Tracy Menzies faced a constant battle with slugs in her backyard garden, losing out on the harvest in past years. However, this season, her strawberries flourished remarkably. The reason behind the slugs’ decline is the increasing presence of the invasive European wall lizard, rapidly spreading across the region and devouring various creatures, including slugs.
Living near the Gorge Waterway in Saanich, Menzies observed a surge in the lizard population in her yard recently, indicating a probable connection to the diminishing slug numbers. These wall lizards, mostly a few inches in size, have been spotted in various locations, some growing as large as eight to ten inches, even inhabiting crawl spaces, as informed by Menzies, who works as a real estate agent.
Gavin Hanke, the curator of vertebrate zoology at the Royal B.C. Museum, estimated the presence of around 800,000 to a million European wall lizards in British Columbia, primarily concentrated on Vancouver Island and extending up to Campbell River, 220 kilometers north of Victoria. Hanke expressed concerns over the lizards’ rapid expansion and the potential adverse effects on the environment, emphasizing the need to adapt to coexist with them despite their impact on local wildlife.
Biologist Nicholas Wong from the Invasive Species Council of B.C. highlighted the absence of official management programs to regulate the lizard population growth. Wong emphasized the competition between European wall lizards and native species for resources and territory.
The proliferation of wall lizards in British Columbia originated from a deliberate release of a dozen lizards in 1970 following the closure of a roadside zoo in Central Saanich. The favorable climate conditions on Southern Vancouver Island, characterized by mild winters and warm, arid summers, have facilitated the lizards’ establishment and expansion. These lizards typically spread at a rate of about 100 meters annually but can travel further by hitchhiking on vehicles or goods like firewood.
While the European wall lizards have aided in controlling pests like slugs in gardens, concerns persist regarding their unchecked spread. Menzies expressed a desire not to eradicate them entirely but harbored reservations about their intrusion into residential spaces. Hanke recommended maintaining a plain, well-groomed garden to deter the lizards and emphasized the need for collective efforts to manage their population effectively.
Acknowledging that eradicating the lizards at this stage is unfeasible, Hanke attributed their invasion to human interference with natural habitats, enabling these invasive species to thrive in altered environments. He cautioned against relocating the lizards to new areas to prevent further spread and potential ecosystem disruptions. Hanke warned of the possibility of the lizards expanding into Washington state in the coming years due to human-induced environmental changes.