This Week in History: Invasion of the Wall Lizard

This Week in History:  Invasion of the Wall Lizard

Invasive species are a global problem, says Gavin Hanke, curator of Vertebrate Zoology at the Royal BC Museum.

According to Hanke, here in southwestern BC the mild climate makes us particularly vulnerable to invasion by exotic species.

About 50 years ago, a dozen or so European Wall Lizards were released near Brentwood Bay on Vancouver Island, and that small population has now grown to an estimated 500,000.

“The northernmost record is now Campbell River.  We have an isolated population up there” says Hanke.

“They’re on Denman Island, there’s one record in Duncan, Nanaimo, Mill Bay, Shawnigan Lake, and then from the Swartz Bay terminal all the way down to Metchosin.”

The creatures have also been spotted on the mainland.

“One record in Vancouver” says Hanke, “and we’ve got one record in Osoyoos now.

“The specimen in Osoyoos actually was a stowaway in a shipment of grapes, from Vancouver Island to Osoyoos. Luckily that lizard was caught, so it is now out of the population.”

The wall lizard is similar to Vancouver Island’s alligator lizard.

“A lot of people have trouble telling the wall lizard from our native alligator lizard” says Hanke.

“The wall lizard is about the same size, but much more slender.  The tail is more slender, the legs are longer, whereas the alligator lizard has a stocky, thick tail and short little legs.”

There is also a difference in colour.

“The wall lizards generally have a wash of green on them, or they’re vivid green, and the alligator lizards are usually coppery to grey brown” says Hanke.

Hanke is learning everything he can about this invasive species.

“The wall lizard does really well in urban environments.  That’s why its exploded over our region, because we just develop more and more housing districts.  It’s perfect for them.”

He’s grateful for the public’s input about these creatures.

“This is something that’s impacting our daily lives. Just this morning I got an email on lizards in Nanaimo.

“Citizen science is huge. It’s one of the best ways to get observation. I can’t be everywhere, but everyone can contact me.

“I get a lot of information just from ‘who’s found them in their yard, and when they first saw them’ and then they phone me, or email years later to say how the population’s building in their garden. It’s actually a lot of fun, and it’s great to build those connections with the community.”

Hanke wants to learn about their impact on other species, starting with what they eat.

“I’ve seen them eating ants, probably spiders, beetles, flies…actually, I got a photograph of a wall lizard that’s eating wasps, which is really neat.”

So can this invasive species be removed?

“I think we’re stuck with them” says Hanke.

“The original population was from north-central Italy, so, the climate there is just like this.  It’s a Mediterranean climate.

“These guys can actually survive with almost 30 percent of their body water freezing!  They’re remarkably resistant to winter, so this climate is perfect for them.

“It’s almost like they were pre-made for this area.  It’s very lucky for them that [Brentwood Bay is] where they got released.”

Hanke hopes the European Wall Lizard can be contained to Vancouver Island.

“I’m just hoping that we don’t get them in the BC mainland, because they could spread far and wide, and south into the US.”

If you would like to email Dr. Hanke about a wall lizard sighting in your area, you can reach him at [email protected].

Veronica CooperVeronica Cooper

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