Sex Is Driving These Tiny Australian Mammals To Extinction

Mammals are synonymous with sex but two species of recently discovered marsupials in Australia are courting extinction through sex.

Researchers at Queensland University of Technology discovered five new species of Dusky Antechinus in the last three years. Two of these species, Black-tailed and the Silver-headed Antechinus, are critically endangered due to loss habitat, climate change and feral pests. Marathon sex sessions are further denting populations, researchers found.

"The breeding period is basically two to three weeks of speed-mating, with testosterone-fuelled males coupling with as many females as possible, for up to 14 hours at a time," said Dr. Andrew Baker who led the team.

"Ultimately, the testosterone triggers a malfunction in the stress hormone shut-off switch; the resulting rise in stress hormones causes the males' immune systems to collapse and they all drop dead before the females give birth to a single baby," he added.

This year's breeding season will cause the Dusky Antechinus population to halve. Dr. Baker is applying to the government get the threatened species on its list of threatened species.

"In a country with the worst mammal extinction rate anywhere on earth, Australia is in the midst of unprecedented loss of its biological treasures. Millions of native mammals likely fall victim every night to feral cats alone. Other introduced ferals, such as European foxes and poisonous cane toads, account for the deaths of millions more. These threats, together with global warming, fires and habitat loss, may cause local population extinctions of our unique mammals almost weekly," Dr. Baker said.