Seasonal Changes in the Diversity and Numbers of Waterbirds in a Tropical River in Southern Africa
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Although freshwater habitats play a crucial role in most ecosystems in the world, little is known on their functioning in tropical regions even in regard to the most often studied avian communities. In this study, counts on waterbirds were conducted in dry and wet season (in years 2001-2008) in a riverine habitat in southern Africa (Shamvura stretch of the Okavango River). In total, 84 waterfowl species were recorded. The birds were assigned to different guilds according to their migration activity, diet and nesting site selection. In overall, the species number was almost the same (74 vs. 73) in the wet and dry season. The abundance of all resident species recorded was lower in wet (N = 5992) than in dry seasons (N = 6965)(χ2 = 73.1, P < 0.01). In both seasons Palearctic migrants were represented by seven species, which comprised 1-2% of all waterbirds. Six species were classified as dominants: African reed cormorant Phalacrocorax africanus, African openbill stork Anastomus lamelligerus, cattle egret Bubulcus ibis, wattled lapwing Vanellus senegallus, African darter Anhinga rufa and white-faced duck Dendrocygna viduata. In the wet season the dominant species comprised 68%, while in dry season – 52.5% of all birds recorded. Significant seasonal differences in the numbers of individuals were shown for the following species: African reed cormorant, great egret, squacco heron, wattled lapwing and pied kingfisher. Insectivorous and omnivorous birds were more abundant in wet season, while piscivorous, carnivorous and plant eating birds in dry season. These differences can be related mainly to seasonal variation in the availability of food as well as to the timing of breeding.
Bibliogr. 36 poz., rys., tab., wykr.
-  Adam M., Musilova Z., Musil P., Zouhor J., Romportl D.2015 – Long-term changes in habitat selection of wintering waterbirds: high importance of cold weather refuge site – Acta orn.50: 127-138.
-  Allan D. G., Davies G. B.1999 – The birds of the middle Komati River valley, Swaziland – Durban Mus. Nov.24: 22-42.
-  Allan D. G., Jankins A. R.1993 – A count of waterbirds along a section of the lower Orange River – Bontebok, 8: 33-34.
-  Bethunes S.1991 – Kavango River wetlands – Madoqua, 17: 77-112.
-  Carpenter S. R., Cole J. J., Hodgson J. R., Kitchell J. F., Pace M. L., Bade D.2001 – Trophic cascades, nutrients, and lake productivity: whole-lake experiments – Ecological Monographs, 71: 163-186.
-  Dingle H.2008 – Bird migration in the southern hemisphere: a review comparing continents – Emu, 108: 341-359.
-  Hockey P. A. R., Dean W. R. J., Ryan P. G. (eds.). 2005 – Roberts' Birds of Southern Africa.John Voelcker Bird Book Fund, Cape Town.
-  Groom M. J., Meffe G. K., Carroll C. R.2006 – Principles of biological conservation – 3rd ed. Sunderland (MA, USA).
-  Kopij G. 1997 – Quantitative studies on birds in the Willem Pretorius Game Reserve – Mirafra (Bloemfontein), 14 (1/2): 17-21.
-  Kopij G. 2001 – [Avifauna of Niemodlin fishponds] – Chr. Przyr. Ojcz.57: 46-80 (in Polish).
-  Kopij G. 2006 – The Structure of Assemblages and Dietary Relationships in Birds in South African Grasslands – Wydawnictwo Akademii Rolniczej we Wrocławiu, Wrocław.
-  Kopij G. 2012 – Avian assemblages of river valleys in Lesotho lowlands, Senque Valley and foothills – Berkut, 21: 23-30.
-  Kopij G. 2013a – Avian assemblages of river gorges in the Maloti/Drakensberg ‘hotspot’ region, southern Africa – Zoology & Ecology, 23: 171-182.
-  Kopij G. 2013b – Avian assemblages of river valleys in Lesotho lowlands, Senque Valley and foothills – Berkut, 21: 23-30.
-  Kopij G. 2013c – Distribution, abundance and habitat of Palearctic migrant in Lesotho (Maloti/Drakensberg region) – Orn. svec.23: 123-129.
-  Kopij G. 2013d – Seasonal and altitudinal variations in an avian assemblage in an inselberg Olea-Buddleia vegetation in the dry Cymbopogon-Themeda grassveld, South Africa – Orn. Observ.4: 158-167.
-  Kopij G. 2013e – Avian assemblages in natural and modified Koakoland (Mopane) Savanna in the Cuvelai Drainage System, North-Central Namibia – Lanioturdus (Windhoek), 46 (5): 22-33.
-  Kopij G. 2013f – Seasonal changes in avian assemblages in Kaokoland (Mopane) Savanna in the Ogongo Game Reserve, north-central Namibia – Int. Sci. Tech. J. Nam.2: 44-58.
-  Kopij G. 2017a – Migratory connectivity of South African Cattle Egrets (Bubulcus ibis, Ciconiiformes, Ardeidae) – Zool. Zh.95: 1-11.
-  Kopij G. 2017b – Structure of avian assemblages in Zambezian Baikiaea woodland, northern Namibia – Zoology & Ecology, 27: 1-10.
-  Mendelsohn J., el Obeid S. 2003 – Sand and Water. A profile of the Kavango Region – Struik Publishers, Cape Town.
-  Mendelsohn J., el Obeid S. 2004 – Okavango River, the flow of a lifeline – Struik Publishers, Cape Town.
-  Mendelsohn J., van der Post C., Ramberg L., Murray-Hudson M., Wolski P., Mosepele K.2010 – Okavango Delta: Floods and Life – RAISON, Windhoek.
-  Monadjem A. 2000 – An avifaunal (Aves) survey of the lower Usuthu River basin, Swaziland – Durban Mus. Nov.25: 25-31.
-  Morin P. J. 2011 – Community Ecology.2nd ed – Wiley-Blackwell, Oxford.
-  Nilsson L.2008 – Changes in numbers and distribution of wintering waterfowl in Sweden during forty years – Orn. svec.18: 135-236.
-  Nisbet I. T. C., Welton M. J. 1984 – Seasonal variation in breeding success of common terns: consequences of predation) – Condor, 86: 53-60.
-  Pielou E. C. 1981 – The usefulness of ecological models: a stock-taking – Quarterly Rev. Biol.56: 17-31.
-  Shannon C. E. 1948 – A mathematical theory of communication – Bell System Techn. J.27: 37, 9-423, 623-656.
-  Simmons R. E., Allan D. G.2002 – The Orange River avifauna: abundance, richness and comparisons – Ostrich, 73: 92-99.
-  Simpson E. H. 1949 – Measurement of diversity – Nature, 163: 688.
-  Shorrocks B. 2007 – The Biology of African Savannahs – Oxford University Press, Oxford.
-  Sørensen T. 1948 – A method of establishing groups of equal amplitude in plant sociology based on similarity of species and its application to analysis of the vegetation on Danish commons.Kong. Dan. Vidensk. Selsk.5(4): 134.
-  Sutherland W. J.2000 – The conservation handbook. Research, management and policy.Blackwell Science, Malden (MA, USA).
-  Underhill L. G., Tree A. J., Oschadleus H. D., Parker V.1999 – Review of Ring Recoveries of Waterbirds in Southern Africa – Avian Demography Unit, University of Cape Town, Cape Town.
-  Witkowski J., Orłowska B.2012 – [Changes in abundance of breeding avifauna of the Milicz fish ponds between 1995 and 2010] – Ornis polon.53: 1-22 (in Polish).
Opracowanie rekordu w ramach umowy 509/P-DUN/2018 ze środków MNiSW przeznaczonych na działalność upowszechniającą naukę (2019).