Surrey’s Surprise Saurian

Western fence lizard.

By Dr. Gavin Hanke

Curator of Vertebrate Zoology

SURREY’S

When did the western fence lizard (Sceloporus occidentalis) first appear in British Columbia?

Unfortunately, we have no idea. There is an unsubstantiated report on iNaturalist from April 29, 2019, at MacNeill Secondary School in Richmond, but it can’t be verified—neither the specimen nor a photograph of it are available. I also have heard several anecdotes from the Oliver area involving similar lizards, dating back almost 15 years—but were these fence lizards? Or were they elusive pygmy short-horned lizards (Phrynosoma douglasii), a species thought to be extirpated from our province?

Until this year, we had no solid evidence of a fence lizard in BC—no specimen, no photograph, no scrap of skin or DNA. However, on June 9, 2020, that all changed. Someone shared a photograph of a lizard sighted in the Cloverdale area of Surrey, along with a request to confirm its identity. The lizard in the photograph had a stubby tail—lost to a slightly slower predator—but it had the body shape and markings of a western fence lizard. The feature that clinched the identification: a pale yellow-orange tint

Western fence lizard. Photograph courtesy of Ron Farrell.

SURPRISE SAURIAN

to the rear-facing surfaces of its foreand hindlimbs. That alone separates this lizard from the other likely candidate, the sagebrush lizard (S. graciosus).

Like the sagebrush lizard, the western fence lizard is established in Washington State. Fence lizards range north to within a few kilometres of the international border, and they are known to frequent the log-littered shorelines of Puget Sound from Cherry Point on the eastern shore to Port Townsend in the west. According to one field guide, the western fence lizard’s range in the Okanagan ends at the Canadian border. This seems unlikely. Most field guides show western fence lizards, as herpetologist Alan St. John put it, within a stone’s throw of the Canadian border.

It would be nice to think that the Puget Sound populations are native to the area and that a lizard appearing in BC is part of a naturally dispersing population, but this is unlikely. In 1992, Herb Brown of Western Washington University reported that he’d released western fence lizards at least four times between 1986 and 1990 in the Puget Sound area. His closest test site was Cherry Point—not 27 kilometres from where the Surrey specimen was photographed—and he stated that a population did become established in the area. Because of Brown’s experimental translocations, the northernmost western fence lizard population in the United States is non-native. Given the proximity to the Canadian border, the authors of the Royal BC Museum’s 2006 handbook Amphibians and Reptiles of British Columbia (Brent Matsuda, David Green and Patrick Gregory) listed western fence lizards as potential immigrants, and now we know at least one has entered the country.

Has the Cherry Point population spread north since 1990? Did the Surrey specimen hitch a ride in a livestock trailer, a load of firewood or an RV? Stranger things have happened. Or was it an escaped pet, as suggested by Pat Gregory? I haven’t seen western fence lizards in the pet trade in Canada since the 1980s (I had one as a pet in Winnipeg), but their more tropical relatives are commonly sold as emerald swifts, and there are a lot of pet shops in the Vancouver area, so anything is possible. The Surrey saurian is still loose in the province. A domestic cat or a wild bird may catch it—or it may defy the odds and regenerate its tail. Will it be seen again? Time will tell. All I know is that this discovery would not have happened without sharp-eyed citizen scientists. I wonder what other surprises await us this year?