The Garden Warbler is a stocky bird with thick grey bill and grey legs. The plumage is plain looking and olive brown-grey in colour, paler underneath than above. There is just the faintest hint of a supercilium, but no eye stripe.
Juveniles are very similar to adults but sometimes more olive than grey.
This warbler skulks in shrubs and undergrowth and so you may not even be aware of its presence without hearing its song first.
The Garden Warbler can be confused with Common Whitethroats and Lesser Whitethroats, but both of these have white throats, and with the Blackcap, which has a black cap.
| Scientific Name | Sylvia borin |
| Length | 14 cm (4½") |
| Wing Span | 20-22 cm (8-9") |
| Weight | 16-23 g (½-¾ oz) |
| Breeding Pairs | 200000 |
| Present | Summer |
| Status | Green |
Their song is quite beautiful and is confusingly similar to the Blackcap, but is often longer (lasting anything up to 10 seconds or more), mellower, less varied and rather tiresome. They usually sing from a well concealed perch, which adds to the frustration of identifying the bird.
The alarm call is a repetitive "tacc tacc".
Like the Blackcap they have a diet of invertebrates, such as caterpillars, larvae, spiders, flies and worms. In the autumn, it feeds on berries and fruit.
They breed in woods and large gardens with tall trees and shrubby undergrowth or hedgerows. The nest is built by both birds and is usually low in a tree or bush. The cup-shaped nest is made from dry grasses and lined with finer grasses and hair.
The eggs are white or buff with purplish-brown or grey spots, smooth and glossy, and about 20 mm by 15 mm. Both birds share the duty of incubating the eggs and feeding the young.
| Breeding Starts | Clutches | Eggs | Incubation (days) | Fledge (days) |
|---|---|---|---|---|
| late May | 1-2 | 3-8 | 10-12 | 9-12 |
They are a summer visitor to Britain (April to September), and winter in in the scrubby savannah of Africa (south of the Sahara).
Garden Warbler numbers have fluctuated in the same way as other warblers, such as Whitethroat, whose migration takes them across the Sahara and is probably a result of changes in the weather in Africa.
