Circus aeruginosus

The Western Marsh-harrier is classified as Regionally Extinct (RE). It became extinct after the drainage of the Hula Lake and its marshes in the 1950s. Since then only one known nesting attempt was observed in Israel (Kfar Barukh Reservoir in 1982; Shirihai 1996) (although the species is still a common passage migrant and winter visitor). In the previous edition of the Red Book (2002), it was classified as Regionally Extinct (RE). A few individuals have been seen in recent years in the summer months in the Northern Valleys, which raises the possibility of its returning to nest in Israel naturally.

Habitats	Wetland Thickets, Humid Lowlands
Presence In Israel	Resident
Breeding In Israel	Bred in the past
Migration Types	Resident
Zoographical Zones	Mediterranean
Landscape Types	Plains & Valleys, Wetlands, Fresh Water, Marsh
Vegetation Types	Marsh and Riparian
Vegetation Densities	Medium, High
Nest Locations	Wetland Thickets
Diet Types	Terrestrial Vertebrates, Fish
Foraging Grounds	Ground
Body Sizes	Medium (500 - 1000g)
Threat Factors	Pesticide Poisoning, Wetland Drainage & Pollution

The Western Marsh-harrier is the largest and most common of the four harrier species found in Israel. It displays prominent sexual dimorphism: the male is smaller and paler and its wings are bluish-grey, and the female is dark brown with yellowish head and shoulders. Most of the observations in Israel are of females and juveniles. It hunts by gliding and hovering at low altitudes over meadows and at the edges of water bodies, to prey on small birds and rodents that are its main food source.

About 15 pairs of Western Marsh-harriers nested in the Hula Valley up to 1953, and a single pair bred in the Yavne area in 1918. When the Hula was drained, the breeding population became extinct. A few individuals, mainly juveniles, were seen in the 1980s during the summer months in the Northern Valleys and the Golan Heights, and one pair apparently bred in the Kfar Barukh Reservoir in 1982 (Shirihai 1996).

The Western Marsh-harrier nests in marshes, lakes and streams with extensive bank vegetation thickets. In Israel, it is found in areas of wetlands, fishponds and reservoirs.

The main extinction factors were:
Habitat destruction – the drainage and destruction of marshes and wetlands and the drainage of the Hula marshes in particular.
Pesticides – like most birds of prey, the Western Marsh-harrier was also hurt by secondary poisoning of rodents and other seedeaters, mainly in the 1950s and 1960s.

The Western Marsh-harrier became extinct as a breeder in Israel during the second half of the 20th century, following the drainage of the Hula marshes and other water bodies in the Northern Valleys along with secondary poisoning by agricultural pesticides. The probability of the species returning to breed in Israel naturally and without directed management is estimated at low to middling.

Expanding marsh thickets in the Northern Valleys and in the Hula Valley in particular, would increase the probability that the species will return to breed in Israel naturally.

• הצופה, א. ומירוז, א. 2015. תכנית אב לשימור העופות הדורסים בישראל. מסמך פנימי של רשות הטבע והגנים.
• פז, ע. 1986. עופות. מתוך אלון, ע. (עורך), החי והצומח של ארץ ישראל. כרך 6. הוצאת משרד הביטחון, ישראל.

• Mendelssohn, H. 1972. The impact of pesticides on bird life in Israel. ICBP 11:75-104.
• Mendelssohn, H. 1975. Report on the Status of Some Bird Species in Israel in 1974. I.C.B.P. 12:265-270.
• Shirihai, H., 1996. The Birds of Israel. Academic Press, London.
• Symes, A. 2013. Species generation lengths. Unpublished, BirdLife International.
• Species page at Birdlife International