Three new species of a rodent-like marsupial renowned for its suicidal sex habits have been discovered in Australia’s Gold Coast hinterland.



The antechinus made world headlines last year when scientists found the males of the species would die en masse at the end of each mating season, after vigorous and sustained sexual encounters caused their bodies to disintegrate from stress.



Now Queensland scientists have discovered three new species, included the latest, the black-tailed antechinus.



“It’s a very exciting time to be a mammalogist,” said Dr Andrew Baker, head of the Queensland University of Technology team who made the discoveries.



“Typically there’s only a couple of new species of mammals found worldwide each year. So to find three new species of this marsupial, all in South-East Queensland is really exciting,” he said.



The black-tailed antechinus is distinctive for its hairiness, as well as its dark tail. It was found at the highest peak of the World-Heritage listed Gondwana Rainforests, in Queensland’s Springbrook National Park.



“It’s been trapped there, at the very highest point of the rainforest at 1,000 metres, where you get fog dripping onto the plants. With its big shaggy coat, it probably likes the coldest and wettest environment possible,” Baker said.



Global warming is causing the rainforest habitat in which the marsupial was found to dwindle. “The animals who can’t fly or move very far become trapped, and they become very different because they can no longer interbreed,” he said.



The rapid discovery of so many new species hinted at an “explosion of diversity” among mammals over the past million years, he said. And thanks to new DNA techniques, they’re easier to identify.



“New species are waiting to be found. This could be the tip of the iceberg.”



Baker said it was “highly, highly likely” that these new species of antechinus bred in the same way as their promiscuous cousins.



Pacific salmon, Caribbean reef squid, and many arachnids also engage in what scientists call semelparous, or big-bang reproduction. But the antechinus is rare among mammals.



After a four-month adolescence spent suckling at their mother’s teat, the males of the species grow up quickly. At around 11 months old, they stop producing new sperm, and embark on a feverish, weeks-long mating campaign to dole out their stockpile.



The marsupials romp from one sexual encounter to the next in sessions that can last up to 14 hours. It takes it toll.



“By the end of the mating season, physically disintegrating males may run around frantically searching for last mating opportunities,” biologist Diana Fisher from the University of Queensland told National Geographic last year.



The same rush of hormones that propels the males’ furious mating can also cause their muscles to degenerate and immune system to shut down. The frenzy finally ends when the male antechinus keels over and dies of stress, infection or internal bleeding.



Research published last year in the Proceedings of the National Academy of Sciences revealed why the furry philanderers reproduced in this way.



Citing a link between large testes size and semelparous reproduction, scientists said the fatal mating spree was actually a canny evolutionary strategy. Those antechinus who had the most sex produced the most offspring. Competitive copulation, even to the point of death, was a means to ensure the male’s genes lived on.



Baker and his team have applied for the black-tailed antechinus to be listed as an endangered species. News of its discovery is published in the latest edition of the biology journal Zootaxa.

