Movements and Migration

In Free State Province, breeding pairs are widely scattered in the south during the winter breeding period (July‒September), but concentrate to molt at certain large freshwater wetlands in the center of the province during November‒December, and then disperse to temporary brackish pans in the west for the late summer and autumn periods (97 Geldenhuys, J. N. (1975). Waterfowl (Anatidae) on irrigation lakes in the Orange Free State. Ostrich 46:219–235. Close , 98 Geldenhuys, J. N. (1976). Relative abundance of waterfowl in the Orange Free State. Ostrich 47:27–54. Close , 28 Geldenhuys, J. N. (1977). Feeding habits of South African Shelducks. South African Journal of Wildlife Research 7:5–9. Close , 1 Geldenhuys, J. N. (1980). Breeding ecology of the South African shelduck in the southern Orange Free State. South African Journal of Wildlife Research 10:94–111. Close ). Such movements are probably typical throughout the species’ range. It was previously reported to be a partial migrant in Namibia, being commonest in the north, in Damaraland, during winter (70 Winterbottom, J. M. (1971). A Preliminary Check-list of the Birds of South West Africa. South West Africa Scientific Society, Windhoek, Namibia. Close ), but more recent atlas data suggest that it is now mainly a summer visitor to far northern Namibia (43 Harrison, J. A., D. G. Allan, L. G. Underhill, M. Herremans, and A. J. Tree, Editors (1997). The Atlas of Southern African Birds. Volume 1. Non-passerines. BirdLife South Africa, Johannesburg, South Africa. Close ).

Recoveries of South African ringed birds (393 of 9,507 individuals ringed) reveal widespread movements across the South African range and occasionally into southern Namibia (99 Underhill, L. G., A. J. Tree, H. D. Oschadleus and V. Parker (1999). Review of Ring Recoveries of Waterbirds in Southern Africa. Avian Demography Unit, University of Cape Town, Cape Town, South Africa. Close ). The median distance covered was 249 km (of 328 ring recoveries) (100 Oatley, T. B., and R. P. Prŷs-Jones (1986). A comparative analysis of movements of southern African waterfowl (Anatidae), based on ringing recoveries. South African Journal of Wildlife Research 16:1‒6. Close ). The longest movement was 1,075 km, from Barberspan, North-West Province, to Vogelvlei, Western Cape Province, and an additional 12 recoveries were each in excess of 900 km (101 Milstein, P. le S. (1975). The biology of Barberspan with special reference to the avifauna. Ostrich (Supplement) 10:63. Close ). One bird moved across the virtual width of the range in one month (99 Underhill, L. G., A. J. Tree, H. D. Oschadleus and V. Parker (1999). Review of Ring Recoveries of Waterbirds in Southern Africa. Avian Demography Unit, University of Cape Town, Cape Town, South Africa. Close ).

Information needed.