An ANU researcher was the first to discover a baby southern brown bandicoot in a small population recently reintroduced to Booderee National Park.
The baby is the first bandicoot born in the park in more than a century, and researchers expect there are more yet to be discovered.
But the find happened by complete accident.
ANU Fenner School of Environment senior research officer Chris MacGregor, who is based at Booderee in the Jervis Bay Territory, was trying to trap another of the animals that had lost its tracking device.
"While I was trapping, I happened to catch a young bandicoot that had obviously been born and bred at Booderee," Mr MacGregor said.
"It was amazing, just to have the first southern brown bandicoot born in Booderee in your hands. It was precious cargo.
"It was pretty special to let her go again of course, I'm quite sure the bandicoot wasn't that happy about being poked and prodded."
Mr MacGregor said the young female didn't have a microchip, so he knew straight away it was new.
"I couldn't believe it. I triple checked, quadruple checked to see if it had a microchip."
"It's pretty exciting and I'm pretty sure she wouldn't be the only one out there, it's just a matter of time before we catch more of them and try and get a better idea of their breeding success at Booderee."
Mr MacGregor said while it wasn't unusual for the females to carry young, it was unusual for them to survive.
"Last November when I was trapping, I caught all four females and at that point they all had pouch young, so we knew they were breeding. But southern brown bandicoots are renowned for having a high infant mortality rate. They're at that end of the food chain where they have to not only compete with their siblings, they have to avoid predators likes snakes and owls as well.
"To see an animal born at Booderee that has obviously survived through to at least six months of age is very exciting."
The bandicoot has one of the shortest gestation periods of any mammal. It takes just 15 days from conception to birth, and the young then spends about 60 days in the pouch.
"They only live for two to three years. It's a very short, action-packed life," he said.
Mr MacGregor said it would still take a few more years before researchers were confident the population, which will welcome a further 15 animals next year, would have a foothold at Booderee.
Parks Australia senior project officer Nick Dexter said it was great news.
"It shows the population we translocated last year is not only surviving, but may be growing," Dr Dexter said.
"We're only halfway through the project but signs are good."
The animals were captured from state forests near Eden on the far south coast, and relocated to Booderee where they hadn't been sighted since 1919.
The bandicoot relocation project is a collaborative effort between Parks Australia, Forestry Corporation of NSW, the ANU, the Threatened Species Recovery Hub and the Taronga Conservation Society.
CLARIFICATION: A previous version of this story contained an incorrect image supplied to The Canberra Times.