POPULATION SIZE AOO EOO TREND
210 mat. ind. - 170,180 km2
NORTH AFRICA REGIONAL ASSESSMENT: ENDANGERED (EN) C2a(i); D (IUCN version 3.1)
This species has declined in North Africa, with only ca. 100 pairs remaining in Morocco and no more than five pairs in Algeria, while in Tunisia there have been no breeding records for 20 years. Therefore, the population size in North Africa is approximately 210 mature individuals. The species could potentially be listed as Critically Endangered under criterion C2a(ii), as based on these figures >90% of the population may be in the Moroccan subpopulation. However, with the ongoing decline in the country it is uncertain whether this is definitely the case and so the species is tentatively assessed as Endangered under criteria C2a(i); D.
DISTRIBUTION
Montagu’s harrier is a rare, local, summer breeding resident in north-west Africa: in the Rharb, at the Moulouya estuary and possibly at Oualidia in Morocco and in north-western Algeria (Thévenot et al., 2003; Isenmann et al., 2005; Clark and Davies, 2018). It used to breed in north-eastern Tunisia (Isenmann and Moali, 2000) but there has been no record of breeding in the last 20 years (M. Chokri and H. Azafzaf, pers. obs.). It is a common passage migrant from Eurasia in all North African countries (Clark and Davies, 2018).
POPULATION
In the late 20th century, the population in Morocco was estimated at 500 breeding pairs, but numbers have declined markedly to ca. 100 breeding pairs (Bergier, 1987; Thévenot et al., 2003; I. Cherkaoui, pers. obs.).
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There has been only one recent breeding record in Algeria, a breeding pair observed at Dayet El Fed, and the population in this country is unlikely to be more than five breeding pairs (H. Benmammar, pers. obs.). In Tunisia, there have been no breeding records in the last 20 years (M. A. Chokri and H. Azafzaf, pers. obs.). Therefore, the breeding population in North Africa can be estimated at ca. 105 breeding pairs (210 mature individuals).
North Africa is the southern limit of the species’ range, so the North African population probably survived due to immigration from the larger Spanish population, but this too has suffered a major decline in the last decade (Arroyo, 2017) due to conversion of its habitat to intensive agricultural land (Ferguson-Lees and Christie, 2001;
Bergier, 1987; Orta et al., 2020d).
HABITATS AND ECOLOGY
The species occurs in open grasslands, cereal fields, upland plateaux, wetlands and marshes in coastal regions (Thévenot et al., 2003; Clark and Davies, 2018). It nests in tall vegetation on the ground. The nest is a small, nar-row platform, 20–40 cm wide, made of grass stems or thin twigs. Clutches normally consist of three to five eggs (Orta et al., 2020d). In North Africa, the breeding season lasts from early April to early June (Thévenot et al., 2003).
It is a migratory species, wintering in sub-Saharan Africa (Ferguson-Lees and Christie, 2001; Orta et al., 2020d). It leaves its breeding grounds from the end of July until mid-October and begins its return in March and April (Snow and Perrins, 1998; Thévenot et al., 2003; Orta et al., 2020d). This is a loop migration, with birds passing further to the west in autumn (García and Arroyo, 1998). Birds tend to migrate on broad fronts, but there are concentrations in Gibraltar and along the Rift Valley (Ferguson-Lees and Christie, 2001; Orta et al., 2020d). Nevertheless, they will readily migrate over expanses of water (Brown et al., 1982).
Birds tend to hunt alone, although they do gather at high prey concentrations and will roost in groups of often more than 50 individuals, sometimes communally with Circus macrourus and C. aeruginosus (Ferguson-Lees and Christie, 2001). They mainly feed on small mammals, birds, reptiles, sometimes insects (particularly in winter) and occasionally birds’ eggs (Clark and Davies, 2018).
THREATS
In the past, the use of organochlorine pesticides seemed to cause a decline in Europe (Ferguson-Lees and Christie, 2001), which could still be happening at least in Morocco (Strategy for Conservation of Birds of Prey Workshop, 2020, Rabat). The species is currently in decline owing to the conversion of its habitat to agricultural land, an environment in which crop gathering by combine harvesters causes frequent breeding failure (Orta et al., 2020d; Moroccan Strategy for Conservation of Birds of Prey Workshop, 2020, Rabat). Intensification of agricul-ture increases this threat (Ferguson-Lees and Christie, 2001). It is commensal with some forms of agriculagricul-ture, and therefore changes in these practices could make it potentially vulnerable by depleting the supply of small birds and mammals for it to prey on (Ferguson-Lees
and Christie, 2001; Orta et al., 2020d). It is highly vulnerable to the impacts of wind energy developments (STRIX, 2012), so the increasing number of massive wind energy projects in northern Morocco could be a major threat to individuals migrating across the Strait of Gibraltar.
In Morocco, nests are systematically de-stroyed on farmland (Thévenot et al., 2003;
I. Cherkaoui, pers. obs., Strategy for Con-servation of Birds of Prey Workshop, 2020, Rabat) and shooting has been documented (MaghrebOrnitho, 2018g). Additionally, in
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Distribution range of the Montagu’s harrier, Circus pygargus (Linnaeus, 1758) in North Africa. Source: The IUCN Red List of the breeding birds of prey of North Africa.
Merja Zerga, rush burning and vandalism can destroy nests (I. Cherkaoui, pers. obs., Strategy for Conservation of Birds of Prey Workshop, 2020, Rabat), and very few broods now succeed at the species’ best breeding site in Morocco (A. Qninba, pers. comm.).
Lastly, as a consequence of global climate change, harvests are taking place earlier, coinciding with nesting times, and chicks may be killed by the harvesting machines.
CONSERVATION
Conservation actions in place: CITES Appendix II and CMS Appendix II. In Morocco, the species is in-cluded in the preparation of a raptor conservation strategy (https://www.iucn.org/news/mediterranean/202001/
first-steps-towards-a-moroccan-strategy-raptor-conservation-iucns-guidance).
Conservation actions needed: Tall vegetation should not be removed during the breeding season due to the high rates of chick mortality when it is harvested on agricultural land. Key management practices that include moving nestlings to safe places during harvesting, and leaving areas around nests unharvested should be im-plemented (Orta et al., 2020d). Removed chicks can also be reintroduced in other suitable areas. Mediterranean populations are highly dependent on these measures owing to high nest-failure rates in the absence of interven-tion (Orta et al., 2020d). Where possible, strict and effective protecinterven-tion of breeding sites should occur, and more broadly there should be an effort to increase awareness of biodiversity conservation. In addition, research on migration routes and on the location and structure of stopover sites and wintering quarters of the species would assist the development of conservation measures (Trierweiler, 2010). A population and habitat viability assess-ment should be produced in addition to a manageassess-ment plan and conservation action plan; and the populations should be monitored to determine, protect and manage key breeding, wintering and dispersal sites.
Assessor(s): Cherkaoui, I., Azafzaf, H., Chokri, M.A., Benmammar Hasnaoui, H., Monti, F. & Garrido López, J.R.
Reviewer(s): Numa, C. & Qninba, A.
Contributor(s): Gyenge, P., Bakass, B., BirdLife International & Qninba, A.
Date: 2020–09–07
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