The Catalan Herpetological Society (SCH) is a scientific organization dedicated to the study, conservation, and dissemination of herpetological fauna (amphibians and reptiles) in Catalonia. Our activities include conservation projects, population monitoring, habitat creation and restoration, outreach and awareness campaigns, and coordination with other organizations and administrations to ensure the protection of native species.

Amphibians and reptiles have distinct ecologies and behaviors, meaning monitoring protocols must be tailored to each group’s specific characteristics. For amphibians, monitoring typically involves night visits to water points and river stretches to count egg masses, tadpoles, and juvenile and adult individuals.

For reptiles, the monitoring techniques vary depending on the species. One of the most commonly used methods is capture-recapture, especially for turtles. This involves pitfall traps where individuals are caught, marked, and released. Multiple recaptures allow us to estimate population trends and gather data on population structure.

One of our most important protocols is the Distance Sampling Methodology, where two observers walk marked transects and record all reptiles seen, along with specific environmental data, including the distance and angle to each individual. This technique is especially effective for species such as the Pyrenean lizard, the viviparous lizard, and the ocellated lizard. The method allows us to estimate population densities and track changes over time. Recently, it has been a key tool in assessing populations of the Pyrenean lizard, a species classified as “Endangered” in the Catalogue of Threatened Native Wildlife of Catalonia.

The presence of these species in the Pyrenees is a key indicator of the health of these mountain ecosystems. Protecting them is essential to preserving the biodiversity of these unique and fragile environments.

The viviparous lizard is generally found in Catalonia at elevations above 1,400 meters and is associated with high-mountain wetlands, known as molleres. These areas are particularly sensitive to drying out due to rising temperatures from climate change and degradation caused by overgrazing.

The Pyrenean lizard is found at altitudes above 1,600 meters and is restricted to very specific mountain zones. This subspecies (Lacerta agilis garzoni) is classified as “Endangered” in Catalonia’s official list of threatened wildlife. It depends on highly specific mountain ecosystems that are threatened by habitat loss, rising temperatures, and other climate-related changes, making it especially vulnerable.

The ocellated lizard, the largest lizard species in Europe, although more common at lower altitudes, also inhabits the Pyrenees up to 2,000 meters. This species has seen a marked decline in recent decades due to habitat loss, fragmentation, and other human-caused threats. It is currently classified as “Near Threatened” by the International Union for Conservation of Nature (IUCN).

The survival of these species—and many others—is directly linked to the conservation of their mountain habitats. Protecting these areas is essential for maintaining biodiversity and ensuring ecosystem stability in the Pyrenees.

Reptiles play a key role as bioindicators of climate change. As ectothermic animals, they rely on ambient temperature to regulate their body temperature. This dependence makes them highly sensitive to temperature changes. These shifts affect various biological aspects such as reproduction, mobility, and feeding.

Reptiles also show changes in their biological cycles (phenology) in response to global warming, including earlier activity and breeding periods. Therefore, changes in their populations and distribution can serve as early warning signs of how ecosystems are responding to climate change.

There are several complex challenges facing reptile conservation in Catalonia, particularly in mountain ecosystems. One major issue is overgrazing, which disrupts ecological balance by eliminating shrub and herbaceous vegetation that reptiles use for shelter and food. Overgrazing can also lead to the degradation of wetlands critical for species like the viviparous lizard.

Another significant challenge is overuse of natural areas, especially when visitors leave marked trails. This high level of disturbance affects not only reptiles but all the wildlife in these habitats.

Habitat fragmentation is also a serious concern. The construction of ski resorts, roads, and urban development in mountainous areas breaks up habitats and creates barriers that limit animal movement and access to food and shelter.

Climate change and the overall rise in temperatures pose one of the biggest threats, particularly in high-mountain ecosystems. Many species adapted to cold climates are forced to move to higher altitudes in search of suitable conditions. However, once they reach the mountain tops, they have nowhere else to go, making them extremely vulnerable.

People who visit natural habitats where reptiles live can play a fundamental role in their conservation by adopting good practices. It is important to respect established paths and avoid stepping off them in order not to cause alterations in natural habitats, especially in areas that are sensitive for wildlife.

Likewise, capturing or handling animals should absolutely be avoided, as it causes them stress and alters their natural behavior. It is also essential not to throw waste into the environment, as it can contaminate the surroundings and disrupt the ecosystem. Additionally, loud noises should be avoided, since excessive noise can disturb wildlife and alter their behavior, especially during breeding and feeding periods.

Invasive species should not be introduced, as they may compete with local species for vital resources such as food and shelter, endangering their survival.

Finally, we would like to add that if people visiting these habitats observe a reptile or any other type of wildlife they can identify, it would be very helpful if they recorded the observation on citizen science platforms such as Ornitho.cat or iNaturalist. Knowing the exact location of species is essential for their conservation, as it facilitates population monitoring and helps collect valuable data for the protection of biodiversity.