Breeding habitat suitability of the endemic Tristram’s Warbler Curruca deserticola in North Africa: a micro- and macro-scale approach

Abstract

Tristram’s Warbler Curruca deserticola, a North African endemic, remains poorly understood in terms of its ecological niche and habitat preferences. This study offers a comprehensive multi-scale habitat assessment combining macroecological species distribution modelling across Algeria and Tunisia with fine-scale microhabitat analysis at occupied sites using generalised linear models. The species’ distribution was concentrated in mountainous regions of northeastern Algeria and northwestern Tunisia, highlighting its reliance on structurally heterogeneous shrublands. Elevation emerged as the most influential factor, with optimal suitability at ∼1 250 m, while intermediate Enhanced Vegetation Index values (0.15–0.2) and moderate annual temperatures (12–14 °C) further defined suitable habitats. The integration of both spatial scales highlights the species’ strong association with structurally heterogeneous shrublands in moderately elevated, semi-arid zones. Microhabitat modelling highlighted preferences for abundant small trees, moderate shrub cover (2–4 m), and steeper slopes. These findings demonstrate the species’ vulnerability to habitat fragmentation and climate change, reinforcing the need for scale-integrated conservation strategies focused on structurally heterogeneous highland habitats.