Human activity is negatively impacting urban red squirrels, a study led by Chester researchers has found.

The newly-published research from the universities of Chester and Oulu explores how human presence affects urban red squirrels' problem-solving skills and potentially their chances of thriving.

Researchers looked at the ways different levels of human presence and types of human activity influence squirrels' innovative problem-solving ability.

This includes walking, dog walking, cycling and playground activities - in addition to how close humans are.

Problem-solving is regarded as an important part of how squirrels and other wildlife acquire, store and use information to react to the environment. 

Across 15 green spaces in urban areas of Oulu, Finland, the team from the University of Chester and the University of Oulu, monitored the effects of human intensity and activity on the proportion of Eurasian red squirrels.

The squirrels would solve a novel problem, extracting hazelnuts from a puzzle box by pushing and pulling levers. Solving the puzzle also required them to change from their typical foraging pattern in trees to the ground.

The team measured solving success at the site level, individual level, as well as how fast individuals were in releasing the hazelnuts. 

The findings, published in the Behavioral Ecology journal, revealed, overall, greater human presence significantly reduced the number of squirrels that solved the task.

Playground activity had the most negative effect overall, while walking significantly reduced the chances of an individual squirrel solving the puzzle.

The results highlight that human presence and activity are stressors for urban squirrels and that squirrels perceive humans as potential threats. 

The impact of playground activity could also be attributed to loud noises masking the ability to detect predators. 

However, for those few that were successful first time, dog walking led them to solve the task faster which may be an adaptive strategy to avoid predators.

Dr Pizza Ka Yee Chow, lead researcher, said: "Our field experiment demonstrates that human intensity and activities, most notably walking, dog walking and playground activity, significantly affect Eurasian red squirrels' performance in solving a novel food-extraction task.

"The research has identified specific features of human activity that likely exert pressure and shape urban wildlife cognition, which can help us understand the traits and mechanisms that enable urban wildlife to adapt to or thrive in urban environments."

Dr Olli Loukola, a collaborator at the University of Oulu, shared more on the findings: "Our motion-triggered cameras revealed that nearly two-thirds of dog walkers ignored the leash law in public parks in Oulu.

"While Finns are usually great at following rules, it seems many simply don't realise that letting dogs roam freely can stress out urban wildlife.

"This study helps raise awareness of how small everyday choices can affect animal behaviour."

To read the research paper, visit the Behavioral Ecology website.