A new dispute has erupted over the management of snake traps used in Ibiza's fight against invasive species, after biologist Antònia Maria Cirer and Sargantana Power spokesperson Marilina Serra Cardona reported finding dead bait mice, decomposed snakes and trapped Ibiza wall lizards inside some devices.

The two campaigners say the condition of several traps raises concerns about animal welfare, maintenance and the effectiveness of Ibiza's efforts to control the invasive horseshoe whip snake.

Traps Reportedly Left Without Maintenance

According to the allegations published by Noudiari, some traps managed by the Consorcio para la Recuperación de la Fauna de les Illes Balears (COFIB) had apparently gone without inspection for extended periods.

The campaigners say they found traps containing dead mice reduced to bones and fur, decomposed snakes and dead lizards.

Some of the traps were reportedly located in areas including the Parc Natural de ses Salines.

The concern is particularly serious because the traps are designed to catch invasive snakes but can also attract the very native wildlife that conservation efforts are intended to protect.

Why Are Lizards Getting Caught?

The campaigners have raised concerns about the type of food being used as bait for the mice.

They say some traps use a pellet-based feed with a strong smell that can attract not only rodents but also Ibiza's native wall lizards.

According to their account, lizards can enter the traps after being attracted by the food and then become unable to escape.

They also claim that large quantities of feed placed inside traps can be pushed around by mice, potentially obstructing parts of the trapping mechanism and reducing its effectiveness.

Dead Mice and Snakes Found Inside

The campaigners allege that some mice have died from lack of food or water, while others were found in poor conditions surrounded by waste.

They also report finding water containers that had become blocked.

In some cases, snakes that had entered the traps were allegedly left long enough to die, with their remains subsequently consumed by insects.

The report also raises concerns about the health of some of the mice used as bait, with campaigners claiming that animals showing mites or other health problems had been used.

These are allegations made by the campaigners and are disputed by the Balearic Government.

The Govern Says Its Traps Are Checked Weekly

Following the publication of the allegations, the Balearic Government's Department of Natural Environment rejected the suggestion that its active traps are being left without maintenance.

The Government says COFIB currently has around 3,000 traps across Ibiza, Formentera and surrounding islets, monitored by 13 people dedicated to snake control.

It says all traps under COFIB management are geolocated and checked weekly, with established protocols covering maintenance and the welfare of the mice used as bait.

The Government also says the number of staff dedicated to snake control has increased by almost 50% compared with previous resources.

What About the Abandoned Traps?

The Government says an important distinction needs to be made between traps under its active control and traps that have been stolen or vandalised.

According to the administration, around 50 traps have been stolen across Ibiza, including approximately 15 in the Ses Salines Natural Park.

The Government says some of the photographs used in the criticism show traps that had already been reported missing and therefore were no longer under COFIB's control.

It says one particular trap shown in the photographs had been recorded as stolen on March 11.

The administration has therefore rejected the claim that photographs of dead animals inside missing or vandalised traps demonstrate a failure to maintain the traps that remain under its management.

A Much Bigger Battle Against Invasive Snakes

The controversy comes as Ibiza continues to fight a rapidly expanding population of horseshoe whip snakes (Hemorrhois hippocrepis).

The species is an invasive predator on Ibiza and has been linked to the decline of the island's endemic Pityusic wall lizard (Podarcis pityusensis).

The Government says its control programme captured more than 4,400 invasive snakes across the Pityusic Islands during the 2025 campaign, while trapping has now been maintained throughout the entire year rather than only during the warmer months.

The administration has also expanded its strategy beyond trapping. A new European LIFE Reptiles project is bringing €2.18 million in funding to conservation work in the Balearics, including environmental DNA monitoring, artificial intelligence, drones and improved trapping technology.

The Lizards Are Running Out of Time

The urgency comes from the increasingly serious situation facing Ibiza's native lizards.

The Government itself has acknowledged that the rapid expansion of invasive snakes has significantly worsened the conservation status of the Pityusic and Balearic wall lizards, which are currently classified as vulnerable.

Authorities have also begun creating snake-proof refuges where lizards can survive and reproduce safely. The first such refuge in Ibiza was established at Can Marines, with additional refuges planned.

The Government says the objective is not only to remove snakes but also to create conditions in which native lizard populations can survive and eventually recover.

A Dispute Over How Ibiza Should Fight the Invasion

The latest controversy highlights a difficult balance.

The island needs effective trapping to slow the spread of invasive snakes, but conservationists and campaigners argue that the control measures themselves must not cause unnecessary suffering or accidentally harm native animals.

Cirer and Serra are calling for more frequent inspections — particularly during the summer — as well as changes to the bait system, including fresh water and feed that does not attract lizards.

The Government, meanwhile, maintains that its active traps are systematically checked every week and says citizens should report damaged or missing devices rather than moving them themselves.

With the snake invasion continuing to expand toward some of Ibiza's last important lizard habitats, the dispute is ultimately about more than the condition of individual traps.

It is about whether Ibiza can control an invasive predator quickly enough — while ensuring that the measures used to save the island's native lizards do not end up harming them in the process.

Source: Noudiari