RESEARCHERS have documented a booming population of the threatened tiny Tasmanian marsupial mouse Swamp Antechinus close to Wilsons Promontory.
A four-day expedition to two islands just off the coast Wilsons Promontory National Park by specialist crews from Parks Victoria has provided new hope for the survival of this little-known native predator.
Zoos Victoria recently found a small group of these rare marsupials on the mainland.
Swamp Antechinuses characterised by cinnamon coloured fur, large dark eyes and an impressive array of whiskers may be small enough to fit in the palm of your hand but have razor sharp teeth.
Isolated by the rising waters of Bass Strait for more than 12,000 years the marsupials on these two islands surprised researchers with a significantly higher capture rate than their mainland counterparts.
Males die before their first birthday dedicating their final days to marathon mating sessions lasting up to 14 hours forsaking sleep and food over two weeks of copulation.
Enlarged testes eventually trigger a stress-induced immune system collapse.
Without adult males new mothers and their offspring have greater access to food.
Females can store sperm from multiple partners meaning litters often include half-siblings with robust females living long enough to raise litters over at least two seasons.
Researchers spent three nights navigating challenging terrain to lay traps and set up motion-sensing, infrared cameras on the islands skilfully positioning cameras and traps between dense tussock grass and deep seabird burrows.
The traps ensured the safe and temporary capture of Swamp Antechinuses while providing food and vital bedding insulation against the cool and blustery conditions that are common on these remote islands.
Small tissue samples taken from the marsupials will help researchers analyse the genetic health of these island populations.
The expert crew also detected 26 other native animal species across the two islands, including larger-than-average native Bush Rats and a range of nutrient-distributing birds such as Short-tailed Shearwaters and Sea Eagles.
The former Promontory hilltops experience little pressure from introduced pests and predators due to restrictions on human visitation and their isolation.
The Parks Victoria’s Prom Sanctuary Project will help transform this area into a 50,000-hectare safe haven for Victoria’s rich wildlife and habitats.
Dr Mark Norman, Chief Scientist Conservation and Climate Action for Parks Victoria said documenting 36 threatened Swamp Antechinuses thriving on islands off Wilsons Promontory National Park is a powerful sign.
“It highlights the Prom’s role as an ark offering safe harbour for vulnerable species as the climate changes,” said Dr Norman.
“These islands, like life rafts hold unique populations with valuable genetic diversity.”
By studying these island populations Dr Norman believes we can unlock the secrets to the resilience of rare mammals and help bring their mainland relatives back from the brink of extinction.
Dr Marissa Parrot, Senior Conservation Biologist for Zoos Victoria said Antechinus are beautiful and amazing animals, but their remarkable reproduction followed by a total male die-off evolved in more predictable environments now leaves them particularly vulnerable to climate change.
“The protected Promontory islands provide insurance against extinction and a brighter future for Swamp Antechinus,” said Dr Parrot.
“Researching the genetic health of the island Swamp Antechinuses adds important information to the wider conservation program.”
