Courtship behaviour in lacertid lizards: Phylogenetic interpretations of the Lacerta kulzeri complex (Reptilia : Lacertidae)

We investigate whether at a low taxonomic level an analysis of courtship pr ovides useful phylogenetic information in lacertids. This leads to an under standing of the evolutionary development of courtship behaviour, In a concise general description of lacertid courtship behaviour, four phas es are distinguished: introduction. copulation, post-copulatory bite, and t he period immediately after physical separation. The composing elements are described. Observations on courtship displays of seven closely related put ative species of lacertid lizards, Lacerta cf. kulzeri, are summarised in 3 8 behavioural traits, resulting in a data matrix analysed by PAUP. One most parsimonious cladogram (MPC) with 61 steps (corrected Consistency Index = 0.62) is found. The study demonstrates that at a low taxonomic level (putative species) in lacertids, a behavioural analysis provides useful phylogenetic information, from which a reconstruction of the evolutionary development of courtship b ehaviour results. In the L. cf. kulzeri complex, courtship seems to evolve towards a lengthening of the total duration. This trend is possibly correla ted with an increased preference for a progressively more vegetated, horizo ntal microhabitat, after coming from a similar ancestral environment in low land areas and going through an evolution in a more open, drier ecosystem o f rocky outcrops at higher elevations. The character sets on the internal n odes of the cladogram do not seem to represent a coherent evolutionary path way. These stages of evolutionary development appear to be interchangeable. Moreover, behavioural syndromes can hardly be recognised in this phylogene tic context. Our cladogram is strictly based on apomorphic similarities, and all relatio nships among taxa are based on recency of common ancestry, The only other d iagram for this group available from the literature is based on overall mor phological similarity. This dendrogram is considerably longer (69 steps) wh en the behavioural characters are mapped onto it. Parsimony mapping of beha vioural characters on an as yet unpublished preliminary cladogram based on 12S rDNA data results in 65 steps. Consequently, we favour the behavioural cladogram.