Widespread and common breeding visitors to the UK, sedge warblers arrive on marshlands and reedbeds in April, and spend up to 6 months on British soil (or wetlands, to be more accurate), raising their young, before preparing for lengthy migrations to wintering grounds in sub-Saharan Africa each autumn.
Sedge Warbler foraging for food
Close up of a Sedge Warbler
Sedge Warbler singing from a perch
17cm to 21cm
10g to 13g
Male and female sedge warblers are identical in appearance. Their backs and wings are streaked dark, and a dull light brown, and their rump is unstreaked and a richer brown.
Sedge warblers have a prominent white eyebrow stripe, and their crown is streaked with black. Beneath their rust-coloured flanks, their underparts are pale, and their legs are brownish-grey.
Juvenile sedge warblers have fairly similar markings to adults, but can be accurately distinguished from some distance due to their yellowish colouring, and the presence of a buff-coloured striped along the centre of their crown.
Close up of a perched Sedge Warbler
Male and female sedge warblers are identical in size as well as plumage. They are classed as a medium-sized warbler, and are larger than chiffchaffs and willow warblers, and the same size as reed warblers.
Sedge Warbler singing from a reed
It is claimed that a male sedge warbler never sings the same song twice, relying on a varied and original repertoire of songs to attract a female. Songs are a random series of chattering notes and phrases, and some mimicry of other species may be incorporated.
Sedge warblers are omnivorous, with insects and invertebrates forming the bulk of their diet for much of the year. Typical prey includes larvae, caterpillars, beetles, moths, aphids, flies, beetles and grasshoppers. Slugs, snails, and worms are also eaten.
Before sedge warblers set off on their long migration flights southwards to trans-Saharan Africa, insects may be supplemented by seeds, fruit and flowers as they build their fat stores ahead of their lengthy journey.
Newly hatched sedge warblers are fed tiny insects, such as aphids, initially regurgitated by both male and female parents. For two further weeks after fledging, young sedge warblers will continue to beg for food before learning to forage for their own insect prey.
Sedge Warblers mainly consume insects and invertebrates
While typically associated with marshlands, and vegetation around the edges of rivers and freshwater pools, sedge warblers are equally at home in a wider range of landscapes, including scrubland, nettle patches, overgrown or neglected orchards and agricultural land, and ditches and hedgerows not immediately close to water.
Non-breeding habitats of sedge warblers include marshes, lowland tropical rainforests, papyrus beds, and wet grasslands.
Sedge warblers breed throughout northern Europe, as far south as central France, northern Germany, and the Balkans, with more dense concentrations of the population the further east you go.
The range extends eastwards to western Siberia, Turkey and Central Asia. Wintering grounds are found across Africa south of the Sahara desert, as far south as northern Namibia and South Africa.
Sedge warblers are not limited to one particular habitat type and are common throughout Britain. Only small tracts of the most uninhabitable uplands of northern England and the Scottish highlands lack any presence of the species.
Wetland habitats, waterside willow perches, marshlands, and grassy scrublands all support foraging and nesting sedge warblers.
Sedge Warblers are typically associated with marshland, but they occupy a range of habitats
During the breeding season, from April to late August, sedge warblers are widespread across the UK, and can be seen throughout the country until October, by which point the latest stragglers will have set off on their migrations.
During winter, any sighting of a sedge warbler on UK soil would certainly be classed as rare and highly unusual.
Sedge warblers breed on UK wetlands and marshes, arriving from April onwards and almost immediately establishing a breeding territory and singing to attract a mate.
Sedge Warbler singing at sunset to attract a mate
The typical lifespan of a sedge warbler is around 2 years, although records show individual birds have reached 8 years 8 months. Breeding occurs for the first time at one year.
There is not much data available about bird species that are the leading threat to sedge warblers, but it’s likely that they are similar to other warblers living in wetland habitats. Warning alarm calls are heard when birds such as sparrowhawks, doves and cuckoos enter their territories.
Nests are likely to be at risk of predation from foxes, weasels, crows, jays and squirrels.
Like most wild bird species that breed in the UK, legislation is in place that offers protection to sedge warblers, their nests and their eggs. The Wildlife and Countryside Act, 1981, makes it an offence to knowingly kill, injure or capture a sedge warbler, or to destroy or damage their nests and eggs.
Sedge warblers are ranked as an Amber species on the British Birds of Conservation Concern list. Between 1967 and 2020, the number of sedge warblers breeding in the UK was noted to have declined by 42 percent, leading to this status as a higher risk species.
Throughout their wider range, sedge warblers have the rating as a species of least concern.
Sedge Warblers are an Amber species in the UK
Female sedge warblers are solely responsible for nest construction, weaving an outer structure of grass, leaves, moss and sedge around a deep cup, made from fine leaves and stems, and lined with flowers, hair, and down.
A typical nest site is among weeds or tall grasses, or in shrubbery above marshy ground, but typically no higher than 50 cm (20 in) above ground level. The nest is usually well hidden by vegetation, and woven around the vertical stems of plants.
Sedge warblers’ eggs are rounded and greenish-yellow in colour, heavily mottled with brown speckles. They measure 18 mm x 13 mm (0.7 in to 0.5 in) and weigh 1.6 g (0.1 oz).
On average between 3 and 5 eggs are laid but some clutches may contain as many as 8 eggs. These are then incubated for 13 to 15 days by the female. The first clutches are laid in late May, and it’s typical for just one brood in a season, although sometimes a second is attempted.
Sedge warbler pairs usually remain together for the duration of a breeding season, although polygamy is not uncommon, and males may breed with an additional female once their original mate has hatched her young.
If a nesting attempt fails, females will seek a new mate before trying again.
Close up of the nest of a Sedge Warbler, with chicks inside
Some degree of territorial behaviour may be shown between paired males and unpaired individuals entering their patch. It isn’t thought that sedge warblers use song as any form of aggressive behaviour or territorial defence, but purely for the purpose of attracting a female.
Sedge warblers are migratory birds throughout their range, and arrive on their breeding grounds of marshes and wetlands across Britain in April, before departing for their wintering territories by late August or early September.
Winters are spent in trans-Saharan Africa, from Senegal to Ethiopia, and as far south as northern Namibia and northern South Africa.
Sedge Warbler in flight
Sedge warblers are considered widespread summer visitors to Britain, and can be seen and heard in marshland habitats during spring and summer. 2016 data estimates 240,000 breeding territories in the UK.
This small but long tailed, large headed warbler, is a resident of the Balearic Islands in the western Mediterranean where it is common, although is not present on the island of Menorca.
Wood warblers are tuneful breeding visitors, arriving in British woodlands from April onwards. Well hidden in their preferred tree-filled landscapes, their bright yellow breast makes them easily distinguishable from other similar warbler species.
The diminutive Willow warbler is a small bird from the Leaf Warbler family Phylloscopidae which contains 80 species. Willow warblers are primarily insectivorous and are energetic, constantly moving birds that dart their tree and hedgerow habitats. They possess soft and subtle green plumage with a pale green-grey back, wings and tail with a pale grey stomach that has a slight yellow tinge.
Whitethroats are active warblers that can be seen and heard in hedgerows around Britain during spring and summer months, as they raise their young and busily forage for insects. Each autumn, they depart for wintering grounds in sub-Saharan Africa, returning in April to breed once more.
Not to be confused with the Great Reed Warbler, this relatively nondescript, solitary little bird is an annual visitor to the UK from sub-Saharan Africa, arriving in mid April and departing early in October.
A well-camouflaged visitor to grasslands and reedbeds, grasshopper warblers arrive in Britain to breed each spring. You may stand a better chance of hearing one than actually getting a sighting, as their secretive nature of creeping through vegetation makes them almost impossible to spot.
This mainly plain, solitary, short billed, stocky little warbler is widespread throughout Europe and a long distance migrant to Africa, crossing the Sahara Desert without pause.
Mainly confined to lowland heaths in southern England, the Dartford warbler is an elusive little resident breeder with distinctive plumage and physical characteristics.
Until recently this small, solitary, old world leaf warbler was classified as being a member of the family Sylviidae, but following extensive research and reclassification, now falls within the family of Phylloscopidae.
Named after the 18th century Italian zoologist and Jesuit priest, Francisco Cetti this small plain looking bush warbler is frequently heard but difficult to spot.
Within its range and to differentiate it from other similar species, it is often referred to as an Eurasian Blackcap. This sexually dichromatic, stocky little warbler, is a member of the genus Sylvia and is sometimes nicknamed the Northern Nightingale due to its beautiful and frequent song.
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