Castellano Bueno, J. | bioRxiv Science

bioRxiv2026

Addressing the Elephant in the Room: A Quantitative Approach to Understanding 'Wild'

The concept of "wild" is poorly defined when applied to non-human animals, despite its central role in conservation, wildlife management and environmental policy. Despite numerous attempts to define "wildness", the distinction between "wild" and "non-wild" remains inconsistently applied. A shared, empirically grounded understanding of wildness would strengthen communication, support policy and legislation, and clarify human attitudes towards wildlife and nature. We assessed whether a shared understanding of wildness exists within the research community. A total of 358 professionals from different fields completed an online survey comprising 44 wildness-related statements along established measures of attitude and acceptability toward wildlife (AATW) and nature-relatedness (NRS). . Exploratory Factor Analysis revealed six components (19 statements): Human-mediated animal availability, Urbanisation, Independence from humans, Human-wildlife perceived conflict, Individual history of wildness, and Feralisation. These factors explained 43.91% of the variance. Mediation analysis showed that urbanisation and human-wildlife perceived conflict shape nature-relatedness by influencing attitudes and acceptability towards wildlife. Respondents demographic and professional backgrounds influenced their conceptualisation of wildness. While there is a shared latent structure of wildness across fields, it is multidimensional. This has implications for developing working definitions applicable to research, policy and practice.

scientific communication and education↗

bioRxiv2025

Effect of fluid control on the affective state of laboratory macaques

Fluid control protocols are widely used in neuroscience to motivate laboratory macaques to engage with behavioural tasks. Despite strong evidence that the physiology of the animals is not compromised by such protocols, fluid control remains controversial due to its potential impact on the psychological well-being of the animals. To address this concern, we investigated the effect of fluid control on the affective state of 23 socially-housed adult macaques (10 females) engaged in neuroscience experiments. The protocol involved up to five consecutive days of fluid control per week, followed by a minimum of two days with unrestricted fluid access. The affective state of the animals was primarily assessed by quantifying the frequency of pharmacologically-validated behavioural indicators of high-arousal negative affect (self-scratching, body shaking, self-grooming). The analysis was subsequently extended to validated behavioural indicators of low-arousal negative affect (Inactive not alert) and other behaviours suspected of indicate high-arousal negative affect but lacking proper validation (pacing, yawning). In total, 700 hours of video footage spanning up to seven years of intermittent fluid control per animal were analysed. Despite this extensive dataset, the study found no significant impact of fluid control on average, or any evidence of habituation or sensitization over the years on any of the affective state indicators. Additional results indicate that these null results are not due to a lack of sensitivity, supporting the view that fluid control, as implemented in this study, does not have an adverse impact on the psychological well-being of laboratory macaques. We argue that macaque welfare will be best served by focusing future refinement on other procedures.

animal behavior and cognition↗