Three-banded Warbler Basileuterus trifasciatus Scientific name definitions

The Three-banded Warbler is confined to the Tumbesian center of endemism in southwest Ecuador and northwest Peru, although it has sometimes been considered to be conspecific with the much more geographically widespread Golden-crowned Warbler (Basileuterus culcivorus). The underparts are largely yellow and the upperparts olive-green, whilst the head is mainly gray, with black lateral coronal stripes, and a paler supercilium. Three-banded Warbler is practically confined to well-forested areas, although it will tolerate well-developed second growth, and it occurs locally to 3000 m.

12·5 cm; 8·5–11 g. Nominate race  has pale grey central crownstripe  (may have faint yellowish wash in worn plumage) bordered laterally with black, broad greyish-white supercilium and lores, narrow black eyestripe; ear-coverts mid-grey with narrow blackish rear edge; nape and upper mantle  mid-grey, becoming olive-grey on rest of upperparts and distinctly olive on rump and tail; throat white grading into yellow lower breast, all smudged grey, remainder of underparts pale yellow ; iris dark; bill blackish-horn, paler horn lower mandible; legs dusky pinkish. Sexes similar. Juvenile undescribed. Race nitidior  is similar to nominate, but upperparts more olive, less grey, and central crownstripe has stronger yellow wash, especially in fresh plumage.

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Editor's Note: Additional distribution information for this taxon can be found in the 'Subspecies' article above. In the future we will develop a range-wide distribution article.

Probably feeds mainly, if not entirely, on invertebrates. At one nest, various arthropods recorded as sole food source. Forages mainly by gleaning at low to middle levels, mainly in understorey. Individuals, pairs or family groups sometimes join mixed-species foraging flocks.

Song  a warbling and pulsating trill, rising slightly in pitch; usual call  a sharp "tsit", repeated regularly.