However, the baby koala will remain in the mother's pouch for breastfeeding for five to six months before it is strong enough to venture into the outside world - probably in July, according to zoo veterinarian Somchai Chotapisitkul.

The pregnancy came as a surprise. Somchai recalled that zoo staff had observed how one koala named Coco had something moving in her pouch near her abdomen so they kept her apart for safety.

Zoo officials then consulted an Australian professor who told them it was Coco's first pregnancy and should not be interrupted - as there was a risk it would fail.

Somchai said the zoo did not run a physical check such as an x-ray or ultrasound on Coco as the procedure required stretching the animal and might have proved dangerous. So they let Coco deliver the baby naturally, he said.

Dr Sopon Damnui, director of Thailand's Zoological Park Organisation, said Coco became pregnant on December14 and gave birth on January 14.

The baby had climbed into her front pouch and would stay there for five to six months before it would emerge and cling to its mother's back.

The surprise pregnancy took place in Chiang Mai Zoo, where public attention has been focused on the female panda from China, Lin Hui, who still shows no signs of getting pregnant to her over-weight companion, despite Bt15 million being spent creating a suitable environment for the pair. Lin Hui was recently artificially inseminated.

Chanjira Charusuphawat

The Nation