The Western Subalpine Warbler breeds on the Iberian Peninsula and winters in the Sahel south of the Sahara. A 2023 study examined both sexes at a Moroccan oasis used by the Iberian population as a spring stopover.
Males have a gray head and upperparts, an orange throat and breast, and a white moustachial stripe. Females are browner above, paler below, and have a white eye-ring.
During spring migration at Yasmina Oasis in Morocco, males defended temporary home ranges and broadcast their positions with song. The study did not find repeated home ranges in females.
An extinction-risk assessment has not been added yet.