The Effect of Human Presence and Activity Type on Innovative Problem-Solving of Urban Eurasian Red Squirrels.

O_LIHumans impact wildlife positively and negatively, and increasing evidence shows that humans potentially play a major role in shaping cognition in wild animals. Recent evidence suggests, in particular, that the ability to innovate (an important cognitive ability for urban wildlife) can be affected by humans. However, the specific anthropogenic factors associated with shaping animal cognitive performance remain unclear. C_LIO_LIHere, across 15 urban areas in Oulu, Finland, we recorded 64 wild Eurasian red squirrels interactions with a novel puzzle box (innovative problem-solving) to obtain a highly preferred food, hazelnuts. C_LIO_LIWe then examined how different levels of human presence nearby, types of activity (walking, dog walking, cycling, and playground activities), and distance to the nearest footpaths influenced squirrels innovative problem-solving ability - measured as solving success at the population level and solving latency at the individual level. C_LIO_LIAt the population level, higher mean human presence nearby significantly decreased the proportion of squirrels that successfully solved the novel food-extraction problem ("innovators"), and greater human presence nearby decreased first-visit solving latency at individual level. Except for cycling, all types of human activities (walking, dog walking, and playground activity) significantly decreased first-visit success rate. Dog walking and playground activity had a greater negative impact on success rate at the population level than walking. Dog walking was the only outstanding factor affecting first-success latency. We also detected interaction effects between the types of human activities and nearest footpath on overall success rate of all innovators. C_LIO_LIThese results provide evidence for the negative effect of specific human-related factors on squirrels innovative problem-solving abilities. These factors may also exert selective pressure, potentially shaping the evolution of wildlife cognition. C_LI