Nesting hollows carved into trees to help save the critically endangered swift parrot have proved "amazingly" popular with the birds.

More than 30 arborists travelled to Tasmania to carve out hollows in younger trees to make up the shortfall of natural hollows available for nesting.

A fortnight later, seven pairs have claimed hollows and three eggs have been laid.

Swift parrot research Doctor Dejan Stojanovic from the Australian National University, said they were great early results for the pilot program.

"Within three-and-a-half days we had swift parrots going in and out of the carved hollows," he said.

"It's just the most amazingly fast uptake of these holes. It was just totally unexpected; it was incredible."

Grant Harris from the Victorian Tree Industry Organisation, which organised the carving project, said the arborists were overwhelmed.

"It's amazing. I'm so, so happy. It's just fantastic," he said.

"Everyone is really excited and it's just amazing to be able to do something which benefits the natural world."

Arborist Pat Kenyon was integral in developing the hollow carving technique. ( ABC News: Natalie Whiting )

There are only 2,000 swift parrots left in the wild and they only breed in Tasmania.

Nesting boxes are also being trialled this year, with early success, but the take up of the new hollows has outpaced them.

Researchers will be comparing the different nesting options and monitoring things like temperature fluctuation and the performance of the birds over the breeding season.

"So we'll see how they actually perform in cut hollows, compared to boxes, compared to natural hollows to know whether there are any differences in the quality and number of parrots that are bred in them. So it's really early days," Dr Stojanovic said.

He said he was incredibly grateful to the volunteer arborists.

"It's not just a feel good thing, they've actually really helped in terms of researching how do we actually manage and conserve this species."

The early success of the nests has drawn interest from South Africa. ( ABC News: Natalie Whiting )

Interest from overseas in nest carving

Grant Harris, an ecologist and arborist, said there were hopes the technique could help a range of species.

"We really want to see if this technique works long term, and if we can show that it works it can be applied to many other species, really as a band-aid to tide over species that depend on hollows until natural hollows can develop in natural trees," he said.

Following 7.30's story on the nesting hollow project, the Victorian Tree Industry Organisation has been approached by a conservation group in South Africa.

Mr Harris said they were interested in trialling the technique on the cape parrot.

"This is what we were hoping for, for this technique to be used for hollow dependent species really anywhere in the world, where there's an absence of old, large trees," he said.