Female arboreal skinks can reproduce even if they haven’t met a male for over a year, according to a new study. Scientists from Macquarie University and Dalhousie University in Canada published their findings in the Journal of Heredity.
A new study by Australian and Canadian scientists has shown that female arboreal skinks can reproduce offspring, even if they have not mated with a male for more than a year. This discovery is the first evidence of this type of reproductive behavior in social lizards.
Arboreal skinks (Egernia striolata) are usually monogamous and live in family groups. Researchers separated women from men for a completely different study. Much to their surprise, some of the lizards gave birth a year after the start of the experiment, and some offspring came from a male who was not a partner of the female.
A study published in the Journal of Heredity suggests that keeping sperm from other males could be called “genetic hedging,” or in other words, a safety net. It reduces the risk of inbreeding and improves offspring survival by choosing to mate with more genetically diverse males than the main mate.
At the same time, mating “on the side” is a risky undertaking for the female arboreal skink. If she is caught at the scene of the “crime”, then the partner may reject the female and offspring. “The ability to store sperm from meeting other males for long periods of time is likely to provide reproductive benefits for females,” explains Dr. Julia Riley of the Department of Biology at Dalhousie University.
Study co-author Professor Martin Whiting of the Department of Biological Sciences at Macquarie University says the study’s findings highlight the real, but underestimated, control of women in reproduction.
In future studies, scientists want to find out how widespread storage of sperm by female lizards is, how their reproductive tract allows sperm to remain viable after such a long time, and under what conditions females tend to continue the race with other than their partner.