Bottlenose dolphin mothers whistle continuously when they deliver their babies. Why? As the newborn emerges to swim amid a sea of dolphins, each with its own whistle, it will be better able to locate ...

But Haffenden’s approach, apart from the occasional clicker, which is more for novelty value than anything, is uncontroversial. It’s clear that it’s the parents who need training, not the children.

Bottlenose dolphin mothers whistle continuously when they deliver their babies. Why? As the newborn emerges to swim amid a sea of dolphins, each with its own whistle, it will be better able to locate ...