Western Bonelli's Warbler vs Yellow-browed Warbler

In short

Western Bonelli's Warbler and Yellow-browed Warbler are both small Phylloscopus warblers, but they can be distinguished by the Western Bonelli's Warbler's plainer face and lack of wingbars, compared to the Yellow-browed Warbler's bold supercilium and wingbars. Vocalizations also differ, with Western Bonelli's Warbler having a descending trill, while the Yellow-browed Warbler's call is more high-pitched and repetitive.

Identification tips

1. Look for the bold supercilium and wingbars on the Yellow-browed Warbler. 2. Note the plain face and lack of wingbars on the Western Bonelli's Warbler. 3. Listen for the descending trill of the Western Bonelli's Warbler versus the high-pitched calls of the Yellow-browed Warbler. 4. Consider habitat and behavior, as Western Bonelli's Warbler prefers the canopy, while Yellow-browed Warbler may be lower in the foliage.

Size

Western Bonelli's Warbler is slightly larger at about 11.5 cm compared to the Yellow-browed Warbler's 10 cm.

Plumage

Western Bonelli's Warbler has a plain face with a pale cream supercilium and lacks wingbars, while the Yellow-browed Warbler features a bold white supercilium and two distinct white wingbars. The Western Bonelli's Warbler has a bright greenish-yellow rump, whereas the Yellow-browed Warbler has olive-green upperparts with a slightly paler rump.

Behaviour

Both species forage actively in trees, but the Western Bonelli's Warbler may be seen more often in the canopy, while the Yellow-browed Warbler can be found lower in the foliage.

Habitat

Both species are found in woodland habitats, but the Western Bonelli's Warbler is more associated with Mediterranean woodlands, while the Yellow-browed Warbler is often found in a wider range of forested areas during migration.

Voice

Western Bonelli's Warbler has a distinctive descending trill, while the Yellow-browed Warbler's call is a high-pitched, repetitive 'tsee-wee' or 'tsee-tsee'.