CALL OF THE WILD

From tweets to underwater songs, discover the astonishing ways animals use sound to survive and thrive

- HELEN PILCHER

THE BLACK-CAPPED chickadee is wonderfully onomatopoeic. When the diminutive songbird, which is Canada's answer to the great tit, spots a great-horned owl perched in a tree, it broadcasts a shrill 'chickadee-dee' noise to highlight its disapproval. It's unimpressed but not too alarmed, because the bulky raptor is slow and unlikely to cause trouble.

Then the chickadee spots a pygmy owl, also seated. This is a smaller, more agile predator, with a taste for small birds. In response, the chickadee ups the ante in the only way it knows how, adding an extra couple of 'dees' to the end of its call: 'Chickadee-dee-dee-dee!'

The sound is an avian call to arms, signalling flock members to mob the intruder. All at once, half a dozen small birds dive-bomb, harry and berate the hapless raptor, which - if all goes according to plan - then skulks off in search of a quieter life. Danger is averted.

Versions of this story play out routinely in the woodlands of North America, providing a glimpse into the rich and varied world of animal communication. Animals communicate in many different ways, including sounds, smells and gestures. From the earsplitting cry of howler monkeys in the jungle to the bellowing of deer in northern forests, from the calls of songbirds to the whistles of dolphins, from the clicks of sperm whales to the low-frequency rumbles of elephants, research is now revealing just how diverse, complex and nuanced animal communication is.

We humans may like to think that our communication system is superior, but the strategies evolved by other animals to suit them and their lifestyles are perfect in their own way, too.