Information on the reptiles of the Sierra de Guadarrama, some of them very little known.
24 species of reptiles are inventoried in the Sierra de Guadarrama National Park and its Peripheral Protection Zone, giving an idea of the crucial role the Sierra de Guadarrama plays in this fauna group preservation. Various directories focussed on the Iberian herpetofauna conservation critical zones, show the significance the Peñalara Massif and the Upper Manzanares Basin have. To some extent, both enclaves are river headwaters zones and they have stayed long time under different regional protection modalities, so they have maintained environmental conditions conducive to the conservation of these species ecosystems. Some taxa specimens flourishing populations, together with the existence of many endemism, uphold these territories wealth, not only ato the regional level, but also to the national and European scale. The Sierra height and topographical features result in a progression of the temperature/rainfall ratio, enabling a great variety of biotopes which are optimal for the presence of reptiles.
Among the 23 mentioned species, the Iberian rock lizard, the Iberian emerald lizard, and the Common wall lizard distribution areas are limited to mountain environments. In the National Park, the highest species wealth appears significantly at intermediate altitudes, between 1,000 and 1,650 m, being undermined by the higher or lower altitude. This proves the importance of preserving the mid-altitude sites, that is to say the Sierra de Guadarrama slopes, which are conducive to the reptiles’ distribution.
Reptiles living in the National Park have a high rate of endemicity in a relatively small area, with the presence of 3 Iberian endemism -the Mediterranean worm lizard, the Iberian cylindrical skink, the Iberian emerald lizard - and one Sierra de Guadarrama endemism, the Cyren’s rock lizard. In addition, 6 of these species are classified at the Community of Madrid level (extinction danger status for the European pond turtle, vulnerable status for the Horseshoe whip snake, the Western false smooth snake, the Iberian rock lizard and the Mediterranean turtle, and special interest status for the Iberian emerald lizard), although none is classified at the national level.
One of the above mentioned species is included in the community of Madrid region Threatened Species Catalog as Lacerta monticola cyreni, having recently been elevated to the category of species currently called Cyren’s rock lizard (Iberolacerta cyreni). In addition, this species has healthy populations in the National Park, although this site is critically important for the preservation of this endemism, since it hosts the best population among those known in the Sierra de Guadarrama.
Down below you will find a brief description of the most representative reptiles living in the National Park high mountain environments:
Iberian emerald lizard (Lacerta schreiberi): robust medium-sized lizard (up to 12-13 cm head-to-body length). The overall coloration varies according to individuals. The comparison of equal age males and females length has not shown a sexual dimorphism in body size. Adult males have a reticular green and black dorsal design. During mating period, the sides of the head and the gular region are bright blue coloured. The ventral coloration is yellow and black dotted. More brownish tones on which dark spots are laid, predominate in females. They reach sexual maturity at a minimum age of four years, at which point they are larger than males, which usually mature a year earlier, whereas the comparison of equal age males and females length has not shown a sexual dimorphism in body size. Younger specimens have overall brownish colorations, with white or yellowish ocelli on the sides of the body, being the tail also yellowish. It is a species very attached to the rivers and streams banks and it seems to be in regression in the Sierra.
Cyren’s rockl lizard (Iberolacerta cyreni): it is a robust medium-sized lizard that can reach 8 cm head-to-body length. The tail is almost twice the length of the body, with alternating wide and narrow rings. The dorsal design is variable, from brown with darker longitudinal lateral bands to bright green with dots or uneven irregular black spots. The ventral coloration is a mixture of blue and green or whitish, without pigmentation or just some dark spots in the more lateral scales rows.
Common wall lizard (Podarcis muralis): robust appearance, medium-sized lizard (up to 7 cm head-to-body length). The dorsal design is brown, with black lateral longitudinal bands. There is frequently an interrupted half back line formed by small black spots. The ventral coloration is clear, although it usually presents a dark puncture, bolder in the males. On the sides, some blue scales usually appear. The gular region is densely pigmented, including the submaxillary scales, which have continuous dark bands. Younger specimens, unlike other small lizards species living in Guadarrama, never have greenish colorations on the tail. It can be observed in the National Park from 1,190 m height, occupying earthy slopes, with scattered rocks and small vegetation, usually on the edges of the forest.
Lusitanian wall lizard (Podarcis guadarramae): previously known as Podarcis iberica (which has been splited in a few species). Medium-sized lizard, which can reach up to 7 cm in head-to-body length, though being usually smaller. The tail can reach up to 10 cm, almost twice as much as the rest of the body. The dorsal design is highly variable. In the Sierra de Guadarrama the specimens tones are generally brown with a more intense dark irregular grid in the half back. Light bands may appear on the sides. The gular region lacks pigmentation, or if it exists, it is usually limited to some dark dots on the sides. They may have whitish or reddish ventral colorations, usually without dark pigmentation. The Iberian lizard lives more frequently in rocky terrain, taking advantage both of platforms where to sunbath and shelters where to hide in case of danger.
Smooth snake (Coronella austriaca): small size snake, between 50 and 60 cm overall length. The dorsal coloration is grey. On this background colour, there are black spots forming transverse bars. A dark band from the nostrils to the neck is characteristic. The ventral coloration is grey, with a darker central band. The scales are smooth. It is a species that adapts well to mountain areas, living in grasslands with rocks, scrubland areas with bushes or junipers or open coniferous and deciduous forests. It is relatively numerous in the Iberian peninsula, although the populations living in the Iberian Mediterranean region are scarce, since they are isolated in mountainous systems such as the Sierra de Guadarrama. Their distribution on a small number of areas make them very vulnerable to their habitats alteration.