The icterine warbler (Hippolais icterina) is among the most talented songbirds found in Finland. Its high-pitched, powerful song consist of an extremely varied warble with a passionately tense tempo. The singer can be identified by themes reminiscent of a rubber duck being squeezed as well as mimicry: the rattling of the fieldfare, the chirping of the swallow and the nagging of the wryneck. Their singing is so passionate that it seems to consist of several, simultaneous voices. The icterine warbler’s song is similar to those of the Blyth’s reed warbler and the marsh warbler, but the icterine warbler always perches atop a broadleaved tree while singing, and only sings during the day.
The icterine warble makes its nest high up in the dense foliage of a broadleaved tree. Spotting one requires peering at the treetops. The icterine warbler looks like a large, brightly-coloured willow warbler with a long beak. While singing, the icterine warbler reveals that it has an orange gullet.