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.
Listen to the sound of Pallid Harrier
Copyright remark: Most sounds derived from xeno-canto
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|incubation min.:||29||days||incubation max.:||30||days|
|fledging min.:||33||days||fledging max.:||30||days|
habitat of the Pallid Harrier. These habitats still exist in southern Russia and Kazakhstan. However, many of these habitats have been developed or cultivated. Pallid Harrier rarely nest in agricultural fields, although it can use them apparently without difficulty in years of good food abundance. The limiting factor in this habitat is therefore probably the food availability (food being in general less available in agricultural fields). The preferred breeding habitats in the steppe are wet grasslands close to small rivers and lakes, and marshlands. The Pallid Harrier can even nest in swamps or moist islands on lakes. More recently, it has been noted to colonise clearances and other openings in forests in the north. The Pallid Harrier breeding range consists of three zones. They are: (1) the optimal one (mostly humid habitats in steppe, forest-steppe and semi deserts upon Northern Eurasia); (2) areas of sporadic breeding (a forest zone in Europe and northern desert grasslands in Kazakhstan; (3) incidental breeding during invasions of northern, central and even western Europe.
Harrier has a number of structural characteristics consistent with adaptation to catch agile prey, especially small birds. Observation of males early and late in the day in the surroundings of the big roost site at Velavadar in India, has shown that hunting flight is fast, low and direct, using the stands of taller grass to steal up on flocks of larks feeding on the ground. Habitat structure is, therefore, important and at risk from overgrazing or excess harvesting. Territorial behaviour has been observed between males, probably limiting the carrying capacity of prime foraging habitat. In Africa, precise knowledge of diet is still required. In several accounts from Africa it is said to hunt near grass or savanna fires.
Video Pallid Harrier
copyright: T. Tarrant
Agricultural development has resulted in fragmentation of the Pallid Harrier’s former core breeding range and has caused a population decline. This has been particularly noticeable in Eastern Europe, west of the Volga River. At the same time there have been instances of breeding in new areas, mostly far north of the range indicated in the standard handbooks. Most breeding pairs shift nesting places from year to year, probably tracking changes in the abundance of small rodent prey. Thus, local fluctuations in the Pallid Harrier population and range movements have hampered survey work. A preliminary assessment of the total breeding population of the Pallid Harrier at the beginning of the XXI century is 9,000 – 15,000 pairs, and it is evidently in decline. There is an urgent need for a structured program of surveys, research, monitoring and conservation action at breeding grounds. Reliable records of the species on migration routes and on winter grounds are also difficult to
obtain due to the rarity of the species, its broad-front migration strategy, and difficulties in field identification. Further survey work and research is needed on this species in the winter range in order to be able to target conservation action effectively. However, some important concentrations have already been located in India and Africa where strict conservation measures are required now.
In Europe the breeding range is highly fragmented and its western limits shift from year to year. At the same time there is some evidence of recent expansion of Pallid Harriers to the north, due either to a shortage of typical humid habitats in the south or as a result of long-term fluctuations of the species’ breeding range.
The principal wintering grounds of the Pallid Harrier are open country throughout the Indian subcontinent,
the savanna belt in Africa south of the Sahara, and the East African steppes. The Pallid Harrier occupies this vast distribution area during the northern winter, from October to March, and shares it with (the generally more common) Montagu’s Harrier. Because of plumage similarities, it is difficult to differentiate between these two species in the field, especially female and juveniles. They also mix at the same night roosts. Roost site conservation measures (mainly in grasslands) will
therefore benefit both, but it is important to be aware that they can occupy different foraging niches.
By day, harriers are very mobile, widely dispersed and therefore difficult to count. However, their
use of communal night roosts in winter enables counts to be made. They roost on the ground, typically
in favoured patches of rank ground vegetation at traditional sites in natural or semi-natural habitats
such as grassland and marshes, but occasionally on bare ground. The largest one reported was of ?hundreds’ of migrating harriers roosting in grassland in the SE Serengeti near Mti Mwili, Tanzania in March 1998.