A nocturnally-active predator is mainly a diurnal hunter

• Published in: Journal of arid environments 2023-07, Vol.214, p.104998, Article 104998
• Main Authors: Tesler, Itay, Sivan, Jaim, Degen, A. Allan, Kam, Michael
• Format: Article
• Language: English
• Subjects: adults; air temperature; burrows; Cathemeral predator; Caudal luring; Cerastes vipera; defecation; Diel activity; Diurnal hunting; Hunting strategy; lizards; nocturnal activity; Sit-and-wait ambush; snakes
• ISSN: 0140-1963; 1095-922X
• DOI: 10.1016/j.jaridenv.2023.104998

The sit-and-wait hunter, Cerastes vipera, is a presumed nocturnally-active desert snake, although it feeds mainly on the diurnally-active lizard, Acanthodactylus spp. We hypothesized that nocturnal activity of C. vipera is primarily to locate an ambush site, and that Acanthodactylus spp. is predated mainly diurnally. We used the proportion of free-ranging C. vipera that defaecated per day to estimate daily feeding rate, and prey capture per night to estimate nocturnal feeding rate. In adult snakes (n = 161), defaecation was observed in 20.5% and nocturnal feeding in 3.1% per day. The difference between the two estimates represented the diurnal feeding rate, that is, 85% of the daily feeding was diurnal. All vipers ceased movement near midnight, when approximately 50% were in ambush. They maintained their position until morning and four individuals of each sex were followed during the day. These vipers displayed caudal luring in the presence of Acanthodactylus spp., ended ambush at approximately 10:00 when air temperature reached 40 °C, and then moved into a nearby burrow. We concluded that nocturnally-active C. vipera adults are mainly diurnal hunters, but could be classified as cathemeral predators. Diurnal caudal luring and differences in ambush strategy in C. vipera are documented for the first time. •Defaecation rate in free-living C. vipera was used to estimate daily feeding rate.•Prey capture at night was used to estimate nocturnal feeding rate.•Diurnal feeding was estimated to be 85% of the daily feeding rate.•Caudal luring was documented as late as 10:00 when air temperature reached 40 °C.•Nocturnally-active C. vipera was found to be mainly a diurnal hunter.