New Species of Mammal Is a Sex Fiend
A new species of marsupial, the black-tailed antechinus, lives in southeastern Australia.
Credit: Gary Cranitch

A newly discovered pink-nosed rodentlike marsupial gives its all for sex — really. Males of the species mate so intensely that they die before their young are born.

The creature's discoverers caught the little lothario in Australia's Springbrook National Park with traps baited with peanut butter and oats. They've dubbed it the black-tailed antechinus. 

Other members of the antechinus group have already been discovered, some by the same team that found the newest species. Mammalogist Andrew Baker of the Queensland University of Technology had previously found two new species of the genus Antechinus in southeastern Queensland. The discovery of new mammal species is relatively rare, with only a few found each year.

The researchers first saw the black-tailed antechinus in May 2013. It looked unlike the dusky antechinus, a relative that lives in the region, so Baker and his colleagues suspected they had seen something new.

The black-tailed antechinus has orange markings around its eyes and rump.
The black-tailed antechinus has orange markings around its eyes and rump.
Credit: Gary Cranitch

"When we caught the first black-tailed antechinus in a trap, we knew we were onto something pretty special," Baker said in a statement.

The black foot of the black-tailed antechinus.
The black foot of the black-tailed antechinus.
Credit: Gary Cranitch

The new species has a long, black tail and a five-toed foot, also black. The fur around its eyes and rump is yellow-orange, helping distinguish it from other species.

Marsupials in this genus are promiscuous maters. Females give birth to large broods that include offspring from several fathers. To raise their chances of siring more offspring, males mate for hours at a time with many females, Baker said. This sex bacchanalia sends the animals' stress hormone levels skyrocketing, which eventually results in death.

Females collect sperm from their doomed mates all breeding season and then ovulate, allowing for the fertilization of many half-siblings all at once. Some females survive to breed multiple times, but most die after their first litter is weaned. Baker and his colleagues are applying for endangered species protection for the newly discovered marsupial. They published the finding Feb. 17 in the journal Zootaxa.

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