Pest control on Ibiza and Formentera: snakes.
Snakes on Ibiza and Formentera: biodiversity, health risks and economic losses.
Snakes in Ibiza and Formentera.
Historically, there have been no snake species in the ecosystems of the Pitïusas. It has not been until about 15-20 years ago that they have started to enter the islands. The first case of presence of snakes in Ibiza was detected in May 2003, their naturalisation (reproduction on the island in a natural way) is estimated from 2007 onwards.
The spread of snakes in the Pitïusas has occurred in two ways:
1º: Through the massive importation of centenary olive trees from the peninsula.
2º: In a slow but constant process of naturalisation thanks to this regular entry of specimens over the years, and due to the conditions they have found here, they have been able to reproduce until they have become a plague and a threat to the current ecosystems of Ibiza and Formentera.
This, until reaching the current situation, where today, and after years of effective control by the administrations to limit the problem in some way (or at least prevent the entry of new specimens that come to add to those that were already beginning to reproduce in Ibiza and Formentera), we have catalogued as invasive species 2 different species of snakes: the horseshoe snake (Hemorrhois hippocrepis), and the ladder snake (Rhinechis scalaris).
On the other hand, there is a third snake, the bastard snake (Malpolon monspessulanus), which although specimens have been detected at large, it has not been possible to confirm its naturalisation in Ibiza or Formentera.
The process of importing olive trees, in order to achieve a higher percentage of success in the transfer of the tree, is done in the winter months, which aggravates the problem. Snakes, in the winter months, become lethargic due to the cold (they are cold-blooded animals), and many of these snakes do so in the hollows and nooks and crannies that olive trees have in their trunks and roots.
The arrival of snakes to island ecosystems (such as Ibiza and Formentera) where they are not present and have optimal environmental conditions poses a serious threat to the survival of some of the species that make up the ecosystem. Snakes are predators, and in many cases (such as the species that have reached Ibiza and Formentera), their range of prey is very wide: rats, mice, dormice, birds, eggs and even other reptiles such as lizards or geckos.
Another characteristic common to all invasive snake species currently present on Ibiza and Formentera is the absence of natural predators that exert serious pressure on them.
As a consequence, the only limitations they have in their expansion process are the depletion of food sources (extinction of species), and the controls that the administration carries out on their populations, but above all (given the limited resources of the public body to reach everywhere), the active participation of companies and individuals.
Without the participation of these last two parties, the capacity of the public administration to face this serious threat on its own will be limited to delaying the inevitable: the disappearance of certain species from our ecosystems due to the predatory action of snakes, such as the lizard of the Pitiusas (Podarcis pityusensis).
Snakes: a threat to the natural biodiversity of Ibiza and Formentera.
The uncontrolled expansion of snakes on Ibiza and Formentera is posing a serious problem for some endemic species, as in the case of the Pitïusa lizard (Podarcis pityusensis). The seriousness of this problem does not need to be sought in remote islands in the Caribbean. You only have to go to our neighbouring island of Menorca to find the example of how the arrival of the viperine snake (Natrix maura) led to the extinction of the ferret (Alytes muletensis).
In the same way, the introduction of the leaf-nosed snake (Macriprotodon mauritanicus) is considered to have been an important player in the extinction of the Balearic lizard (Podarcis lifordi) both in Menorca and Mallorca... are we going to allow the same thing to happen in Ibiza and Formentera?
Snakes and economic losses.
Unless there is a very high infestation of snakes, these, due to their elusive nature, are not going to represent a serious threat of loss of clientele due to a bad image...the losses generated by the presence of these reptiles in our environment are of a different type: they are environmental losses in the form of extinction of endemic species, such as the Pitïusas lizard (Podarcis pityusensis).
No one who is aware of the presence of these reptiles in their environment should leave them alone. Nowadays, fortunately, both the population and the administrations seem to be becoming aware of the serious problem that snakes represent in Ibiza and Formentera, and without the need to hire the services of a pest control company, you can access traps for their capture that are very easy to use.
Nova Control can carry out the service for you or provide you with traps if you wish to carry out the control yourself. But if you also want to make the traps yourself, in the following link you have some instructions distributed by the Govern and easy to build: instructions for assembling snake traps.
And for those who do not want to hire a service, nor make or buy their own traps, we recommend that you go to your local council or to the Consell, to find out about the possibility of acquiring some completely free of charge.
Snakes and health risks.
In no case (at least to date), these are snakes whose venom represents a serious danger to the health of people or pets.
Of the 3 species detected so far in the Pitïusas, only 1, the bastard snake (Malpolon monspessulanus), is classified as venomous.
Normally, when bitten, the effect does not go beyond an intense pain at the moment of the bite, accompanied by a swelling that lasts 2-3 days. It should be noted that of the three species detected on Ibiza and Formentera, it is the only one that to date has not been found to be naturalised (i.e. it does not reproduce on the islands, but always comes from outside).
However, given that the objective conditions that have led to the appearance of snakes on Ibiza and Formentera continue to exist (i.e. the massive importation of olive trees for ornamental purposes without any kind of effective control), it cannot be ruled out that in the future the presence, or even naturalisation, of a species may be detected which, due to its venom, could represent a real risk to human health.
Identification and control of snakes.
Identification of the snake pest:
-Sighting of specimens.
-Location of skin shedding.
-Localisation of nests with egg shells.
Snake control through Integrated Pest Management (IPM):
-Prior inspection.
-Bloodless trapping.
For a more detailed description of our work methodology, see the description of our Integrated Pest Control (IPC).
Serpientes plaga en Ibiza y Formentera, principales especies.
Horseshoe snake (Hemorrhois hippocrepis): this is the most common invasive snake currently present in the Pitïusas. And although the average length of an adult snake is usually around 0.89 cm, given the optimal conditions for its development on Ibiza and Formentera, it is not unusual to find specimens that are well over one and a half metres long, with the record being 2 metres.
The horseshoe snake reaches sexual maturity, on average, at 3 years of age. They lay only one clutch of between 8 and 14 eggs, and it is estimated that 85% of adult females reproduce each year. The average life expectancy in the wild is around 20 years.
It is a versatile predator, and therefore a serious threat to lizards, sargantanas, dormice, dormice, shrews... even small birds and their eggs can form part of their diet.
Ladder snake (Rhinechis scalaris): this snake is smaller in size than the horseshoe snake, 0.72 cm on average. Unlike the horseshoe snake, a tendency towards gigantism has not been observed that differentiates them notably from the populations of the peninsula.
They reach sexual maturity at 3 years of age, but their reproductive potential is lower than that of the horseshoe snake: 6 eggs on average per year, with 60% of females reproducing per year. Its life expectancy in the wild is around 20 years.
As with the horseshoe snake, they have a wide range of prey, from small birds to micro-mammals, with a slight tendency towards the latter.
Adult ladder snake.
Ladder snake, juvenile specimen.
Bastard snake (Malpolon monspessulanus): this snake has an average length of 1.15m, with a maximum of 2.15m for large adults. However, a certain tendency towards gigantism has been noted in the Balearic Islands through specimens captured in Mallorca, so it cannot be ruled out that in an environment such as Ibiza and Formentera, they could exceed these dimensions if they were to become naturalised on the islands.
To determine the gigantism of a snake, not only are they measured, but the degree of development of the bones per year is also studied, and this was found to be larger for the specimens captured in Mallorca than on the mainland. This means that an individual of, for example, 6 years old will be considerably larger than one of the same age on the mainland.
It takes about 5 years to reach sexual maturity. It lays an average of 10 eggs and has a life expectancy of about 15 years.
This snake shares prey with the other two invasive snake species detected on Ibiza and Formentera: micromammals (mice, shrews, dormice...), small birds and their eggs, and other reptiles (such as sargantanas and lizards). A large adult specimen may also feed on larger prey, such as young rabbits.
It is the only one of the 3 snake species that has venom, effective in killing its prey, but harmless to most healthy people. Normally, its bite will not cause more than intense pain at the time of the bite, which may be accompanied by itching and some swelling for the next 2-3 days.
It should be noted, once again, that the bastard snake has only been detected on specific occasions. Therefore, to date, its naturalisation (natural reproduction) has not been confirmed, neither in Ibiza nor in Formentera. But we must be aware that the entry routes that allowed its arrival in the past are still active, so the fact that its naturalisation has not been confirmed is not synonymous with the fact that it may not be in the process of arriving.
Nova Control has the professionals, resources and experience necessary to guarantee the correct control of pests and microorganisms both in Ibiza and Formentera, always seeking to cover the service in a discreet and professional manner.
At Nova Control, we always try to adapt to the needs and requirements of our clients, whether they are public, private or private entities.
For further information, please do not hesitate to contact us:
