Living Organisms / Animalia / Craniata / Aves / Ciconiiformes / Accipitridae / Circus / Species
Circus cyaneus - Northern 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)

  • Hen harrier (Circus cyaneus cyaneus)
  • American harrier (Circus cyaneus hudsonius)
  • Busard Saint-Martin (French)
  • Kornweihe (German)
  • Albanella reale (Italian)
  • Aguilucho pálido (Spanish)
  • Blå kärrhök (Swedish)
  • Blauwe 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
  • 45-55cm (B164); 43-51cm / 17-20 ins. (B166)
  • Wingspan: 97-118cm (B164)
Adult weight General  
Male 300-400g (B104)
Female 410-708g (B104)
Newly-hatched weight 15-27g (B104)
Growth rate Increasing to 472g by 31-38 days (B104)

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Head

Adult Bill Male Black (base blue-tinged), cere yellow; hooked (B104, B166).
Variations (If present) --
Eyes Male Yellow (B104, B166).
Variations (If present) Amber in females of 3-4 years old and very pale in old females.-- (B104)
Juvenile Bill (B104)
Eyes (Iris) Dark brown in nestling, becoming grey then yellow in male, brown gradually becoming yellow in female (B104)

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Legs

Adult Male Yellow, with black claws (B104, B166).
Variations (If present) --
Juvenile Yellow with black claws (pink to about seven days old) (B104, B164).

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Plumage

Adult Male
  • Head including throat, and upperparts grey/blue-grey..
  • Breast grey/blue-grey, abdomen white.
  • Wings grey, except primaries black, trailing edge (tips of secondaries) dark.
  • Tail long, square grey; upper tail coverts white.

(B164, B166)

Variations (If present) Female:
  • Head and upperparts brown, collar line pale
  • Throat, breast and abdomen buff-white with brown streaking.
  • Tail long brown with paler brown barring; upper tail coverts white.
  • Wings: long dorsal surface brown with coverts variably yellowish, ventral coverts pale with brown streaks, flight feathers (primaries and secondaries) white with dark bands and dark tips.

(B164, B166)

Juvenile
  • Similar to female, but underparts more yellow-rufous and less streaked, upperwing coverts more rufous, greater coverts pale tipped (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-June (B166).
No. of Clutches One (B163, B166)..

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Nest placement and structure

Platform of sticks and grass on the ground, hidden in low vegetation, often in loose colonies (B163, B164, B166).

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Egg clutches

No. of Eggs Average 4-6 (B163).
Range 4-12 (B163).
Egg colour Blue-white/pale blue, sometimes with markings. Length 46mm (B163, B166).

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Incubation

29-31 days (B163); 29-39 days (B166).

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Hatching

Asynchronous (B163)..

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Fledging

32-42 days (B163); 37 days (B166).

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Sexual Maturity

Males Occasionally one year old, more usually 2-3 years old. (B104)
Females Occasionally one year old, more usually 2-3 years old. (B104)

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Behaviour

Feeding Behaviour

Adults
  • Flies low, over moors, young conifer plantations, quartering ground.
  • May also fly along forest edges.
  • Pounces quickly onto prey.

(B163, B166).

Newly-hatched Requires feeding (B163).

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Parental Behaviour

Nest-building By female (B163, B166).
Incubation By female (B163).
Newly-hatched Tended by both parents but mainly by female (B163).
Juveniles

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Social Behaviour

Intra-specific Solitary or in pairs (B166).
Inter-specific --

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Sexual Behaviour

  • Young males monogamous, but polygyny by older males, with up to five females (B163).
  • Male passes food to female in flight during courtship-feeding (B163).

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Predation in Wild

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Activity Patterns

  • High circling displays and flight displays, deeply undulating flight and alternating steep dives and steep climbs. (B163).
  • Hovers, soars and glides; flight may be laboured (B166).
  • Perches openly (B166).
  • Takes off from vegetation and also lands on and takes off from ground (B166).
Circadian Diurnal.

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Natural Diet

Adults

  • Small birds.
  • Small mammals (particularly voles).

(B163, B164, B166).

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Newly-hatched

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Range and Habitat

Distribution and Movement (Migration etc.)

Normal Holarctic (B89); population fragmented over Europe but wide distribution in Asia and in North America, South America. (B163)
  • Britain: small population breeding in hill areas (B164, B166).

Movement:

  • Winters to northern Africa, south and south-east Asia, northern South America (B89).
  • Western populations resident (B163).
  • Northern and eastern populations migratory: winter in southern and western Europe (B163).
  • Britain: winter on coasts (B166).
Occasional and Accidental --
Introduced

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Habitat

Open habitats, moorland, heaths, marshes, young conifer plantations, shallow well-vegetated lakes, bogs in open taiga; winter in open country e.g. open farmlands, marshes (B163, B164, B166).

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Conservation

Intraspecific variation

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Conservation Status

Wild Population -
(Importance)

Former marked decreases in many areas, but more recent recolonisation of some areas including mainland Scotland, northern England, Wales (B163).

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 Persecution (B163).

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Captive Populations

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Trade

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