Secret Life of the City: How Nature Thrives in the Urban Wild

Biologist Bjørgaas debuts with an enchanting paean to the overlooked marvels of metropolitan wildlife. “Our idea of spectacular nature, untouched by human hands, has stood in the way” of appreciating urban ecosystems, Bjørgaas contends, surveying the plants and animals that thrive in the cities of her native Norway. Some urban animals, she writes, have developed adaptations that distinguish them from their rural counterparts: city squirrels depend on “visual signals, such as wagging their tails” to warn other squirrels of danger because their auditory communications are drowned out by noise pollution, and some birds sing at higher frequencies than their nonurban counterparts to better stand out against the din of urban life. Other organisms didn’t have to adapt because they were already well suited to city conditions, such as house sparrows, whose undiscerning eating habits enable them to thrive on human leftovers, and the “city rim lichen” that, owing to its origins in Iceland’s sulfur-rich geothermal hot springs, flourishes even in the sulfur vapor of smog. The stimulating research findings offer a nuanced understanding of urban flora and fauna and push back against common assumptions about where nature ends and the human world begins. City dwellers will see their environs in a new light. (Apr.)