The essence of mate choice is to
select a partner that will give you the most offspring, and that will in turn
be able to pass their genes on to the next generation. Females’ preference
is often driven to the fittest males do this. Males often display their fitness by having
colourful visual marking, advertising their resource acquisition ability. However, a colourful male will be more likely
do to attract attention from predators as well. With these to pressures, a trad-off
between pretty or eaten is established. However, female guppies (Poecilia reticulata) have shown their
ability to select correctly.
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| Three morphs of male guppies |
This was demonstrated when, females from two populations high and low predation , were tested to see what effect having a predator had on mate choice. Researchers found that if a predator was could not be seen, females preferred males with colourful markings. However when tested and the female could see a predator, the one from a high predation environment demonstrate a change in mate preference selecting less ornate males. This seems show that, female guppies can account for this trade-off and select the males that will give the most offspring for the environmental pressures.
Godin, J.J. & Briggs, S.E. 1996, "Female mate choice under predation risk in the guppy", Animal Behaviour, vol. 51, no. 1, pp. 117-130.
That’s interesting! How exactly did the researchers allow females to observe predators, without the predators selecting more brightly coloured males? Was there a difference in rate of courtship between males from high predator and low predator environments, which could explain why females select less brightly coloured males?
ReplyDeleteThey had a set up similar to what we used but with aquariums
Deletelooking top down,the female tank was in the center,with zones of preference; on the left and right small holding tanks, with the stimulus males, bright and non-bright colouration; and at the top a tank holding a cichlid (guppy predator) that only the female could see, as not disturb the male behavior. They tested presents and absents of the predator on both populations (I.e. with and without natural predator)
Great post Merric! Is crypsis a factor as well? Can they be colourful AND blend in to their environment with spots or strips?
ReplyDelete