It is often the case that males use their bright
colours and strong presence to attract females and also to warn off other males.
Male Augrabies flat lizards, Platysaurus
broadleyi, have brightly coloured appendages that are used for both
courtship and to deter other males. For courtship, males use visual cues for
gender recognition and chemical cues for enticing females. If she permits close
proximity then the male will use a tongue-flicking technique at her posterior
end which is presumed to be in order to assess her reproductive viability.
Males only use visual cues to present their masculinity to other males.
This system of honest signalling can be problematic for
young males as gaining territory and proximity to females can be quite tough
with other mature males around. Therefore some males employ a tactic known as
female mimicry.
This involves delaying the onset of their colours,
therefore their male appearance, to look like a female. This allows them to
walk around other males with a decreased chance of getting into an altercation,
as males can be very territorial, and get close to females without other males
knowing. This can work as its mainly chemical cues that females use to assess
the males.
There are limits to this adaptation though as the
disguise only works in a visual sense. If these young males stay far enough
away from other males they will be fine however if they stray too close, mature
males will sense, through chemical cues, that they are males, not females, and
therefore are more likely to frighten off or hurt the young males.
References
Whiting M. J, Webb J.
K & Keogh J. S. (2009). Flat lizard female mimics use sexual deception in
visual but not chemical signals. Proceedings of the Royal Society B: Biological Sciences, 276(1662),
1585-1591.
Nice video Martin Whiting was my honours supervisor so his work on flat lizards is quite familiar to me, but I hadn’t realised that males can use sneaky mimicry. The video seems to suggest that females experience quite high levels of harassment. Do you know if this has been studied in this, or other, species of lizard? Nice post.
ReplyDeleteThat's very interesting, that they delay the maturation of their own colors when they know they won't be very impressive at a young age. I'm curious however as to how frequently young males do it, is it sort of like a phase all male lizards go through or do some still just go right to developing coloration even if it's not as impressive? You would think if every young male did it when they reached adulthood they'd all be far more aware of the possibility of sneaky males in their territory.
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