Do wild raccoons (Procyon lotor) use tools?

Abstract

Being able to make and use tools was once considered to be an evolutionary hallmark of our species, but has since been documented in other animals. However, for reasons that remain unclear, not all species naturally use tools. Racoons (Procyon lotor) are generalist carnivores that possess many of the physical, cognitive, and behavioural characteristics linked to tool use in other species (e.g. manual dexterity, tactile exploration, relatively large brains, extractive foraging, and sociality). Although raccoons have not been observed using tools outside of experimental captive conditions, wild data involving objective psychometric tests are needed. The current study administered a tool-related task to a wild population of raccoons from 20 locations within the Croatan National Forest, USA. The task required participants to use a stick to extract food from a pipe. To facilitate interpretations of their performances on the task, data were obtained on natural tool availability at the field site and participants’ mode of exploring the novel task. None of the participants solved the task despite natural sticks (suitable for solving the task) being widely available across testing locations. Participants were equally likely to smell versus handle novel sticks, which were provided at testing platforms. Limited tactile exploration, but not tool availability, could be at least one factor that reduces these raccoons’ opportunities to interact with and learn about novel tools like sticks.

Bold but not innovative in an urban exploiter, the red fox (Vulpes vulpes)

“…Age, sex, dominance, associative learning, and/or personality are also some of the many other factors that might influence foxes' decision-making (Fawcett et al, 2017;Griffin et al, 2013;Padovani et al, 2021;Soulsbury et al, 2011a). As previously discussed, foxes may simply prefer to exploit easy-access resources wherever possible, similar to what has been proposed for challenging tasks in some populations of wild raccoons (Procyon lotor) (Morton, 2021). Finally, as with some other species (e.g., corvids), foxes' responses to novel objects may be very nuanced and depend on the particular context, such as the type of novel object encountered.…”

“…A myriad of factors can underpin animals’ responses to novelty, which are not necessarily underpinned by any one variable (Lee & Moura, 2015; F. B. Morton et al, 2021; Reader & Laland, 2003).…”

“…Each object contained desirable food items (e.g., dried dog food and chicken) (Table S1). Some of the designs were based on studies in other species (Morton, 2021;Rossler et al, 2020;Thornton & Samson, 2012;Visalberghi & Limongelli, 1994). Objects varied in terms of design and materials to test whether the type of novel object impacted foxes' behavioural responses.…”

Cytoarchitectural characteristics associated with cognitive flexibility in raccoons

“…As evident in their proficiency in obtaining anthropogenic sources of food in urban habitats (Prange et al, 2004), raccoons are known to approach novel challenges in innovative ways (Daniels et al, 2019; Morton, 2020; Stanton et al, 2017). The reported problem‐solving flexibility in raccoons may be influenced by their primate‐like cortical neuronal density (Herculano‐Houzel et al, 2006; Jardim‐Messeder et al, 2017).…”

“…Cognitive flexibility of raccoons was recently assessed in a reversal‐learning task and the animals exhibited rapid associative learning by successfully completing reversals with observed trends in improvement over time (Stanton et al, 2020). Interestingly, in a task requiring the use of a stick to push desired food through a pipe, wild raccoons exhibited a dependence on olfaction and somatosensory exploration instead of manipulating the stick to obtain the food reward (Morton, 2020).…”