Growth, longevity and age at maturity in the European whip snakes, Hierophis viridiflavus and H. carbonarius

Age and size at maturity are major life history traits, because they influence lifetime fecundity. They represent the outcome from complex interactions among environmental pressures (abiotic and biotic) and individual characteristics. They are also difficult to measure in natural populations and thus they are rarely appraised, especially in reptiles due to the elusive nature of juveniles. Using skeletochronology to circumvent these difficulties, this study aims to compare age structures, longevity, age-size relationships, growth curves, age and size at maturation and potential reproductive lifespan in three populations of the European whip snake (two Hierophis viridiflavus, one H. carbonarius). We measured the body size and counted the skeletal growth marks on 132 specimens, accidentally killed or from museum collections (72 from NW France [Chizé]; 28 from Tuscan Archipelago [Montecristo], Italy; 32 from S Italy [Calimera]). General patterns of age at maturity and longevity were consistent with previous studies based on recapture investigations. Strong differences among populations suggest local adaptation to contrasted environmental conditions. These results suggest that skeletochronology is a useful technique that can be applied opportunistically in snakes (e.g. using road-kills) in order to collect otherwise unavailable data that are essential to address fundamental questions regarding longevity, life-history traits and to perform population viability analyses

Water-soluble proteinase activity of gastric fluids in the European whip snake, Hierophis viridiflavus: an experimental preliminary survey

Understanding the mechanism of metabolic digestion and of food assimilation in wild snake species is of fundamental importance to compare trophic niches, their adaptive significance and evolutionary patterns of diet selection for different snake species. From two adult Hierophis viridiflavus males in fasting condition, we sampled gastric fluids using fiberoptic endoscopy. We analyzed the proteolytic activities (optimal pH and temperature, response to inhibitors) of snake samples by zymography techniques. The two major protease activity bands were always detected at every tested pH. Activity bands were also detectable over 37 °C; in particular both bands showed the highest activity ranging from 55 °C to 60 °C. Ranging from 65 °C to 85 °C, one band remained visible while the other band disappeared over 60 °C. The pattern of proteolytic enzymes activity of sampled gastric fluids highlighted a scenario composed of few active proteases, reflecting the feeding status (e.g., fasting) of studied snakes. Detection of proteolytic activity until 85 °C, as in prokaryotic organisms, supported the hypothesis about the presence of proteases of exogenous source

Colour pattern variation in populations of the European Whip snake, Hierophis viridiflavus: does geography explain everything?

Different colour patterns in European Whip snake, range from normal (“viridiflavus” pattern), to abundistic (dark pattern), to melanic-melanotic (black) patterns. Sexes are highly dimorphic, with more abundistic and melanotic-melanic males, than females. Colour patterns are also distributed in well defined areas of the species’ distribution range. Normal colour is distributed in N Europe, N, NW and C Italy, while abundistic snakes are typical of Corsica and Sardinia, and melanic-melanotic snakes are very common or exclusive of NE, S Italy and Sicily. Proximal causes that may have driven the distribution of present colour patterns are linked to palaeogeographic events, even if fossil reconstruction of past colonization or a suitable phylogeographic hypothesis are not available

Trophic niche and feeding biology of the Italian wall lizard, Podarcis siculus campestris (De Betta, 1857) along western Mediterranean coast

Trophic niche of the Italian wall lizard was studied at three different sites in Tuscany (central northern Italy), two along the Mediterranean sea, one inland. Fecal pellet analysis was carried out on 71 pellets (37 of male and 34 of female adult lizards), accounting on the whole for 184 prey items. Coleoptera, Hymenoptera (ants), Araneae and Gastropoda were the most represented taxa (numerical abundance of ca 22, 7, 7, 6% respectively). We found Brillouin diversity index similar in females and in males, with a marked overlap between sexes, but differences in niche overlapping among localities. Diet spectrum was quite different with that found in other central Italy localities, in the Tuscan Archipelago, or in areas where P. siculus has recently introduced. Our study confirms the opportunistic pattern and adaptability of this lizard species, and increases the range of sampled localities within the species’ range

The observations on the biometry and the reproductive biology of the Leopard snake, Zamenis situlus, in Italy

Museum specimens of the Leopard snake, Zamenis situlus, were considered for these observations. Strong sexual size dimorphism was evident when raw data were considered. Males had longer body sizes and longer tails than females; also head length and width, but not interorbital distance, were greater than those of females. Subcaudal scales were higher in number in males, while ventral and total scales were similar among sexes. When influence of sex and covariation of snout to vent length were controlled for log transformed data, it was found that head size features varied according to snout to vent length and no effect of sex was detected. Growth trajectories are likely similar between sexes and suggest that male maturity is reached at older age than that of females

Trophic niche and feeding biology of the Italian wall lizard, <em>Podarcis siculus campestris</em> (De Betta, 1857) along western Mediterranean coast

Trophic niche of the Italian wall lizard was studied at three different sites in Tuscany (central northern Italy), two along the Mediterranean sea, one inland. Fecal pellet analysis was carried out on 71 pellets (37 of male and 34 of female adult lizards), accounting on the whole for 184 prey items. Coleoptera, Hymenoptera (ants), Araneae and Gastropoda were the most represented taxa (numerical abundance of ca 22, 7, 7, 6% respectively). We found Brillouin diversity index similar in females and in males, with a marked overlap between sexes, but differences in niche overlapping among localities. Diet spectrum was quite different with that found in other central Italy localities, in the Tuscan Archipelago, or in areas where P. siculus has recently introduced. Our study confirms the opportunistic pattern and adaptability of this lizard species, and increases the range of sampled localities within the species’ range

Notes on the population reinforcement project for Emys orbicularis (Linnaeus, 1758) in a natural park of northwestern Italy (Testudines: Emydidae)

Reinforcement of an Emys orbicularis (LINNAEUS, 1758) population was carried out during a two Years pilot project in "Parco Lombardo della Valle del Ticino" (northwestern Italy), where the species seems to be seriously threatened. The acclimation (continuous presence, winter survival) of the reintroduced specimens seemed to be satisfactory, but reproduction was never observed. The ecological traits of the area meet well with the needs of the tortoise. Paucity of suitable nesting sites, due to human activities, probably causes the current scattered distribution of Emys in the park

Frequency and effort of reproduction in female Vipera aspis from a southern population

The frequency of reproduction of the asp viper (Vipera aspis, Viperidae) was studied in a population living along the coasts of central Italy. An annual reproductive cycle seemed to be the rule during the 5-year study period. Annual reproduction, high average mass of reproductive females, and large size of neonates, compared with other northern or continental populations, are presumably due to the particularly suitable climatic conditions of the area, as in most coastal habitats of the Mediterranean region. Such a scenario should influence the extent of the feeding period, which allows females, within a few months after parturition, to regain their previous body condition and reproduce again the following year

The reproductive strategies in neighbouring populations of the European pond turtle, Emys orbicularis, in central Italy

Two large Emys orbicularis populations of coastal central Italy, from San Rossore and Camp Darby (Tuscany), were studied to test patterns of reproductive biology variability, and life history traits. No significant difference was found between the localities for any of the considered linear measurements (raw data), either of males or females. Despite this, analysis of covariance revealed differences for most of the parameters examined (log-transformed variable). Females from San Rossore were significantly larger, heavier and longer than those from Camp Darby, and produced a significantly larger clutch than those of Camp Darby (six vs five eggs). Combining radiographic, ultrasonic and manual techniques, it was found that more than 77% of all adult-sized females reproduced annually and more than 50% of them laid a second clutch during the same season. While egg size did not vary between localities (raw data), analysis of covariance on egg shape (all variables considered together) revealed a significant difference. The observed differences in reproductive traits of these populations are significant and hypothesised to be related to ecological as well as to demographic constraints