Coast to Coast : Annual Cycle Movements, Habitat Use and Ranging Behaviour of GPS‐Tracked (…)

ABSTRACT

A comprehensive understanding of migratory landbirds' ecology requires detailed knowledge of the factors shaping their spatial and temporal distributions throughout the annual cycle. Tracking technologies provide crucial insights into individual decisions during migration, helping to clarify timing, routes, and convergence at ecological barriers. In this study, we investigate the migration ecology of six Eleonora's falcons (Falco eleonorae) breeding in the Galite Archipelago (Tunisia), tracked by high-resolution GPS-GSM devices across their full annual cycle in Africa. We modelled the variation in migratory behaviour—movement probability, instantaneous flight speed and altitude—as a function of season, overflown habitat, time of day and age class. Movement probability was significantly higher during daylight, in autumn, and when crossing ecological barriers such as seas and deserts. Migration speed differed by age (> adults), season (> spring) and habitat type, with the highest values recorded over deserts, followed by montane grasslands, seas, rainforests, savannahs, Mediterranean woodlands and tropical broadleaf forests. We found considerable individual variability in migratory routes and timing between adults and juveniles. In addition, we report a new migratory route across the Arabian peninsula as well as extensive post-migratory ranging movements across the Mediterranean region which are highly relevant for assessing potential connectivity with other Mediterranean breeding colonies. These findings provide the first complete tracking data for Falco eleonorae from North Africa, and align with results from other Mediterranean breeding populations. Such findings could serve to strengthen ongoing international initiatives that integrate ecological research on migratory strategies, thereby enhancing coordinated efforts for Afro-Palearctic migratory landbirds at the flyway scale.