Francis Quang-Hai Dinh explored Montreal’s parks on his bike during his first summer at McGill University, studying over 800 grey and black squirrels in nearly 200 green spaces from Mirabel to Saint-Bruno. His casual task soon evolved into a passion project, delving into how the city’s layout and waterways influence evolution.
Dinh, now pursuing integrative biology at the University of Illinois Urbana-Champaign, discovered that black squirrels are more prevalent in northern areas due to cooler temperatures, which benefit their black coloration’s heat absorption. He found that approximately 12% of Montreal’s squirrels are black on average, with percentages increasing further north, such as up to 40% just north of Laval.
The study identified temperature and forest cover as key factors influencing squirrel coat colors. The denser tree canopy in northern areas provides a darker backdrop, aiding black squirrels’ camouflage. Allison Roth, the study’s senior author, emphasized that Montreal’s segmented layout, particularly by the St. Lawrence River and its tributaries, creates unique environmental variations that drive genetic adaptations in animal populations.
The research, titled “Fine-scale spatial variation in eastern grey squirrel melanism across a complex urban landscape,” breaks new ground by examining wildlife changes on a neighborhood level within cities. It highlights that while urbanization affects local temperature and tree cover, riverways act as natural barriers influencing wildlife evolution indirectly through environmental factors.
Dinh acknowledged his changed perspective on wildlife, emphasizing the coexistence of urban environments and nature. He noted that despite human modifications, wildlife continues to adapt and thrive. The study’s findings will contribute to a special feature by ecology journals focusing on collaborative approaches to address significant ecological questions.