Proximity to humans is leading raccoons to adapt and self-domesticate, with less aggression and shorter snouts.
Raccoons living in American cities appear to be evolving in unexpected ways, including developing shorter snouts. A new publication in Frontiers in Zoology analyzed more than two decades of raccoon images to compare the city-dwelling animals with their rural counterparts and discovered what appear to be the first phases of self-domestication driven by urban life.
The team analyzed thousands of photographs of raccoons Americans taken between 2000 and 2024 across the United States. Using specialized analytical software, they measured skull and snout characteristics, finding that raccoons living in urban environments had snouts that were, on average, 3.56% shorter. According to lead author Raffaela Lesch, this anatomical change is in line with a well-known phenomenon called domestication syndrome.
Domestication syndrome refers to a set of physical and behavioral characteristics observed in animals that are have adapted to living in close proximity to humans. These characteristics may include reduced aggression, shorter snouts, smaller teeth and brains, and changes in coat patterns or ear shape. Although often associated with intentionally domesticated species, such as dogs or cats, the process can also occur without direct human intervention, says .
“I wanted to know if living in an urban environment would boost domestication processes in animals that are not currently domesticated,” Lesch said. “Do the raccoons would be on the path to domestication just because they live close to humans?”
The study suggests the answer may be yes. In urban areas, raccoons find fewer predators and have easier access to food, mostly rubbish. Adaptations that favor tolerance to humans and the reduction of aggressiveness become advantageous, encouraging characteristics that mirror early domestication. “Trash is really the kicker“, Lesch explained. “Everywhere humans go, there is trash. Animals love our trash.”
If the trend continues, Lesch jokes that the future could hold a new domesticated animal: the so-called “trash panda“, or Procyon trashicus. While the idea is humorous, the findings highlight how quickly urbanization and proximity to humans can reshape wildlife.
