A snake orgy study has shown that males will mate until they die, whereas females prioritise staying alive.

An international team led by University of Sydney researchers has found that the frenzied approach to the mating season by red-sided garter snakes in North America results in males dying earlier and in worse condition than their female counterparts, who prioritise body-maintenance over short-term reproductive success.

The study found:

· males undertake energetically expensive mating for 2-4 weeks a year

· males do not eat during this time, as they must compete with thousands of other males

· females stayed at the orgy site for as little as one day

· snakes hibernate underground for eight months in their communal dens and emerge en masse in spring, to form large aggregations where males scramble to locate and mate with females

The research has been published in the Royal Society journal Proceedings B. 

Senior author Dr Christopher Friesen explains that the males make good use of the relatively short amount of time to procreate, having only four months a year to breed, feed and have babies.

“Although we believe that all females mate every year, they only stay at the den sites [where mating takes place] for a short period of one- to three days; much less than males, who remain at least a week and up to 21 days,” Dr Friesen said.

“Females reproduce every other year, which depends on their stored fat/energy reserves. Our previous research has shown that females can store sperm for up to 15 months or more before she uses the sperm to fertilise her eggs!”

The paper reported: “The relationship between body condition and age differed strikingly between sexes, with females maintaining their body condition with age, while condition decreased with age in males.”

In addition to prioritising self-preservation over sex, the female garter snakes studied in Manitoba, Canada, did not waste energy on looking after their babies postnatally, which is in line with the parenting approach of other snakes.