This paper covers the domestication and distribution of chickens in different parts of the world and describes the global data bases containing information on chicken genetic resources. The review shows the dispersion of chickens from the putative centres of domestication to different parts of the world, although introduction of the domesticated chicken into Africa is poorly documented. Currently, there are three globally accessible data bases containing information on chickens; however none of these provide a comprehensive system for systematically classifying domestic chickens in developing countries in terms of their present-day uses, potential for the future and distribution within and across countries.
Such a system should be developed to include indigenous chicken genetic resources at the same level of detail as for other farm animals. The data management systems should incorporate all available information at the molecular level. Such information is important not only for discerning the existing diversity but also for making decisions on conservation priorities. Addressing the gaps in information on indigenous chicken genetic resources should primarily be the focus on the Domestic Animal Genetic Resources Information System (DAGRIS). DAGRIS, as a virtual library of indigenous animal genetic resources in developing countries, could play a leading role in delivering systematic information on the diversity, distribution and classification of domestic chicken in the tropics.