Behavioural responses are key mechanisms by which animals cope with environmental variability. In mountainous habitats, elevation gradients provide a natural framework to investigate such responses. In this study, boldness-related behaviours, such as mobility and escape tendency, were examined in four sympatric rodent species, namely, Apodemus flavicollis , A. sylvaticus , A. alpicola and Clethrionomys glareolus , across an elevational gradient in the Western Italian Alps. Using arena tests and Bayesian modelling, the effects of elevation, shrub diversity, sex and species identity on behavioural traits were assessed. Results revealed strong interspecific differences. C. glareolus exhibited lower mobility and a higher likelihood of not attempting escape, indicating a shy behavioural profile. By contrast, Apodemus species showed higher mobility and faster escape responses, indicating bolder behavioural strategies. Elevation and shrub diversity had weak or inconsistent effects on behaviour, and no clear sex-related differences were detected. Notably, C. glareolus displayed the highest among-individual variance in escape behaviour, particularly when accounting for individuals that did not jump during the test. This result indicates a broader behavioural spectrum and greater plasticity, which may be linked to its generalist ecology and ability to exploit diverse habitats. By contrast, Apodemus species exhibited more consistent behavioural profiles, likely reflecting their specialized habitat preferences and competitive dominance. These findings highlight the role of species identity in shaping behavioural traits, which can be interpreted in the context of differential habitat use and microhabitat segregation caused by interspecific competition. The differentiation of niches (spatial, trophic and temporal) between the taxa may have led to differences in behavioural traits, indicating that generalist species may be better equipped to cope with environmental heterogeneity. • Boldness-related behaviours were investigated in four Alpine rodents. • Species identity primarily drives behavioural variation. • Elevation and shrub diversity have weak or inconsistent effects on behaviour. • Clethrionomys glareolus ’s high variance in escape indicates behavioural plasticity. • Generalist species may be better equipped to cope with environmental heterogeneity.
Melcore et al. (Mon,) studied this question.