Francis Quang-Hai Dinh spent his first summer at McGill University exploring Montreal parks on his bicycle, on a quest to study squirrels. Dinh cycled to around 200 green spaces across the area, from Mirabel to Saint-Bruno, observing and documenting over 800 grey and black squirrels.
Initially an undergraduate task, Dinh’s project evolved into a personal mission to understand how the city’s layout and water systems influence evolution. He developed a fascination for squirrels, considering them wildlife rather than just pests, after spending significant time observing them.
Due to limited public transit options in suburban regions and not owning a car, Dinh relied on his bicycle to conduct manual squirrel surveys in various parks, making him the sole researcher known to have done so across the region.
In his research, Dinh discovered that black squirrels are more prevalent in northern areas. He found that approximately 12% of squirrels in Montreal are black on average, with higher percentages of black squirrels as he ventured further north. In locations just north of Laval, he noted up to 40% of squirrels being black, while the percentage dropped to only 2-3% on the south shore of Montreal.
The study attributed this phenomenon to temperature variations, as black squirrels absorb heat better than grey squirrels. Additionally, the density of forest cover plays a role, with darker backgrounds providing better camouflage for black squirrels.
Allison Roth, the study’s lead author and a University of Missouri assistant professor, emphasized that the research focuses on using squirrels as a model to explore how urban environments drive evolutionary changes. Montreal’s unique urban layout, segmented by waterways like the St. Lawrence River, creates diverse environmental conditions that influence genetic and physical adaptations in animal populations.
The study, titled “Fine-scale spatial variation in eastern grey squirrel melanism across a complex urban landscape,” challenges the notion that human development is the primary driver of wildlife changes in cities. It highlights the indirect influence of urbanization on melanism through factors like local vegetation structure and winter microclimate.
Dinh, now pursuing integrative biology at the University of Illinois Urbana-Champaign, reflected on how his perspective on wildlife has shifted through his research. He noted that despite urban modifications, wildlife will persist, blurring the boundaries between city and nature.