Montagus Harrier (Circus pygargus)

Montagus Harrier

[order] ACCIPITRIFORMES | [family] Accipitridae | [latin] Circus pygargus | [authority] Linnaeus, 1758 | [UK] Montagus Harrier | [FR] Busard cendre | [DE] Wiesenweihe | [ES] Aguilucho Cenizo | [NL] Grauwe Kiekendief

Subspecies

Monotypic species

Genus

The genus Circus is a cosmopolitan genus of about ten species. They are medium-sized, slender hawks, the female being considerably larger than the male. They are characterised by long, narrow, rounded tails, small beaks and long, slender legs. The most notable characteristic is the owl-like ruff of facial feathers that cover unusually large ear openings – an adaptation not for low-light hunting, but to locate prey by their rustling and squeaking in tall grasses.

Physical charateristics

Sexual dimorphism is particularly apparent in the plumage of this species. Adult males are characterized by their overall pale grey plumage contrasting with black wingtips. Compared with other harriers this species has characteristic black bands along the secondaries, both above and below the wing and rusty streaks on belly and flanks.
Adult females have a broadly similar plumage to that of Pallid and Hen Harriers. The underparts are mostly pale yellow-brown, the belly with longitudinal stripes and the wing coverts spotted. The upper parts are uniform dark brown except for the white upper tail coverts (“rump”), and the sightly paler central wing coverts.
The juvenile plumage resembles that of the female, but differs by the belly and under wing coverts which are not spotted, but uniformly red brown in colour.
A melanistic form occurs regularly in this species. In this form the male is much darker than usual, with a black head, brownish black above and grey underparts. The melanistic female is entirely chocolate brown except for grey flight feathers. Partially melanistic morphs can also be found.

Listen to the sound of Montagus Harrier

[audio:http://www.planetofbirds.com/MASTER/ACCIPITRIFORMES/Accipitridae/sounds/Montagus Harrier.mp3]

Copyright remark: Most sounds derived from xeno-canto


wingspan min.: 96 cm wingspan max.: 116 cm
size min.: 39 cm size max.: 50 cm
incubation min.: 27 days incubation max.: 40 days
fledging min.: 28 days fledging max.: 40 days
broods: 1   eggs min.: 4  
      eggs max.: 5  

Range

Eurasia : West, Central. The Montagu’s Harrier has a breeding range that has changed over time, and is subject to occasional extensions and contractions. Mainly confined now to warm temperate parts of Europe and Russia, the species is strongly migratory and winters in sub-tropical Africa and India, and around the Mediterranean Sea.
It is essentially a lowland species, and breeds readily in dry areas, such as heath land, sand dunes and young plantations. It does not tolerate disturbance, and avoids areas that are subject to any form of human habitation and use.

Habitat

This species can be found in a middle-latitude band of predominantly temperate climates, but also in Mediterranean, and boreal zones. Although it has been found nesting up to 1500 m, it is essentially a lowland species, and nests mostly in broad river valleys, plains, and levels bordering lakes and the sea. It can breed in wetlands, though these are often smaller and dryer than those used by the Marsh Harrier. It also utilizes heaths, dunes, moors, and can be found in the steppe. It adapts to shrublands in gorse or heather and to areas planted with young conifers.

When no other suitable habitat is available this harrier will nest in agricultural farmlands where it is vulnerable to early harvesting. Amongst these it chooses especially grasslands and cereal crops such as wheat, barley, oats and colza. In western Europe, up to 70 percent of the population breeds in artificial habitats.

Reproduction

At 2 to 3 years of age, a pair is formed that sometimes lasts for the lifetime of the birds, although there is evidence not only of pair-changes in successive years, but also of occasional polygyny during a single season.
The courtship ritual involves the pair circling together to a great height, and playing a number of mid-air games including food-passes, diving, rolling and talon presentation.
The nest is constructed on the ground, in natural or cultivated vegetation, moorland, young forestry plantations or even sand-dunes. Building, mostly by the hen, takes about 4 days. The hen also takes the brunt (if not all) of the incubation duty, which lasts for about 30 days per egg – up to around 40 days for the full clutch of up to four or five eggs.
The young remain in the nest for about 3 weeks, when they start to crouch in surrounding vegetation, although still very much under the protection of the adults until they fledge at bout 42 days. Full independence is achieved about 14 days after fledging.

Feeding habits

Its prey is mostly small mammals, mainly rodents. It also takes, as the occasion demands, small birds – open country passerines and occasionally the young of ground-nesting birds. Small reptiles and large insects are also taken.

Video Montagus Harrier

httpv://www.youtube.com/watch?v=yUPgAfTZtEk

copyright: youtube


Conservation

This species has an extremely large range, and hence does not approach the thresholds for Vulnerable under the range size criterion (Extent of Occurrence <20,000 km2 combined with a declining or fluctuating range size, habitat extent/quality, or population size and a small number of locations or severe fragmentation). Despite the fact that the population trend appears to be decreasing, the decline is not believed to be sufficiently rapid to approach the thresholds for Vulnerable under the population trend criterion (>30% decline over ten years or three generations). The population size is very large, and hence does not approach the thresholds for Vulnerable under the population size criterion (<10,000 mature individuals with a continuing decline estimated to be >10% in ten years or three generations, or with a specified population structure). For these reasons the species is evaluated as Least Concern.
The Montagu’s Harrier is possibly the most slender and elegant of its genus. Its body and wing form can, at times, cause it to be mistaken for a falcon. In flight it is the most buoyant of the Harriers and is reminiscent of the flight pattern of a tern – the slow glides interspersed with half a dozen wingbeats of such power that the bird lifts visibly.
Its hunting method is typical of its genus, quartering the land at low speed and low altitude, but with the ability to drop quickly and silently onto its prey once located.
Being a ground-nesting and roosting bird, this species, as well as suffering the persecution and indiscriminate shooting that has been the lot of many raptors over the last century or so, falls prey to the ravages of farm machinery (except where the farmer is aware of their presence and sufficiently interested to take some positive action). As a result of these problems, numbers of this species in much of Europe, and particularly in Britain, are only now recovering from disastrous losses., where it is almost as common as the very numerous resident Brahminy Kite Haliastur indus.
In its breeding areas, like other harriers, it spends a lot of the day on the wing, although probably less than many other harriers. It flies higher than other harriers, usually at ten to fifteen feet, and in a less buoyant and easy manner, though it has the harrier habit of gliding with wings held well above the level of the back. Although it appears, probably due to its larger size, to fly slower than other harriers its hunting speed has been estimated at 31-36 miles an hour, faster than most harriers.

This harrier inhabits steppes and open marshes of a large part of Eurasia, from the Iberian Peninsula and England to Mongolia. It breeds also in Morocco. Its winter quarters are in sub-Saharan Africa. The population of the European Union amounts to about 6100 breeding pairs, which represent about 20% of the total European population. This species is shows wide fluctuations, but since several decades seems to decrease. The population for the western Palearctic is estimated at 35,000-50,000 pairs. The global population is unknown and could be anything between 150,000 to 200,000 individuals(Birdlife International, 2004). This uncertainty is due to the fact that most of the world’s population is situated in Russia and former Soviet republics where it is not quantified.
Montagus Harrier status Least Concern

Migration

The Montagu’s Harrier is a long distance migrant. Birds from Eurasia spend the winter in sub-Saharan Africa, while those from the eastern part of the range migrate to the Indian subcontinent. In Europe, the first birds start to move at the beginning of August and most have left by mid-October. They travel over a broad front, crossing the Mediterranean at various points, and only a small number are observed at migration choke points. Western birds don’t go further south than the gulf of Guinea, but some eastern birds travel as far as South Africa. In Africa their diet is composed mostly of insects and birds, and it is possible that they follow locust swarms. Spring return peaks in April, and most birds have arrived by May though there is evidence that first-year juveniles spend their first summer in the winter quarters.

Distribution map

Montagus Harrier distribution range map

Literature

Title Copulatory Behavior Of Semi-Colonial Montagu’s Harriers
Author(s): Beatriz E. Arroyo
Abstract: The copulatory behavior of the monogamous Montagu’..[more]..
Source: The Condor 101:340-346

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Title Age-related differences in foraging behavior
of Montagus harrier Circus pygargus males in south-east Poland
Author(s): Ignacy Kitowski
Abstract: The hunting behaviour and habitat use of second-ca..[more]..
Source: acta ethol (2003) 6:35-38

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Title Veranderungen in der Zusammensetzung der PCB- und DDT-Gemische in verschiedenen Lebensstadien der Wiesenweihe (Circus pygargus) und der Rohrweihe (Circus aeruginosus) in Nordrhein-Westfalen, Deutschland
Author(s): Eckhard Denker, Annegret Buthe, Doris Glimm, Manfred Holker, Werner Prunte und Theodor Trendelkamp*
Abstract: Egg and liver samples of Montagu’s and Marsh Harri..[more]..
Source: J. Ornithol. 144, 411-417 (2003)

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Title Satellite tracking of two Montagu?s Harriers ( Circus pygargus ): dual pathways during autumn migration
Author(s): Christiane Trierweiler, Ben J. Koks et al.
Abstract: Autumn migration routes of two Dutch female Montag..[more]..
Source: J Ornithol (2007) 148:513-516

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Title Food-niche differentiation in sympatric Hen Circus cyaneus and Montagu’s Harriers Circus pygargus
Author(s): J. T. GARCIA & B. E. ARROYO
Abstract: Hen Harriers Circus cyaneus and Montagu’s Harriers..[more]..
Source: Ibis 147 (1), 144-154

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Title The diet of Montagu’s Harriers Circus pygargus in relation to land-use systems in pseudosteppe areas of Extremadura (SW Iberian Peninsula)
Author(s): Casimiro CORBACHO, Ricardo MORN and Mara A. VILLEGAS
Abstract: The feeding of Montagu’s Harriers Circus pygargus ..[more]..
Source: Ardeola 52(1), 2005, 3-19

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