Around 2.8 million tourists annually visit Gran Canaria, the third largest of the eight Canary Islands. Scandinavians, British and Germans feel particularly at home on the round, scenically varied island – whether in the capital Las Palmas or coastal towns such as Maspalomas and Puerto de Mogán.
In 1957, mass tourism began with the first charter aircraft. Forty years later, visitors of a completely different kind arrived: Under circumstances that have not yet been clarified, an invasive species of snake found its way to the island in 1998 at the latest. The dark brown, patterned with yellow stripes, a meter long Californian chain snake has since felt at least as comfortable on Gran Canaria as the human tourists. The snake species, which is actually native to Mexico and the southwest of the USA, has multiplied, spread, and as we now know: it has almost wiped out the native reptile fauna.
The animal, which is harmless to humans (even if it sometimes snaps), has found its ideal habitat on the Canary Island. It loves the barren, dry landscape as well as the temperatures, which are similar to those in the southwestern United States. The food also fits perfectly. The latter consists, among other things, of the lizard species typical of Gran Canaria, including the Gran Canaria giant lizard, which is up to 80 centimeters long (Gallotia stalini).
Julien Piquet and Marta López-Darias from the Instituto de Productos Naturales y Agrobiología recently published the extent of the destruction of native reptiles in a journal Proceedings of the Royal Society B. figured. Things are not looking good for the island’s typical lizards: According to the studies, the population of the Gran Canaria giant lizards in the areas infested by the chain snake is 90 percent smaller than in the areas that are still uncontaminated. Another species of lizard called Canary Skink with a brightly colored tail has declined by 80 percent. There are only half as many of the striped Canary Islands geckos as there would be normal.
Various campaigns to contain the chain snake failed
Local scientists report that the Canarian environmental authorities did not take the problem seriously until 2007. Then the vipers were so common in some ravines in the northeast of the island that the residents sounded the alarm. Despite various campaigns and initiatives in which dogs and birds of prey were also used, all attempts failed, the advance of Lampropeltis californiae, according to the species name of the adder. An EU funding program did not help either.
Bird keepers in Gran Canaria have already had to drag the snakes out of their animals’ cages. With the loss of native animal species, the flora is also threatened, because animals like the Gran Canaria giant lizard contribute a lot to the spread of seeds. Lizards also regulate the insect population. How the voracious adder once came to the Canary Island is controversial. However, because of its pattern, the snake is a popular choice for home terrariums. The first specimens may have escaped from a private enclosure or were abandoned.