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Urbanization is the fastest form of landscape transformation on the planet, but researchers' understanding of the relationships between urbanization and animal behaviour is still in its infancy. In terms of foraging, bold and innovative behaviours are proposed to help urban animals access, utilize and exploit novel anthropogenic food sources. Red foxes, Vulpes vulpes , are one of the most widespread carnivores on the planet. However, despite frequent stories, images and videos portraying them as 'pests' in urban areas due to their exploitation of food-related objects (e.g. raiding the contents of outdoor bins), it is unknown whether they are bolder and more innovative in terms of their likelihood of exploiting these resources compared to rural populations. In the current study, we gave novel food-related objects to foxes from 104 locations (one object per location) across a large urban–rural gradient. To access the food, foxes had to use behaviours necessary for exploiting many food-related objects in the real world (e.g. biting, pushing, pulling or lifting human-made materials). Despite foxes from 96 locations acknowledging the objects, foxes from 31 locations touched them, while foxes from 12 locations gained access to the food inside. A principal component analysis of urban and other landscape variables (e.g. road, greenspace and human population density) revealed that urbanization was significantly and positively related to the likelihood of foxes touching, but not exploiting, the objects. Thus, while urban foxes may be bolder than rural populations in terms of their willingness to physically touch novel food-related objects, our findings are inconsistent with the notion that they are more innovative and pose a general nuisance to people by regularly exploiting these anthropogenic resources on a large geographical scale. • The impact of urbanization on animal behaviour remains unclear. • Bold and innovative behaviour may help some urban species thrive. • We studied wild red foxes' responses to novel food-related objects. • Urban foxes were bolder, but not more innovative, than rural foxes. • Urbanization may favour bolder, not more innovative, fox behaviour. [ABSTRACT FROM AUTHOR]

Studies on wild animal psychology are growing in popularity due to the important role they play in understanding how wildlife is responding to human-driven environmental changes. However, communicating psychological information to the general public could undermine specific conservation objectives by encouraging greater persecution of a species (e.g., "bold" predators). Through a national-level survey (n = 1364 participants), we tested whether communicating information about the boldness and problem-solving abilities of a wild carnivore, the red fox (Vulpes vulpes), influences people's tolerance of them. Half of the participants were given information on fox psychology (either a video or a press release about fox boldness and problem-solving), the other half were given content related to basic fox ecology (either a video or a press release about fox habitat use). Afterwards, all participants completed the same 24-item questionnaire evaluating their tolerance of foxes. Although the participants given information about fox psychology were more likely to report a perceived attitude change due to the content they were given, this effect was relatively small and did not impact people's tolerance of foxes more than ecological information. We encourage further research to understand how communicating different types of information might influence, either positively or negatively, people's tolerance of a species as more studies on wild animal psychology are published, and the public's awareness of how animal psychology relates to human-wildlife interactions becomes more widespread. • Studies on wild animal psychology are growing in popularity. • The impact of animal psychology research on public attitudes is unclear. • We tested if fox psychology research influences public tolerance. • People given fox psychology information reported greater attitude change. • This effect did not impact tolerance of foxes more than ecological information. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Data reduction analyses such as principal components and exploratory factor analyses identify relationships within a set of potentially correlated variables, and cluster correlated variables into a smaller overall quantity of groupings. Because of their relative objectivity, these analyses are popular throughout the animal literature to study a wide variety of topics. Numerous authors have highlighted 'best practice' guidelines for component/factor 'extraction', i.e. determining how many components/factors to extract from a data reduction analysis, because this can greatly impact the interpretation, comparability and replicability of one's results. Statisticians agree that Kaiser's criterion, i.e. extracting components/factors with eigenvectors >1.0, should never be used, yet, within the animal literature, a considerable number of authors still use it, even as recently as 2018 and across a wide range of taxa (e.g. insects, birds, fish, mammals) and topics (e.g. personality, cognition, health, morphology, reproduction). It is therefore clear that further awareness is needed to target the animal sciences to ensure that results optimize structural stability and, thus, comparability and reproducibility. In this commentary, we first clarify the distinction between principal components and exploratory factor analyses in terms of analysing simple versus complex structures, and how this relates to component/factor extraction. Second, we highlight empirical evidence from simulation studies to explain why certain extraction methods are more reliable than others, including why automated methods are better, and why Kaiser's criterion is inappropriate and should therefore never be used. Third, we provide recommendations on what to do if multiple automated extraction methods 'disagree' which can arise when dealing with complex structures. Finally, we explain how to perform and interpret more robust and automated extraction tests using R. Highlights • Data reduction analyses are used to interpret animal behaviour data. • Extraction methods determine how many components/factors to extract. • Kaiser's criterion remains a popular, but unreliable, extraction method. • We urge more systematic use of robust, automated extraction methods. • We provide instructions for conducting robust, automated tests in R. [ABSTRACT FROM AUTHOR]

One way to gain insights into personality evolution is by comparing the personality structures of related species. We compared the personality structure of 240 wild white-faced capuchin monkeys to the personality structure of 100 captive brown capuchin monkeys. An ancillary goal was to test the degree to which different personality questionnaires yielded similar personality dimensions. Both species were rated on a common set of 26 antonym pairs. The brown capuchin monkeys were also rated on the 54-item Hominoid Personality Questionnaire. Our cross-species comparisons revealed 3 personality dimensions--Assertiveness, Openness, and Neuroticism--shared by brown and white-faced capuchins, suggesting that these dimensions were present in the common ancestor of these species. Our comparison of the dimensions derived from the antonym pairs and the Hominoid Personality Questionnaire revealed that three common dimensions were identified by both questionnaires. In addition, the dimension Attentiveness was only identified using the Hominoid Personality Questionnaire. These results indicate that major features of capuchin personality are conserved and that the structure of some traits, such as those related to focus, persistence, and attention, diverged. Further work is needed to identify the evolutionary bases that led to the conservation of some dimensions but not others. [ABSTRACT FROM AUTHOR]

Behavioural responses to photos are often used to infer what animals understand about their social environment, but are rarely validated against the same stimuli in real life. If subjects’ responses to photos do not reflect responses to the same live stimuli, it is difficult to conclude what happens in reality based on photo responses alone. We compared capuchins’ responses to photos versus live stimuli in an identical scenario within research cubicles. Subjects had the opportunity to approach food placed in front of an alpha group member and, in a separate condition, photos depicting the same individual. Subjects’ latencies to approach food when placed in front of the real alpha negatively correlated with time subjects spent in close proximity to the alpha in their main enclosure. We therefore predicted subjects’ latencies to approach food in the presence of photos would positively correlate with their latencies to approach food in the presence of the real alpha inside the cubicles, but negatively correlate with time they spent in proximity to the alpha in their enclosure. Neither prediction was supported. While not necessarily surprising, we explain why these results should be an important reminder that care is needed when interpreting results from photo studies. [ABSTRACT FROM AUTHOR]

Social relationships vary in content, quality and patterning. Most researchers focus on whether and how nondispositional factors, including age, sex, kinship and rank, predict variance in the content, quality and patterning of relationships. However, within a species, these factors do not always predict partner choice. We examined whether similarity in any of five personality traits, Assertiveness, Openness, Neuroticism, Sociability and Attentiveness, independently contributed to variation in the affiliative and agonistic relationships of pairs of brown capuchin monkeys, Sapajus sp. Capuchins that were more similar in Neuroticism had higher affiliative relationship scores, while capuchins that were more similar in Sociability shared overall higher-quality relationships (i.e. the difference between the dyad's affiliative and agonistic scores). These effects were independent of age, sex, kinship and rank, suggesting that certain aspects of the psychology of these animals may contribute uniquely to the quality of their social relationships. [ABSTRACT FROM AUTHOR]

Species comparisons of personality structure (i.e., how many personality dimensions and the character-istics of those dimensions) can facilitate questions about the adaptive function of personality in nonhuman primates. Here we investigate personality structure in the brown capuchin monkey (Sapajus apella), a New World primate species, and compare this structure to those of chimpanzees (Pan troglodytes), orangutans (Pongo spp.), and rhesus macaques (Macaca mulatto). Brown capuchins evolved behavioral and cognitive traits that are qualitatively similar to those of great apes, and individual differences in behavior and cognition often reflect differences in personality. Thus, we hypothesized that brown capuchin personality structure would overlap more with great apes than with rhesus macaques. We obtained personality ratings from seven sites, including 127 brown capuchin monkeys. Principal-components analysis identified five personality dimensions (Assertiveness, Openness, Neuroticism, Sociability, and Attentiveness), which were reliable across raters and, in a subset of subjects, significantly correlated with relevant behaviors up to a year later. Comparisons between species revealed that brown capuchins and great apes overlapped in personality structure, particularly chimpanzees in the case of Neuroticism. However, in some respects (i.e., capuchin Sociability and Openness) the similarities between capuchins and great apes were not significantly greater than those between capuchins and rhesus macaques. We discuss the relevance of our results to brown capuchin behavior and the evolution of personality structure in primates. [ABSTRACT FROM AUTHOR]

Social dominance hierarchies play a pivotal role in shaping the behaviour of many species, and sex differences within these hierarchies often exist. To date, however, few physical markers of dominance have been identified. Such markers would be valuable in terms of understanding the etiology of dominant behaviour and changes in social hierarchies over time. Animals may also use such traits to evaluate the potential dominance of others relative to themselves (i.e. a physical “cue”). Facial width-to-height ratio (fWHR), for example, has been suggested as a cue to dominance in humans, with links to both dominant behaviour and the perception of dominance in other individuals. Whether this association is present in non-human animals is currently not known. Therefore, here we examine within-species links between fWHR and dominant behaviour in 64 brown capuchin monkeys (Sapajus spp.) aged between 2 and 40 years. fWHR was positively associated with alpha status and with a dimensional rating of assertive personality in both males and females. Moreover, fWHR showed significant sexual dimorphism in adults but not juveniles, suggesting a developmental change may occur during puberty. In a sub-sample, sex differences were mediated by weight, suggesting fWHR dimorphism does not exceed what would be expected by differences in body weight. This is the first report of an association between face shape and behaviour in a non-human species. Results are discussed in terms of the role that face-behaviour associations might play within capuchin societies, and the possible selective forces that might have led to the evolution of fWHR-dominance associations in humans. [ABSTRACT FROM AUTHOR]

Questionnaires that allow people who are familiar with individual animals to rate the welfare of these animals are an underutilised tool. We designed a 12-item welfare questionnaire and tested its reliability and associations with subjective well-being (SWB), locomotor stereotypy, and personality traits. The welfare questionnaire included questions relating to physical health, stress and coping, satisfaction with social relationships, psychological stimulation, and the display of positive and negative welfare indicators. We collected ratings of 66 brown capuchins ( Sapajus apella ) living in three facilities. Each capuchin was rated on the welfare questionnaire by an average of 2.8 raters. The interrater reliability of the welfare questionnaire items ranged from ICC(3, k ) 0.51 to 0.86. A principal components analysis indicated that the 12 welfare items loaded onto one component. We repeated this process with the welfare and four items used to measure subjective well-being and found all the items were defined by a single component (welfareSWB). We then conducted three sets of analyses, one predicting the welfare component, one predicting the SWB component, and predicting the welfareSWB component. The independent variables were frequency of locomotor stereotypy, personality, age, and sex; facility was included as a random effect. In models including stereotypy, age, and sex we found frequency of stereotypy to be significantly associated with all three predicted components (ps < 0.01). After controlling for stereotypy ( b = −0.25, p = 0.17), age ( b = −0.54, p = 0.01), and sex ( b = −0.32, p = 0.07), the personality traits of Sociability ( b = 1.02, p < 0.001), Assertiveness, ( b = 0.63, p < 0.001), and Attentiveness ( b = 0.54, p = 0.01) were associated with higher scores on the joint welfareSWB component; Neuroticism was negatively associated with welfare SWB ( b = −0.60, p = 0.01). Our results suggest that welfare questionnaires is a useful, reliable, and valid tool for primate welfare assessment. [ABSTRACT FROM AUTHOR]