A Simple Method for Evaluating Small Mammals' Adaptive Capacity to Environmental Change Based on Behavioral Traits

ABSTRACT Ongoing climate change poses a major threat to biodiversity, with current extinction rates highlighting the urgent need to identify species that are most vulnerable. A central determinant of vulnerability is adaptive capacity, referring to the ability of species to cope with or adjust to environmental change, often through phenotypic plasticity. In this context, behavioral plasticity represents a key aspect, as diverse behavioral responses may allow animals to mitigate exposure and sensitivity to changing environmental conditions, thereby influencing short‐term vulnerability. Here, we present a trait‐based framework for assessing the adaptive capacity of small terrestrial mammals to environmental change based on three fundamental behavioral traits: diel activity pattern, habitat use, and diet. These traits are directly linked to how species interact with the environment to sustain energy balance under variable conditions. By combining simplicity with the use of basic biological information available across species, this framework provides an accessible tool for estimating adaptive capacity and developing comparative vulnerability rankings. As such, it is particularly useful for poorly known species for which more complex information is lacking, such as physiological or demographic data. Moreover, it may help identify species for which future research and conservation efforts should be prioritized, while enabling hypothesis‐driven analyses at both intra‐ and interspecific levels on the ecological and evolutionary determinants of adaptive capacity.