Alarm at the Malgrats: Invasive Snakes Threaten the Sargantana

Snakes on the Malgrats: An alarm that must not be ignored

When the sun climbs over the bay of Santa Ponça in the early morning, the boats still gently rocking at the quay and gulls crying above the harbor, fishermen tell of something unusual: snakes crawling ashore on the tiny rocks of the Malgrats. What sounds like a curious anecdote to tourists is a real nightmare for biologists and volunteer conservationists. This is documented in Alarma en los Malgrats: serpientes invasivas devoran a la rara Sargantana.

The central question: How do we protect the Sargantana and prevent permanent introductions?

At the center is the small, endemic lizard Podarcis lilfordi hartmanni – the Sargantana. On tiny skerries like the Illot dels Conills it survived for decades in secluded habitats. Now reports are increasing that ladder and horseshoe snakes have been seen on the rocks, a trend discussed in ¿Encuentro peligroso? Por qué las serpientes aparecen ahora con más frecuencia en Mallorca. The key question is: Do we still have the opportunity to secure the survival of these island populations – or is their fate already sealed because management reacted too slowly?

How did the snakes get here? An analysis of introduction pathways

Locals suspect that the reptiles came aboard unintentionally: in hollowed olive trunks, in cargo or under the decks of leisure and fishing boats. A dock worker told me, while looking at the nets, about pieces of bark and traces that point to cargo vessels. Such “stowaways” are not an isolated case, but on small skerries with little habitat diversity a single introduction can have dramatic consequences. Concerns over tree imports prompted action described in Mallorca detiene la importación de determinados árboles – emergencia contra serpientes introducidas.

Often less considered is that climate change and warmer winters improve the survival chances of exotic species. A snake that would have died earlier in the autumn may now find milder conditions — increasing the risk that it establishes on the islands.

Why we are not just saving a lizard here — but a piece of DNA history

The Sargantana is more than a pretty lizard; it is a genetic window into the past of Mallorca’s islets. Island populations often develop unique adaptations and genetic diversity that are lost on the mainland. The loss of such a subspecies would be irreversible — a local extinction is not the same as an extinction on the mainland, it means the disappearance of a unique genetic heritage.

Measures needed now: concrete, pragmatic, locally anchored

The debate about possible countermeasures is in full swing. What is missing now, however, is a clear catalogue of actions — and fast. Our proposals:

1. Immediate surveying and monitoring: Camera traps, regular inspection rounds on the islands and eDNA samples from water and soil to detect snakes early, as outlined in USGS guide on using environmental DNA (eDNA) to detect wildlife.

2. Boat and cargo checks: Inspections at the landing sites in Santa Ponça and other ports, checks of cargo and equipment, training for boat crews and fishermen who are often the first observers.

3. Targeted capture operations and traps used with care: Focused capture actions by trained teams, using species-friendly methods. Traps must not be set indiscriminately — many other protected species also live on the small islands.

4. Public outreach and a reporting platform: A local hotline, clear reporting routines and information material at the harbor. If locals, charter captains and divers know what to look for, the chances of stopping introductions quickly increase. If you spot something, photograph it and report it through networks such as EASIN European Alien Species Information Network.

5. Coordination and funding: Municipality, island government and conservation organizations must finance coordinated measures. Short-term emergency funds are needed, but also long-term monitoring programs.

What is often overlooked: side effects and legal hurdles

Rapid reactions carry risks: traps can catch non-target species, and uncoordinated actions can damage sensitive habitats. Protocols are needed to determine who takes which measures and when. Volunteers also often complain about lengthy permit procedures — in an acute invasion situation such delays can be fatal.

A call to the local community

The situation at the Malgrats is a test of how well the island community responds to biological crises. If you are at the quay of Santa Ponça in the coming days: look closely, photograph anything unusual and report it. A fisherman checking his lines at dawn can make more impact than any press release. And yes, it sounds more dramatic than a hot July day — but for the Sargantana the next weeks will decide between life and death.

On-site inspections, controls, and fast, coordinated measures: only this way do the Malgrats have a chance to preserve their small lizard and thus a piece of Mallorcan natural history.