People are being encouraged to 'adopt' a koala this Christmas amid ongoing concerns about their severely declining numbers.

The Port Macquarie Koala Hospital on the mid-north coast of New South Wales is the only facility in the world dedicated to the care of wild koalas.

The hospital rescues, rehabilitates and, where possible, releases koalas back into their home territory.

The not-for-profit organisation costs about $650,000 per year to run and receives more than 100,000 visitors a year.

A Koala in a Port Macquarie Nature Reserve. There's concern koala numbers in NSW and Queensland are declining rapidly. ( ABC News: Emma Siossian )

Much of its funding comes from donations and koala adoptions, where people pay to 'adopt' one of the hospital's permanent-resident koalas which can no longer survive on their own in the wild, and for some former patients which have been released.

Koala Hospital clinical director Cheyne Flanagan said the adoption program was helping raise money and awareness — and was a great Christmas gift idea.

"It gives people an awareness of what's going on with koalas, as each koala here has an individual story," she said.

"Some of those stories are quite warm and fuzzy and people become possessive of their adoptee, it makes people want to do more.

"There's nothing worse than those presents you shove in the cupboard and never use, this is something that's going to have great value, not only for you, but wildlife in general.

Koala survives after being hit by train

This koala, Breeza Grant, was hit by a freight train in western NSW and is now cared for a permanent resident at the Port Macquarie Koala Hospital. ( ABC News: Emma Siossian )

One koala at the hospital, a male named Breeza Grant, has won many people over after he was hit by freight train between Tamworth and Gunnedah in NSW.

He was named after the train driver who stopped to help him — Grant.

The mature animal suffered a broken bone, brain damage and the loss of half an ear, yet is now one of the hospital's great characters.

"He's a bit of a lad, a character with a very distinct personality and is one of the favourites of most people here," volunteer Vanessa Smith said.

"He's been through a lot, but he's very resilient."

'Breeza Grant' requires daily treatment and is a favourite at the Koala Hospital. ( ABC News: Emma Siossian )

Numbers on the decline

Ms Flanagan said the number of koalas arriving at the hospital had been much lower than usual this year and had been steadily declining for the past decade.

She said it reflected a disturbing and dramatic drop in the overall koala population in New South Wales and urgent action was needed to turn things around.

"The plight of koalas is not good, without a doubt, they are in serious decline in NSW and Queensland," Ms Flanagan said.

"Victoria and South Australia are not so bad, but it's only a matter of time — it's all about habitat loss, that's what's driving it.

"It's the urbanisation and human development — the removal of trees."

A koala appears to be smiling as it sleeps in a gum tree. ( Supplied: Sally Hinton, Australian Photographic Society )

Despite this, Ms Flanagan said the past month had seen an increase in the number of koalas needing help.

"We are still under our usual numbers, but we've had a huge influx recently," she said.

"At the moment it's breeding season, they are more active, it's hotter, koalas also get affected by chlamydia more when it's hot and dry," she said.

Increasing numbers to fight extinction

Port Macquarie-Hastings Council ecologist Dr Rebecca Montague-Drake has helped develop a population viability analysis of the local koalas.

"Using all sorts of variables and being a little bit optimistic as well because not all of our habitat is occupied, eventually in the perfect world koala numbers could increase," she said.

"But what we could see, unless action is taken, koalas are likely to experience functional extinction within 50 years.

"That means there might be a few kicking out there in the landscape, but their genepool is so limited, they're on a downward and nasty path."

The most at-risk koala populations are in NSW, Queensland and the ACT.

Across NSW, koala numbers have dropped by 26 per cent in the last 21 years, and the marsupial is listed as vulnerable to extinction under the Biodiversity Conservation Act.

The NSW Government said it was taking koala preservation seriously.

In May, it launched the NSW Koala Strategy, committing $44 million to secure the future of koalas in the wild.

The strategy included $20 million to purchase and permanently conserve land that contained priority koala habitat in the national park estate.

[Rebecca]

Volunteers, leaf collectors and clinicians

The Koala Hospital's Sue Ashton said the facility would not survive without the work of volunteers.

"We only have four paid positions, including a clinical director and also a leaf collector position, which is shared between a few people, and the rest is done by volunteers," Ms Ashton said.

"A leaf collector goes out every day to get fresh leaves for the koalas.

Volunteers help keep the facility running and assist with the day-to-day care of the animals. ( ABC News: Emma Siossian )

"We have around 160 volunteers at the moment, they help in the yards, the kiosk and manage the adoption program — without the volunteers there wouldn't be a koala hospital."

Money received through koala adoptions and donations will be used to build more enclosures, where the hospital's non-releasable patients can live.

The Koala Hospital's Jan Campbell said school children were also being encouraged to adopt a koala, raising awareness in a younger generation.

"We have a lot of schools where a teacher will approach us and have someone to talk to the children and they usually will adopt a koala as well and it makes the children aware of what's happening to our wild animals," she said.