In 2012, a Canadian documentary crew chanced upon a remarkable scene: a family of bottlenose dolphins rescuing a small seal pup on the verge of drowning.
In the footage they captured, which you can view above, the lone baby seal is seen struggling helplessly against a strong current pulling it towards the danger of a rocky beach. With only 100 metres between it and the shore, the exhausted pup appears to run out of energy, and stops swimming.
But just at this moment, a family of dolphins arrives and, with gentle nudges, encourages the seal to start swimming again. It seems to work and, with a new lease of life, the baby seal swims off into the safety of the deep.
There are many documented cases of dolphins coming to the aid of animals in need, and it is possible that this behaviour is generally altruistic, rather than purely instinctual. According to Dr Lori Marino, a neuroscientist and expert on cetacean intelligence at Emory University, "these are behaviors driven by psychological processes, including empathy and sympathy. What drives individuals is their recognition that someone needs help – not their evolutionary history".