We review here the tick species sensitive to climatic variations and which also clearly changed their distribution following the sub-Saharan drought of the 1970s. Namely 2 Argasina of the family Argasidae, sub-family Ornithodorinae: Alectorobius (Theriodoros) sonrai and Ornithodoros (Ornithodoros) savignyi, and 7 Ixodina of the family Amblyommidae, subfamily Rhipicephalinae: Hyalomma (Hya.) anatolicum excavatum, Hya. (Hya.) dromedarii, Hya. (Hya.) impeltatum, Hya. (Hya.) impressum, Hya. (Hya.) marginatum rufipes, Hya. (Hya.) nitidum and Hya. (Hya.) truncatum. To the recent recognition of the occurrence of Or. (Ori.) savignyi at all stages in the Sahelian zone, data on the recent appearance of Hya. (Hya.) anatolicum excavatum are added. Progressively, this species of Hyalomma is colonizing the northern third of Senegal. Moreover, Hya. dromedarii can be found at all stages in the north of the country. The other species quoted above progressed towards the south or their relative abundance changed. The known hosts for each species are quoted in their new distribution areas. Following the redescription of Hya. nitidum and the new recognition of the occurrence of Hya. anatolicum excavatum in Senegal, we propose a new identification key for the Hyalomma tick species of Senegal and Mauritania. This key also remains applicable to the ixodid fauna of the Occidental sub-Region of the Afro-tropical Region.