Invasive squirrels have big ecological impacts
For most people, the term ‘invasive species’ evokes a vision of something horrible. An invasive species can take over a habitat, destroy the environment and compete with native plants and animals in its path.
But what if the invader is furry. And cute. Therein lays the issue with invasive squirrels. At least one of the issues.
There are two invasive squirrel species in the Okanagan: Eastern Grey and Eastern Fox Squirrels.
The Fox Squirrel first arrived in B.C. in the 1980's in Osoyoos, probably from an introduced population in Okanagon County in Washington. It is now found north to Okanagan Falls.
It is native to eastern North America where it is found in the eastern states (excluding New England) west to Colorado and Texas, and in Canada (southern Manitoba and southwestern Ontario).
The Fox Squirrel is found in a variety of habitats, but often in forest patches with an open understorey. In the Okanagan, it is found in urban areas, orchards and open forests.
While not new to B.C., Eastern Grey Squirrel has only recently made its way to BC’s Southern Interior.
In the early 1900s, a small number of these squirrels were released in Stanley Park, where they are now a thriving resident.
Native to central and eastern North America, the squirrels take up residence in the deciduous woodlands of the Lower Mainland and Vancouver Island. The Eastern Grey Squirrel tends to dominate the headlines, presumably due to its rapid spread.
As noted in a recent article in a Kelowna publication, Thompson Rivers University professor Karl Larsen warned Okanagan municipalities and the province about the potential impacts caused by invasive Eastern Grey Squirrels five years ago.
At that time, reports of this species were uncommon with none from the South Okanagan. Fast forward to today when reports of these squirrels regularly come from landowners and city parks staff, from Penticton through to Vernon.
So what’s the problem? These invasive squirrels have some big ecological impacts. They deplete populations of native squirrels through competition and disease, and displace native birds of their nesting habitat, eating the birds’ eggs and nestlings. They also compete with native mice and voles.
Interestingly, the Eastern Grey Squirrel is ranked by the Invasive Species Specialist Group (ISSG) as one of the Top 100 Invasive Species in the world.
Eastern Grey Squirrels are identifiable by their dark to pale grey backs that may be brushed with cinnamon on hips, feet, and head. Ears are buff to grey to white, and its tail is white to pale grey. The larger Eastern Fox Squirrel has a long, bushy tail and variable colouration.
However, the common name ‘fox squirrel' refers to the yellowish-red, fox-like colour that is common in this species.
Unfortunately, Karl Larsen informs us that without a concerted ‘top down’ action plan for controlling the Eastern Grey Squirrel, he feels there is little that can be done.
To prevent their spread, landowners can consider the following measures: • Don’t feed or relocate squirrels • Keep all compost, garbage and pet food covered • Use squirrel-proof bird feeders. For further information on invasive species go to our website: www.oasiss.ca Facebook page www.facebook.com/invasivespeciessociety or contact the Program Manager for the Okanagan-Similkameen, Lisa Scott, at 250-404-0115 or oasiss@shaw.ca