The Ministry of Environment's squirrel alert for Vancouver Island, issued in 2009, puts two photographs side by side. The caption under the first reads "GREY SQUIRREL with grey colouring". The caption under the second, a squirrel black from nose to tail, reads "GREY SQUIRREL with black colouring". That pair of labels answers most of what people in Nanaimo ask when a black squirrel crosses the lawn.
The black squirrels in BC that turn up on Vancouver Island are eastern grey squirrels, Sciurus carolinensis, wearing a dark coat. They are not a native animal and not a separate species. The more interesting questions are how the species got here, how it reached Nanaimo, and why some of its members are black at all.
One species in two coats
Provincial material describes two common colour morphs of the eastern grey squirrel, grey and black. The Invasive Species Council of British Columbia adds that melanistic, entirely black individuals are common, while white or leucistic animals turn up less often. The province's current alert sheet allows for grey, brownish or black fur with a white or reddish underside, sometimes with a cinnamon tinge on the hips, feet and head.
Colour aside, the animal is the same. The alert gives a body length of 23 to 30 centimetres and a tail of 19 to 25 centimetres, and describes the grey squirrel as about twice the size of the native squirrels. Its large, bushy tail folds over its head when the animal rests. Anglia Ruskin University, whose researchers have studied the black form, puts it simply: the only difference is the fur.
Three squirrels from Ontario: the 1966 Metchosin escape
The island's eastern grey squirrel population began in Metchosin, near Victoria on the island's southern tip. A 2009 conference poster by Elizabeth Gillis and colleagues records that eastern grey squirrels were transported from Ontario to a game farm there in 1966 and "quickly escaped". A paper presented at a 1999 conference in Kamloops, by Corrie Bruemmer and three co-authors, is more specific: citing a 1975 account, it says the founders were two females and one male imported from Ontario. The Invasive Species Council's page says only that "several" escaped. None of these sources says whether any of the founders was black.
The island population was not the province's first. Grey squirrels were introduced to Vancouver's Stanley Park much earlier, but the date depends on the source. The Invasive Species Council and a 2005 study in The Canadian Field-Naturalist by E. K. Gonzales both give 1909. The province's own invasive species alert says the squirrels were given to Stanley Park as a gift "around 1914". The Gonzales study treats Vancouver and Metchosin as separate introductions that spread through their regions over roughly 30 years, mostly in residential land.
North to Nanaimo
For a while the Metchosin animals stayed close to home. The 1999 Bruemmer paper says the population remained fairly concentrated near the release site at first, then spread dramatically over the 15 years before the paper was written: north through Goldstream Provincial Park, through Esquimalt to beyond Sooke, and up the Saanich Peninsula almost to the Swartz Bay ferry terminal.
The same paper names a human hand in the spread. As numbers around Victoria grew, pest controllers were called in to trap squirrels, and some of the captured animals were released farther north on the island. Citing a 1998 communication from a provincial ministry official, the authors reported grey squirrels at Bamberton on the north end of the Malahat, in Duncan, and in Nanaimo.
That record sits awkwardly beside later provincial outreach. The ministry's 2006 brochure and 2009 alert asked the public to report any eastern grey squirrel seen north of Duncan, west of Sooke, around Lake Cowichan or Cobble Hill, or on the Gulf Islands, explaining that the ministry wanted to find the northern extent of the range. Either the 1998 Nanaimo animals were a scattered few, or the province did not have a reliable map a decade later. The sources do not say which.
By 2017 the question had moved further up the coast. The Parksville Qualicum Beach News ran a photograph by wildlife photographer Mike Yip of an eastern grey squirrel at Qualicum Beach, which Yip said he had seen in the area several times over the years. Gail Wallin, executive director of the Invasive Species Council, told the paper the species was particularly well established around Duncan and south. The Gonzales study had already predicted continued spread wherever housing replaced the conifer forest that holds the squirrels back.
The most detailed effort to map the front line in these sources ran through a sightings page hosted by Vancouver Island University. The 2009 poster by Gillis, Karen Morrison and Haley Matkin set out a public web-based reporting system linked to a GIS map, and a one-year trial, July 2009 to July 2010, of a hormonal implant called Suprelorin as a possible control. The design called for 40 females to be ear-tagged, half of them implanted, and 15 squirrels to carry radio collars to track home ranges. The project was funded in part by the federal Invasive Alien Species Partnership Program. No published results of the trial turned up in the sources reviewed for this article.
The grey colour form has its own page on eastern grey squirrels.
Why some grey squirrels are black
The black coat comes from one gene. In 2014, Helen McRobie of Anglia Ruskin University in England showed that black grey squirrels carry a pigment gene with a small piece of DNA missing. In 2019, working with colleagues from the University of Cambridge and the Virginia Museum of Natural History, her team published a follow-up in BMC Evolutionary Biology that tested squirrels from across the United States and from British Columbia.
The result pointed to another species. The same faulty gene turns up in the fox squirrel, a close relative that also has black forms, and the genetic signatures around it are closer to the fox squirrel's version. The university's summary concludes that the mutation most likely arose in fox squirrels and passed to grey squirrels through interbreeding, probably when a black male fox squirrel joined a grey squirrel mating chase. McRobie's team also suggested black fur may give a thermal advantage in cold winters, which could have helped the species push north into Canada after the last ice age.
The same black form has travelled well beyond North America. According to the university, England's black squirrels are believed to descend from animals imported from the United States that escaped from a private zoo, with the first wild one recorded at Woburn, Bedfordshire, in 1912.
That explanation is about where the gene came from, not about Nanaimo. The province's alert lists the fox squirrel in British Columbia only in the interior, near Okanagan Falls, so a black squirrel on the island is not a fox squirrel and not a hybrid. It is a grey squirrel carrying a gene that, on the 2019 study's reading, entered the species from fox squirrels.
Telling it apart from the native red squirrel
The province's look-alike chart lists two native squirrels: the red squirrel, Tamiasciurus hudsonicus, found across the province including Vancouver Island and Haida Gwaii, and the Douglas squirrel of the south-western coast. If you see a squirrel in a Nanaimo park and want to know which it is, size and tail are the quickest tests.
The ministry's material describes the red squirrel as roughly half the size of the grey, olive brown or rusty red on the body, head and tail, with a white eye ring and a narrower tail that does not curl over its head when it rests. Its tail is sometimes tipped with black, but the body is not. On the island, a large, heavy-tailed squirrel that is grey or black all over is the introduced species. Look for dreys, too: the ministry notes that grey squirrels often build nests of leaves and twigs out on tree branches.
What the province asks people to do
The concern is ecological as much as domestic. Provincial material says eastern grey squirrels compete with and displace native red squirrels and can pass disease to them; the Invasive Species Council names parapoxvirus. They compete with native birds for tree cavities, eat eggs and nestlings, strip bark from Garry oak and eat its acorns, and dig up camas bulbs. The Invasive Species Council adds that the squirrels prefer the tips of some acorns, Garry oak among them, which may slow the oaks' regeneration, and that the virus may also infect some livestock. The Garry Oak Ecosystems Recovery Team counts the species among seven mammals in its list of 173 invasive species of concern, according to the Invasive Species Council. Nanaimo's Garry oak and arbutus meadows on the north-end shore are exactly the kind of habitat that warning describes.
In gardens the list is familiar: lawns dug up, bulbs eaten, hazelnuts and walnuts stripped, wires and shingles chewed, attics and chimneys turned into nests. The province's advice is to stop feeding them, secure garbage, compost and bird feeders, use squirrel-proof feeders, and never relocate a trapped animal. Its current alert asks people not to possess, breed, release, sell or transport the species. The Invasive Species Council lists it as a regional containment and control species on the provincial priority list, and the province takes sightings through the Report Invasives app and webform.
One gap runs through every source consulted here. None gives a count or a proportion of black animals in Nanaimo or anywhere on the island, and none records the colour of the animals that left the Metchosin game farm in 1966.
Questions
Are black squirrels a separate species?
No. Black squirrels in British Columbia are eastern grey squirrels with an all-black coat. Provincial outreach material shows the two colours side by side and labels both as the same species, and researchers who study the black form say fur colour is the only difference.
Are black squirrels native to Vancouver Island?
No. The eastern grey squirrel is native to eastern North America and was introduced to Vancouver Island in 1966. The native red squirrel, which the province lists across B.C. including the island, is olive brown to rusty red rather than black.
Where did the squirrels on Vancouver Island come from?
They were brought from Ontario to a game farm in Metchosin, near Victoria, and escaped in 1966. A 1999 conference paper put the founders at two females and one male, while other provincial sources say only that several escaped.
When did grey squirrels reach Nanaimo?
A provincial ministry contact reported them in Nanaimo by 1998, according to a paper presented in 1999. Later provincial outreach from 2006 and 2009 still asked for sightings north of Duncan, which suggests the northern edge of the population was poorly mapped for years after that.
Why are some grey squirrels black?
A version of a pigment gene with a small piece of DNA missing makes the fur black. Research published in 2019, which included squirrels sampled in British Columbia, found the same gene variant in fox squirrels and concluded it most likely passed to grey squirrels through interbreeding.
Can you relocate a squirrel caught in your yard?
No. Provincial guidance from 2009 says relocating a live-trapped eastern grey squirrel more than one kilometre on Vancouver Island without a permit is illegal, and current provincial invasive species material asks people not to release or transport them at all.
Is it legal to kill eastern grey squirrels in BC?
Provincial guidance from 2009 and a 2017 report both describe the species as listed under Schedule C of the Wildlife Act, which allows it to be captured or killed without a hunting licence. Firearm and trapping bylaws still apply, and the rules should be checked with the province before acting.
Do black squirrels harm gardens?
They can. Provincial material lists digging up lawns, eating garden bulbs, stripping bark, and raiding hazelnut and walnut trees. They also chew wires and shingles and nest in attics and chimneys.
How do you report a squirrel sighting?
The province asks people to report eastern grey squirrels through the Report Invasives app or the webform at reportinvasives.ca. A photo and the exact location make a report useful.
Are there fox squirrels on Vancouver Island?
Not according to the province's current alert. It lists the introduced fox squirrel only in the interior near Okanagan Falls, which rules it out as the black squirrel seen around Nanaimo.
Sources
- Alien Species Alert: Eastern Grey Squirrel (Vancouver Island), B.C. Ministry of Environment, 2009
- Alien Species Alert brochure: Have you seen this squirrel in your area?, B.C. Ministry of Environment, 2006
- Frequently Asked Questions: Eastern Grey Squirrels, B.C. Ministry of Environment, 2009-07-10
- The Eastern Grey Squirrel on Vancouver Island, British Columbia: Monitoring Range Expansion and Evaluating Hormonal Sterilization as a Potential Control Strategy, Elizabeth A. Gillis, Karen F. Morrison, Haley M. Matkin (conference poster, B.C. Ministry of Environment), 2009-07-28
- Invasive Species Alert: Eastern Grey Squirrel (Sciurus carolinensis), Government of British Columbia, Inter-Ministry Invasive Species Working Group
- Impacts and Management of the Alien Eastern Gray Squirrel in Great Britain and Italy: Lessons for British Columbia, Bruemmer, Lurz, Larsen and Gurnell, Proceedings of a Conference on the Biology and Management of Species and Habitats at Risk (B.C. Ministry of Environment, Lands and Parks), 2000
- The distribution and habitat selection of introduced Eastern Grey Squirrels, Sciurus carolinensis, in British Columbia, E. K. Gonzales, The Canadian Field-Naturalist 119(3), 2005
- Eastern grey squirrel, Invasive Species Council of British Columbia
- Grey squirrels invading Island habitats, Parksville Qualicum Beach News, 2017-03-02
- Interbreeding turned grey squirrels black: study, Anglia Ruskin University, 2019-08-13
