WINTERING OF BLACK STORKS (CICONIA NIGRA) FROM THE CZECH REPUBLIC IN DIFFERENT PARTS OF AFRICA

Miroslav Bobek1, Frantisek Pojer2, Lubomir Peske3 & Jaroslav Simek4

1 Czech Radio, Vinohradska 12, 120 99 Prague 2, Czech Rep.; 2 Agency for Nature Conservation and Landscape Protection of the Czech Republic, Kalisnicka 4-6, 130 23 Prague 3, Czech Rep.; 3 Slezska 43, 120 00 Prague 2, Czech Rep.; 4 Univ. of South Bohemia, Fac. of Biological Sciences, Branisovska 31, 370 05 C. Budejovice, Czech Rep.; e-mail capi@fido.cz; http://capi.internet.cz

Adult Black Storks (Ciconia nigra), fitted with satellite (PTT) and VHF transmitters in the Czech Republic in 1995-2000, flew to their wintergrounds both along the south-west migration flyway (six birds out of ten) and along the south-east one (four birds). One of the south-west migrants spent its winter in southern Spain, in the Guadalquivir estuary, whereas all others reached their main wintergrounds in sub-Saharan Africa in a belt approximately designated between 16.00 N and 5.00 N. Wintergrounds was located in different habitat types: in dry Sudanese savanna, in moist savanna of the Guinean type and in quite different Ethiopian highlands. Several expeditions have been carried out to explore five different wintergrounds. Three storks were successfully monitored in consecutive years (female Kristyna even four times) and all of them showed strong winter site fidelity in terms of few hundred square kilometres. Dependently on migration route, storks arrived to main wintergrounds from late September till early December, however arrival was variable also for repeatedly monitored storks. A ”buffer zone” in western and central Africa at the southern edge of the Sahara was found. In the zone storks aggregated into more numerous groups up to few dozens of individuals. Some storks stayed for the whole winter period in such areas - mainly in western Africa in inundated areas of the Senegal river in the Maghama region, Mauritania-Senegal border (probably also the Karakoro river area, Mauritania-Mali border). Other storks can use the zone for resting and feeding to restore fat reserves before other migration to main wintergrounds. Nevertheless, such other migration can be forced by increasing competition for water resources as has been shown in eastern Chad. Main wintergrounds of storks from the south-west migration group were localised in eastern Senegal, central and western Mali and in southern Mauritania; the south-east migrating storks finished their migration in northern Ethiopia, eastern part of Central African Republic (two birds) and in south-eastern Nigeria. Only short local movements up to few dozen kilometres were recorded at main wintergrounds where storks spend the winter season solitarily or in small groups. Several expeditions monitored also different threats to wintering storks. Besides the above mentioned competition (with both another wildlife and people with their livestock) for quickly drying water resources, main conflicts arise from wintering in areas of dense human settlement, where storks can become victims of vandalism (Ethiopia) or may be even of intended hunting (Nigeria). Lack of appropriate habitats for Black Storks is closely connected with expansion of agricultural lands. Tracked birds left their wintergrounds from mid-February till late March. Short-distance and two long-distance (520 km from western Mali to northern Sierra Leone and 960 km from eastern Senegal to northern Ivory Coast, respectively) movements were found just right before return migration. Such movements were probably forced by dry feeding sites. The Black Stork is one of the threatened European bird species; therefore it should be appropriate to ensure effective protection of sites and habitats with higher stork aggregation in wintergrounds. It would be very useful to declare the above Maghama area in southern Mauritania, which is an important stopover site as well as a main winterground for many Black Storks, as specially protected.

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