As many as 350 koalas are estimated to have died in the fires at the Lake Innes Nature Reserve, according to Koala Conservation Australia President Sue Ashton.

The reserve, which was home to a colony of as many as 600 koalas, lost most of its habitat last week. Strong winds again hampered fire-fighting efforts in the area on Friday night.

"We think most of the animals were incinerated - it's like a cremation," Ms Ashton said. "They have been burnt to ashes in the trees."

Rescuers have brought in a total of 16 injured koalas to Port Macquarie's Koala Hospital over the weekend. The area had been home to one of the state's most healthy populations of animal whose status is now deemed "vulnerable".

Rescued koalas were being treated by animal carers who have been feeding them eucalyptus leaves and formula, and bandaging their wounds.

"Our clinical director Cheyne Flanagan says we will be pushing up daisies before this koala colony recovers to their previous numbers," Ms Ashton said.

Ms Ashton called on residents to bring in injured animals to the hospital, to help with a breeding program aimed at reversing the animal's long-term decline.

She recommended catching ailing animals found on the ground in laundry baskets.

James Tremain, a spokesman for the NSW Nature Conservation Council, said koalas across the state were very vulnerable to bushfires, while the widespread destruction of their habitat as farming and housing expanded was also a threat.

"Port Macquarie had one of the healthiest koala populations in the state," Mr Tremain said. "If we continue at this rate, koalas will be extinct by 2050."