Patterns of species richness and narrow endemism of terrestrial bird species in the Afrotropical region
Date
2002
Journal Title
Journal ISSN
Volume Title
Publisher
Wiley-Blackwell
Abstract
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.
Description
The original publication is available at www.blackwell-science.com/ddi
Keywords
Species richness, Narrow endemism, Afrotropical birds
Citation
De Klerk, H.M., Crowe, T.M., Fjeldsa, J. & Burgess, N.D. 2002. Patterns of species richness and narrow endemism of terrestrial bird species in the Afrotropical region. Journal of Zoology, 256, 327-342.