Time in the city: Exploration and problem-solving behaviours reveal long-term urban adaptation in wild red foxes (Vulpes vulpes)

Urbanisation is one of the most important forms of human-driven landscape change, creating novel situations in which some species thrive. Animals’ willingness to touch, explore, and solve novel challenges, such as exploiting unfamiliar resources, are thought to be key behavioural characteristics for urban adaptation. Little is known about the impact of spatiotemporal patterns of urbanisation, particularly historical patterns of change, on these behaviours. We tested this in the world’s most urbanised carnivore, the red fox, using novel tasks deployed across 284 sites in the United Kingdom. We compared tactile and problem-solving behaviours in rural populations, recently colonised urban populations, and long-established urban populations (>40 years). Similar to previous work, urban foxes were more likely to touch the tasks compared to rural populations; however, in our new extended dataset, we show for the first time that older urban populations – particularly from London – display greater exploratory diversity and higher problem-solving success, despite more recent urban populations being equally likely to touch them. Our findings suggest that certain population characteristics, such as the likelihood of touching/engaging with novelty, emerge early in urbanisation while other characteristics, such as exploratory diversity and behavioural innovation, may emerge after long-term urban exposure across many decades.