Like every year, we have been tracking the amphibians in the wetlands of Peñalara, where we count all the species in all the areas of the ponds. This intense tracking since 15 years, allows us to know the populational tendencies of the 9 species that can be found in Peñalara mountain.
The wetlands are organized in 28 areas with a variable number of ponds in every one of them, making a total of 242. Most of this ponds are temporary as they get dry in summer, others, like the Laguna Grande, the Laguna de los Pájaraos, the Charca de la Mariposa and some smaller ponds spread in different areas, are permanents.
The species that can be found are the Common Midwife Toad (Alytes obstetricans), the Common Toad (Bufo spinosus), the Natterjack Toadk (Bufo calamita), the Green Frog (Pelophilax perezi), the Iberian Frog (Rana iberica), the Tree Frog (Hyla molleri), the Common Salamander (Salamandra salamandra), the Marbled Newt (Triturus marmoratus) and the Alpine Newt (Mesotriton alpestris).
The counting of all the species is focused in the egg laying (for the two species of Bufo) and in the larvas (for the rest of the species) and we use categories to determined the maximun annual abundance of every specie in every water mass. We visit every pond 6 times a year, so that way, we can cover all the reproductive seasons of all the species and the peak of maximum abundancie of every one of them.
Many of the changes that we have noticed in the amphibians comunity are due to the chytridiomycosis, that has seriously affected many species. So, while the Midwife Toad was the most abundant specie, you can hardly find it now. In turn, the extiction of this specie from most of the water masses has allowed the expansion the Common Toad to more ponds and lakes, although at the same time, it is reducing in abundance due to the illness.
Other big changes have been the quick expansion of the Alpine Newt. This specie is from the north of the peninsula, supposedly introduced at the end of the 80s in Peñalara. The Alpine Newt not only competes with other species and prey on them, but also acts like vector of the pathogenic fungus, moving it from some point to others; because it is very resistant to the illness.
To end with, the rising temperatures of the last decades has allowed to the species of the foot of the mountains, like the Tree Frog, to colonize the high areas.
In this video you can see some footages of the sampling work in the wetlands of Peñalara and of some amphibians species that live there.