Tracy Menzies struggled with battling slugs in her backyard garden for years, often losing out on her harvest. However, this year, her strawberries flourished and were described as “absolutely beautiful.”
The reason for the decline in the slug population was attributed to the increasing presence of European wall lizards in Menzies’ area near the Gorge Waterway in Saanich. These invasive lizards have been rapidly spreading and consuming various creatures, including insects, spiders, and slugs.
Noticing a surge in lizard numbers in her yard, Menzies suggested that the lizards may be feasting on the slugs, as she hasn’t seen any slugs in her yard since the lizards appeared.
Gavin Hanke, the curator of vertebrate zoology at the Royal B.C. Museum, estimated that there are around 800,000 to a million European wall lizards in British Columbia, predominantly on Vancouver Island. Their reach has extended as far as Campbell River, 220 kilometers north of Victoria, raising concerns about their environmental impact.
Hanke expressed worry about the lizards’ rapid expansion and emphasized the need to adapt to coexist with them. He highlighted the negative effects on the local ecosystem, particularly on invertebrate populations, citing instances of the lizards preying on baby garter snakes.
Biologist Nicholas Wong from the Invasive Species Council of B.C. mentioned the absence of official management programs to control the lizard population growth. He noted that these lizards compete with native species for resources and space.
The introduction of European wall lizards to British Columbia can be traced back to the intentional release of 12 lizards in 1970 after a local zoo closed down. The lizards have thrived in Vancouver Island’s climate, characterized by cool winters and hot, dry summers, similar to their native habitat in Italy.
The lizards, being omnivores, consume a wide range of insects, spiders, invertebrates, and fruits, posing a threat to local biodiversity. Despite aiding in protecting Menzies’ strawberries from slugs, she expressed concerns about the lizards’ spread and invasion of homes.
Efforts to stop the spread of the European wall lizards include maintaining unattractive habitats for them, such as plain, closely-cut lawns. Wong stressed the importance of collective action in managing the lizard population, as individual eradication efforts may prove ineffective if neighboring properties are not involved.
Hanke acknowledged the impossibility of eradicating the lizards at this stage, emphasizing human responsibility for introducing and enabling their proliferation. He cautioned against relocating the lizards to new areas, as it could lead to further expansion of their range.
Ultimately, Hanke warned that it may only be a matter of time before the European wall lizards migrate southward, underscoring the need for ongoing vigilance and responsible environmental stewardship.