Less than 12 months after the launch of a captive-breeding program for the endangered Pookila mouse, more than 20 pups have been born and planning is underway to return some to the wild.
Fewer than 3,000 Pookila mice are thought to be left in the wild in Victoria, and the mouse has become extinct at seven of the 12 sites the species was known to inhabit in the state, with the remaining five known sites contained to Gippsland.
A team including Melbourne Zoo and Moonlit Sanctuary last year captured 22 mice from the wild populations for the captive-breeding program, with 14 pups born in recent weeks at Melbourne Zoo, and six at Moonlit Sanctuary.
Threatened species reproductive biologist at Melbourne Zoo, Marissa Parrott, said more pups had been born in recent days.
"We can hear the tiny little squeaks coming out from their nests," Dr Parrott said.
"We started the new captive-breeding conservation and research program back in June last year and to have this many babies in our very first breeding season healthy and happy is just such a thrill for everyone involved."
The mouse is listed as endangered in both Victoria and Tasmania and vulnerable in Queensland and the ACT.
Return to the wild
Plans are underway to return some of the pups to the wild, but others will be kept in the breeding program.
"Depending on the genetics that we have in the program at the end of the breeding season, we'll be looking at the best release locations for these animals out to current populations to increase their genetic diversity and their health," Dr Parrott said.
"And also to areas where the species used to occur, but are now locally extinct.
"We're working with partners in predator-free areas to reintroduce the species back out to the wild where they may not have been seen for 50 years.
"So that'll be a real celebration when we get to that point."
The Pookila mouse is about the size of a person's thumb, with large eyes and a two-tone tail with pink on the bottom and grey on the top.
Threats to the tiny mouse include drought, loss of genetic diversity, and predation from feral cats and foxes.
They play an important role in spreading seeds and fungal spores.