Garden warbler

The garden warbler is a common and widespread small bird that breeds in most of Europe and in the Palearctic to western Siberia. It is a plain, long-winged and long-tailed typical warbler with brown upperparts and dull white underparts. Despite a small population decline in much of its European range, the bird’s breeding distribution is expanding northwards in Scandinavia.

About Garden warbler in brief

Summary Garden warblerThe garden warbler is a common and widespread small bird that breeds in most of Europe and in the Palearctic to western Siberia. It is a plain, long-winged and long-tailed typical warbler with brown upperparts and dull white underparts; the sexes are similar and juveniles resemble the adults. The preferred breeding habitat in Eurasia is open woodland with dense low cover for nesting; despite its name, gardens are rarely occupied by this small passerine bird. The clutch of four or five blotched cream or white eggs is laid in a robust cup-shaped nest built near the ground and concealed by dense vegetation. The birds are strongly migratory, wintering in sub-Saharan Africa. Despite a small population decline in much of its European range, the bird’s breeding distribution is expanding northwards in Scandinavia. The large and fairly stable numbers and huge range of the garden Warbler mean that it is classed as least concern by the International Union for Conservation of Nature. The genus Sylvia, the typical warblers, forms part of a large family of Old World warbler, the Sylviidae. Fossils from France show that the genus dates back at least 20 million years. The garden warblers are an ancient species pair which diverged very early from the rest of the genus, between 12 and 16 million years ago. The nearest relatives of the Garden Warbler outside the sister group are believed to be the African hill babbler and Dohrn’s thrush-babbler, both of which should probably be placed in Sylvia rather than their current genera, Pseudoalcippe and Horizorhinus respectively.

There are two recognised subspecies. Intermediate birds occur where the recognised forms meet and interbreed, and have sometimes been given subspecies status, including S. b. kreczi in Poland and S. b. pateffi in Bulgaria, but these are generally not accepted as valid taxa. The bird has a whitish eyering and a faint supercilium, there is a buff wash to the throat and the eye is black. The eye is typically 16–22cm with a 7.8cm wing length, but can be up to 35 g. It has a strong grey upper bill, a paler lower mandible and a pale blue-grey upperparts. It can be confused with a number of other unstreaked warblers. It may be host to various fleas, mites and internal parasites, and it is a host of the common cuckoo, a brood parasite. The chicks are altricial, hatching naked and with closed eyes, and are fed by both parents. They fledge about 10 days after hatching. Only about a quarter of young birds survive their first year. A wide range of habitats are used in Africa, but closed forest and treeless Sahel are both shunned. Insects are the main food in the breeding season, although fruit predominates.