Horseshoe Snakes thrive in Balearic waters

COFIB, the Consortium for the protection of the Fauna of the Balearic Islands, with numerous volunteers, conducts annual operations to capture these snakes, installing traps both in fields and suburban homes. “While non-threatening to humans, these invasive snakes pose significant risks to endemic species like the lizard,” explains Víctor Colomar, COFIB coordinator for Ibiza and Formentera.

He explained that such species have adapted in surprising ways, including swimming, requiring increased vigilance and controls on islands that were once safe havens for indigenous wildlife.
Initial studies in 2016 underestimated the snakes’ capabilities, believing them to be solely terrestrial. However, sightings of them swimming has led to enhanced protection measures to safeguard native species in Mallorca’s islets, such as Dragonera and Cabrera. COFIB’s comprehensive control initiatives have extended from Formentera and Ibiza to include targeted efforts in Pollensa and Alcudia.

The High Commission on Invasive Species has also taken action by introducing regulations to prevent further incursions by limiting imports of potentially contaminated goods, particularly during the snakes’ hibernation periods. “This is a breakthrough in EU regional policy, crucial for preventing unintended introductions,” Colomar said. Still, climate change presents additional hurdles and further studies are required to understand its full implications.

The local community plays a vital role in these tasks, with groups like Amics de la Terra (Friends of the Earth) and GOB getting involved in trap installations and snake capturing projects across the islands, sometimes finding snakes within urban areas in Ibiza. In contrast, Mallorca remains relatively less affected in populated areas. Anyone interested in volunteering is encouraged to connect COFIB.