In several reptile species there are differences in thermal requirements of gravid and non-gravid females, the fonner ones basking more frequently and/or maintaining higher body temperatures. An alpine population ofthe live-bearing anguid Anguis fragilis LINNAEUS, 1758 was studied in this respect. Body temperatures were measured with a cloacal thermometer. Mean body temperature was higher in gravid than in non-gravid females (27.04 °C versus 25.28 °C). Also modal body temperatures of active animals were higher in gravid females. Correlation between ambient and body temperature was weak in both gravid and non-gravid females. A. fragi- lis appears as a thermoregulator rather than a thennoconfonner, at least during sunny days suited for basking activities. Gravid individuals bask by exposing their body directly to the sun, while non-gravid ones usually bask by staying under sunwanned objects. As a consequence, gravid females are probably more exposed to visually orientated predators. This is an important life-history feature, as increased prédation on gravid females means increased costs associated with reproduction.

A biennial reproductive cycle was found in female Anguis fragilis Linnaeus, 1758 from a locality in the eastern Italian (Carnic) Alps. Clutch size ranged from 6 to 13 and the constancy of the ratio of clutch size and female snout-vent length was statistically highly significant. The female reproductive pattern observed was quite similar to that of another ovoviviparous reptile from the same geographic area, i. e. Vipera be rus (Linnaeus, 1758). The occurrence of a biennial reproductive cycle in these two distantly related ovoviviparous reptiles could be due to scarce female foraging success, which is probably a consequence of unfavourable (e. g. high altitude) climate conditions.

Data on diet composition of Slow Worms, Anguis J. fragilis LINNAEUS, 1758, living in alpine regions of north-eastern Italy (Tarvisio Forest, province of Udine) are given. All information comes from an analysis of gut contents of specimens found dead in the field. Slow worms preyed on a wide variety of invertebrates, essentially earth-worms (33.33% of the prey individuals) and slug-snails (35.41%) The high incidence of these prey types in the diet of A. fragilis probably depends on the activity pattern of this lizard, which is active mainly after rain, in the first daylight hours and in the twilight. The A. fragilis specimens investigated preyed on both very small (shorter than 5 mm in length) and larger (more than 40 mm in length) invertebrates, but most (70.8%) of the prey individuals were found to measure more than 10 mm in length.

Phylogenetic relationships of the Western Palearctic legless lizard genus Anguis were inferred based on a fragment of mitochondrial DNA and two nuclear protein-coding loci, C-mos and PRLR. A. cephallonica from the Peloponnese was confirmed as a valid species. It is the sister taxon to a clade comprising all other evolutionary lineages, which were shown to represent three distinct species: (1) A. fragilis sensu stricto occurring in Western and Central Europe, the north-western Balkans, with possibly isolated populations in the eastern Balkans, and presumably also in western Scandinavia and Italy; (2) A. colchica distributed from the eastern Czech Republic and the Baltic region eastward to northern Iran, presumably also in eastern Scandinavia, and the north-eastern Balkans; (3) A. graeca restricted to the southern Balkans, and partially sympatric with A. cephallonica. According to the more variable mitochondrial marker, A. graeca appears to be the sister species to A. colchica, and these taxa together form a sister clade to A. fragilis, whereas the less variable nuclear markers show A. colchica to be closer to A. fragilis. The C-mos gene has not provided substantial variation within this species complex, while the PRLR gene, which was used for the first time in phylogeographic study in a reptile, distinguished all species successfully. Intra-specific differentiation of A. colchica is discussed, and subspecific status of the Caucasian and Caspian populations is proposed. The uncovered genetic differences should be taken into account in all future biogeographical, morphological and ecological studies, as well as in conservation.