Francis Quang-Hai Dinh spent his first summer at McGill University exploring Montreal’s parks on his bicycle, searching for squirrels. He visited nearly 200 green spaces, documenting over 800 grey and black squirrels. What began as a university task evolved into a personal project to understand how the city’s layout and waterways impact evolution.

Dinh, who now studies integrative biology at the University of Illinois Urbana-Champaign, discovered that the percentage of black squirrels in Montreal varies by location. The further north he ventured, the higher the prevalence of black squirrels. In regions just north of Laval, he found up to 40% of squirrels were black, while on the island of Montreal, the percentage was around 15%. The study attributes this trend to temperature differences, with black squirrels being more common in cooler climates due to their ability to absorb heat efficiently.

Additionally, forest cover plays a role in squirrel coloration, as denser tree canopies provide a darker background where black squirrels blend better. The study’s senior author, Allison Roth, an assistant professor at the University of Missouri, emphasized that urban environments like Montreal offer unique conditions for studying evolutionary changes in wildlife.

Unlike previous studies comparing urban and rural areas broadly, this research delves into neighborhood-specific wildlife adaptations. It challenges the notion that human development alone drives these changes, highlighting the complex interplay of factors such as local temperature, vegetation structure, and natural barriers like rivers.

The study, titled “Fine-scale spatial variation in eastern grey squirrel melanism across a complex urban landscape,” examines how urbanization indirectly influences animal coloration through environmental factors. It is part of a special feature by five ecology journals focusing on collaborative research to address significant ecological questions.

For Dinh, this project has transformed his perspective on wildlife and urban spaces. He reflects on the coexistence of wildlife in urban settings, emphasizing that nature perseveres despite human modifications.