Important Bird Areas in Kenya.—L. Bennun and P. Njoroge. 1999. Nature Kenya, Nairobi, Kenya. 318 pp., 69 line drawings, 58 maps, 97 tables. ISBN 9966-9921-1-1. £18.00 (paper).
Where are the important areas for on-the-ground conservation in Africa? At the Eighth Pan-African Ornithological Congress in 1992 in Burundi, BirdLife International launched an ambitious program to answer this question by identifying Important Bird Areas (IBAs) across the continent (Bennun and Fishpool 2000). IBAs are defined as sites holding: a) globally threatened species (IUCN 2000); b) species with restricted ranges (<50 000 km2); c) “biome-restricted” species; or d) large concentrations of particular birds. Directories of IBAs have already been published for Egypt, Ethiopia, Madagascar, and Southern Africa (Botswana, Lesotho, Namibia, South Africa, Swaziland, and Zimbabwe). Important Bird Areas in Kenya is the latest in the series.
This book is a gem. It demonstrates both how much and how little we need to do to implement conservation in the country, and in the tropics generally. The difficulty of the task is determined by its human dimensions. Kenya's human population growth has fallen to 2.7%, but absolute pressure is high with ∼25 million people concentrated in the fertile highlands and coast (only 20% of the country). Further, the institutional capacity for conservation is weak, being divided between no fewer than ten government ministries, and hampered by the scarcity of resources for implementation. On the bright side, the task is eased by the concentration of species in relatively few sites. Kenya's IBAs cover only 10% of its land area, and nearly three-quarters of this 570 000 km2 is already protected.
The layout of Important Bird Areas in Kenya is simple and easy to use. Its introductory chapters are comprehensive but not stolid, totalling 57 pages. The first eight pages are a summary, with two of text plus a full tabulation and clear map of the IBAs. This brevity is extremely important: the people in whose hands this book will do the most good are land managers and policy-makers with little time to read more than a page or two. The second section is a page of acknowledgments; that nearly a hundred individuals and a dozen institutions are credited is testimony to the amount of work that this book represents. The third section, of six parts, gives useful overviews: of the book, Kenya's geography, conservation issues, its “institutional, legislative and policy framework,” and a summary and justification of the selection of Kenya's 60 IBAs.
The sixth part, “Priorities for action,” concludes the introduction by classifying sites as “critical” (19 sites), “urgent” (18) or “high” (23). This classification is not an attempt to elevate importance artificially by making the lowest class “high” (in the manner of, say, the sizes of McDonald's fries), but instead implicitly designates the rest of the landscape as low priority. The classification system assigns scores for each site's risk and its importance for both birds and “other biodiversity.” Sites scoring highly in both categories are designated as the top priorities. I am unconvinced by the token inclusion of “other biodiversity” here or by the complex ranking system of the four categories used to define the IBAs in the first place. But no matter: I have no quarrel with the final prioritization of sites.
The bulk of the book is composed of accounts of each of the 60 sites, averaging three pages per site and ranging from a single page for the Masinga Reservoir (IBA 30) to no less than seven for the Tana River Delta (IBA 22). The layout of each account is logical, with a site description, discussions of the birds and of other wildlife, summary of conservation issues, and extensive bibliography (I was happy to see that references are also given in the text, where relevant). All sites are mapped; some together, all to a very high quality. Comprehensive tables for each site detail all of the species for which the site has been designated, along with all regionally threatened species (Bennun and Njoroge 1996). Each site is introduced with a very handy header, giving a logical code number, geographic center-point coordinates, province, district, extent (in ha), altitude, legal status, and the IBA categories of species represented (I was sorry not to see each site's priority ranking also given here). Five potential IBAs which only just fail to meet the criteria for inclusion are also briefly detailed.
Following the main accounts is an impressive reference section including little-known reports, popular literature, and extensive coverage of the scientific journals. Two appendices give the distribution by site of species triggering each of the four IBA categories and calculation details for the bird importance scores; and four indexes conclude the book: two of birds (by scientific and common names), one of other taxa (scientific and common names combined), and one of sites (by code and name). Overall the book is wonderfully easy to use, with very effective use of light blue shading to highlight important text. It is also lightened throughout by delightful line drawings (illustrating key species for nearly all sites) by Edwin Selempo.
Does Important Bird Areas in Kenya have any shortcomings? This sort of project is vulnerable to an overarching criticism: are these Important Biodiversity Areas? Or, more importantly, how well do the conservation priorities for birds represent species in other groups (Howard et al. 1998)? We can test this for Kenya using a dataset compiled at the Zoological Museum of the University of Copenhagen on the distribution of all African birds, mammals, snakes, and amphibians (Brooks et al., in press). As it turns out, IBAs represent Kenyan terrestrial vertebrate biodiversity extremely well, although the degree to which they represent plants and invertebrates, and biodiversity processes, remains untested. IBAs capture 1593 of the 1640 (97%) species occurring in the country, which is better than a random set of the same number of areas (which, based on 1000 repetitions, captures 1501 ± 82 of the country's species), and not much worse than a “greedy” set of areas which represent 1625 species in the same area. Further, IBAs represent all but one Kenyan endemic species (the gerbil Gerbillus cosensi from Ngamatak on the Turkwel River) and all but two globally threatened species (G. cosensi, and the bat Taphozous hamiltoni from the Kaitherin Hills).
A neat summary of the degree to which IBAs capture biodiversity more generally comes from Leon Bennun's own paper at the Tenth Pan-African Ornithological Congress. He compared Kenyan IBAs to conservation priorities for other taxa in the country, and classified IBAs into three categories as a result. The first are the obvious, sites clearly important for other biodiversity as well as birds, like Arabuko-Sokoke Forest (IBA 7). The second are the overlooked, sites which once discovered to be important for birds have also been seen to be important for other taxa, such as the Kinangop Grasslands (IBA 4). And the third are the odd, sites which although important for birds are of little importance more generally, exemplified by Nairobi's sewage facility at Dandora Ponds (IBA 35). Happily, it seems likely that a fourth category of sites not included as IBAs but nonetheless important for biodiversity—the omitted—is a small one.
There is little else to criticize with the book. Of course, a few typos have slipped through. Those that caught my eye include the omission of two dots from the priority matrix (both from the threat 2 row, one each from the biological importance 7 and 6 columns) on p. 51, and the designation of the coordinates for the Cherangani Hills (IBA 43), on p. 187, as south of the equator whereas they are actually north. The referencing is also not perfect, with some references given in the text but not listed, some mis-cited, and a few inconsistencies in the reference list format. The chaotic volume numbering for the Journal of the East African Natural History Society is a historical legacy, but it would have been possible to give logical volume numbers for their Bulletin, and very nice to have provided page numbers for the excellent series of Research Reports of the Centre for Biodiversity, National Museums of Kenya: Ornithology.
The trivial nature of these problems only serves to highlight the quality of this work. To conclude, if you have any interest whatsoever in African birds, or in conservation priority-setting, you simply must buy this book. As a practical example of how to select areas for conservation on the ground, it is unrivalled.