Yes, I talked about sand by the photo´s substrate. But I´ve never found a good habitat in Sidi Ifni for horned viper, with or without sand. Some kilometers out of the argans, in Guelmim for example, Cerastes c. is quite common. And from Guelmim to the east in rocky areas (Guelmim, Assa, Akka, Tata, Ouarzazate, Agdz, Tinejdad, Erfoud, Bouarfa, etc..,). A rare thing is that in Morocco C. cerastes it´s not common in dunes as Tarfaya, Mhamid, Merzouga... where C. vipera occurs whereas in Israel C. cerastes is very very common in dunes, without any rock, and in sympatry with C. vipera
Maybe in Mhamid is possible to find both species together???