Community structuration
The corresponding data (limited to the seven most captured small mammal species) were subjected to cPCA at the scale of the 9 areas encompassing the 49 localities, the first axis of which (Fig. S2) showed distinct distribution trends for the exotic M. musculus and all other small mammals. Mus musculus appears to be highly dominant overall on the coastal area North of the Gambia as well as on the Kaolack-Tambacounda axis, and present at high frequency in Tambacounda, in localities around Kidira (at the Senegal – Mali border) and in Haute-Casamance. Conversely, this species is absent from Basse-Casamance and south-Eastern Senegal, where the exotic R. rattus or native species mainly occur (Fig. 1). The second axis of the cPCA mostly showed a contrasted distribution of both exotic species and C. olivierivs. the native M. natalensis which is largely dominant in the Kédougou region, and is limited in the west by the eastern limit of Niokolo-Koba National Park, and the locality of Bransan (n°7 in Fig. 1) to the north. The other native rodent species (M. erythroleucus ,P. daltoni , A. niloticus in particular) are generally present in low frequency at all localities. However, we can note their particularly high proportions in villages of the Senegal river Valley north of Bakel (locality n°1 in Fig. 1). Crocidura olivieri is rarely absent from sampled localities (only 10/49), and regularly (co)dominant in catches around Tambacounda and on both sides of the Tambacounda-Kidira axis.