Ibiza Snake Swim to Santa Eulària Shows Sea Crossing
A snake was filmed swimming from Ibiza toward the islet of Santa Eulària in April 2024, giving biologists the first proper evidence that the species can cross that 450-metre stretch of water. The grainy video showed a pale horseshoe whip snake in the channel off Ibiza’s east coast.
Oriol Lapiedra, a biologist at the Centre for Ecological Research and Forestry Applications in Catalonia, said earlier sightings from fishermen and tourists had suggested the behaviour for some time. “There’d been increasing anecdotal evidence from fishermen and tourists who’d seen the snakes swimming, so we’d thought it was happening very often,” he said. “But this was the first proper [evidence] we’d had of a snake swimming from Ibiza to the islet.”
Ibiza’s East Coast Channel
The islet of Santa Eulària sits 450 metres from Ibiza’s east coast, and the April 2024 footage showed the horseshoe whip snake moving through that gap. The species has been appearing on Ibiza for two decades and is now established on much of the island, with forecasts suggesting it could be found across 100% of Ibiza by the end of 2027.
On the mainland, horseshoe whip snakes tend to be skinny creatures that seldom exceed 1.8 metres in length. Specimens found on Ibiza have been more than 2 metres long and weigh 2, showing how well the species has adapted since it arrived on the island from the Spanish mainland about 20 years ago.
Ibiza Wall Lizard Under Pressure
The spread has already hit the Ibiza wall lizard, which has been almost wiped out by the invasive horseshoe whip snake. The International Union for Conservation of Nature moved the lizard from near threatened to endangered in October 2022, and Lapiedra said the loss goes beyond one species. “They control insect populations – including agricultural pests – so that all changes when they disappear,” he said. “But they also pollinate flowers and disperse seeds.”
The Balearic regional government said more than 3,500 horseshoe whip snakes were captured on Ibiza last year, and more than 16,000 have been culled since 2016. That total shows how far the response has already gone, yet the April video indicates the snakes are still moving into new territory by sea rather than only across land.
Balearic Islands Response
The latest footage gives officials and conservation workers a clearer picture of the next phase of the infestation on Ibiza. A snake that can reach the islet of Santa Eulària from the mainland side of Ibiza can also reach other nearby places in the same channel, and that makes the April 2024 recording more than a one-off image: it is evidence that the island’s containment effort is dealing with a species that can travel farther than many people had assumed.
For residents and landowners on Ibiza, the practical issue is no longer whether the snake is established. More than 90% of the island already has the species, and the pressure now falls on whether capture and culling can keep pace with a snake that keeps spreading outward while the Ibiza wall lizard continues to lose ground.
