Tracy Menzies faced a long-standing battle with slugs invading her garden, but this year, she successfully protected her strawberries from them. The culprit behind the decline of slugs in her garden seems to be the European wall lizard, an invasive species rapidly spreading through British Columbia. Menzies, residing near the Gorge Waterway in Saanich, noticed an increase in lizard sightings in her yard, indicating a shift in the ecosystem.
Gavin Hanke, the curator of vertebrate zoology at the Royal B.C. Museum, estimated that there are between 800,000 to a million European wall lizards in B.C., predominantly on Vancouver Island. These lizards have extended their reach up to Campbell River, posing a significant environmental threat. Hanke emphasized the impact of the lizards on the native ecosystem, particularly on invertebrate populations.
Nicholas Wong, a biologist at the Invasive Species Council of B.C., highlighted the lack of management programs to control the growing lizard population. The competition for resources with native species adds to the ecological concerns. The origin of the lizard invasion dates back to a deliberate release in 1970, following the closure of a roadside zoo in Central Saanich.
These lizards, known for their omnivorous diet, consume various insects, spiders, and invertebrates, including slugs and bees. While they inadvertently aided Menzies in protecting her strawberries, concerns about their unchecked proliferation remain. Hanke suggested maintaining a simple garden landscape to deter the lizards, though eradicating them entirely at this stage is deemed unfeasible.
The inadvertent introduction of the European wall lizards serves as a lesson on the consequences of human interference in natural habitats. Hanke warned against relocating the lizards, as this could further expand their territory. The irreversible impact of this invasive species underscores the need for collective action to mitigate their spread and safeguard local ecosystems.