Lizard Protection Project

Barcelona Zoo

Formentera, June 8, 2025

In recent years, the importation of centuries-old olive trees from mainland Spain for purely ornamental landscaping purposes has brought with it a major ecological problem for the islands of Ibiza and Formentera. Hidden within the hollow trunks of these trees were hibernating snakes that, undetected, were transported along with the trees to the islands.

Once in their new environment, these invasive species—introduced due to human negligence—found in the Pityusic wall lizard (Podarcis pityusensis) a constant and easy food source. The lizard, an endemic species and a symbol of identity for both Ibiza and Formentera, lacks natural defenses against these predators.

While the situation in Formentera remains relatively under control in the La Mola area, the scenario in Ibiza is far more concerning. The snake population has expanded uncontrollably, colonizing almost the entire island.

For this reason, the Balearic Government, together with the Barcelona Zoo, has decided to launch a pilot project for the ex situ breeding of the Pityusic wall lizard (Podarcis pityusensis), with the goal of ensuring the conservation of this endemic species.

New Populations in Captivity

The Ministry of Agriculture, Fisheries and Natural Environment, together with the Barcelona Zoo, has launched an innovative ex situ breeding project to preserve the Pityusic wall lizard (Podarcis pityusensis), an emblematic species of Ibiza and Formentera. This initiative aims to establish new populations outside their natural environment in order to ensure the survival of this unique species of the Balearic archipelago.

As part of the initiative, three controlled populations have been created—two from Ibiza and one from Formentera. Seventeen healthy individuals with genetic diversity (10 from Ibiza and 7 from Formentera) have been captured and are now housed at the Barcelona Zoo. These animals will serve as the first breeding group in the new captive breeding program.

The Threat of Invasive Snakes

Anna Torres, Director General of Natural Environment and Forest Management, highlights that this project “makes it possible to work on the viability of future repopulation efforts and contributes to the protection of the Pityusic wall lizard.” She also emphasizes the importance of continuing actions to curb the spread of invasive snakes, currently considered the greatest threat to native lizard populations.
This project stems from a collaboration agreement signed in 2024 between the Balearic Government and the Barcelona Zoo Foundation. The agreement sets out a cooperation framework for the conservation of protected wildlife in the Balearic Islands. In addition to the breeding program, scientific studies will be developed focusing on genetics, ecology, and conservation strategies.

A Symbolic Species of Ibiza and Formentera

The studies resulting from the project will not only help preserve the genetic diversity of the Pityusic wall lizard but will also make it possible to assess the feasibility of reintroducing the species into its natural habitat. This is part of a comprehensive strategy to support well-informed and effective conservation decisions.Sito Alarcón, Director of the Barcelona Zoo, noted that “collaborating in this type of project strengthens our commitment to Mediterranean biodiversity, one of the most threatened by climate change.”

The Pityusic wall lizard is one of the most representative natural symbols of Formentera and Ibiza. However, its survival is at risk due to the introduction of exotic species—especially snakes—resulting once again from human malpractice and disregard for the natural environmental balance. For this reason, Podarcis pityusensis was included in 2023 in the Balearic Catalogue of Threatened Species, listed as a vulnerable species.