Marsh Warbler

Least Concern

Acrocephalus palustris

A master of musical mimicry, this small warbler's song is a globe-trotting symphony of borrowed tunes.

Visual Identification

Appearance

The Marsh Warbler is a small, slender bird with brownish-buff plumage. Its underside is slightly paler and more of a yellowish cream. The eyebrows have a faint pale stripe, and its long, pointed bill is ideal for catching insects.

Males and females are visually indistinguishable. Both have pink legs, dark brown eyes, and a light grey bill.

Juveniles closely resemble adults but may have a slightly bronze or yellower tinge to their plumage, particularly on the underparts, and their legs are slightly darker.

Size

Length

12.5cm to 14cm

Wingspan

17cm to 21cm

Weight

10g to 15g

Colours

Males and females have similar plumage

Primary Colour

Brown Buff

Secondary Colour

White Grey

Beak Colour

Brown

Leg Colour

Pink

Habitat and Distribution

Habitats

Woodland

Garden

Wetland

Coastal

Urban

Farmland

Grassland

Desert

Tundra

Rainforest

Mountain

Savanna

Distribution

Marsh Warblers breed across much of Europe and western Asia, favouring damp areas with tall vegetation such as nettles, meadowsweet, and willowherb. They are often found near water bodies but not exclusively in wetlands.

These birds are long-distance migrants, wintering in southeastern Africa. In the UK, they are rare breeders, with small populations in southern England and occasional sightings during migration.

Elevation Range

Up to 2,000 meters

Climate zones

Temperate, Subtropical

Distribution Map

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Resident
Breeding
Passage
Vagrant

Distribution by Region

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Behaviour and Ecology

Bird Attributes

Tap the icon next to each attribute for more information.

Agility 85
Strength 20
Adaptability 90
Aggressiveness 30
Endurance 75

Diet

Marsh Warblers primarily feed on insects and their larvae, including flies, beetles, and small moths. Snails, larvae, caterpillars and spiders are common prey.

They forage by gleaning prey from vegetation, occasionally catching flying insects in short aerial pursuits. During migration, they may supplement their diet with small berries.

Behaviour

Marsh Warblers are known for their secretive nature, often skulking in dense vegetation. They are agile climbers, moving swiftly through reeds and tall grasses.

During the breeding season, males become more conspicuous, perching prominently to deliver their complex songs.

Vocalisation

The Marsh Warbler's song is renowned for its complexity and mimicry. It incorporates imitations of up to 80 different bird species, both from its breeding grounds and wintering areas.

The song is a rapid, varied warble, often described as more melodious than that of the closely related Reed Warbler.

Nesting & Breeding

Breeding occurs from late May to July. Males attract females with elaborate songs that mimic other bird species and even frogs or insects. Pairs are monogamous during the breeding season, raising one brood together.

Nests are deep cups constructed of grass and plant stems, typically placed low in dense vegetation. Females lay 3-5 eggs, which are pale blue or greenish-white with dark speckles.

Incubation lasts about 12-13 days, primarily by the female. Both parents feed the nestlings, which fledge after 10-12 days but continue to receive parental care for another 1-2 weeks.

Lifespan

Typical Lifespan Range 3 - 5 years
0
2
4
5
7

years

The Marsh Warbler typically lives for 3 to 5 years.

Like all birds, lifespan can be affected by factors including predation, habitat quality, disease, and access to food sources.

Conservation and Status

Global Conservation Status

Least Concern [1]

While currently listed as Least Concern, Marsh Warblers face threats from habitat loss due to drainage of wetlands and changes in agricultural practices.

Conservation efforts focus on preserving and restoring suitable wetland and grassland habitats across their range.

Population Data

Global Population Estimate

8,750,000 - 16,000,000 mature individuals [2]

Global Population Trend

Stable[3]

Birdwatching Tips

  • Listen for their distinctive, mimicking song, especially at dawn and dusk
  • Look for movement in dense vegetation near water bodies
  • Visit suitable habitats during the breeding season (late May to July) for the best chance of sightings
  • Be patient and quiet, as these birds can be elusive

Additional Information

Quick Facts

Other names:

European Marsh Warbler

Predators

Main predators include sparrowhawks, shrikes, and various mammalian predators such as weasels and rats.

Did You Know?

  1. Marsh Warblers can memorise and mimic the calls of birds from their African wintering grounds.
  2. They are one of the latest spring migrants to arrive in Europe, often not reaching breeding grounds until June.
  3. Despite their name, they are not strictly tied to marshes and can thrive in various habitats with suitable vegetation.

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FAQs

Do Marsh Warblers flock?

Marsh warblers gather into mixed-species flocks during migration and spend time on their wintering grounds closely associating with other warblers and similar-sized songbirds.

References

  1. 1 2

    website: BirdLife International. 2019. Acrocephalus palustris (amended version of 2016 assessment). The IUCN Red List of Threatened Species 2019: e.T22714741A155434933.

    View source
  2. 3

    report, 2015: EBCC