Sedge Warbler

Appearance & Identification

What do Sedge Warblers look like?

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

How big are Sedge Warblers?

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.

• Length: 13 cm (5.1 in)
• Wingspan: 17 cm to 21 cm (6.7 in to 8.3 in)
• Weight: 10 g to 13 g (0.4 oz to 0.5 oz)

Sedge Warbler singing from a reed

Calls & Sounds

What sound does a Sedge Warbler make?

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.

Diet

What do Sedge Warblers eat?

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.

What do Sedge Warbler chicks eat?

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

Habitat & Distribution

What is the habitat of a Sedge Warbler?

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.

What is the range of a Sedge Warbler?

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.

Where do Sedge Warblers live?

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

How rare are Sedge Warblers?

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.

Where can you see Sedge Warblers in the UK?

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

Lifespan & Predation

How long do Sedge Warblers live?

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.

What are the predators of Sedge Warblers?

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.

Are Sedge Warblers protected?

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.

Are Sedge Warblers endangered?

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

Nesting & Breeding

Where do Sedge Warblers nest?

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.

What do Sedge Warbler eggs look like?

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.

Do Sedge Warblers mate for life?

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

Behaviour

Are Sedge Warblers aggressive?

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.

Migration

Do Sedge Warblers migrate?

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

FAQs

Are Sedge Warblers common?

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.