BRISBANE, Australia, June 2 (UPI) -- The males of two new species of dusky antechinus discovered in Australia spend their annual mating season coupling with as many females as possible and then die within weeks -- yet that isn't what threatens the species' existence.
Researchers who discovered the two new species, one in remote Tasmania and the other in mainland Australia, already have been working to get at least one of them on the threatened species list because climate change, feral pests and development, in addition to their annual suicidal sexcapades, threaten their existence.
"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, a mammologist in Queensland University of Technology's Science and Engineering Faculty, said in a press release.
"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."
These mating habits leave females with enough food, and no competition for it, to feed themselves and their young before getting to the next mating season.
Baker and his research team have now discovered five new species of antechinus in the last three years, a 50 percent increase in the genus of an animal that has been known for nearly 200 years.
The study is published in Memoirs of the Queensland Museum - Nature.