blackcap

The Eurasian blackcap (''Sylvia atricapilla''), usually known simply as the blackcap, is a common and widespread typical warbler. It has mainly olive-grey upperparts and pale grey underparts, and differences between the five subspecies are small. Both sexes have a neat coloured cap to the head, black in the male and reddish-brown in the female. The male's typical song is a rich musical warbling, often ending in a loud high-pitched crescendo, but a simpler song is given in some isolated areas, such as valleys in the Alps. The blackcap's closest relative is the garden warbler, which looks quite different but has a similar song.

The blackcap breeds in much of Europe, western Asia and northwestern Africa, and its preferred habitat is mature deciduous woodland. The male holds a territory when breeding, which is defended against garden warblers as well as other blackcaps. The nest is a neat cup, built low in brambles or scrub, and the clutch is typically 4–6 mainly buff eggs, which hatch in about 11 days. The chicks fledge in 11–12 days, but are cared for by both adults for some time after leaving the nest. The blackcap is a partial migrant; birds from the colder areas of its range winter in scrub or trees in northwestern Europe, around the Mediterranean and in tropical Africa. Some birds from Germany and western continental Europe have adapted to spending the winter in gardens in Great Britain and Ireland. Insects are the main food in the breeding season, but, for the rest of the year, blackcaps survive primarily on small fruit. Garden birds also eat bread, fat and peanuts in winter.

Despite extensive hunting in Mediterranean countries and the natural hazards of predation and disease, the blackcap has been extending its range for several decades, and is classified by the International Union for Conservation of Nature as least concern. Its rich and varied song has led to it being described as the "mock nightingale" and it has featured in literature, films and music. In Messiaen's opera ''Saint François d'Assise'', the saint is represented by themes based on the blackcap's song.

Taxonomy

The genus ''Sylvia'', the typical warblers, forms part of a large family of Old World warblers, the Sylviidae. The blackcap and its nearest relative, the garden warbler, are an ancient species pair which diverged very early from the rest of the genus at between 12 and 16 million years ago. In the course of time, these two species have become sufficiently distinctive that they have been placed in separate subgenera, with the blackcap in subgenus ''Sylvia'' and the garden warbler in ''Epilais''.Shirihai ''et al'' (2001) pp. 25–27. These sister species have a breeding range which extends farther northeast than all other ''Sylvia'' species except the lesser whitethroat and common whitethroat. 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.

The blackcap was one of the many bird species originally described by Carl Linnaeus in his landmark 1758 10th edition of '' Systema Naturae'', as ''Motacilla atricapilla''.Linnaeus (1758) p. 187. The current genus name is from Modern Latin ''silvia'', a woodland sprite, related to ''silva'', a wood.Jobling (2010) p. 376. The species name, like the English name, refers to the male's black cap. ''Atricapilla'' is from the Latin ''ater'', "black", and ''capillus'', "hair (of the head)".Jobling (2010) p. 59.

Fossils and subfossils of the blackcap have been found in a number of European countries; the oldest, dated to 1.2–1.0 million years ago, are from the Early Pleistocene of Bulgaria. Fossils from France show that the genus ''Sylvia'' dates back at least 20 million years.Mason (1995) p. 11.

Subspecies

The differences between subspecies are small, making subspecific boundaries hard to define, and the exact distribution of ''S. a. heineken'' is unclear, since birds from northwest Africa may be of this form.Mason (1995) pp. 15–18. About 2% of male blackcaps on Madeira and the Azores are melanistic, with black plumage on the whole head and upper breast. Melanistic females are rarer, and are characterised by grey-brown underparts. This dark morph has also been recorded from the Canary Islands, but not from Cape Verde. The melanistic birds were formerly sometimes considered to be a distinct subspecies, ''S. a. obscura''.Shirihai ''et al'' (2010) pp. 54–56.

Description

The blackcap is a mainly grey warbler with distinct male and female plumages. The nominate subspecies is about long with a wing length. The weight is typically , but can be up to for birds preparing to migrate. The adult male has olive-grey upperparts, other than a paler grey nape and a neat black cap on the head. The underparts are light grey, becoming silvery white on the chin, throat and upper breast. The tail is dark grey, with an olive tint to the outer edge of each feather. The bill and long legs are grey, and the iris is reddish brown. The female resembles the male, but has a reddish-brown cap and a slightly browner tone to the grey of the upperparts. Juveniles are similar to the female, but their upperparts have a slight rufous tinge, and the breast and flanks have a more olive tone; young males have a darker brown cap than their female counterparts. This species is unmistakable; other dark-headed ''Sylvia'' species, such Sardinian and Orphean warbler