.