Read about the animal that indulges in sex to the point of disintegration. No, it's not us Humans.
Discovered in Australia, a little mouse-like creature known as an antechinus engages in sexual intercourse to the point of its death. A virgin till now, but a little lothario has been going at it nonstop for the past two to three weeks. In violent, frantic interactions that can last up to 14 hours, he mates with as many females as he can.
He’s a wreck, but he still wants to have sex. “By the end of the mating season, physically disintegrating males may run around frantically searching for last mating opportunities,” says Diana Fisher from the University of Queensland. “By that time, females are, not surprisingly, avoiding them.”
It’ll all be over in no time. Like every other male antechinus in the vicinity, he died a few weeks before his first birthday.
Semelparity, derived from the Latin words for “to beget once,” is the technical term for this phenomenon. Sex is a once-in-a-lifetime affair for semelparous species, from salmon to mayflies, and it is frequently fatal. Many animal species engage in this behavior, but mammals are an exception. Only 12 species of antechinuses and a few near cousins, all of which are small, insect-eating marsupials, are known to have it.
Why do these mammals practice suicidal reproduction?
For three decades, biologists have struggled with this subject, and many have given solutions. According to some, males are obliged to hedge their bets by mating with as many females as possible. Females do not survive well after breeding; thus, males are compelled to breed with as many as feasible. Others argue that it’s simply a trait of the species, which has been trapped in an odd breeding system due to some undiscovered evolutionary quirk. Others believe that the guys are acting altruistically by sacrificing themselves to provide greater resources for the following generation.
A team of researchers gathered information on 52 insect-eating marsupials, ranging from totally semelparous antechinuses to relatives with a tiny percentage of males surviving past their first sexual liaisons to species that reproduce regularly.
It is their diet that is important. These creatures eat insects, and some have a surplus of food once a year but very little the rest of the year. The further you travel away from the equator, the more seasonality you’ll find. Males from the most seasonal menus had shorter breeding seasons and were more likely to die after mating.
The researchers believe that as antechinuses expanded south through Australia and New Guinea, their food supply saw significant yearly changes. Females that gave birth just before the annual feast and were well-fed enough to wean their joeys were better at raising their young. Their mating seasons became shorter and more synchronized, condensing into a small window of opportunity.