Scientists have finally figured out why the males of certain insect eating marsupial species die soon after mating season. Scientist initially thought that food availability, or some biologically embedded sense of altruism were the likely causes, but the reason is far less convoluted. They f*ck themselves to death.
A new study published in Proceedings of the National Academy of Sciences, denotes “sperm competition” as the primary cause for mass die offs of male marsupials. Semelparity (suicidal breeding) occurs in about a fifth of all insectivorous marsupials. The males remain immature until just before the breeding season. Once mature, they shut down all sperm production. Permanently. At this point, they either “use it or lose it”, and boy, do they use it.
“This gives them some urgency to mate, so it is no wonder that the breeding season is so frantic. Each mating can take 12 to 14 hours and they do this over and over again. Even if they survived the breeding period, they would be infertile anyway.”
In order for the male to have sex for 12 hours repeatedly during the month long breeding season, the male will need as much metabolic energy as possible. To accomplish this, the male’s body undergoes a transformation in which vital proteins are stripped from cells and the immune system is supressed. Once the month long deed is done, the male succumbs due to extreme stress, total immune system collapse and internal bleeding.
There is one way to avoid such a violent fate:
“The only way for males to avoid die-off is for them to be raised independently of any females so they are never exposed to the hormones that kickstart the mating frenzy.”
“But that’s not much fun for them either.”
So true, Mr. Marsupial Scientist, so true . . . .