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Contents : Accipitridae: vultures kites hawks eagles buzzards and harriers 239 Montagu s Harrier 14 Bloupaddavreter MONTAGU S HARRIER Circus pygargus 5 18 1 Montagu s Harrier is a Palearctic nonbreeding migrant to southern Africa where it is largely restricted to the northeast. It occurs widely in subSaharan Africa but is generally an uncommon visitor as far south as southern Africa. In southern Africa birds are likely to be of Russian origin. It is 2 usually encountered singly or in loose associations but may roost in small groups. Immatures and females of this species and of the Pallid Harrier C. macrourus are very difficult to tell apart in the field. Male Montagu s Harriers however are distinctive and most records probably represent males. 3 The vegetation analysis shows that it was recorded mainly from savanna and grassland regions. Most records are concentrated in the grasslands of northern and eastern Botswana: Chobe floodplains 4 Savuti Marsh Northern Plains Makgadikgadi depression and fossil valleys in the Kalahari (Abernethy & Herremans 1994 Penry 1994) the plateau 10 of central Zimbabwe and the northern Transvaal especially in the northern Kruger National Park and in the grasslands of the central plateau of South Africa. It appears more restricted to the relatively mesic northeast than the Pallid Harrier which extends further into the drier southwest of southern Africa (Steyn 1982b). It arrives mainly during December reaches peak numbers in January and February and is mostly gone by the end of March. Arrival in Zones 1 and 5 is earlier than further south and the models indicate that it arrives about a month earlier in the east compared with the west. Once common in the Transvaal at least in the 1800s it is now relatively rare in most of southern Africa except Botswana where it is still locally fairly common (Boshoff et al. 1983 Tarboton et al. 1987b Abernethy & Herremans 1994). This reflects an overall decline on its breeding grounds although it is stable and even locally increasing in part of the breeding range (Clarke 1990 Del Hoyo et al. 1994). Causes include habitat loss and nest failures as the result of harvesting in cereal fields where many pairs nest. R.E. Simmons 2 22 6 26 7 8 34 14 18 26 22 30 Reporting rates for vegetation types %0 0.8 Okavango 1.4 Northern Kalahari 1.3 Miombo 0.8 Mopane 0.7 E Zimbabwe Highlands 0.5 Arid Woodland 0.4 Central Kalahari 0.3 Sweet Grasslands 0.2 Southern Kalahari 0.2 Sour Grasslands 0.2 Mixed Grasslands 0.1 Moist Woodland 0.1 East Coast Littoral 0.0 Also marginally in East Coast Littoral. 1 5 2 6 3 7 4 8 Occurrence reporting rate (%) 1 2 1 2 1 J A S O 34 Recorded in 215 grid cells 4.7% Total number of records: 309 Mean reporting rate for range: 2.6% 1 2 30 J ASONDJ FM NDJ FMAMJ Models of seasonality for Zones. Number of records (top to bottom left to right): Occurrence: 42 26 5 0 92 59 56 4. A M J 1.6

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