HUYGHE, K.*; VANHOOYDONCK, B.; HERREL, A.; VAN DAMME, R.; Univ. of Antwerp, Belgium; Univ. of Antwerp, Belgium; Univ. of Antwerp, Belgium; Univ. of Antwerp, Belgium: Ecological and behavioural correlates of colour polymorphism in a lacertid lizard, Podarcis melisellensis

The co-existence of different colour morphs within a single population occurs in many animal and plant species. Several adaptive hypotheses have been put forward to explain this phenomenon (e.g. negative frequency-dependent selection, niche variation, non-random mate choice), but often it remains unclear how different selective forces create a balance that allows a permanent polymorphism. Most of the explanations predict that the colour morphs will differ in aspects of their life history and behaviour. For instance, male colour may be related with a specific reproductive strategy, territorial behaviour, and dominance. In turn, the diversity in life history and behaviour should be reflected in differences in animal design and performance. In a population of the Croatian wall lizard Podarcis melisellensis we found a striking polymorphism in abdomen and throat coloration: animals are white, yellow or orange. Testing hypotheses about the evolution of colour polymorphism requires an integrative approach. Here, we present data on various life history aspects of Podarcis melisellensis. We quantified the frequency of the different morphs along a transect on the island of Lastovo, Adriatic Sea, Croatia. The three colours exist in males and females, but in different proportions. In males, yellow individuals are the least common morph; in females, orange is the rarest colour. For a limited set of individuals we quantified morphological, performance and habitat characteristics. Orange males are clearly bigger than white or yellow, resulting in a different performance capacity. Also, behavioural observations were made in the field for several individuals of every morph. Colour morphs seem to differ in some aspects of their behaviour and microhabitat use.