In 2013, a study reported something remarkable about bottlenose dolphins. They could recognise the calls of animals they had once lived with but had not heard for more than 20 years, one of the longest social memories ever documented in a non-human animal. Two dolphins separated for two decades, it seemed, still knew each other’s [...] The post A 2013 study found that bottlenose dolphins could recognise the signature whistles of former companions they had not heard for more than 20 years — one o