caa a22 4500 465757030 CHVBK 20180323111850.0 cr unu---uuuuu 170327e19900301xx s 000 0 eng 10.1007/BF00177283 doi (NATIONALLICENCE)springer-10.1007/BF00177283 Waterfowl of a subtropical African floodplain [Elektronische Daten] I. Seasonality of community composition and food resources [K. Rogers, C. Breen] Many water bodies in arid southern Africa are seasonal and waterfowl habitats become restricted during the dry winters. Nevertheless, some tropical species, such as the white-faced duck, are expanding their ranges into more temperate regions where summer habitats are available, thus increasing pressure on overwintering habitats. The subtropical Pongolo River floodplain is an important overwintering area for a diverse water-fowl community that includes 13 of the 16 species that breed in South Africa and one of the few regular migrants. Historical evidence suggests that numbers of white-faced duck, which represent over 70% of the floodplain community, have increased 10-fold over the last two decades. An abundant, nutritious food (Potamogeton crispus turions) attracts waterfowl to the Pongolo floodplain during winter and an increase in bird fat reserves suggests that they leave for summer breeding grounds in good condition. Unseasonal flood releases from an upstream reservoir may cause low food supplies in late spring before the onset of the summer rainy season when breeding habitats become available. This study emphasizes the need for a better understanding of the role of winter habitats in maintaining waterfowl populations. SPB Academic Publishing bv, 1990 African floodplains nationallicence Pongolo nationallicence Potamogeton crispus nationallicence waterfowl grazing nationallicence white-faced duck nationallicence winter habitat nationallicence Rogers K. Pongolo River Research Group, Department of Botany, University of Natal, Pietermaritzburg, South Africa aut Breen C. Pongolo River Research Group, Department of Botany, University of Natal, Pietermaritzburg, South Africa aut Wetlands Ecology and Management Kluwer Academic Publishers 1/2(1990-03-01), 85-97 0923-4861 1:2<85 1990 1 11273 https://doi.org/10.1007/BF00177283 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF00177283 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Rogers K. Pongolo River Research Group, Department of Botany, University of Natal, Pietermaritzburg, South Africa aut NATIONALLICENCE 700 1- Breen C. Pongolo River Research Group, Department of Botany, University of Natal, Pietermaritzburg, South Africa aut NATIONALLICENCE 773 0- Wetlands Ecology and Management Kluwer Academic Publishers 1/2(1990-03-01), 85-97 0923-4861 1:2<85 1990 1 11273 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer