The Official State Gazette (BOE) has disseminated this Tuesday a modification of the Spanish Catalog of Invasive Exotic Species that extends to the entire Balearic territory the consideration of invasive for the introduced snakes of the colubrid family, maintaining the exceptions provided for native species.
This regulatory change, promoted by the Govern, strengthens the legal framework to develop actions for prevention, control, and, if appropriate, eradication of these snakes in Mallorca.
According to what the Ministry of Agriculture, Fisheries and Natural Environment detailed in a statement, the review comes a year after the regional government formally requested that this categorization be extended to the entire archipelago in October 2025.
The text of the BOE specifies that the expansion is approved at the proposal of the Govern and responds to the need to facilitate management tasks and prevent the spread of introduced species among the different islands.
To date, the categorization of colubrids as invaders was only applied in Eivissa and Formentera. In addition, the regulation already included as invasive the introduced allochthonous species that reproduce on the uninhabited islets of the Balearic coast. With the modification, this framework now encompasses the entire archipelago, with the exceptions established for species considered native.
Planned actions in Mallorca
The Ministry is finalizing a specific campaign to reinforce the control of invasive snakes in Mallorca and its islets. The measures will aim to decrease the presence of these species in areas of interest for conservation, reduce predation on native fauna, and curb their expansion.
Currently, monitoring, trapping, and control work is already being carried out on the island, especially in protected natural spaces, islets, and other sensitive areas. The new categorization consolidates the legal coverage of these actions and allows them to be framed within the particular management, control, and possible eradication regime provided for the species included in the Catalog.
The official information emphasizes that early detection and prevention of new introductions are particularly critical on the islets, where the presence of snakes can affect populations of native fauna with very limited distribution.
Exceptions for native species
The Order keeps the hooded snake and the viperine snake out of the consideration of invaders in Mallorca and Menorca, as well as the ladder snake in Menorca, recognized as native species in these islands.
This differentiation implies that the same species receives different treatment depending on the island. This is what happens with the ladder snake, classified as invasive in Mallorca but exempted in Menorca.
In Mallorca, in addition to the ladder snake, the presence of other introduced snakes has been confirmed, such as the horseshoe snake, the bastard snake, and the green-yellow snake.
Protection of native fauna
Introduced snakes feed on reptiles, birds, and small mammals, among other prey, and can cause significant alterations in island ecosystems. In Eivissa and Formentera, their expansion has had a particularly severe impact on the populations of Pitiusan lizards.
In Mallorca, control tasks aim to reduce risks to wildlife, with special attention to islets that host populations of Balearic lizards and other relevant enclaves for the conservation of species such as the ferreret and the European storm petrel.
Monitoring of snake populations and interventions on detected hotspots are part of the measures aimed at limiting their spread and reducing pressure on these native species.