Tuesday, September 27

An American snake is killing two indigenous canarian lizards: the latest effect of the exotic pet craze

For years in Gran Canaria there has been a small creature – small is relative, since reaches 180 cm long– which brings biologists and authorities in charge of preserving the environment head over heels: california king snake (Lampropelties californiae), a reptile with a docile and timid character, a native of western North America and Mexico, which once triumphed as a pet and now generates the same effect on the island ecosystem as a time bomb. The reason: his voracity. Or rather, the voracity with which gobble up two of your favorite island dishes: the giant lizard (Gallotia stehlini) and the skink (Chalcides sexlineatus).

After years of havoc and despite attempts by the authorities to control its impact, experts warn that the Californian snake has drastically reduced the population of both native species. An article published by Julien C. Piquet and Marta López-Darias – both from the Institute of Natural Products and Agrobiology (IPNA-CSIC) – in The Royal Society Publishing, they warn of a level of decline that exceeds, in invaded areas, 50%.

From pet to headache

For their study, the scientists analyzed the density of native reptiles in spaces occupied by the Californian snake. Also in areas free from its scourge. After capturing specimens and even looking for them under the stones, they came to a clear conclusion: “The abundance of all species was lower in the invaded sites.” In the case of the giant lizard the reduction exceeded 90% and in that of the skink it exceeded 80%. The experts also studied a third indigenous species, Boettger’s wall gecko (Tarentola boettgeri). Their fall in the “invaded” spaces was less than that of the other two reptiles, but equally remarkable: more than 50%.

“Our results illustrate the severe impact of Lampropeltis californiae in endemic herpetofauna of Gran Canaria and highlight the need to reinforce the measures to manage to manage this invasion “, concludes the report, and ditch:” Invasive snakes represent a series of threats to the islands’ biodiversity, since they are responsible for far-reaching impacts that they are remarkably little studied, particularly with regard to native reptiles. “

The impact –write down the magazine Research and Science– it’s related to the role of indigenous reptiles on the islands, where they play a crucial role in food webs and substitute ecological functions that are carried out by other species in continental areas. Aware of the problem and the tremendous impact of the California king snake, the island authorities have long tried to control its footprint on the island. Last year alone, the #Stopculebrareal (Post-LIFE LAMPROPELTIES) project resulted in 1,990 captures of specimens.

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The presence of the Californian snake in the lands of Gran Canaria is not new. The first records date from 1998, more than two decades ago. By 2007 its naturalization and reproduction in the east of the island had already been confirmed. In the tab that the Spanish Catalog of Invasive Alien Species dedicated to Colubridae —The colubrids— it is detailed that “one of the species of this family that is causing the most problems on the islands is the California royal snake” and the efforts made on the ground to reduce its tremendous impact are recalled.

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The entry and dispersal of the snake in the archipelago is related to the pull he had years ago as a pet. In 2019 the Civil Guard reported for example, that he had seized a copy from a man who had it at his home in Tenerife. The Lampropelties californiae It is not, in any case, the only example of a species that went from being confined in terrariums to bringing environmental authorities head first. Something similar happened at his time with Florida turtles (Trachemys scripta) The the Argentine parrot (Parakeet Monk), to cite just two cases.

Images | gilaman (Flickr) Y California Department of Fish and Wildlife (Flickr)