Peregrine falcons perch atop towering skyscrapers. Coyotes were caught on camera playing in someone’s backyard. The pale green wings of a cabbage white butterfly perch on a flower. Urban areas are teeming with wildlife that face increasing pressure from climate change, according to a study published today in PLOS ONE. The study, which examined the effects of climate on animals ranging from mammals to insects in 60 of the most populous cities in the United States and Canada, found that global warming is pushing many animals out of their historical geographic ranges and into new ones. scope.

“Within a few years, the animals you feed at a bird feeder may look very different,” said Alessandro Filazzola, lead author of the study at the University of Toronto Mississauga. This research was completed while working as a postdoctoral fellow at the Canadian Center for the Urban Environment. .

Filazzola and his team used data from the Global Biodiversity Information Facility, which pulls data from community science applications like iNaturalist and eBird, to roughly estimate the number of species currently present in urban areas. They then paired this information with United Nations climate projections, known as Shared Socioeconomic Pathways (SSPs). The researchers looked at what wildlife would do under three different scenarios, ranging from a modest 1.4°C warming above pre-industrial levels by 2100 (in line with the Paris Climate Agreement), to a moderate 3.6°C warming, to the most extreme possible warming. As fossil fuels continue to grow, temperatures will rise to 4.4C. So far, Earth’s temperature has increased by 1.3 degrees Celsius above pre-industrial levels.

“We’re seeing huge changes happening in many cities,” Ferrazzola said. “A lot of species are moving in, a lot of species are moving out.”

The overall trend identified in the study is that most vertebrates, including loons, canids (including coyotes) and amphibians will become increasingly rare in the cities studied. The same goes for the seemingly ubiquitous earthworms, although only one species appears in the data. At the same time, the prevalence of sea turtles, scorpions, and rats (with the exception of declining vertebrate species) is expected to increase.

“Ecologists have become very clear that species ranges are changing with climate change, so this is happening in cities as well,” said Carly Ziter, an assistant professor of biology at Concordia University who was not involved. This is not surprising.” In the study. “But that’s not something that I’ve seen that’s gotten that much attention.”

The researchers found that even at the lowest temperatures, the cities studied were expected to see at least 50 new species move in and 40 new species move out, although the movement of species was not evenly distributed. For example, Toronto is projected to lose 40 to 195 of its 888 species but may gain 159 to 360 new species by 2100 (where higher rates of warming are associated with increased species losses and gains). Quebec City and Omaha, Neb., are also among the cities expected to see the largest increases in new species and the fewest losses. By contrast, places like Atlanta, San Antonio and Austin are expected to lose more species than they gain.

Research points out that it’s not just wildlife that’s at risk: Atlanta, for example, is expected to lose 13.5% of its tree species by the end of the century.

Cities with the lowest projected species turnover are in the arid Southwest, including Las Vegas and Mesa and Tucson, Arizona. While climate change may make these places drier, researchers suspect these ecosystems are already resilient to the increasingly severe changes.

Ferrazzola cautions that his study is a modeling study and therefore has limitations. While the researchers only included climate as one factor, the model did not capture other factors, such as species interactions, that could influence the results. But he hopes the findings will encourage other researchers to follow this line of research.

Ferrazzola points out that species replacement is not just an important indicator of climate impacts: When animals leave their ecological niches, they cause problems for humans. Southern Californians already have to contend with a growing mosquito problem as Aedes, a mosquito that loves to bite humans, has moved into the region over the past decade.

Cities are also sites of frequent interactions between humans and wildlife, including conflict and joy. “As cities change dramatically, many people will need to relearn how to interact with the wildlife around them,” Zitter said. “Specific species can also have huge cultural or relational value to humans. Even for city dwellers who may feel they are disconnected from nature, I think many people would feel disconnected from their own homes if familiar species disappeared from the landscape. Places are less connected.”

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