Jeroen Speybroeck wrote:At least in US deserts, it is considered rather crucial. This is one of the reasons why I chose the timing of my forthcoming Arizona trip in September like I did. Hopefully, it pays off. Would be nice to hear other people's opinions...
Yes Jeroen, I know this, some USA studies about the activity in Crotalus sp. They found in same month 15 in a night without moon and 2 in a night with full moon. But the rare thing is that we didnt find any track! And next day in a Cerastes cerastes habitat no vipers actived, in creeks, nothing. Just a juvenile/subadult under a rock. I am really surprised with this low activity in "mating season"
Mario Schweiger wrote:So one fail is Cerastes vipera - should be C. cerastes then!
Gabri, also during our visit in Merzouga, we found not one trail of C. vipera. Both specimens observed have been detected close to their hiding place.
As I know from my other trips before, it is much to early (1st half of May) to find C. cerastes, C. vipera, Lytorhynchus at night.
Visiting the area in summer and autumn, the dunes are full with tracks, and then you find the animals too.
You may not compare the coastal dunes, like Khnifis lagoon and others with the interior.
Yes, this is a Cerastes cerastes.
OK, you found them basking
. Last year in Khifiss I found about 10 tracks in 5 minutes, but in a hot wave in june. But we also found 9 Cerastes vipera last year in Negev dunes in final april, In interior and with cold (13-15º). Also in Knifiss we found a Lytorhynchus actived at night in final march. In the last trip when we arrived Merzouga the weather was 20º!! No wind. I hope to find at least 3 or 4 tracks. But no viper tracks. Maybe as you said, in Morocco interiorvipers are waiting the hot months for activity.
although with hard work, many kilometers and luck we have found some interesting species. 
