Biogeography and conservation of terrestrial afrotropical birds

Includes bibliography.This study aimed to describe patterns of distribution in terrestrial Afrotropical birds, to investigate the causes of these patterns, and examine how aspects of distributional patterns may be used to prioritize local regions for conservation attention. Presence-only data were gathered and digitized at one-degree square scale for 1686 terrestrial bird species that breed on or regularly visit sub-Saharan Africa as non-breeding migrants. Biogeographical analysis of the 1437 species that are globally restricted to sub-Saharan Africa (Afrotropical endemics) revealed a suite of geographical areas that have a homogenous and characteristic avifaunal composition, termed avifaunal zones. The approach used in this study ensured representativeness in the resultant biogeographical classification scheme, which was not biased towards avifaunas that are species rich or that contain many narrow endemics, and further included avifaunas that consisted of few, but taxonomically and ecologically distinct species (e.g. the Namib Province). Analysis of zonal boundaries exhibiting high levels of turnover, defined specifically as species replacement, were distinguished from zonal boundaries that are characterised by species richness gradients. For instance, the northern forest-savanna boundary between the Guineo-Congolian and Northern Savanna Subregions was shown to consist of a sharp ecotone between forest and savanna, whereas the boundary between the Northern Savanna and Northern Arid Subregions was shown to be dominated by species drop-outs. This shows that whereas the Northern Savanna Subregion represents a unique avifauna that is distinct from that of the Guineo-Congolian Subregion, the Northern Arid Subregion is merely a depauparate subset of the Northern Savanna avifauna. Patterns of species richness and narrow endemism where shown to differ between species groups that exhibit different life history characteristics (e.g. residents vs. migrants) and distributional characteristics Atrotropical endemics vs. nonendemics). Differences can probably be attributed to island biogeography and aerography theory

Where are the major gaps in the reserve network for Africa's mammals?

The original publication is available from http://www.cambridge.org/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.Postprint versio

A pragmatic assessment of the usefulness of the MODIS (Terra and Aqua) 1-km active fire (MOD14A2 and MYD14A2) products for mapping fires in the fynbos biome

The moderate resolution imaging spectroradiometer (MODIS) fire-affected area data are not currently available for download by the public; therefore, 1-km pixel MODIS active fire data (MOD14A2 and MYD14A2) were assessed as a potential source of fire history data for the fynbos biome. These data mapped between 60.1 and 65.7% of the area within fire boundaries mapped by reserve managers between July 2002 and April 2005. These results should not be taken as a negative reflection on the MODIS team, as active fires do not aim to map fire-affected area. Rather this exercise has helped identify specific limitations in the fynbos, which will provide insight into the fine-tuning of other MODIS fire products for use in the fynbos. Limitations are likely to be primarily due to sun-glint around coastlines; topographic shadows; highly reflective, light soils exposed after a fire; partial burning of pixels; patchy and irregular-shaped fires; and large pixel size. The MODIS active fire data are not sufficient for the purposes of developing a 4-year fire history of the fynbos. The publication of the 500-m MODIS fire-affected area data is eagerly anticipated as a solution

Geo-information pyramids for up-to-date and flexible conservation plans : a case study for Transfrontier Conservation Areas

The initiative to link habitat and parks across political borders, to form large Transfrontier Conservation Areas (TFCAs), has gained momentum in Africa and the world. TFCAs hold many advantages, one of them being the restoration of habitat connectivity in order to conserve ecosystem functioning. A feasibility study in 2002 highlighted 22 sites as potential TFCAs in southern Africa, and the Peace Parks Foundation is facilitating the implementation of eight of them. This paper describes a methodological framework with which to map remaining large, natural habitat fragments (or remnants) in southern Africa, the distribution, shape and size of which will provide the foundation and stakeholders with information on possible coarse-scale landscape linkages. This framework, which maps remnants, was designed to be transparent, systematic and dynamic to facilitate easy updating as TFCA projects mature, or updated data become available. This is intended to be the first in a series of studies towards developing an integrated, systematic framework for TFCA planning at a sub-continental scale. It does not aim to prioritize remnants or linkages

Avian endemism in northeastern tropical Africa

Proceedings of the Third International Symposium on the Flora of Ethiopia and Eritrea at the Carlsberg Academy, Copenhagen, August 25-27, 1999.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

Gaps in the protected area network for threatened Afrotropical birds

The original publication is available at www.elsevier.comProtected areas established for wildlife conservation (IUCN category I–VI protected areas) or for forest and watershed conservation (forest reserves) across mainland sub-Saharan Africa have high biodiversity values. However, they fail to cover over half of the 106 threatened bird species, and thus leave these vulnerable to extinction. An analysis of Red List bird species that are not represented in existing reserves indicates gaps in the current network of protected areas, namely: Mt. Cameroon-Bamenda highlands (Cameroon), the Angolan scarp (Angola), the Drakensberg Highlands (South Africa), the Highveld (South Africa), the Eastern Arc Mountains (Tanzania), the eastern African coastal forest mosaic (Kenya and Tanzania), the Albertine Rift (Uganda, Rwanda, Burundi, eastern Democratic Republic of Congo and western Tanzania), and the Ethiopian Highlands. The addition of Forest Reserves to the existing protected areas closes some of the reservation gaps for threatened birds in Africa. We suggest that these Forest Reserves should be included within official lists of protected areas, and that National forestry authorities be encouraged to manage these areas. Publication of scientific articles showing the conservation value of Forest Reserves is needed to raise local and international support and funding.Post-prin

Patterns of species richness and narrow endemism of terrestrial bird species in the Afrotropical region

The original publication is available at www.blackwell-science.com/ddiGeographical 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.Dr de Klerk was funded by the Foundation for Research Development (FRD)(Postgraduate Bursary and various grants to Prof. T.M. Crowe), the University of Cape Town (Gordon Sprigg Postgraduate Scholarship), the Percy FitzPatrick Institute, the Zoological Museum, University of Copenhagen. The FRD, Human Sciences Research Council, and Danish Research Academy provided funds for a collaborative research trip to work with Prof. FjeldsaÊ and Dr Burgess in Denmark. BirdLife International are thanked for allowing use of their Restricted Range Bird database. Our thanks to Dr Jane Turpie, Prof. Phil Hockey, Dr Peter Ryan, Dr Richard Dean, Louis Hansen, Rene Navarro, Alex Flemming, Prof. John Field, Gavin Heale, Andrew Lewis, Dirk Eisinger, and Melanie Simpson for comments and help with various aspects of this work. Two anonymous referees are thanked for their constructive comments. Finally a word of tribute to the late Richard Brooke for his help and inspiration with the mapping of bird species distributions.Postprint versio

Biogeographical patterns of endemic terrestrial Afrotropical birds

The original publication is available at http://www.blackwell-science.com/ddiBiogeographical zones are described for terrestrial bird species endemic to the Afrotropics using up-to-date distributional data and multivariate statistical techniques. This provides an objective basis for a hierarchy of subregions, provinces and districts, based on a set of rules. Results are compared to previous studies at continental and regional scales. Biogeographical zones for passerines and non-passerines are compared and found to be similar. Peaks of species richness and narrow endemism are described for the six major subdivisions (subregions) identified by the cluster analysis. Coincidence of peaks of species richness and narrow endemism is found to be low, such that areas selected to represent high species richness tallies will often fail to represent narrow endemics. Strong regionalization of Afrotropical birds indicates the need to use a biogeographical framework in conservation priority setting exercises to ensure that unique, but species-poor, avifaunas are not neglected.Postprint versio

Fire‑mediated disruptive selection can explain the reseeder–resprouter dichotomy in Mediterranean‑type vegetation

CITATION: Altwegg, R., De Klerk, H.M. & Midgley, G.F. 2014. Fire‑mediated disruptive selection can explain the reseeder–resprouter dichotomy in Mediterranean‑type vegetation. Oecologia, 177(2):367-377, doi:10.1007/s00442-014-3112-6.The original publication is available at www.springer.comCrown fire is a key selective pressure in Mediterranean-type plant communities. Adaptive responses to fire regimes involve trade-offs between investment for persistence (fire survival and resprouting) and reproduction (fire mortality, fast growth to reproductive maturity, and reseeding) as investments that enhance adult survival lower growth and reproductive rates. Southern hemisphere Mediterranean-type ecosystems are dominated by species with either endogenous regeneration from adult resprouting or fire-triggered seedling recruitment. Specifically, on nutrient-poor soils, these are either resprouting or reseeding life histories, with few intermediate forms, despite the fact that the transition between strategies is evolutionarily labile. How did this strong dichotomy evolve? We address this question by developing a stochastic demographic model to assess determinants of relative fitness of reseeders, resprouters and hypothetical intermediate forms. The model was parameterised using published demographic data from South African protea species and run over various relevant fire regime parameters facets. At intermediate fire return intervals, trade-offs between investment in growth versus fire resilience can cause fitness to peak at either of the extremes of the reseeder–resprouter continuum, especially when assuming realistic non-linear shapes for these trade-offs. Under these circumstances, the fitness landscape exhibits a saddle which could lead to disruptive selection. The fitness gradient between the peaks was shallow, which may explain why this life-history trait is phylogenetically labile. Resprouters had maximum fitness at shorter fire-return intervals than reseeders. The model suggests that a strong dichotomy in fire survival strategy depends on a non-linear trade-off between growth and fire persistence traits.http://link.springer.com/article/10.1007/s00442-014-3112-6Post-prin