invasive snakes that devour their lizards

The ecosystem of the island of Ibiza, and the Pitiusas (the archipelago formed by the Western Islands in the Balearic Islands) It has been threatened for years for a unique fight. It is the battle for the survival of a local species of lizard with a snake that has decorated the population.

An unequal struggle. Balearic Islands is witnessing the progressive disappearance of one of its endemic species as a result of the introduction of a predatory snake. An imbalance that is leading to the brink of the disappearance of the local lizard, an animal that had thrown out without the threat of predators and now faces a voracious snake whose numbers do not stop growing.

The protagonists. Let’s introduce the species that star in this story. The lizard in question is the so -called lizard of the Pitiusas (Podarcis Pityusensis), An endemic species of the Pitiusas. These animals are distributed in various areas of the Ibizan geography, but its presents is more common in coastal areas with denser vegetation.

The one that has become the main threat of this species is the horseshoe snake (Hemorrhis hippocrepis). The habitat of this Office covers a good part of the western Mediterranean coasts, from Tunisia to the south of the Iberian Peninsula, also in areas of the Island of Sardinia.

When everything started. The first time the horseshoe snake was detected in the Pitiusas It was in 2003although it is likely that this species had begun before its island journey. It is suspected that the Office was taken to the islands accidentally, with some specimen or its eggs traveling inside the trunk of an olive tree used as a decorative element.

By land and by sea. 20 years have served the European snake to settle on the island and expand through it, pressing more and more to the native lizard and other non -endemic species. But the expansion of the snake has not been there.

According to experts, the animal is a good swimmer who threatens the islands of Ibiza and Formentera, also to the islet network that completes the Pitiusa archipelago, each with ecological characteristics that make it unique.

From Ibiza to Euskadi. The lizard of the Pitiusas is considered an endemic species of the Balearic archipelago, but in recent years a small population of these animals seems to have arrived in a very different place: the Basque coast.

It is estimated that Ibizan reptiles They arrived in Bizkaia In the mid -90s and by 2011 they had displaced the Roquera lizard (Pruning muralis) In the islet of San Juan de Gaztelugatxe, belonging to Bermeo. The reptile It has been expanding in other coastal and interior environments, including the immediate vicinity of San Sebastián, where Threat to the Urgull lizard (Podarcis loolepis Sebastiani).

The Basque Country, we introduced, is not the only place in the peninsula to which the species has taken. An initiative to avoid its disappearance has led this Balearic reptile to the Barcelona Zoo. The first part of this project contemplates the arrival of 17 specimens of the species to the Catalan center in order to guarantee the conservation of the species.

A delicate ecosystem. Insular ecosystems are particularly vulnerable in these cases: well -defined geographical borders and a more limited biodiversity may imply that the loss of a species has repercussions on local ecosystems.

According to He explained to the newspaper The country Oriol Lapiedra, researcher at the Center for Ecological Research and Forest Applications (CREAF), the disappearance of a certain species can cause “a waterfall reaction” that leads to new extinctions.

Echoes from another archipelago. It is not surprising that to change the archipelago We can find a similar case. On the island of Gran Canaria, the introduction of a foreign snake, the real snake of California (Californiae Lampropelties), he has also put local fauna, including reptiles such as the giant lizard (Gallotia Stehlini) and the slut (Sexlineatus Chalcides).

In Xataka | Some reptiles just revealed a secret that we had millennia looking for: eternal youth

Image | Dirk Pothen / Raymond Petrik