Tracy Menzies had been struggling with slugs in her backyard garden for a while, but this year, she finally triumphed as her strawberries flourished beautifully. The reason behind the slugs’ decline seems to be the increasing presence of the invasive European wall lizard in the area. These lizards, experts explain, are rapidly expanding their territory, devouring various creatures like insects, spiders, and even slugs.
Menzies, a resident near the Gorge Waterway in Saanich, noticed a surge in wall lizard numbers in her yard recently, indicating a potential link to the reduction in slug sightings. The lizards, mostly a few inches in size, have been observed in areas like North Saanich, reaching lengths of up to eight to ten inches, as Menzies, who works as a real estate agent, shared.
Gavin Hanke, the curator of vertebrate zoology at the Royal B.C. Museum, estimated the population of European wall lizards in B.C. to be between 800,000 to a million, primarily concentrated on Vancouver Island. Their spread has extended as far as Campbell River, 220 kilometers north of Victoria, raising concerns about the environmental impact.
Worried about the consequences of the lizards’ rapid proliferation, Hanke emphasized the need to adapt to coexist with them. He highlighted the adverse effects of the lizards on the local ecosystem, citing instances of predation on invertebrates and baby garter snakes, which disrupt the natural balance on Vancouver Island.
Biologist Nicholas Wong from the Invasive Species Council of B.C. noted the absence of official programs to manage the growing lizard population. Wong pointed out that the wall lizards are not only competing with native species for resources but also spreading beyond control due to their adaptability and reproductive success.
The origin of the European wall lizard surge in B.C. traces back to a deliberate release of 12 lizards in 1970 from a closed roadside zoo in Central Saanich. The lizard population found the island’s climate, characterized by cool winters and hot, dry summers, conducive to their proliferation, enabling them to thrive and expand their territory.
To curb the spread of the lizards, residents like Menzies and experts like Hanke and Wong recommend collective efforts to manage their presence effectively. However, Hanke acknowledged that eradicating the lizards at this stage is impractical, underlining the responsibility of human activity in introducing and facilitating the invasive species’ establishment in the region.