Francis Quang-Hai Dinh spent his first summer at McGill University exploring Montreal’s parks on his bicycle, on a mission to study squirrels. Covering nearly 200 green spaces from Mirabel to Saint-Bruno, he meticulously observed and documented over 800 grey and black squirrels. What began as a college project evolved into a personal quest to understand how the city’s landscape and waterways influence the evolution of these creatures.
Dinh, who is now pursuing integrative biology at the University of Illinois Urbana-Champaign, became fascinated with squirrels during his research. He emphasized that squirrels, often seen as mere pests, are indeed part of the wildlife ecosystem and deserve attention. Lack of access to a car and limited public transportation in suburban areas led Dinh to rely on his bike, making him the sole researcher known to manually survey squirrels park by park across the region.
His findings revealed that approximately 12% of Montreal’s squirrels are black, with higher concentrations of black squirrels found in northern areas. Locations just north of Laval showed up to 40% black squirrels, while on the island of Laval, around 20% were black. In comparison, the island of Montreal had about 15% black squirrels, and on the south shore of Montreal, only 2-3% were black. The study attributed this variation to temperature differences, with cooler climates in the north favoring black squirrels due to their better heat-absorbing black coloration.
Dinh’s research, under the guidance of Allison Roth, an assistant professor at the University of Missouri and former McGill postdoctoral fellow, aimed to use squirrels as a model to explore how urban environments drive evolutionary changes. Roth highlighted the unique environmental factors in cities like Montreal, such as diverse neighborhoods, varying tree cover, and natural boundaries like waterways, leading to distinct genetic adaptations within animal populations.
The study, titled “Fine-scale spatial variation in eastern grey squirrel melanism across a complex urban landscape,” emphasizes the importance of examining wildlife changes at a neighborhood level rather than broadly comparing urban and rural settings. It challenges the notion that human development alone influences wildlife evolution, showcasing that cities are just one piece of the evolutionary puzzle. Urbanization indirectly impacts squirrel melanism through factors like local vegetation structure and winter microclimate.
Dinh expressed a newfound perspective on urban wildlife, emphasizing the coexistence of nature and city life. He recognized that despite human modifications, wildlife persists and adapts, underscoring the interconnectedness of urban environments and wildlife evolution.
