The Antechinus family of rodents has one of the most peculiar sex lives in the animal kingdom, and just recently another species was discovered. These small dasyurid marsupial are carnivores who live in Australia and New Guinea. The most extraordinary aspect of the Antechinus family is their sexual cycle. Most males live only long enough to breed, being born in November and reaching sexual maturity around August of the following year. By the time the males are old enough, they cease to function except for the sole purpose of finding a mate. The shrews stop eating and sleeping and begin to shut down bodily functions deemed ‘unnecessary’ so as to save energy for finding a mate and passing on genetic material. This ‘sacrifice’ of bodily functions goes so far as to shut down the immune system and strips the body of vital proteins. As a result of these sacrifices, the males do not long outlive their first sexual experience, which can last about 12 hours. The females live slightly longer, lasting the entire mating season and storing all of the semen within their bodies until ovulation at the end of the season, producing liters with children from various fathers. Although some females manage to survive up to 3 seasons, most die after their first litter.
The new species, the black-tailed antechinus, was previously thought to be part of the dusky antechinuses species which is significant in that males are larger and commonly live for multiple mating seasons. It is unknown at this point whether the black-tailed antechinus shares that advantage or if the males simply die after their first season like most of the members of their genus. Other than their peculiar mating habits, the fact that a previously unknown species was discovered in Australia is remarkable, because new mammal species are extremely rare. However finds such as this of new species demonstrate how many new and interesting species of mammals and other organisms may still be out there.