When a Western Australian man dragged a hollow log on to the roof of his farmhouse and strapped it to the chimney with old fencing wire, he hoped endangered cockatoos would come home to roost.

Five years later, the unusual decision is improving the survival odds of the native Carnaby's cockatoo which faces extinction.

The latest figures suggest Carnaby's numbers continue to decline in southern Western Australia due to habitat fragmentation caused by large-scale land clearing.

The naturally placid cockatoo now competes with corellas, galahs and even bees in the remaining eucalypt woodlands for nests in hollow trees which may take 100 years to form.

Two newborn Carnaby's cockatoos have hatched on Leo Page's rooftop. ( Supplied: Leo Page )

Cockatoos in the chimney

Back in 2012, Leo Page watched as several Carnaby's nests near his home in Tambellup in the Great Southern region were taken over by pink galahs.

Soon after, Mr Page found a one attempting to build a nest in his chimney.

That was when he tied a hollow log to his roof to provide a better site.

"When I put that (hollow log) up on my chimney it was pretty much when the breeding season started," he said.

Nesting hollows on the roof of Leo Page's Tambellup home. ( ABC Great Southern: Aaron Fernandes )

"For the first year they didn't nest, a couple of them came and looked and I thought 'oh well, at least they're interested'.

"The next year, they came back and laid there."

Since 2012, Mr Page has watched 14 new cockatoos hatch from his rooftop.

"I heard that they were dying out and I thought that every one that I could raise is one more that is going to be in the wild," he said.

"If I can help in any way, help save a species. It's something isn't it?"

Push to rebuild hollows

Mr Page's efforts coincide with a program by the WA Department of Biodiversity Conservation and Attractions to rebuild nesting sites across southern WA by introducing artificial hollows.

DBCA senior wildlife officer Rick Dawson said an artificial hollow meets all the nesting requirements of the Carnaby's cockatoo and has increased nesting success by 25 per cent.

"These birds are not dumb, they're smart … they take a long time and effort to pick their hollows," Mr Dawson said.

Over a hundred artificial hollows have been installed at sites in Lake King, Newdegate and Borden.

"We're pretty close to what I believe is perfecting the ideal artificial hollow, and if we were to roll that over the range it will make quite a substantial difference," Mr Dawson said.

"People in the community have made a big difference. [However] if members of the community install an artificial hollow you have to maintain it to ensure we get nesting success."

Natural bird lover

For Leo Page, the breeding season and the hatching of Carnaby's cockatoos is an annual event.

He seems to enjoy the birds as much as they need the nests.

"I've had birds all my life and I just love birds, animals and that sort of thing," he said.

Leo Page has kept birds for as long as he can remember. ( ABC Great Southern: Ben Gubana )

Last year, he attached a small camera to the inside of the hollow to monitor the birds' movements from a remote computer screen.

"They say the male doesn't do a lot, according to the experts, but in my log the male comes and sits on the egg and he comes in and feeds the young 'uns," he said.

"The experts say (the males) don't do that, but I have proof they do.

"(The Carnaby's) migrate here around the middle of August to claim their hollow nest, they breed and then they leave at the end of February.

"They always come back out to the country for nesting time".