She-Male Lizards Can’t Fake Female Smells

The purpose of this study was to test whether she-male Augrabies flat lizards were able to mimic visual and chemical female signals. Dominant male flat lizards (he-males) are very aggressive and fiercely maintain territories. Thus, younger males (she-males) sometimes mimic the appearance of females presumably to avoid fights, gain access to females and other resources, and avoid predators. To determine whether she-males mimicked both female coloration and scent the researchers ran a series of experiments on a wild population of flat lizards. Female and she-male lizards were captured and their scents were removed (except from control groups). Then, some females were given she-male scent and some she-males were given female scent. A last group was left with no scent. The test lizards were then tethered to a pole near a he-male and the male’s behavior was recorded. Researchers found that from a distance, he-males courted all test lizards suggesting that the she-male lizards’ visual display is not distinguishable from a true female. However, once the he-males were close enough to sense chemical signals, they based courtship behaviors on the “female scent” regardless of the true gender of the test lizard. Test lizards without scent or with she-male scents were not courted. This suggests that she-male lizards are not able to send dishonest chemical signals and that he-males can distinguish true sex through pheromones. In fact, she-males generally tried to avoid the he-male tongue flicks, further suggesting that their normal behavior is to stay far enough away from he-males to not be scented and recognized as male.

This paper gives an example of an animal that communicates courtship behaviors using two modalities: vision and olfaction. While she-males are able to send dishonest visual signals, they are not able to fake female scents. I would hypothesize that female flat lizard pheromones are not particularly volatile because males must be close enough to lick the female to detect her scent. As we discussed in class, there is also the possibility that the pheromone are “activated” by the male licking before it becomes volatile. I am not sure which is true for the flat lizard, however, it is clear that she-males are able to pass as females from a distance which suggests the chemical signals are not being used for long-distance communication.

Whiting, M. Webb, J., & Keogh, S. (2009) Flat lizard female mimics use sexual deception in visual but not chemical signals. Proc. R. Soc. Biological Sciences (Downloaded from rspb.royalsocietypublishing.org on 11 March 2009)