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Fish response to the annual flooding regime in the Kavango River along the Angola/Namibian border
Item type: Journal Article • Journal: South African Journal of Marine Science • Authors: C. H. Hocutt P. N. JohnsonThe results of the first seasonal survey of the fish of the Kavango River flood-plain along the Angola/Namibia border are reported. The river experiences peak flooding from February through June, with the 375-km long floodplain extending up to 5 km... -
A LIMNOLOGICAL PROFILE OF THE UPPER OKAVANGO DELTA AT LOW WATER LEVEL
Item type: Journal Article • Journal: Southern African Journal of Aquatic Sciences • Authors: Rob C. Hart --- ,Selected limnological attributes of the Okavango Delta panhandle were measured during a brief summer survey of “open-water” habitats extending from the permanent mainstream channel, through contiguous off-channel lagoons and still backwaters, to seasonally isolated floodplain lagoon and temporary pool biotopes... -
The influence of Pechuel-Loeschea leubnitziae (wild sage) on grass sward and soil seed bank composition
Item type: Journal Article • Journal: African Journal of Range & Forage Science • Authors: MJ Tedder --- Grassland Science, School of Life Sciences, South Africa KP Kirkman --- Grassland Science, School of Life Sciences, South Africa CD Morris --- Agricultural Research Council, c/o School of Life Sciences, South Africa WSW Trollope --- Research and Development, South Africa MC Bonyongo --- Okavango Research Institute, BotswanaSoil seed banks provide not only a historical record of vegetation composition but also the potential for post-disturbance revegetation. Pechuel-Loeschea leubnitziae (wild sage) is a multistemmed, aromatic shrub, occurring in Namibia, Botswana, Swaziland, Zimbabwe and the northern regions of South... -
Potential environmental impacts associated with the proposed abstraction of water from the Okavango River in Namibia
Item type: Journal Article • Journal: African Journal of Aquatic Science • Authors: P AshtonThe Namibian Department of Water Affairs has in the past faced considerable pressure to relieve the water shortages caused by recent droughts. One of the options considered in 1996, following poor runoff during the 1994/95 and 1995/96 seasons, was a... -
An analysis of plant species distributions on the floodplain of the Okavango River, Namibia, with respect to impacts of possible water abstraction
Item type: Journal Article • Journal: African Journal of Aquatic Science • Authors: NJ Diederichs WN ElleryThe proposed abstraction of water from the Okavango River in Namibia could potentially result in significant changes in the vegetation of floodplains downstream of the abstraction point. Direct gradient analysis was used to determine the distribution of the most common... -
Low allozyme variation in tigerfish Hydrocynus vittatus (Teleostei: Alestidae) from the Okavango panhandle, with notes on the selection of candidates for artificial breeding
Item type: Journal Article • Journal: African Journal of Aquatic Science • Authors: M Soekoe --- Centre for Aquatic Research, Department of Zoology, South Africa NJ Smit --- Centre for Aquatic Research, Department of Zoology, South Africa H van der Bank --- Centre for Aquatic Research, Department of Zoology, South AfricaTo ensure the utilisation of optimal tigerfish gene pools for artificial propagation, the hypothesis that tigerfish from the Okavango system should have greater heterozygosity than those from smaller river systems was tested. This electrophoretic analysis provides the first report of... -
Water quality dynamics in the Boro-Thamalakane-Boteti river system, northern Botswana
Item type: Journal Article • Journal: African Journal of Aquatic Science • Authors: G Tubatsi --- Okavango Research Institute, Botswana MC Bonyongo --- Okavango Research Institute, Botswana M Gondwe --- Okavango Research Institute, BotswanaThe quality of water in aquatic systems is subject to temporal and spatial variations due to varying effects of natural and anthropogenic factors. This study assessed the dynamics of water quality in the Boro-Thamalakane-Boteti river system along an upstream–downstream gradient... -
Diversity, dispersal and disturbance: cladoceran species composition in the Okavango Delta
Item type: Journal Article • Journal: African Zoology • Authors: Markus Lindholm --- Norwegian Institute for Water Research/NIVA, Norway Dag O. Hessen --- Department of Biology, Norway Lars Ramberg --- Harry Oppenheimer Okavango Research Centre, University of Botswana, BotswanaCommunities exposed to intermediate disturbances have been shown to be more diverse than more stable or unstable systems. We recorded the diversity pattern of zooplankton in the Okavango Delta, Botswana, a system which include water bodies with different stability with... -
Flocking dynamics and roosting behaviour of Meyer’s parrot (Poicephalus meyeri) in the Okavango Delta, Botswana
Item type: Journal Article • Journal: African Zoology • Authors: Rutledge S. Boyes --- University of KwaZulu-Natal, South Africa Michael R. Perrin --- University of KwaZulu-Natal, South AfricaFor most of the year, Meyer’s parrots in the Okavango Delta do not form large feeding flocks, and groups larger than two or three are probably the result of opportunistic aggregation at favoured food items after dispersion from communal roosts... -
Ecology of diplostomid (Trematoda: Digenea) infection in freshwater fish in southern Africa
Item type: Journal Article • Journal: African Zoology • Authors: Andri Grobbelaar --- Department Zoology and Entomology, South Africa Liesl L. Van As --- Department Zoology and Entomology, South Africa Hennie J.B. Butler --- Department Zoology and Entomology, South Africa Jo G. Van As --- Department Zoology and Entomology, South AfricaThe complex life cycles of most trematode parasites include three hosts. The first intermediate host is a snail, the second is normally a teleost fish and a piscivorous bird serves as the definitive host. Lymnaeid snails are most likely to... -
Pathology of eyes and brain of fish infected with diplostomids, southern Africa
Item type: Journal Article • Journal: African Zoology • Authors: Andri Grobbelaar --- Department Zoology and Entomology, University of the Free State, South Africa Liesl L van As --- Department Zoology and Entomology, University of the Free State, South Africa Jo G van As --- Department Zoology and Entomology, University of the Free State, South Africa Hennie JB Butler --- Department Zoology and Entomology, University of the Free State, South AfricaOnly a few reports exist on diplostomid metacercariae found in southern African fish and even less information is available on the pathology associated with these infections. During surveys conducted in December 2008 and August 2010, different fish species were collected... -
Small farmers’ adoption behaviour: Uptake of elephant crop-raiding deterrent innovations in the Okavango Delta, Botswana
Item type: Journal Article • Journal: African Journal of Science, Technology, Innovation and Development • Authors: Sekondeko R. Noga --- Okavango Research Institute, Botswana Oluwatoyin D. Kolawole --- Okavango Research Institute, Botswana Olekae Thakadu --- Okavango Research Institute, Botswana Gaseitsiwe Masunga --- Okavango Research Institute, BotswanaThis paper invokes the adoption-diffusion model to examine two introduced elephant crop-raiding deterrent innovations (ECDIs), and the factors influencing their adoption by small farmers in the Okavango Delta, Botswana. Two communities (Gudigwa and Eretsha) were purposefully selected as case studies... -
A baseline classification of riparian woodland plant communities in the Okavango Delta, Botswana
Item type: Journal Article • Journal: Southern Forests: a Journal of Forest Science • Authors: Gaolathe Tsheboeng --- Okavango Research Institute, Botswana Mike Murray-Hudson --- Okavango Research Institute, Botswana Keotshepile Kashe --- Okavango Research Institute, BotswanaIn the Okavango Delta information on the riparian woodland vegetation community composition and distribution is generally lacking. Past studies in the Delta were mainly focused on the quantitative classification of seasonal floodplain herbaceous vegetation communities. The aim of this study... -
New insights into the taxonomic status, distribution and natural history of De Witte’s Clicking Frog (Kassinula wittei Laurent, 1940)
Item type: Journal Article • Journal: African Zoology • Authors: Werner Conradie --- , South Africa Chad Keates --- , South Africa Javier Lobón-Rovira --- , Portugal Pedro Vaz Pinto --- , Portugal Luke Verburgt --- , South Africa Ninda L Baptista --- , South Africa James Harvey --- , South Africa Timóteo Júlio --- , South AfricaKassinula is a monotypic genus of small frog in the family Hyperoliidae, only represented by Kassinula wittei. This species morphologically resembles both Kassina Girard, 1853 and Afrixalus Laurent, 1944, and its taxonomic status has been debated for decades. It has...