Le Compte Ory - Lizards Got There First


By Dmitri Dergun
08/03/2009

In Rossini's opera, the Count and his men infiltrate a nunnery dressed as nuns. Now it seems that this would be no news to lizards.

The male Augrabies Flat Lizard is a highly territorial animal: fully grown adult males dominate their territories, which contain multiple females - harems - by attacking and driving off younger males.

The adult males are highly coloured whereas females are a dull brown colour. A team of South African and Australian researchers has discovered that some young male lizards protect themselves from older males by pretending to be females, gaining access both to a territory and its resident females, where they are probably a lot more welcome than the Count and his men were.

As juveniles, all males look like females before gradually developing their extravagant adult male coloration at the onset of sexual maturity. Young males are most vulnerable to aggressive adult male rivals when these first signs of masculinity develop. Experienced males will chase and bite their young rivals.

"Young males purposefully only develop colours on their belly, so they reach sexual maturity by still looking like a female," says co-author Associate Professor Scott Keogh, of the School of Biological Sciences at the Australian National University. Professor Keogh says that the young transvestite males appear to have a dual advantage: ?They can avoid potentially dangerous bouts with dominant males and still have access to normally inaccessible females.?

?By delaying the onset of colour to a more convenient period, these males (termed she-males) are making the best of a bad situation,? said team member Associate Professor Martin Whiting of the University of the Witwatersrand. An immediate advantage of this phenomenon is freedom of movement in the normally treacherous zones which make up the territories of highly aggressive males that already have fighting experience. At the same time, the female mimics are able to court the myriad of females that share the territorial male?s residence.

The researchers also tested whether she-males are able to mimic the chemical ?signature? of females. In a clever experiment performed in the wild, they removed all pheromones and skin lipids that might signal gender and relabelled a group of females and she-males with either male or female scent, before presenting them to typical adult males. Males use their tongues to sample chemical scent and responded by courting she-males labelled as females, but not she-males labelled as males. ?Males are fooled by looks, but not by scent? said researcher Dr Jonathan Webb of the University of Sydney. ?She-males are able to maintain this deception by staying one step ahead of a prying male, and thereby avoiding a nosey tongue that might give the game away.?

Question: at what level do the young transvestite males 'know' that they are deceiving the older males? Clearly a lizard can tell a male from a female both by sight and by smell. A she-male is aware at some level that it doesn't look like an older male - it has to, or its behaviour would be a give-away on the older male's territory. It has to walk and behave like a female, or it would immediately be spotted and attacked by the reisdent tyrant male. The lizard is not 'conscious' of course, in the sense of being self-aware in the way that humans are. But some part of its brain knows that it looks like a girl. An early component of intentionality.



 

 

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