According to a new study just published in Memoirs of the Queensland Museum – Nature, researchers have discovered “suicidally-sexed” male marsupials that go on 14-hour sex binges and die before the female gives birth. The two new species of antechinuses, a genus of carnivorous marsupials are appropriately named the Dusky Antechinus and the Mainland Dusky Antechinus. They were found on the island of Tasmania (in the Tasman Peninsula) and on the mainland of Australia.
These animals are reportedly well-known for the males’ biological propensity of engaging in a two-to-three week fighting and mating frenzy that eventually leads to death. Study leader Andrew Baker, a professor at Queensland University of Technology (QUI) in Australia said in a university statement: “The breeding period is basically two to three weeks of speed-mating, with testosterone-fueled males coupling with as many females as possible, for up to 14 hours at a time.”
An increase of testosterone sets off a malfunction in the animal’s stress hormone shut-off switch. Baker explains: “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 purpose of this testosterone-fueled yearly springtime “die-off” is purportedly to ensure the longevity and future well-being of the species. Baker calls the events “yearly male suicide mission[s]” that actually halves the antechinus population.
He notes it guarantees that the females will be able to provide enough food—insects and spiders—for the next generation of offspring. He adds: “The future of each species is entrusted to the mothers alone.”.
There are now five known species of these marsupials. Three of them have populations that the investigative team feel are threatened. They are not, however, threatened by their manic mating habits but by other issues including such predators as feral cats.
Baker concludes they are “vanishing before our eyes . . . These threats, together with global warming, fires and habitat loss, may cause local population extinctions of our unique mammals almost weekly.”
Sexed-Up Marsupials Do It ‘Til They Die