Snakes, particularly the horseshoe whip snake (Hemorrhois hippocrepis), have become increasingly common in Ibiza. Their presence on the island has surged in recent years due to ineffective control over trees imported from mainland Spain, which sometimes harbour hidden serpents in their roots. Once in Ibiza, they have thrived due to the absence of natural predators.
As a result, these reptiles are now appearing in more places than ever—on rural trails, in urban areas, and even swimming in the sea. While they are harmless to humans, encountering a snake can be an unsettling experience. Knowing what to do when you come across one is essential.
Are Ibiza’s snakes dangerous?
Herpetologist Enrique Ayllón reassures that there is no need to fear them, as the species found on the island are neither venomous nor aggressive towards humans. The most common specimens on the island are:
- Horseshoe whip snake (Hemorrhois hippocrepis)
- Ladder snake (Zamenis scalaris) – also known as the ‘white snake’ in some areas of Catalonia and the ‘sparrow snake’ in the Valencian Community
Both species are non-venomous, and their bites are generally harmless. In most cases, if a serpent were to bite a human, the person might not even notice until they see a few drops of blood. The sensation is often compared to a bee sting, causing minor pain and slight swelling. Cleaning and drying the bite thoroughly is sufficient treatment.
What should you do if you encounter one?
If you come across a snake in Ibiza, follow these steps:
- Stay calm – They are not aggressive unless provoked. Avoid sudden movements that could startle the animal.
- Prevent its escape – If possible, try to stop the specimen from fleeing.
- Capture it if you can – The recommended course of action is to catch the colubrid safely and contain it. If you do not feel comfortable doing so, there are two other options:
- Call 112 – Emergency services can dispatch someone to capture the ophidian.
- Kill it (if necessary) – Since these serpents are not a protected species, it is legal to kill them, though this should be a last resort.
How to safely contain a colubrid?
If you choose to capture the specimen, place it in a secure container, such as:
- A plastic box with no openings.
- A large bottle with a cap.
- A fabric bag or even a pillowcase.
Once contained, call local authorities to ensure the animal is handled appropriately.
Why are serpents a problem in Ibiza?
Although these legless reptiles pose no danger to humans, they have become an environmental threat. The Ibiza wall lizard (Podarcis pityusensis), an endemic species, is at serious risk of extinction due to snake predation.
- These lizards are crucial for maintaining the island’s ecosystem balance, as they help control insect populations.
- Studies predict that the autochthonous wall lizard could disappear from the main island by 2030 if colubrid numbers continue to rise.
The ophidians are also highly adaptable and are now spreading into urban areas. Reports of them inside homes, hotel gardens, and even swimming pools are becoming more frequent.
How many specimens are in the island?
The problem is growing. In 2024 alone, over 4,200 snakes were captured across the Pityusic Islands, with around 3,000 in Ibiza and nearly 800 in Formentera.
- This was an increase of 1,000 captures compared to the previous year.
- The number of traps deployed has now reached over 1,500 across the island.
- Gigantism has been observed in Ibiza’s snake population, meaning some of them are growing larger than their mainland counterparts.
Despite these efforts, local conservation groups believe the situation is still not under control. The Institut d’Estudis Eivissencs (IEE) has warned that without stronger action, serpents could permanently alter the island’s wildlife.
What can you do to help?
If you live in or visit Ibiza, there are a few simple actions you can take to help control the serpent population:
1. Report sightings
- If you see a specimen, call 112 and provide its location.
- You can also report sightings in community groups on Facebook.
2. Protect your holiday home
If you chose to spend your holiday in a house in the countryside, you should bear in mind the following tips:
- Seal entry points – Check for gaps under doors and in walls where these reptiles could enter.
- Keep the garden tidy – Avoid overgrown vegetation that provides shelter for them.
- Be careful with firewood and stones – Serpents often hide in piles of wood or under rocks.
3. Avoid transporting them
- If you buy plants or trees, inspect them carefully to make sure no specimens are hidden in the roots.
- Serpents originally arrived to the island by hiding in imported olive trees, and the same could happen again with other plants.
What is being done to control the invasion?
1. Large-scale trapping
Authorities and conservationists are deploying more traps, often baited with live mice. This method is proving effective, but it requires constant monitoring and maintenance.
2. Habitat management
New measures are being introduced to reduce snake-friendly environments, including:
- Tighter controls on imported trees to prevent new specimens from arriving.
- Encouraging natural predators like birds of prey to thrive, which may help keep the ophidian population in check.
3. Community awareness campaigns
Education campaigns are being launched to inform residents and tourists about the issue, encouraging them to:
- Report serpent sightings.
- Avoid killing autochthonous wall lizards, which are already under threat.
- Take precautions to prevent colubrid introductions in urban areas.
While snakes in Ibiza are not dangerous to humans, they are significantly impacting the island’s ecosystem. Their increasing numbers threaten the survival of the autochthonous wall lizard, one of the island’s most iconic species.
If you encounter a serpent, remember: stay calm, avoid provoking it, and report it to local authorities whenever possible. By working together, residents, conservationists, and tourists can help control these reptiles population and preserve the island’s unique biodiversity.
