A total of 35 dibblers have been released onto feral predator-free Gunton Island, near Esperance, to expand the small population established on the island last year.
Environment Minister Albert Jacob said the small carnivorous marsupials, which were bred at Perth Zoo, were released on Friday by the Department of Parks and Wildlife as part of the Liberal National Government's Western Shield wildlife conservation program.
Last October, Parks and Wildlife released 29 dibblers at Gunton Island followed by 12 more in April this year to create a new insurance population.
"We are working very hard to save the dibbler and we are seeing promising signs," Mr Jacob said.
"Camera monitoring shows the dibblers released last year are doing well.
"The animals are persisting at both release sites on the island. Scientists trapped a male that had put on considerable weight since being released, which indicates there is sufficient food.
"There are just five established populations of dibblers elsewhere in Western Australia, of which four comprise less than 50 animals each, so this captive breeding and release program is vitally important for the long-term survival of the species in the wild."
The Minister said the Liberal National Government's new Biodiversity Conservation Act 2016, allowed for the listing of threatened ecological communities and critical habitat to protect species such as the dibbler.
"The new biodiversity conservation laws are a big boost for Western Shield. For the first time, the Minister for Environment can specially protect areas of habitat that are critical for the survival of threatened species," Mr Jacob said.
"This is a big step forward for conservation."
Since European settlement, dibblers declined from their original range in the western and southern coastal regions of WA due to predation by cats and foxes, and reduction of habitat.
The species was believed to have been extinct until it was rediscovered at Cheyne Beach, east of Albany, in 1967.
The South Coast dibbler program is funded by South Coast Natural Resource Management.
Original dibbler populations persist in the Fitzgerald River National Park on the south coast and on Boullanger and Whitlock islands off the coast of Jurien Bay
The State Government has established new dibbler populations at the proposed Peniup nature reserve near Jerramungup and on Escape Island off Jurien Bay
Minister's office - 6552 5800