The Balearic government has urged Spain’s Ministry for Ecological Transition to amend the national catalogue of invasive exotic species. The proposal seeks to classify all introduced colubrid snakes as invasive across the entire archipelago, while exempting native species such as the Maghrebian snake (Macroprotodon mauritanicus) and the viperine water snake (Natrix maura) in Mallorca and Menorca, as well as the ladder snake (Zamenis scalaris) in Menorca.
The proposed change would strengthen the technical and legal framework for ongoing control operations in Mallorca, integrating them into existing management plans modelled on successful initiatives in Ibiza and Formentera. These efforts fall under the Strategy for the Management, Control and Potential Eradication of Invasive Snakes on Islands, approved by the ministry in July 2018.
Royal Decree 630/2013 had already included these species in the catalogue, though its scope was limited to Ibiza and Formentera. The islands first saw snake invasions in the early 2000s, largely through imported olive trees and ornamental plants. The reptiles have had a devastating effect on native fauna, particularly the endemic Ibiza wall lizard (Podarcis pityusensis).
Rising threat in Mallorca
While snake populations in Mallorca have not yet reached the densities seen in Ibiza and Formentera, their spread poses an increasing threat to local wildlife. Species recorded on the island include the horseshoe whip snake (Hemorrhois hippocrepis), ladder snake (Zamenis scalaris), Montpellier snake (Malpolon monspessulanus) and European whip snake (Hierophis viridiflavus).
Conservation and control efforts
The government has committed 2.5 million euros to snake control in Ibiza and Formentera, almost tripling previous investment. The campaign now employs 2,600 traps – a 35% increase on 2024 – and an expanded COFIB team of 13 dedicated technicians. Eighteen urban reserves have also been established for the Ibiza wall lizard in parks and schools, alongside a collaboration with Barcelona Zoo on the ex-situ conservation of the Balearic Islands’ endemic lizard species.