[Odonata-l] Sexual dimorphism question?

[Rob van Bemmelen]

I have a little guess:
Cryptic colored females may be less easily detected by males and thus less 
often harassed.

Female-based colour-polymorphism (or polychromatism), in which there is 
always one male-like female, has been explained by frequency-dependent 
advantage, as males only get to learn to recognize male-like females once 
they become more abundant. This shows that the rare colourmorph is always in 
advantage of the other. Thus, both a cryptic or a male-like appearance have 
advantage(s).

However, this does not explain the bright coloration of males......

I hope somebody else has a better answer...

Cheers, Rob




>From: "Pilon, Michel" <mipilon at nrcan.gc.ca>
>To: <odonata-l at listhost.ups.edu>
>Subject: [Odonata-l] Sexual dimorphism question?
>Date: Sun, 4 Feb 2007 16:10:23 -0500
>
>Hello again,
>
>I hope I don't annoy all of you with my naive questions...
>
>After reading the answers about my id's request and considering that in 
>both case the sexual dimorphism is important, I would like to ask you the 
>following question which came to my mind:
>
>What justify that sexual dimorphism amongst dragonflies...?
>
>With birds we know that the female is attracted by the colorful male and 
>that she has to be duller because she has to lay over the eggs and should 
>not be seen by predators...
>
>Is it the same thing amongst Odonata? Does the female attracted by the male 
>colors? And why usually are they duller than the male? (I'm thinking also 
>of Sympetrum obtrusum (white-faced Meadowhawk))
>
>Excuse-me again for my maybe so naive question...
>
>Michel Pilon
>Sherbrooke
>Quebec Canada
>
>Mes Parcours Nature:
>http://parcours.pilonm.org
>
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