The Balearic environmental group GOB has warned that the recent ‘invasion’ of snakes arriving from the mainland in Ibiza and Formentera is putting the Pitiusas sand viper, a species endemic to the Balearics, at risk of extinction. Efforts by the authorities to control the spread of these snakes, especially the horseshoe snake, are proving ‘insufficient’ and the future of the sand viper ‘looks very bleak’, the organisation said in a statement.
However, the problem between snakes and sargantanas, according to the GOB, is not exclusive to the Pitiusas but is also affecting Cabrera and some islets of Mallorca and Menorca where the endemic species lives. Up to 25 subspecies have been described, of which five live on islets in Mallorca, 10 in Menorca and another ten in Cabrera. One of these is exclusive to the Malgrats Islands, located off the coast of Calvia.
According to GOB, the snakes that have arrived from Mallorca to the Malgrats may have already wiped out all the sand lizards on the islet of Conills, while on Es Malgrat the population has already suffered a significant decline. If this trend continues, this subspecies of reptile will eventually disappear from the two islets, leading to its global extinction in the wild. According to the organisation’s count, the Balearics have 149 small islands or islets that contain terrestrial fauna and flora, whose physical separation from the rest of the archipelago has made them unique in the world.
The best-known case is that of the sand lizards, but there are also some invertebrates and plants that are endemic. They also often serve as refuges where seabirds rest and breed. Although 80% of these islets are protected in some way, 40% of the total do not have approved management plans establishing the limitations and conservation measures necessary to preserve their biodiversity.
Addressing this ‘obvious’ need has so far been neglected by the regional environmental administration, GOB said. On the other hand, the organisation has criticised the fact that, unlike in other island territories around the world, in the Balearics these issues are only addressed when an invasive species can affect sensitive economic sectors such as agriculture.
Controls to prevent the entry of invasive species, however, are ‘insufficient’, which is why, in the opinion of GOB, it would be necessary to coordinate a biosecurity strategy. This could monitor and anticipate the arrival of invasive species, generate regulations and protocols, control the points of entry of agricultural goods and gardening establishments, eradicate these species once they are detected and inform the public.
The organisation has pointed out that something similar is already included in the amendment to the law for the conservation of environmentally important areas that was approved during the last legislative session, but ‘unfortunately, it has not gone beyond the drawing board’. Environmental legislation also establishes that species classified as threatened must have recovery or conservation plans.
Right now, however, of the 88 endangered or vulnerable species in the Balearics, 20 still do not have a legally approved plan, including the sargantanas. Of the 68 that do have a plan, 58 have already reached the end of their implementation period, most of them more than a decade ago. ‘It is urgent to draft and approve the conservation and recovery plans for species that are still pending, as well as to update those that have already expired. Without them, we are reacting to impacts, but we must plan for possible threats in order to make progress on the problem,’ said GOB.
The organisation has also criticised all regional governments for not giving the conservation of biodiversity in the Balearics ‘the importance it deserves due to its uniqueness’. Although GOB has acknowledged its ‘lack of confidence’ that the current government will find a solution to this problem, it has called for a ‘change of course to avoid irreparable losses to our natural heritage’.