Controlling Snakes on Ibiza

For centuries Ibiza was famous for being completely free of snakes, but that is no longer the case. Over the past 15 years thousands of these slithering creatures have made the island their home, and they are changing its natural ecological balance. How did this happen and what is being done about it? Since the beginning of the 21st century there has been a building boom of luxury homes and resorts in Ibiza. This spurred the importation of numerous olive trees from the mainland that were destined to be re-planted as decoration for those properties. Olive trees have countless holes and niches in the trunks and roots that give snakes plenty of places to hide. They hibernate in these imported trees while being shipped, and then emerge when the trees are replanted here.
The snakes that have been brought to Ibiza are not poisonous, so they pose no great physical danger to humans. However, the same cannot be said for our iconic Ibizan wall lizards. These harmless little reptiles provide more than half of the snakes’ diet, and this is threatening their survival. After a slow start, the government began a comprehensive eradication program in 2016, and thousands of traps have been set on Ibiza and Formentera. Many snakes are caught every year, but new ones keep arriving because the steps that were taken to regulate the importation of olive trees have not been effective. That is set to change.
The new general director of Espais Naturals i Biodiversitat, Llorenç Mas, is determined to stop the influx of snakes to the Balearics. “This problem dates back to 2004, when we did not act quickly enough. The opposite example would be how we handled the incursion of the Asian hornet. In that case, our rapid response quickly eradicated an invasive species. In contrast, the hornet is wreaking havoc in the North of Spain because they did not act fast enough.” He vows to make the import controls at the ports much more vigilant. “It is ridiculous to dedicate efforts and money to eradicating snakes in the Pitiüses, while ornamental trees continue to enter with hardly any control for snakes.”