Two newly discovered marsupial species were found to engage in gruesome sexual suicide.
The new Dusky Antechinus species were discovered in Tasmania and on the mainland, the Queensland University of Technology reported. The deadly sexual behavior is especially concerning because these new species are believed to already be threatened by climate change and habitat loss.
"It's a shame that mere moments after discovery, these little Tasmanian marsupials are threatened with extinction at human hands," said QUT's Andrew Baker.
Every year the male marsupials "mate until they drop," and the researchers believe this makes them more susceptible to extinction.
"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," Baker said. "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."
The sex-fueled suicide mission cuts the antechinus population in half annually, but this does have one known benefit: the mother antechinus have less competition for the spiders and insects that make up their diets. The researchers hope to have the three known threatened antechinus species added to Australia's federal threatened species list to boost their protection.
"In a country with the worst mammal extinction rate anywhere on earth, Australia is in the midst of unprecedented loss of its biological treasures," Baker said. "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."
The findings were published in a recent edition of the journal Nature.