We did a study in Niger during the 2003 rainy season to assess malaria vector presence and abundance across a south-north transect containing isohyet curves of 800-100 mm, corresponding to the most variable rainfall zone. 14 villages were sampled in the Soudanian, Sahelian, and Saharan regions. Members of Anopheles gambiae complex were found in all three zones, as expected. However, A funestus was also found in eight of the villages: all four of those in the Soudanian region and four of six in the Sahelian zone. This distribution is similar to that seen in the 1960s, but more recent studies have failed to show it. Irrigation is limited to the Niger valley and could not explain the comeback of A funestus in these regions. Although a global decrease in rainfall is still evident, groundwater levels are increasing in several areas of the Sahel. 3