The Sierra de Guadarrama has a high richness of amphibian species.
The amphibian inventory of the National Park and its Peripheral Protection Zone is made up of 15 species, of which 5 are Iberian endemism. Several studies on the areas of interest for the conservation of amphibians in the Iberian peninsula, have pointed out the Sierra de Guadarrama importance, and particularly the Peñalara Massif, in a number of species preservation.
This environment has a considerable diversity of species. Only in the Peñalara Massif wetlands, included in the RAMSAR list, there are usually nine species: the Common salamander (Salamandra salamandra), the Marbled triton (Triturus marmoratus), the introduced Alpine newt (Mesotriton alpestris), the Common frog (Hylo molleri), the Common toad (Bufo spinosus), the Natterjack toad (Epidalea calamita), the Common midwife toad (Alytes obstetricans) and the European tree frog (Hyla molleri). Some Iberian painted toad (Discoglossus galganoi) samples have also been detected.
It should also be noted that in the National Park live populations of species standing at the upper limit of their altitudinal range (Hyla molleri, Pelophylax perezi, Discoglossus galganoi and Triturus marmoratus). Therefore, the Park can be considered one of the most important European mountain areas in terms of its amphibian fauna. In fact, the number of species found here is greater than the total number of species known in some European countries (England, Ireland), and exceeds the other Iberian mountain systems.
The last samples taken in the National Park have revealed that the mottled newt, the common toad, the runner toad, and the frog of San Antonio, have experienced a decline in number compared to previous years. In contrast, the common frog and the Iberian frog have increased their abundance. There has also been a considerable expansion of the Alpine newt, a non-native specie from the center of the peninsula, which can be regularly observed in some Peñalara Massif wetlands.
Down below you will find a brief description of the most National Park representative amphibians:
Perez’s frog (Pelophylax perezi): brownish and greenish toned with dark spots, it has smooth skin. Females can reach up to 10 cm in size. Although they are more typical of lowlands, its populations in the National Park are expanding in the Peñalara Massif, reproducing in ponds located at more than 2,100 m height.
Iberian frog (Rana iberica): brown color, small size (up to 6 cm) and long hind legs. It prefers high mountain streams, with clean and well oxygenated waters. It is an Iberian endemism distributed over the North western quadrant of the peninsula. It is threatened in the Sierra de Guadarrama by the introduction of fish in water courses where they did not exist before, and by the pressure of the visitors. For this reason, a captive breeding program is being carried out..
European tree frog (Hyla molleri): bright green color with a dark lateral line, and small size (up to 5 cm). It is often found in pools with abundant vegetation. Its distribution in the Sierra de Guadarrama is very uniform. It is expanding towards zones of higher altitude in the Peñalara Massif.
Iberian painted toad (Discoglossus galganoi): smooth-skinned and more like a frog than a toad. Unlike other species, males reach a larger size than females (up to 8 cm). It lives in places soaked with abundant vegetation, generally in zones of average or low altitude. The National Park population is exceptional, being the Park one of its most elevated habitats (1,900 m).
Common toad (Bufo spinosus): brownish and rough skin, females are larger than males and can reach 20 cm. The sets are large cords with thousands of eggs. It reproduces only in National Park ponds and permanent lakes. In recent years, it is occupying the areas where the common midwife toad has disappeared.
Natterjack toad (Epidalea calamita): has a dorsal coloration of greenish tones and can reach a size of up to 9 cm. It is present in the Sierra de Guadarrama, from low zones to altitudes above 2,000 m. and has in the National Park an acceptable state of conservation.
Common midwife toad (Alytes obstetricans): greyish coloration and small size (up to 6 cm). The males carry the egg on their hind legs for about a month, until they deposit it in the water. The larvae, in mountain areas, remain in the water for several years, until their development, reaching large size. Their populations have almost disappeared in the Peñalara Massif, due to a disease caused by an introduced fungus. For this reason, a captive breeding program is being carried out and its populations are being monitored with frog-loggers.
Common salamander (Salamandra salamander): they are black, with yellow spots and can reach 20 cm whole length. The Peñalara Massif contains very abundant populations that, however, are in regression due to the same disease the common midwife toad suffers.
Marbled triton (Triturus marmoratus): it is green with black spots and a very characteristic orange line on the back. It can reach a size of 15 cm. Prefers ponds with abundant aquatic vegetation. It has in the National Park an acceptable state of conservation, expanding towards zones of greater altitude in the last years.
Alpine Triton (Mesotriton alpestris): bluish-colored back and orange belly, with a size of 7 to 12 cm. It is present in much of Europe territory, although in the Peninsula it lives only in the Cantabrian Mountains. The population of the Peñalara Massif, according to genetic studies, comes from specimens from Lake Ercina (Picos de Europa), introduced irresponsibly in the eighties. Since then, it has been expanding, displacing native species.