Wikipedia
The icterine warbler (Hippolais icterina) is an Old World warbler in the tree warbler genus Hippolais. It breeds in mainland Europe except the southwest, where it is replaced by its western counterpart, melodious warbler. It is migratory, wintering in sub- Saharan Africa. The genus name Hippolais is from Ancient Greek hupolais, as misspelt by Linnaeus. It referred to a small bird mentioned by Aristotle and others and may be onomatopoeic or derived from hupo,"under", and laas, "stone". The specific icterina is Greek for "jaundice-yellow". 'Icterus'' was an old word for jaundice, and also referred to a yellowish-green bird, perhaps the golden oriole, the sight of which was believed to cure the disease. '
This small passerine bird is a species found in open deciduous woodland with bushes and also parks and gardens, often near water. Four to six eggs are laid in a nest in a tree or a bush.
This is a medium-sized warbler, 12–13.5 cm in length, similar to melodious warbler. The adult has a plain greenish-brown back with a paler wing panel, and yellowish underparts. The bill is slightly orange, strong and pointed, and the legs blue-grey. The sexes are identical, as with most warblers, but young birds are paler on the belly.
Like most warblers, the icterine warbler is insectivorous, but will take other small food items, including berries.
The song is a fast nasal babbling incorporating mimicry of other species. The call is described as teck or tec, tec, tec.
It is colloquially referred to by birders as icky.