Fabio Pupin

Male-male combats in a polymorphic lizard: residency and size, but not color, affect fighting rules and contest outcome.

Theoretical models predict that the outcome of dyadic agonistic encounters between males is influenced by resource-holding potential, resource value, and intrinsic aggressiveness of contestants. Moreover, in territorial disputes residents enjoy a further obvious competitive advantage from the residency itself, owing to the intimate familiarity with their territory. Costs of physical combats are, however, dramatically high in many instances. Thus, signals reliably reflecting fighting ability of the opponents could easily evolve in order to reduce these costs. For example, variation in color morph in polymorphic species has been associated with dominance in several case studies. In this study, we staged asymmetric resident-intruder encounters in males of the common wall lizard Podarcis muralis, a species showing three discrete morphs (white, yellow, and red) to investigate the effects of asymmetries in color morph, residency, and size between contestants on the outcome of territorial contests. We collected aggression data by presenting each resident male with three intruders of different color morph, in three consecutive tests conducted in different days, and videotaping their interactions. The results showed that simple rules such as residency and body size differences could determine the outcome of agonistic interactions: residents were more aggressive than intruders, and larger males were competitively superior to smaller males. However, we did not find any effect of color on male aggression or fighting success, suggesting that color polymorphism in this species is not a signal of status or fighting ability in intermale conflicts.

Photographic identification in reptiles: a matter of scales

Photographic identification is a promising marking technique alternative to the toe-clipping, since it is completely harmless, cheap, and it allows long time identification of individuals. Its application to ecological studies is mainly limited by the time consuming to compare pictures within large datasets and the huge variation of ornamentation patterns among different species, which prevent the possibility that a single algorithm can effectively work for more than few species. Scales of Reptiles offer an effective alternative to ornamentations for computer aided identification procedures, since both shape and size of scales are unique to each individual, thus acting as a fingerprint like ornamentation patterns do. We used the Interactive Individual Identification System (I 3 S) software to assess whether different individuals of two species of European lizards ( Podarcis muralis and Lacerta bilineata ) can be reliably photographically identified using the pattern of the intersections among pectoral scales as fingerprints. We found that I 3 S was able to identify different individuals among two samples of 21 individuals for each species independently from the error associated to the ability of the operators in collecting pictures and in digitizing the pattern of intersections among pectoral scales. In a database of 1043 images of P. muralis collected between 2007 and 2008, the software recognized 98% of recaptures within each year, and 99% of the recaptures between years. In addition, 99% and 96% of matches were ranked among the top five, and no more than 5 minutes were needed for digitizing and processing each image. The lepidosis of reptiles is a reliable alternative to ornamentation patterns in photographic identification of reptiles, which can be effectively analysed using the I 3 S software. This result represents a significant improvement in photographic identification of reptiles since (i) this procedure can be easily extended to most other species of reptiles, (ii) all kind of individuals within a species can be marked (i.e., young, subadults and adults) despite the differences in ornamentation patterns, and (iii) it is the only technique for species, like the western green lizard, which lack a clear ornamentation pattern.

Morph-specific immunity in male Podarcis muralis

Permanent colour polymorphism in lizards is maintained by complex interactions between environmental pressures and physiological traits (such as immune responsiveness) that differ among morphs. In this study we investigated whether T-cell mediated immune response vary among male colour morphs in the trimorphic (white, yellow and red) common wall lizard, Podarcis muralis . We found that yellow males showed a lower immune response compared to both red and white males, whose responses were similar. Thus, immune responsiveness is morph-specific in male common wall lizards, suggesting that this physiological trait could play an important role in maintaining colour polymorphism in this species. Moreover, immune responsiveness significantly increased with increasing male size, irrespective of colour morph, indicating that it could be regarded as a condition-dependent trait.

Forgotten in the ocean: systematics, biogeography and evolution of the Trachylepis skinks of the Socotra Archipelago

Sindaco, R., Metallinou, M., Pupin, F., Fasola, M. & Carranza, S. (2012). Forgotten in the ocean: systematics, biogeography and evolution of the Trachylepis skinks of the Socotra Archipelago. —Zoologica Scripta, 41, 346–362.

Sex-, morph- and size-specific susceptibility to stress measured by haematological variables in captive common wall lizard Podarcis muralis.

In polymorphic species of animals, colour morphs may show alternative physiological properties, and hence evolve or be maintained as an indirect response to selection exerted on these physiological attributes. In this study, we investigated if different colour morphs (white, red and yellow) of the polymorphic common wall lizard differed in their physiological responses to a long-term stress by determining variation between capture and release in leukocytes profiles, haemoparasite loads and body condition of male and females maintained in captivity throughout the breeding season. We found that most blood parameters of lizards varied significantly following captivity, and this variation was sex-, morph- and size-dependent. In particular, the heterophil:lymphocyte ratio (H:L), a sensitive measure of immunodepression and long-term stress, varied significantly among yellow females, larger individuals significantly increasing and smaller individuals decreasing their H:L ratio after captivity. This trend was reversed in red females, where smaller individuals presented raised H:L index at release. Our study indicated that response to long-term stressful conditions, such as those induced by captivity, differed among common wall lizard colour morphs, implying a sex-, size-(i.e. age) and morph-specific sensitivity to stress, and hence a different physiological profile of colour morphs, which may contribute to the maintenance of colour polymorphism in this species.

Origin and in situ diversification in Hemidactylus geckos of the Socotra Archipelago

The Socotra Archipelago is an ancient continental fragment of Gondwanan origin and one of the most isolated landforms on Earth and a biodiversity hot spot. Yet, the biogeography and evolutionary history of its endemic fauna still remain largely overlooked. We investigate the origin, tempo and mode of diversification in the Hemidactylus geckos of the Socotra Archipelago. Concatenated and multilocus species coalescent analyses of Hemidactylus from Arabia and North Africa indicate that the Hemidactylus from Socotra do not form a monophyletic group and branch as three independent and well‐supported clades instead. Both the chronogram inferred using the gene tree approach of BEAST and the age‐calibrated multilocus species tree obtained using *BEAST suggest that the origin of Hemidactylus from Socotra may have involved a first vicariance event that occurred in the Early Miocene, followed by two independent transoceanic dispersal events that occurred more recently, during the Pliocene. Within Socotra, we analysed patterns of genetic diversity, the phylogeography and the demographic history in all seven nonintroduced species of Hemidactylus. Results based on two mitochondrial and two nuclear loci from 144 individuals revealed complex patterns of within‐island diversification and high levels of intra‐species genetic divergence. The interplay of both historical and ecological factors seems to have a role in the speciation process of this group of geckos. Interestingly, the case of H. forbesii and H. oxyrhinus, which inhabit the island of Abd al Kuri with an area of 133 km2, may represent one of the most extreme cases of intra‐island speciation in reptiles ever reported.

Effects of female mating status on copulation behaviour and sperm expenditure in the freshwater crayfish Austropotamobius italicus

Sperm competition models predict that males should adjust their sperm expenditure according to the risk and/or intensity of sperm competition. In this paper, we analysed copulatory behaviour of both sexes and sperm expenditure in relation to female mating status (virgin or mated) in the freshwater crayfish Austropotamobius italicus, a species where males have been reported to feed on and remove sperm laid by other males. The same females were allowed to be inseminated sequentially by two males, and we compared the sexual behaviours of partners between the first (virgin females) and the second mating (mated females). We found that female resistance did not differ between the first and the second mating, nor males refused or took more time to mount a mated female. However, when mating with a mated female, males reached an effective copulation position significantly later. This occurred because second-mating males removed, by eating, all or most spermatophores previously deposited by first males. As removal was often incomplete, this resulted in a larger amount of sperm being deposited on female ventral parts after the second mating, although second males did not allocate more sperm to mated females than first males did. Thus, the peculiar mode of sperm competition, where males remove previously deposited sperm, and the consequent predictable strong last male prevalence in paternity likely led to the observed lack of adjustment of sperm expenditure to female mating status in this species.

Bergmann's rule and the Italian Hermann's tortoises ( Testudo hermanni ): latitudinal variations of size and shape

We used geometric morphometric analysis to investigate latitudinal variation in size and shape of carapace and plastron of 111 Testudo hermanni hermanni (60 males and 51 females) collected in 6 different Italian regions. Basing on a sample of 14 landmarks for carapace and 18 landmarks for plastron, we showed that the size and shape of both sexes changed according to a North-South cline following the Bergmanns rule, tortoises of Northern Italy being 1.1-1.2 larger than that of Southern Italy. Shape variation was higher in carapace probably because sexual selection in this species acts stronger on plastron than on carapace shape.

Leukocyte differential counts and morphology from twelve European lizards

Abstract The present study reports the morphology of leukocytes of 12 European lacertid lizards (Podarcis sicula, P. tiliguerta, P. melisellensis, P. bocagei, P. muralis, Algyroides nigropunctatus, Lacerta viridis, L. bilineata, L. trilineata, L. oxycephala, Timon lepidus, and Zootoca vivipara) stained using May–Grünwald/Giemsa method. The morphology of white blood cells was very similar among species, suggesting a relative morphological uniformity within the lacertid lizards. For six species (i.e. P. sicula, P. tiliguerta, P. melisellensis, P. bocagei, P. muralis, and A. nigropunctatus), we determined the leukocyte differential counts, which may be considered representative of the normal values of the corresponding populations. These results may be useful either in clinical investigation to detect pathologies in wild individuals, as in management and conservation projects to assess the general health conditions of natural wild lizard populations.

Presence of rivals reduces mating probability but does not affect ejaculate size in the freshwater crayfish Austropotamobius italicus

Sperm competition models predict that males should adjust their sperm expenditure according to the risk and intensity of sperm competition, increasing it when competing with at least one other ejaculate and decreasing it when the number of competing ejaculates rises above two. However, when the raffle to fertilize eggs is strongly loaded due to sperm removal by subsequent rivals, it could be hypothesized that first-mating males progressively decrease their sperm expenditure and/or defer copulation with an increasing number of nearby competitors. Here, by varying experimentally the number of competitors around a mating pair, we analysed mating behaviour of both sexes and sperm expenditure in relation to variation in the immediate risk of sperm competition in the freshwater crayfish Austropotamobius italicus , a species where males remove all or part and feed on sperm laid by previous mating males. We found that male mating behaviour varied significantly with increasing number of rivals, because interactions between focal males and competitors, as well as male refusals to copulate, increased with number of the latter. As a consequence, the probability to reach an effective copulation decreased with increasing number of competitors. However, males released similar amounts of sperm independently of the number of surrounding competitors. Thus, the observed lack of variation in sperm expenditure in relation to the number of surrounding rivals suggests that freshwater crayfish males are unable to adjust the size of their ejaculates to short-term variation in the immediate risk of sperm competition.