She was found in the unlikely setting of a beach towel at North Durras Beach on December 30, in critical condition.

“She looked like a mouse, so it was lucky that the person who found her recognised that she was a marsupial,” Ms Cantle said.

Berry, as she has been named, was between 40 and 60 days old when found and weighed a mere five grams.

“She was very undersized, even for her age,” Ms Cantle said.

“You could see the vertebrae in her tail. She looked awful and was really lethargic.

“They are not ready to leave their mothers until they reach 12 grams, and they usually stay longer than that.” 

She was originally thought to be a feather-tailed glider, but was then identified by a vet as an eastern pygmy possum, the first ever found at South or North Durras.

“National Parks have checked the GPS mapping of threatened species for the Durras area and there is no recorded records of eastern pygmy possums, although there is suitable habitat in the area,” a WIRES spokeswoman said.

That Berry has tripled in weight is no surprise to Ms Cantle.

“She is a very cute little critter but she eats like a lion,” she said.

Berry has been dining on mealworms, moths, wattle and native flowers.

“She was 15-and-a-half grams on Saturday, and when she is up to 18 to 20 grams she will be returned to her territory at Durras,” Ms Cantle said.

“Hopefully there are more like her there.”