Continental scale light-temperature extremes reveal key behavioural trade-offs

This is a Preprint and has not been peer reviewed. This is version 1 of this Preprint. You must log in to post a comment. There are no comments or no comments have been made public for this article. This is a Preprint and has not been peer reviewed. This is version 1 of this Preprint. Add a Comment You must log in to post a comment. Comments There are no comments or no comments have been made public for this article. Daily rhythms determine ecological interactions, but we rarely know how animals convert activity schedules into movement and space use across extreme light–temperature regimes. Using multi-annual GPS data from 76 Golden Eagles (Aquila chrysaetos) tracked across Scandinavia and Iberia (spanning 35° latitude), we quantified diel activity and displacement to test how photoperiod and temperature reshape time budgets and movement. Activity was strongly diurnal with a midday peak, but its relationship with daylight was non-linear and latitude-specific: Scandinavian eagles shifted south in winter and remained active near freezing, whereas Iberian eagles were nomadic and reduced activity during long, hot days. Displacement peaks diverged from activity peaks, showing interactive light–temperature effects, greater movements by immatures, reduced movements during breeding, and winter maxima despite limited daylight. This partial decoupling reveals latitude-dependent movement–activity trade-offs: temperature alters the match between available active time and conditions for efficient travel, reshaping displacement and space use. https://doi.org/10.32942/X2Q66G Life Sciences climate change, daylength, energy landscape, migration, plasticity, space use. Published: 2026-02-16 12:27 Last Updated: 2026-02-16 12:27 CC-BY Attribution-NonCommercial-ShareAlike 4.0 International Language: English