Urban red foxes ‘becoming more similar to domesticated dogs’

Urban red foxes are becoming more similar to domesticated dogs due to how they have adapted to city environments, according to new analysis.

The study found urban foxes in the UK have a smaller brain size capacity than their rural counterparts with a different snout shape also helping forage for food in urban surroundings.

With most lockdown measures still in place, the study also suggested there have been more frequent animal sightings in the cities where red foxes have become well-established.

Dr Kevin Parsons – of the University of Glasgow’s Institute of Biodiversity, Animal Health and Comparative Medicine – led the study team.

He said: “We wondered whether this change in lifestyle was related to adaptive differences between urban and rural populations of red foxes.

“We assessed skulls from hundreds of foxes found within London and the surrounding countryside, and saw that urban foxes had a smaller brain size capacity but also a different snout shape that would help them forage within urban habitats.

“This could tell us whether the evolution of urban/rural differences was completely unique or something that has potentially happened previously.

“It turned out that the way urban and rural foxes differed matched up with a pattern of fox evolution that has occurred over millions of years between species.

“While the amount of change isn’t as big, this showed that this recent evolutionary change in foxes is dependent upon deep-seated tendencies for how foxes can change.

“In other words, these changes were not caused by random mutations having random effects the way many might think evolution occurs.”

Researchers from the universities of Bristol, Edinburgh and Massachusetts were also involved in the analysis which tested the differences of the various species of foxes.

Co-author Dr Andrew Kitchener, from National Museums Scotland, said the study’s findings can also explain how dogs evolved to become pets.

He said: “Human-animal interactions are continuous and some of the basic environmental aspects that may have occurred during the initial phases of domestication for our current pets, like dogs and cats, were probably similar to the conditions in which our urban foxes and other urban animals are living today.

“Adapting to life around humans actually primes some animals for domestication.”

The research paper, Skull morphology diverges between urban and rural populations of red foxes mirroring patterns of domestication and macroevolution, is published in the Proceedings of the Royal Society Series B.