Rarely mentioned and often ignored as an anomaly or an evolutionary dead end (and haven’t we all heard that before?), there are several species of lizard, at least eight in the south-west of North America, who are completely female. There is not a single male in these species and there is no need for reproductive sex: females produce fertile eggs all by themselves.
As we all know – because we’ve been told this lie since birth – animals only have sex to make little baby animals so for a long time scientists assumed these female-only lizards didn’t, wouldn’t or couldn’t have sex. After all, what would be the point?
As you’ve already guessed though, they do. A lot. In fact they follow a highly intricate courtship pattern and two females sharing a burrow and sleeping there together will cycle their hormones, one with high progesterone levels who becomes the top, and one with high estradiol levels who becomes the bottom. After a few weeks, they switch hormone levels and position.
Major scientific journals still refer to the Whiptail lizards as ‘celibate’ despite all the – great deal of – lesbian sex going on right in front of the biologists’ homophobic eyes. Presumably, for some commentators at least, unless there’s a male penetrating a female, there simply is no sex.
Interesting fact: studies have shown that compared with similar species that have both males and females, the female-only whip-tail species are four times less aggressive and have a much less marked dominance hierarchy. Surprised? Didn’t think so.