The Garden Warbler (Sylvia borin) is arguably the most nondescript of Sweden's warblers, uniformly olive-grey-brown above and whitish-buff below, with no eyebrow stripe, wing bars or other patterning to speak of. A thin pale eye-ring surrounds a dark eye, the legs are grey and fairly sturdy, and the bill is short and stout on a compact, rounded body. The very absence of field marks is itself a clue — a plain, grey-brown warbler skulking in dense cover is often this species — and the surest way to confirm identification is by song.
The song is the bird's great asset: a rich, soft, evenly flowing warble that rambles on for twenty to thirty seconds without clear pauses or repeated phrases, often delivered in the evening. It resembles the Blackcap's song but is more continuous and subdued, lacking the Blackcap's clear, rising flourish at the end; the contact call is a hard, smacking "tjeck" or a growling "errr". The species breeds almost throughout Sweden and numbers over 1.1 million pairs (2018), making it one of the country's commonest warblers and a long-distance migrant that winters in tropical Africa south of the Sahara, arriving late, typically in May. It favours scrubby, herb-rich deciduous and mixed woodland with dense undergrowth, parks and overgrown gardens. Before the female arrives, the male builds several rough "cock nests"; one is chosen and the pair finishes it together low in a dense bush or tall herb layer. The female lays 4–5 eggs, both parents incubate for 12–14 days, and chicks fledge after 10–12 days. Diet shifts from insects, spiders and molluscs during the breeding season to berries and fruit in late summer, building fat reserves for the long flight south.
Read about this species in Swedish →