02224nas a2200217   4500008004100000245007300041210006900114260001200183300001200195490000800207520156100215653001401776653001301790653002201803653002101825653001001846653001201856100002001868700001501888856010301903       2003                        eng d00aSexual dimorphism of body size and shell shape in European tortoises0 aSexual dimorphism of body size and shell shape in European torto  c2003///  a353-3650 v2603 aAdult body size and shape were examined in almost 1400 individuals of the tortoises Testudo graeca, T. hermanni and T. marginata from Greece. The size at maturity was greater in females than in males in all three species. Maximum and mean adult sizes were also greater in females than in males in T. graeca and T. hermanni. Males grew to a larger size than females in T. marginata, and mean adult size was similar in the sexes in this species. Sexual dimorphism of shape (adjusted for size covariate) was shown in most of the characters examined, and the degree of this dimorphism differed significantly among the three species. Differences were related to their contrasting courtship behaviours: horizontal head movements and severe biting in T. marginata, vertical head bobs and carapace butting in T. graeca, and mounting and tail thrusting in T. hermanni. There was no difference in the frequency of observations of courtship or fighting among the three species, but courtship was about 10 times more common than combat in males. All species showed greatest courtship activity in autumn; copulation was rarely observed in T. hermanni (only 0.36% of courting males) and not seen in the other species in the field. Observations made throughout the activity season indicated that feeding was equally common in males and females in all three species. Differences in shape were more likely to be the result of sexual selection than of natural selection for fecundity. Detailed predictions are made for sexual dimorphism of other characters in these species.10aCourtship10aReptilia10aSexual dimorphism10asexual selection10aShape10aTestudo1 aWillemsen, R.E.1 aHailey, A.  uhttps://icgf.myspecies.info/content/sexual-dimorphism-body-size-and-shell-shape-european-tortoises02061nas a2200217   4500008004100000245010400041210006900145260001200214300001200226490000600238520136000244653001001604653001701614653001301631653001201644653002101656653001301677100002001690700001501710856011801725       1999                        eng d00aA latitudinal cline of dark plastral pigmentation in the tortoise <i>Testudo hermanni </i>in Greece0 alatitudinal cline of dark plastral pigmentation in the tortoise   c1999///  a125-1320 v93 aThe area of dark pigmentation on the plastron of the tortoise Testudo hermanni shows a latitudinal cline over about 400 km in Greece, with populations in the south being darker. The carapace did not show the clinal trend, and pigmentation was not significantly related to longitude or altitude. We examined several possible explanations for the cline, including an effect of incubation temperature, random genetic variation, and adaptation to several environmental variables. The most likely explanation is selection for thermoregulation, with decreased dark pigmentation in the north reducing heat loss to the substrate by infra red radiation during activity. This hypothesis was supported by data on body (T(b)) and substrate (T(s)) temperatures in populations from northern, central and southern Greece. T(b) was generally above T(s), showing that heat would generally be lost rather than gained through the plastron, and the mean difference T(b)-T(s) was greatest in the north: +6.6 °C, compared to +2.4 °C in the south. Mean T(b) was lowest in the south (26.9°C, compared to 29.3°C in the north) and the slope of T(b) on T(s) was about 1 (compared to 0.5 in the north). Thermoregulation in southern Greece is similar to that of tropical tortoises, with avoidance of overheating being the major problem, rather than elevation of T(b) for activity.10aCline10aPigmentation10aReptilia10aTestudo10athermoregulation10aTortoise1 aWillemsen, R.E.1 aHailey, A.  uhttps://icgf.myspecies.info/content/latitudinal-cline-dark-plastral-pigmentation-tortoise-testudo-hermanni-greece