Know thy enemy: how birds ID threats

By AG STAFF | June 4, 2014

Superb fairy-wrens are teaching one another to spot cuckoo interlopers that have crept into their nests.

Ecologists are trying to determine how birds can learn to identify threats.

AGS-sponsored scientists Will Feeney and Dr Naomi Langmore of the Australian National University, Canberra, have shown that superb fairy-wrens can learn to recognise the danger of the Horsfield bronze cuckoo invading their nests.

Once cuckoo chicks hatch in the nest of a superb fairy-wren, the invading cuckoo will kill the young or destroy the eggs.
 
A superb fairy-wren adult, somehow unsuspecting of the difference, will provide food and shelter for this changeling chick, thus allowing the cuckoo adult to waste no effort on rearing its young.

But superb fairy-wrens are not as simple as they seem. Raising their young in groups of 6-8 adults, some fairy-wrens are capable of learning to distinguish between the enemy cuckoo and their own chicks.

Previous AG-sponsored research (Fairy-wren preschool, AG 113), found that wrens will teach their chicks codes to repeat in their calls for food, allowing them to be identified. This new research has added to scientists’ understanding of the species.

“Our study was the first to directly show that a host, such as the superb fairy-wren, can learn from others of its species how to recognise invaders such as the cuckoo,” says Will.