干旱区生态环境知识资源中心

We here present an inventory of rodents from Niger, mainly based on cytotaxonomic data because of the presence of many groups providing sibling species. A total of 39 species are listed, one of which is a new chromosomal form (Taterillus sp.). Moreover, three other cytotypes already described but still not specifically attributed were found (Mastomys sp., Acomys sp. and Tatera sp). New karyotypic data are presented for Gerbillus nancillus, Graphiurus cf. parvus, Massouteria mzabi, and Xerus erythropus. Once again, the efficiency of cytotaxonomy for small mammals inventories is enhanced.

Specific distribution maps of poorly known species are thus completed. No clear gradients could be observed between what is currently defined as the West and the East African faunas. The distributions are mainly structured in a latitudinal manner. The Air massif appears as a continuous prolongation of the Sahelian area, rather than as a Sahelian refuge in the Sahara. Five biogeographical groups of species were distinguished: 1) a Sudanian group in the area receiving less than 700 turn rainfall, 2) a group of very widespread species largely overlapping the Sudanian (more than 700 turn rainfall) and the Sahelian areas, and sometimes including some Saharan localities, 3) a typical Saharan group, 4) some species infeoded to the mountainous Saharan area, and 5) few strictly commensal species. A global southward extension of several taxa confirms the desertification of the Sahel, as a result of both natural global warming and human activities.