The more sex, the better

It is the secret of Australian kangaroos when they don't want to waste time searching for an ideal partner but still creating great children.

Antechinus stuartii is a small marsupial in Australia. They have an unusual sex life. The males gather in a nest, waiting for their children to appear and try to mate with as many females as possible, as if it was the last revelation in their lives. Two weeks later, the male's immune system waned and they died, while the female continued to live to give birth to a single litter and also died a few months later.

(Photo: ABC Online) Diana Fisher, a researcher at the Australian National University in Canberra, and colleagues captured these wild animals and had their children mate once with one of three males, or three times with one male. The team found that the sexually abused females were three times more likely to produce young offspring until weaning.

Experiments show that some males produce more quality young offspring than other males. This proves that higher quality males will produce sperm capable of defeating the opponent's sperm. If so, the children will not need to choose a partner, but they just have to deal with many guys and let sperm compete with each other.

Does this process occur in other mammals? Usually, children often have to choose a partner to reduce the risk of carrying the disease to their offspring. The strange reproductive habit of Antechinus stuartii kangaroo seems to be unique. But its benefits make researchers think that other species can also benefit from that strange habit.

MT