Urban fox evolution 'suggests how dogs became domesticated'

Urban foxes have evolved to have smaller brain capacity and shorter and wider snouts compared with their rural counterparts, says a study.

The experts, who examined the skulls of more than 100 red foxes, said the different snout shape would help the urban foxes forage for food better.

The findings may also shed light on how dogs and cats evolved to become pets.

Co-author Dr Andrew Kitchener said: "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."

Domestication typically involves changes such as reduced brain size, smaller teeth, changes in the bones of the skull and face, and more docile behaviour.

Urban foxes also have a much smaller home range compared with rural foxes, the researchers noted: 0.4 square kilometres versus 30 square kilometres.

They said this suggests "barriers to gene flow could exist and provide an opportunity to adapt to local conditions".

Researchers say the way urban and rural foxes differ matches 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," said Dr Kevin Parsons, from the University of Glasgow, who led the study team.

The research is published in the Proceedings of the Royal Society Series.