Drag lizards, queens of the desert

Lurking amongst the beauteously coloured he-male and less spectacular female populations of flat lizards in the Augrabies Falls National Park in South Africa are those who seem to bat for both sides: the she-males.

When fully mature, male flat lizards are gloriously multi-coloured, while the females remain a drab brown. Males of many species use bling to both attract females and to scare off male rivals.

Amongst flat lizards, those rivals include she-males, young males that pretend to be females, mimicking their drab colour.

Female mimicry is not uncommon in the animal world as it allows young males to avoid aggressive older males, to spring a surprise on rivals in combat, and to spring a surprise on females with some unexpected copulation.

Also known delicately as the sneaky f-cker strategy, female mimicry allows young males to evade the ire of larger, aggressive males but also provides them with the odd opportunity for a quick shag.

Martin Whiting from the University of Witwatersrand, Jonathan Webb of the University of Sydney and Scott Keogh of ANU have now shown that while she-males of this species are able to con males by sight, their smell still gives them away.

Lizards use tongue-flicking to obtain chemical cues about other lizards, particularly when it comes to judging the reproductive status of females.

In a field experiment, the team used the solvent hexane to remove skin surface lipids from male and female lizards.

They then randomly allocated females to a control group with no scent manipulation, a group with their scent removed, and a group with she-male scent added.

She-males were also randomly allocated to a control group, a group with scent removed and a group with female scent.

He-males were not included as a group as they chased everyone else, but one prime suspect served as a focus animal and was tethered to a pole by dental floss, where he was then presented with individuals from each different group.

She-males were able initially to deceive the he-male visually, but once the tongue-flicking started, he woke up pretty quickly.

Females with male scent were rarely courted and sometimes attacked, while she-males scented as females proved quite arousing. The she-males themselves, however, whatever their scent, not surprisingly kept their distance from the he-males. While they may be transvestites in spirit, they are heterosexuals in practice.

Like other sneaky f-cker strategies, this sort of transvestism probably developed as a way for young males to get close to females while avoiding fights with older males. It is temporary, however: all of the she-males eventually develop male colouration, and then they are on their own.

The team’s research was published in the Proceedings of the Royal Society B.