Two species of marsupials whose males die after engaging in hours-long marathon sex sessions have been listed as endangered by Australian officials.

The black-tailed dusky antechinus and the silver-headed antechinus, both of which were discovered only in Queensland, Australia in 2013, partake in sex sessions of up to 14 hours with their mates. Unfortunately, the long bout of lovemaking literally kills the males.

“They are very frantic and try and get from one mate to another and the mating itself can last hours, so it’s very tiring,” Queensland University of Technology mammalogist Andrew Baker told AFP. Baker discovered both species of the marsupials.

The long mating sessions coupled with the males’ attempts to fight off rivals throughout causes an excess amount of testosterone to be produced. This results in their stress hormones being unable to switch off, which eventually affects their organs and leads to their death.

“I’ve seen them stumbling around during the day — they are nocturnal mostly — still looking for mates, bleeding from various parts of their body and their hair has fallen out,” Baker said.

In contrast, the female marsupials manage to survive the two-week annual mating period and enjoy a two-year lifespan. Over 50 percent mate only once.

Size isn’t everything: Tiny animals sex tape shows tardigrade couple's mating marathon https://t.co/vPiChPEyRH — RT (@RT_com) December 4, 2016

The pair of marsupial species are endangered not just because of their fatal mating habits, but as a result of climate change, loss of habitat and feral pests. Scientists fear they could soon be wiped out. The two species live in three known areas of Queensland and it’s estimated that only a few hundred exist.

Scientists are working to find other groups of the marsupials, using a detection dog to help them.

“Australia has the worst mammal extinction rate anywhere on Earth,” Baker said, welcoming the addition of the species to the endangered list. He hopes the protective action will see the populations recover and grow.

Think your friends would be interested? Share this story!