Living Organisms / Animalia / Craniata / Aves / Ciconiiformes / Accipitridae / Circus / Species
Circus aeruginosus - Western marsh harrier (Click photographs/illustrations: full picture & further details)

INFORMATION AVAILABLE

GENERAL & REFERENCES

EXTERNAL APPEARANCES

REPRODUCTION

BEHAVIOUR

NATURAL DIET

RANGE & HABITAT

CONSERVATION

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General and References

Alternative Names (Synonyms)

  • Marsh Harrier
  • Busard des roseaux (French)
  • Rohrweihe (German)
  • Falco di palude (Italian)
  • Aguilucho lagunero (Spanish)
  • Brun kürrhök (Swedish)
  • Bruine Kiekendief (Dutch)

Names for newly-hatched

Chick.

Names for non-breeding males or other colour-phases

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References

Species Author

Debra Bourne

Major References

B89, B104, B162, B163, B164, B165, B166

Aviculture references:

ORGANISATIONS
(UK Contacts)

ELECTRONIC LIBRARY
(Further Reading)
Click image for full contents list of ELECTRONIC LIBRARY

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TAXA Group (where information has been collated for an entire group on a modular basis)

Parent Group

  • Birds of Prey

Specific Needs Group referenced in Management Techniques

  • Birds of Prey

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Aviculture Information

Notes

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Individual Techniques linked in Wildpro

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External Appearance (Morphology)

Measurement & Weight

Length
  • 43-55cm (B164) 48-56cm / 19-22 ins. (B166).
  • Wingspan: 115-140cm (B164)
Adult weight General --
Male 405-667g (B104)
Female 540-800g (B104)
Newly-hatched weight 25-28g (B104)
Growth rate --

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Head

Adult Bill Male Base blue-grey shading to black, cere yellow; hooked (B104, B166).
Variations (If present) --
Eyes Male Yellow (B104, B164).
Variations(If present) --
Juvenile Bill Initially upper bill black, lower bill and cere fleshy; later as adult but cere green-tinged yellow (B104).
Eyes (Iris) Dark brown (B104).

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Legs

Adult Male Yellow with black claws (B104, B166).
Variations (If present) --
Juvenile Yellow with black claws (B104).

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Plumage

Adult Male
  • Head and throat buff/yellow-white, upperparts brown.
  • Breast yellow-white with brown streaking, abdomen brown.
  • Tail long, square grey.
  • Wings broader than other harriers dorsal coverts brown with leading edge buff. Primary coverts, flight feathers grey, primaries broadly tipped black.

(B164, B166)

Variations (If present) Female:
  • Head: crown and throat creamy-white.
  • Dorsal including wings brown, with leading edge creamy-white.
  • Tail red-brown.

(B164, B166).

Juvenile
  • Head: crown and throat creamy.
  • Body and wings brown; forewing may be creamy.

(B164, B166)

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Newly-hatched Characteristics

Semi-altricial. Downy, eyes open, helpless, require feeding (B163, B166).

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Reproduction

Reproductive Season

Time of year April-May (B166).
No. of Clutches One (B163, B166).

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Nest placement and structure

A platform of reeds on the ground in large reedbed. Solitary or in loose colonies (B163, B164, B166).

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Egg clutches

No. of Eggs Average 4-5 (B163, B166).
Range 3-8 (B163).
Egg colour Bluish-white, no markings, length 50mm (B163, B166).

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Incubation

31-38 days (B163); 33-38 days (B166).

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Hatching

Asynchronous; younger chicks may be killed by older chicks (B163).

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Fledging

35-40 days (B163, B166).

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Sexual Maturity

Males Two or three years old (B104).
Females Two or three years old (B104)

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Behaviour

Feeding Behaviour

Adults Flies low over open areas and drops quickly to snatch prey with talons (B163).
Newly-hatched --

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Parental Behaviour

Nest-building By female (B163).
Incubation By female (B163, B166).
Newly-hatched By females (B163).
Juveniles

Juveniles stay with female for several weeks after fledging and may be passed food in mid air (B163).

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Social Behaviour

Intra-specific --
Inter-specific --

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Sexual Behaviour

  • Usually monogamous.
  • Some polygyny, usually by oldest males, who then may supply food to the chicks of several mates.
  • Female may be lost to older male following pairing of young birds early in season.
  • Male courtship-feeds female.

(B163).

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Predation in Wild

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Activity Patterns

  • Males circle high above nest in territorial displays, also sometimes fly calling, with quick jerky wing beats.
  • Perch openly.
  • Take off from vegetation and also from ground.
  • (B166).
Circadian Diurnal.

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Natural Diet

Adults

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Newly-hatched

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Range and Habitat

Distribution and Movement (Migration etc.)

Normal Western and central Palearctic (B89); scattered and fragmented population over south-western Europe and North Africa; more common through Asia (B163).

Movement:

  • Some populations (southern and western) resident.
  • Some populations migrate to Africa and India/south-east Asia.
  • Do not congregate at short sea crossings.

(B89, B163, B164).

Occasional and Accidental  
Introduced

 

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Habitat

  • Breeding: reedy freshwater marshes, well vegetated margins of lakes and slow-moving rivers (B163, B164, B166).
  • Also moors, heaths, estuaries, shores (B166).

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Conservation

Intraspecific variation

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Conservation Status

Wild Population -
(Importance)
  • Declines in western and central Europe; local extinctions following drainage of marsh habitats and persecution (B163).
  • Recolonisation of e.g. UK following substantial conservation efforts, but still only low numbers (B163, B166).
General Legislation
  • All Harriers are listed on Schedule 1 - Part I (Birds protected by special penalties: Notes on the revised schedules state "Birds protected by special penalties at all times") of the LUK2 - Wildlife and Countryside Act 1981 of the United Kingdom. (W5.Oct01)
  • This species is listed on Schedule 4 (Birds which must be registered and ringed if kept in captivity: Notes on the revised schedules state "Any bird, one of whose parents or other lineal ancestor was a bird of a kind specified in the above list") of the LUK2 - Wildlife and Countryside Act 1981 of the United Kingdom. (W5.Oct01)
CITES listing Listing not yet included.
Red-data book listing Listing not yet included.
Threats Habitat loss (marsh drainage), persecution (B163).

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Captive Populations

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Trade

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