A horseshoe whip snake was filmed swimming through the turquoise water from Ibiza to the islet of Santa Eulària in April 2024, giving the clearest proof yet that the invasive reptiles are crossing by sea as well as spreading across land. The islet sits 450 metres off Ibiza’s east coast, close enough to tempt the eye, but far enough to show just how far the snakes can travel when a new front opens.
The video matters now because it answers a question islanders have been asking for years: how a reptile once seen as a mainland problem became one of Ibiza’s most stubborn invasions. Oriol Lapiedra, who identified the footage as the first proper evidence of a snake making the swim to the islet, said there had already been growing anecdotal reports from fishermen and tourists who saw snakes in the water. The footage turned that talk into proof. Lapiedra’s identification also lands at a moment when the Ibiza wall lizard, long a local emblem and a keystone species in the region’s ecosystems, has already been pushed from “near threatened” to “endangered” by the International Union for Conservation of Nature.
Horseshoe whip snakes, or Hemorrhois hippocrepis, are non-venomous reptiles found across southern and eastern Spain, but they began appearing on Ibiza around two decades ago and have since spread to at least 90% of the island. The rapid colonisation has been linked to wealthy property owners importing ancient olive trees from mainland Spain, which gave hibernating snakes and snake eggs a place to travel undetected. Once established, the predators found an island already vulnerable. Ibiza’s endemic wall lizards have been almost wiped out, and the animals are so woven into island identity that they turn up on tourist merchandise across Ibiza.
That is what makes the sea crossing so unsettling. The snakes are no longer confined to olive groves or dry hillsides; they are reaching offshore habitat too, with the Santa Eulària video showing that water is not much of a barrier at all. The regional government says more than 3,500 horseshoe whip snakes were captured on Ibiza last year, and more than 16,000 have been culled since 2016, yet forecasts still suggest they will be found across 100% of Ibiza by the end of 2027. On the mainland, these snakes are usually skinny creatures that seldom exceed 1.8 metres, but some on Ibiza have been found at more than 2 metres, a reminder that the island population has not simply arrived — it has taken hold.
For Lapiedra, the video is more than a rare sighting. It shows the invasion is still moving, even under heavy pressure, and it leaves the island facing a hard reality: the effort to catch and cull the snakes is slowing them, not stopping them. The lizards that remain still have a habitat, but the clock is running toward a point where there may be nowhere left on Ibiza the snakes have not reached.
One of the related stories this week was a different kind of snake clip entirely — the sort that can ricochet across the internet for very different reasons — but on Ibiza the footage carries a local warning that is harder to ignore. A single swim in April 2024 now reads like a map of what comes next.
