Montreal squirrels change their coat colour depending on the neighbourhood where they live, according to a study by McGill University. Researchers have discovered that the specific conditions in each part of the city influence the characteristics of the local wildlife. Despite their name, the eastern gray squirrels—for which the Quebec metropolis is famous—sometimes have black fur. The McGill team found that the coat colour of squirrels in the Montreal area is determined not only by urbanization but also by forest cover and the presence of the St. Lawrence River and its tributaries, which can limit movement and lead to the formation of distinct populations. The squirrels most frequently seen in Montreal have gray fur. However, the researchers found that, although gray fur predominated throughout the city, the proportion of melanistic squirrels—commonly known as black squirrels—was highest in areas where winter temperatures are lower and forest cover is denser. Their dark fur, which retains more heat, may give them a biological advantage in cold weather. Furthermore, unlike in other North American cities, black squirrels were generally less common in the most urbanized areas of Montreal. The study’s findings suggest that wildlife may respond to environmental conditions on a very local scale. According to the McGill researchers, cities are therefore not “uniform habitats,” but rather “complex landscapes.” Differences between neighbourhoods, as well as geographic features such as waterways, could influence how animals adapt and evolve over time. “Cities are often viewed as a homogeneous environment, but our results show that the conditions to which animals are exposed can vary considerably from one neighborhood to another. To understand adaptation in urban environments, we must therefore look beyond simple comparisons between urban and rural settings,” said one of the study’s authors, Allison Roth, a former McGill student who is now an assistant professor in the Department of Biology at the University of Missouri in the United States. To reach these conclusions, the project’s lead author, Francis Quang-Hai Dinh, closely examined more than 800 squirrels in some 200 parks in Montreal. The researchers also used data from surveys conducted in public spaces and observations by residents. This study is part of a special issue published by five ecology journals, which focuses on how researchers use large open-access datasets and collaborative approaches to address major ecological questions. This report by The Canadian Press was first published in French on Sept. 23, 2026.
