Behavioural tactics across thermal gradients align with partial morphological divergence in brook charr.

ABSTRACT: Understanding how animals balance environmental constraints is essential for predicting species persistence under climate change. In thermally stratified lakes, cold water fishes such as brook charr (Salvelinus fontinalis) must navigate vertical gradients in temperature and oxygen to optimize foraging while avoiding physiological stress. We hypothesized that individuals would exhibit behavioural tactics that reflect a trade-off between accessing warm surface waters to exploit profitable prey and avoiding thermal stress, with greater constraints expected on epilimnetic use as surface temperatures rise. Using high-resolution acoustic telemetry, we quantified fine-scale patterns of thermal habitat use, vertical foray behaviour and diel timing in a wild brook charr population across the summer

SUBMITTER: Stahl A 

PROVIDER: S-EPMC12868396 | biostudies-literature | 2026 Feb

REPOSITORIES: biostudies-literature