The phylogeography of the colubrid snake Hierophis viridiflavus was estimated using ND4 mtDNA sequences and a fragment of the nuclear marker β-fibrinogen intron 7. This species has a wide distribution across the Mediterranean region, and is characterized by three distinct colour patterns ("viridiflavus", abundistic, and melanic-melanotic) with a quite well defined geographic distribution. The "viridiflavus" pattern occurs in the northwestern and central areas of the species' range, the abundistic pattern is typical of the individuals from Corsica and Sardinia, and the melanic-melanotic coloration is present in northeastern and southern Italy, and Sicily. A total of 42 individuals from most of the species' range (including Pyrenees, central France, Italian Peninsula, Corsica, Sardinia and Sicily) were analyzed. Results support the existence of two different mtDNA lineages, one from Spain, France, Corsica, Sardinia, and continental Italy mainly west of the Apennines, and another one occurring in the southern part of Italy and northeast of the Apennines, with a 4% genetic divergence between them. Since both mtDNA lineages are found in northwestern Italy, where the "viridiflavus" colour pattern is almost exclusively found, it is clear that colour pattern is not linked to the mtDNA clades. The same is evident for β-fibrinogen, which is not subdivided geographically in the way that the mtDNA lineages are. Regarding Corsica and Sardinia, the limited genetic differentiation of island populations from the western continental lineage, indicates that these populations are a result of a recent colonization in accordance with recent described phylogeographic patterns.

Novelties in systems of sexing and marking less dimorphic species of gekkonid lizards are described and first results are presented on the Moorish gecko, Tarentola mauritanica, used as target and model species. Inspection of cloacal opening and tail basis to detect hemipenes has been done with a small probe and with laser light. Behavioural response to tail basis touch was typical of adult males. Permanent marking has been performed along with the removal of some subdigital scales. Sexing was suitable and feasible on all individuals larger than 45 mm snout to vent length.

The ability of snakes to follow conspecific pheromone trails during the breeding season is of primary importance to locate potential mates, and also to elicit and maintain courtship or other reproductive behaviours, such as agonistic behaviour. Despite the recent increased knowledge on snake chemical ecology, yet little information is available on European species and nothing is known about chemical communication in European colubrid species. The aim of this study was to characterise the pheromone-mediated trailing behaviour in male European whip snake, Hierophis viridiflavus. When tested in trailing experiments using a Y-maze, male European whip snakes displayed the ability to trail both male and female pheromones when presented versus a blank arm of the maze. Moreover, adult males followed the female pheromone trail when presented simultaneously with the male trail. Our study demonstrated that male Hierophis viridiflavus rely on chemical cues for the location and the sexual discrimination of conspecifics during the breeding season. Convergence between different mating systems and chemical communication ability in distantly related species is discussed.

Dimorphisme sexuel, morphométrie et variation phénotypique de la Couleuvre verte et jaune Hierophis viridifl avus dans une région du centre de la Méditerranée. -Généralement les populations animales qui vivent dans des environnements différents divergent dans leurs caractéristiques phénotypiques. Chez les serpents, la taille corporelle varie fortement entre populations disjointes. La Couleuvre verte et jaune Hierophis viridifl avus est largement distribuée en Méditerranée occidentale et sur les îles tant petites que grandes de la mer Tyrrhénienne. Nous avons comparé les patterns biométriques relatifs à l'écaillure ventrale, la taille du corps et de la tête dans divers échantillons provenant du continent, de petites et de grandes îles. Le dimorphisme sexuel est très marqué chez cette espèce, les mâles étant corporellement plus grands, avec une tête plus grosse et moins d'écailles ventrales que les femelles. Une relation forte entre le nombre d'écailles ventrales et l'origine géographique a été clairement mise en évidence, les individus provenant des petites îles étant caractérisés par un nombre signifi cativement élevé d'écailles ventrales. Cette relation se maintient quand on prend en compte la taille corporelle, les individus insulaires étant plus petits que ceux du continent. Nos résultats indiquent clairement une forte différenciation entre les populations étudiées et éclairent l'importance relative de la variation phénotypique.SUMMARY. -Animal populations living in different environments generally exhibit divergent phenotypic characteristics. In snakes, body size varies greatly among disjunct populations. The European Whip snake, Hierophis viridifl avus, is widely distributed in the western Mediterranean area, and on most of both small and large islands of the Tyrrhenian Sea. We compared biometrical patterns regarding ventral scalation, body size and head size among different samples from mainland, large islands and small islands. Sexual Size Dimorphism was very marked in the species, with males attaining larger body size and larger relative head size than females and a lower number of ventral scales. There was a clear evidence of a strong relationship between ventral scale number and the geographic origin, with smaller island snakes characterized by a signifi cantly higher number of ventral scales. This relationship was true even when considering body size, with insular snakes signifi cantly smaller than mainland ones. Our results clearly indicated a strong differentiation among the considered populations, and provided basis to clarify the relative importance of phenotype variation. An organism's external morphology is the result of the interaction between the organism itself and the environment in which it lives (Seigel & Collins, 1993;Greene, 1997). Body size, together with several other external characteristics, strongly infl uences an organism's life,

Feeding strategies and diet patterns have been extensively investigated in vertebrates and, more specifically, in snakes. Although it has been hypothesized that prey species may differ in terms of energy content, almost no theoretical or practical study has been carried out to determine actual nutritional values of the common prey types of wild snakes. Our model taxa were a selection of widely distributed and well known European snake species, which have all been studied in depth: approximately 76% of their diet is composed of mammals, reptiles, and insects. We therefore selected a single model species for each of these categories and proceeded with the analyses. Nutritional values were determined using a standard procedure: lizards and mice were richer in proteins than insects (crickets); insects and mice were richer in lipids than lizards, and mice and crickets have a higher energy content than lizards; lizards were rich in ashes. We then applied our experimental results to a selected sample of European terrestrial snakes (11 populations, ten species, seven genera, two families) characterized by different body size (50-160 cm total length) and reproductive strategies (oviparous versus viviparous), aiming to correlate these parameters with patterns of energy income. A direct relationship was found between body mass/body length ratio (BCI, body condition index) and meal energetics: the higher the BCI, the higher was the metabolic requirement, whereas BCI was independent of species or of reproductive system effect. Large-sized snakes thus need a highly diversified and more energy-rich diet than smaller snakes, supporting previous hypotheses. The simple applicability of this method could be of valuable support in further comparative research work, reducing experimental costs and stimulating further ecological, behavioural, and, possibly, phylogenetic comparisons.