Raccoons living in cities across the United States are showing physical changes that resemble early signs of domestication, according to a new study. Researchers found that urban raccoons have developed shorter snouts compared to their rural counterparts, a trait commonly seen in domesticated animals.
The study, led by Dr Raffaela Lesch of the University of Arkansas at Little Rock and published in Frontiers in Zoology, analysed nearly 20,000 photos of raccoons from the iNaturalist platform. The team observed a 3.56% reduction in snout length in raccoons living in densely populated urban areas.
Dr Lesch said that the ready availability of food scraps and the absence of large predators in cities create a niche that favours bolder yet non-aggressive individuals. This selection pressure for tameness, she explained, may trigger changes in neural crest cells, leading to physical traits such as shorter snouts.
The findings support the Neural Crest Domestication Syndrome hypothesis, which suggests that selection for tameness affects early embryonic development. Similar patterns have been observed in red foxes in London, which also have shorter, wider muzzles than rural foxes.
Stanley D Gehrt, a professor of wildlife ecology at Ohio State University, described the study as “very interesting” and noted that it aligns with other research on how animals adapt to urban environments.
