Project title: AVD - The African Vertebrates Databank
Time span: 2000 - 2005
Study area: The entire mainland Africa
Funding: Conservation International (10000 €) Institute of Applied Ecology (30000 €) Università di Roma La Sapienza (28000 €)
The number of species at risk of extinction around the world is continuously rising. On the other hand, limited resources are available for their conservation. Priorities are thus needed in order to maximise the benefit of conservation efforts (e.g. Myers et al., Nature 403, 2000). The systematic conservation planning approach (Margules and Pressey, Nature 405, 2000) that would enable the prioritisation process, relies on detailed maps of the distribution of target species on the ground. The knowledge on the geographic distribution of species is often poor, or limited to the extent of occurrence (EO), defined as the boundaries of the geographic area where specimens of that species are found. But species do occupy only part of their EO, namely the area of occupancy (AO). The AO is lesser than the EO because of ecological limitations (resources, predators, competitors) and contingency (e.g. barriers preventing the colonisation of an area). A species AO is seldom known. Habitat Suitability Models (HSM, e.g. Scott et al., Predicting species occurrences. Issues of accuracy and scale, 2002) can be used as a surrogate of the AO in biogeographical analyses provided that they have been evaluated and proved predictive within reasonable confidence limits (i.e. validated). HSMs predict to what extent a patch of land is suitable for a species, based on the value of ecological variables (such as vegetation type, elevation, human population density, distance to water) within the patch.
AVD has undertaken the goal of identifying conservation priorities for vertebrates in the African continent in three steps:
- Map distribution and build HSM inside geographic ranges for all African mammals and amphibians (no reptile data are available so far and will be collected by the IUCN Global Reptile Assessment in the neat future; bird models will be available by the end of 2005);
- Use the estimated AOs to highlight gap species in the current system of protected areas;
- Use the estimated AOs to run systematic reserve selection algorithms, in order to identify potential reserve networks for the conservation of mapped vertebrates.
AVD is a collaboration between the University of Rome La Sapienza (Italy), the Institute of Applied Ecology (Rome, Italy), Conservation International (Washington DC, USA), Birdlife International (Cambridge, UK), the Cambridge University (UK), and the Copenhagen Museum of Natural History (DK).