Near the NSW country town of Gunnedah, proudly known as the Koala Capital of the World, researchers have made a startling discovery.

Koalas are being driven to drink.

A koala that regularly drank from a bird bath on Gunnedah farmer Robert Frend's property. Credit:Kate Wilson

Though koalas grow thirsty after bushfires or during heatwaves - even stopping passing cyclists for a sip of water - it has long been believed they do not usually need to drink water, but get the moisture they need from the eucalyptus leaves they eat.

But in Gunnedah the tree-dwelling marsupials have been drinking extensively from custom-made watering stations, even in autumn and winter.