Cross-Context Responses to Novelty in Rural and Urban Small Mammals

Abstract

The Anthropocene is the era of urbanization. The accelerating expansion of cities occurs at the expense of natural reservoirs of biodiversity and presents animals with challenges for which their evolutionary past might not have prepared them. Cognitive and behavioral adjustments to novelty could promote animals’ persistence under these altered conditions. We investigated the structure of, and covariance between, different aspects of responses to novelty in rural and urban small mammals of two non-commensal rodent species. We ran replicated experiments testing responses to three novelty types (object, food, or space) of 47 individual common voles (Microtus arvalis) and 41 individual striped field mice (Apodemus agrarius). We found partial support for the hypothesis that responses to novelty are structured, clustering (i) speed of responses, (ii) intensity of responses, and (iii) responses to food into separate dimensions. Rural and urban small mammals did not differ in most responses to novelty, suggesting that urban habitats do not reduce neophobia in these species. Further studies investigating whether comparable response patters are found throughout different stages of colonization, and along synurbanization processes of different duration, will help illuminate the dynamics of animals’ cognitive adjustments to urban life.

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

“…As previously discussed, studies in other species show urban-dwelling animals are more likely than rural populations to physically touch and gain access to novel food-related opportunities (Dammhahn et al, 2020; Ducatez et al, 2017; Griffin et al, 2017; Mazza et al, 2021; Mazza & Guenther, 2021). However, our findings – along with others – illustrate that the relationship between bold and innovative behaviour, particularly with regards to urbanisation, is complex and difficult to generalise across all situations and species (Griffin et al, 2017; Vincze & Kovacs, 2022).…”

“…Many factors likely contribute to whether or how wildlife can adapt to such environments (e.g., dispersal, morphology, and dietary generalism) (Thompson et al, 2021). In terms of opportunistic behaviour, a growing number of studies show that particular behavioural characteristics (e.g., boldness, neophilia, exploration, persistence, and innovation) can increase urban animals’ willingness to spontaneously or quickly exploit novel resources when first discovered (Dammhahn et al, 2020; Ducatez et al, 2017; Griffin et al, 2017; Mazza et al, 2021; Mazza & Guenther, 2021). Such findings suggest that being able and willing to rapidly exploit novel ecological opportunities, rather than avoid or ignore them, may help at least some species thrive within urban settings.…”

“…In terms of foraging, species dwelling in urban areas are likely to encounter novel anthropogenic food sources (Murray et al, 2015; Murray et al, 2018) and behavioural traits, particularly boldness and innovation, are proposed to help urban animals access, utilise, and exploit these resources (Dammhahn et al, 2020; Ducatez et al, 2017; Griffin et al, 2017; Mazza et al, 2021; Mazza & Guenther, 2021). Having a greater tendency to innovate can provide urban wildlife with the behavioural flexibility needed to exploit a wide variety of resources (Reader & Laland, 2003).…”

“…Urban foxes often encounter food-related objects that are temporally, physically, and spatially “novel” to them, including 1) continuous changes to the combination of objects found on streets or in outdoor bins, 2) objects that look physically different to what animals are accustomed to seeing (e.g., new or modified containers), and 3) new or familiar objects found in unexpected locations (e.g., randomly discarded trash). Such dynamic changes, combined with frequent encounters, may favour bolder and more innovative behaviour in foxes by enabling them to use new or modified behaviours (i.e., “innovations”) to exploit these resources, particularly shortly after discovering them (e.g., overnight) (Dammhahn et al, 2020; Ducatez et al, 2017; Griffin et al, 2017; Mazza et al, 2021; Mazza & Guenther, 2021). However, despite frequent stories, images, and videos within popular culture portraying urban foxes as “pests” due to their opportunistic foraging behaviour (Schell et al, 2021; Soulsbury & White, 2015), it is unclear whether or to what extent such attitudes are due, in part, to their exploitation of food-related objects, including discarded litter and items found in outdoor bins (Baker et al, 2020; Harris, 1981).…”

Does novelty influence foraging decision of a scavenger?

“…For instance, species that invade human-dominated environments are known to be neophilic (Sol, Lapiedra & González-Lagos, 2013). Several studies suggest that urban-living animals have reduced object-neophobia (Tryjanowski et al, 2016; Greggor et al, 2016; Jarjour et al, 2019; Biondi et al, 2020; Miller et al, 2022), but see (Mazza et al, 2021). Yet, plasticity in neophobia can be seen with higher human disturbance levels, and shifts in personality types are assumed in human-dominated environments, involving reductions in neophobia (Grunst et al, 2019).…”