Eurasian Bittern
Botaurus stellaris
Visual Identification
Appearance
The Bittern is a stocky, medium-sized heron with cryptic plumage. Its mottled brown feathers, streaked with black, create an intricate pattern that perfectly mimics the play of light and shadow in reedbeds.
The bird's stout neck, crown, and distinctive black moustachial stripes contribute to its unique appearance. They have short but seemingly oversized yellow legs and feet, straight, pale beaks and small eyes.
Males and females are similar in appearance, though males tend to be slightly larger. Juveniles resemble adults but may have a slightly warmer, more rufous tone to their plumage. The Bittern's plumage remains consistent year-round, aiding in its perpetual camouflage.
Size
Length
69cm to 81cm
Wingspan
100cm to 130cm
Weight
900g to 1.9kg
Colours
Males and females have similar plumage
Primary Colour
Brown
Secondary Colour
Black Buff
Beak Colour
Yellow Brown
Leg Colour
Green
Habitat and Distribution
Habitats
Woodland
Garden
Wetland
Coastal
Urban
Farmland
Grassland
Desert
Tundra
Rainforest
Mountain
Savanna
Distribution
Bitterns are strongly associated with dense reedbeds in freshwater and brackish wetlands, including marshes, lake edges, and slow-flowing rivers. They require extensive areas of tall reeds for both feeding and breeding, making them highly dependent on this specific habitat type.
The species is widely distributed across Eurasia, from the British Isles through continental Europe, Russia, and parts of Central and East Asia. In the UK, they are year-round residents in suitable wetland habitats, with some birds undertaking short-distance migrations in response to harsh winter conditions.
Visit wetlands at the following UK sites for your best chance of a sighting:
- RSPB Minsmere in Suffolk
- The Great Fen in Cambridgeshire
- Leighton Moss in Lancashire
- RSPB Ham Wall in Somerset
- Newport Wetlands, Wales
- RSPB St. Aidan’s, West Yorkshire
Elevation Range
Up to 1,400 meters
Climate zones
Temperate, Subtropical
Distribution Map
This map gives you a rough idea of where you might spot a Eurasian Bittern. The coloured areas show countries where these birds have been seen.
A few things to keep in mind:
- Birds might not be everywhere in the coloured areas, for example, they may be present around the coast of that country
- Where birds live can change with seasons and available food
- This map is quite simple - it doesn't show exact locations
We're working on making our maps even better! Soon, we hope to show you:
- More detailed maps for bigger countries, including state and region
- How birds move around during different seasons
Distribution by Region
Behaviour and Ecology
Bird Attributes
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Share your thoughtsBird Attributes Explained
Our bird attributes system rates various aspects of a bird's capabilities on a scale of 0-100, based on data from field observations, scientific studies, and expert knowledge.
Attribute Categories:
- Agility: Manoeuvrability, speed, and grace in flight or movement.
- Strength: Physical power, often correlating with size and hunting abilities.
- Adaptability: Ability to thrive in various environments or changing conditions.
- Aggressiveness: Territorial behaviour and assertiveness, particularly during breeding seasons.
- Endurance: Stamina, often seen in migration patterns or foraging behaviours.
Understanding the Ratings:
- 0-20: Very Low
- 21-40: Low
- 41-60: Average
- 61-80: High
- 81-100: Very High
Remember, these attributes are relative to other bird species and don't necessarily indicate superiority.
Hover over the icon next to each attribute for more information.
Tap the icon next to each attribute for more information.
Agility
Reflects the bird's manoeuvrability, speed, and grace in flight or movement.
The Bittern displays remarkable agility in navigating dense reedbeds and striking prey with lightning-fast precision. Its ability to compress its body vertically and maintain perfect stillness for extended periods demonstrates exceptional bodily control.
Strength
Indicates the bird's physical power, often correlating with size and hunting abilities.
While not exceptionally strong for its size, the Bittern possesses sufficient strength to spear fish and other prey with its sharp bill. Its robust build allows it to push through dense vegetation and carry materials for nest construction.
Adaptability
Represents the bird's ability to thrive in various environments or changing conditions.
The Bittern's extraordinary camouflage abilities, including its 'freeze' posture and cryptic plumage, showcase exceptional adaptability to its wetland habitat. Its capacity to thrive in various wetland types across a wide geographic range further demonstrates its adaptiveness.
Aggressiveness
Measures the bird's territorial behaviour and assertiveness, particularly during breeding seasons.
Generally solitary and secretive, Bitterns are not notably aggressive. However, they become more territorial and vocal during breeding season, particularly when males compete for mates and defend territories.
Endurance
Reflects the bird's stamina, often seen in migration patterns or foraging behaviours.
Bitterns exhibit good endurance, capable of maintaining their camouflage pose for hours and undertaking short-distance migrations when necessary. Their ability to survive in challenging wetland environments year-round suggests a robust constitution.
Diet
Bitterns are opportunistic predators, primarily feeding on fish, eels, amphibians, and aquatic invertebrates.
They hunt by standing motionless at the water's edge or slowly stalking through shallow water, using their sharp bill to spear prey with lightning-fast strikes. Their diet may also include small mammals and birds when available.
Behaviour
Bitterns are renowned for their remarkable camouflage behaviour, often standing motionless with their bill pointed skyward to mimic surrounding reeds. This 'freeze' posture can be maintained for extended periods when the bird feels threatened.
They are primarily solitary, becoming vocal and more active during the breeding season when males perform their distinctive booming display to attract mates.
Vocalisation
The Bittern's most famous vocalisation is the male's deep, resonant 'boom' used during breeding season. This distinctive call, sounding like a distant foghorn or someone blowing across a bottle, can be heard up to 5 km (3 miles) away.
The boom is produced by inflating the oesophagus and is typically repeated in a series of 2-5 booms. The best time to listen for this impressive call is often in the quiet hour of dawn.
Nesting & Breeding
Bittern breeding season typically begins in late winter or early spring, with males initiating their booming calls to establish territories and attract females. These calls can carry for up to 5 kilometers, serving as a key part of their courtship ritual.
Females construct nests low in the reeds, usually just above water level. The nest is a platform of dead reeds and other vegetation. A typical clutch consists of 3-5 olive-brown eggs, which are incubated solely by the female.
Incubation lasts about 25-26 days, with chicks hatching asynchronously. The female cares for the young alone, feeding them regurgitated food. Fledging occurs after about 50-55 days, though young may remain dependent on the female for several more weeks.
Conservation and Status
Global Conservation Status
While listed as Least Concern globally, Bitterns have faced significant declines in parts of their range due to wetland drainage and habitat loss.
Conservation efforts, particularly in the UK and Europe, focus on restoring and managing reedbed habitats. These initiatives have led to local population recoveries, highlighting the importance of wetland preservation for this species.
Birdwatching Tips
- Listen for the male's distinctive booming call in spring, especially at dawn and dusk
- Scan reedbeds carefully, looking for slight movements or the distinctive shape of a bittern's head and bill
- Visit wetland reserves with viewing platforms for better chances of spotting this elusive bird
- In the UK, try sites like RSPB Minsmere or Leighton Moss for Bittern sightings
Additional Information
Quick Facts
Predators
Did You Know?
- Bitterns can compress their bodies vertically, making them even harder to spot among reeds.
- The species name 'stellaris' refers to their star-like, speckled plumage.
- Bitterns have been known to freeze in their camouflage pose for hours at a time.
FAQs
Are there Bitterns in Scotland?
Bitterns are rare visitors to Scotland. They do not nest there, but it is hoped that their breeding range may expand northwards in time.
What is the best time of day to see Bitterns?
The low light of dawn and dusk provide the best chance of spotting the Bittern. These shy birds rarely break cover and generally fly for short distances, dropping quickly out of sight.
Do Bitterns call at night?
The Bittern’s booming call can be heard by day or night, although their ‘Kaa’ flight call is more likely to be heard after dark.
References
- 1 3
website: BirdLife International. 2016. Botaurus stellaris. The IUCN Red List of Threatened Species 2016: e.T22697346A86438000.
View source - 2
report, 2015: Wetlands International
- 4
website, 2010: Fransson et al., EURING list of longevity records for European birds
View source
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