Browsing by Author "Fjeldsa, Jon"

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    Avian endemism in northeastern tropical Africa
    (Det Kongelige Danske Videnskabernes Selskab, 2001) Fjeldsa, Jon; De Klerk, Helen Margaret
    The avian endemism of Ethiopia and the Horn of Africa was analyzed using a database where all bird distributions in Africa south of the Sahara are recorded in a one-degree grid. Applying a hierarchical classification algorithm, the tropical northeastern Subregion of Africa stands out clearly and can be subdivided in all Ethiopian Highlands Province and the Somalia-Masai. Tana-Jubba and Turkana districts and a Danakil Province. The Horn of Africa Province is associated with the Northern Arid (Sahara) Subregion in this hierarchical classification, although this reflects the replacement of savanna with desert birds more than shared endemism. Although most of the Ethiopian Highland endemics are distributed all over the highland, a more complex pattern of local endemics can also be defined, using a complementarity algorithm. Local endemism is very pronounced among the larks, Alaudidae. The majority of endemics belongs to recently radiated groups, and is mainly related to the fauna of East Africa; however, the fauna of the Sidamo district contains relict elements, two of these of a significant evolutionary age. The pattern of endemism in the birds of northeastern tropical Africa has a number of features in common with patterns found in plants.
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    Patterns of species richness and narrow endemism of terrestrial bird species in the Afrotropical region
    (Wiley-Blackwell, 2002) De Klerk, Helen Margaret; Crowe, Tim M.; Fjeldsa, Jon; Burgess, Neil D.
    Geographical patterns and peaks of species richness and narrow endemism (defined by rangerestrictedness and range-size rarity) are described for terrestrial Afrotropical birds and subsets thereof based on residency, endemism, and taxonomy. Species richness for residents and Afrotropical endemics (species globally restricted to sub-Saharan Africa) peaks along the mountains and adjacent lowlands of eastern and southern Africa. Isolated mountains in central and western Africa and the lowlands of the north-eastern Congo Basin (Ituri) are highlighted to a lesser degree. Peaks of narrow endemism occur in these areas as well as in the Ethiopian Highlands (particularly for non-passerines), Somalia (particularly for passerines), and the Angolan Escarpment. Within residents, patterns of species richness vary greatly between Afrotropical endemics (which concentrate in forests on mountains and adjacent lowlands, and the southern Brachystegia woodlands) and non-endemic residents (which concentrate in Sudanian woodlands and the Ethiopian Highlands). Patterns of species richness of residents (species that breed in the Afrotropics) and non-breeding migrants (non-breeding visitors to the Afrotropics) also show notable differences. The latter concentrate in areas close to the Palaearctic, which forms their distributional range centres. Patterns of species richness and narrow endemism for Afrotropical endemics show broad-scale coincidence within mountains or mountain-lowland complexes, particularly the Cameroon-Bamenda Highland system, East African rift system and Eastern Arc mountains. However, fine-scale coincidence of peaks of species richness and narrow endemism within these complexes is low. Narrow endemism peaks occur in areas of topographical complexity, which may have conferred localized climatic stability over short-, medium-, and long-term climatic cycles (sensu Fjeldsa , 1994; Fjeldsa et al., 1997), allowing these areas to act as `species pumps'. Species accumulate in areas of high productivity. Lack of fine-scale coincidence of narrow endemism and species richness peaks have implications for conservation prioritization exercises.
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    Where are the major gaps in the reserve network for Africa's mammals?
    (Cambridge University Press (CUP), 2004-01) Fjeldsa, Jon; Burgess, Neil D.; Blyth, Simon; De Klerk, Helen Margaret
    The establishment of protected areas for wildlife conservation in Africa was motivated by a number of different reasons (including hunting, recreation and wildlife conservation). The current reserve network provides good coverage of the distributions of the 194 species of larger mammals (> 3 kg) and 51 species of threatened larger mammals. However, it is less effective in covering the distribution of all 197 of Africa's threatened mammal species, which includes >140 smaller bodied species ( <3 kg) often restricted to habitat patches. A fully comprehensive network of areas for the conservation of African mammals, especially those facing extinction, is not yet in place, and further reserves may be needed in the Horn of Africa (Somalia in particular), the Cameroon Highlands, parts of the eastern African coastal forests and Eastern Arc Mountains, and parts of the Albertine Rift Mountains. More and larger reserve areas are also required to adequately cover all the species of South Africa. Parts of these gaps are already covered by government forest reserves, and the importance of this reserve category for the conservation of African mammals, especially threatened species, needs to be better recognized. As many of the gaps in reserve coverage are in areas of high human population and good agricultural potential, conservation goals may be difficult to achieve unless we supplement traditional reserves with novel approaches to maintain natural habitats and wildlife outside reserves.