Herpetology Notes, volume 8: 155-156 (2015) (published online on 10 April 2015) Arabian sand boa Eryx jayakari (Squamata: Boidae) preying on Arabian toad-headed agama Phrynocephalus arabicus (Squamata: Agamidae): a nocturnal-to-diurnal species interaction Tiziano Londei The Arabian sand boa Eryx jayakari Boulenger, 1888, agama Phrynocephalus arabicus Anderson, 1894. is a small snake from the Arabian Peninsula and southern The photograph (Figure 1a) suggests that the snake Iran, highly adapted to life in sandy deserts. It has seized the lizard by the foreleg when it approached morphological adaptations for burrowing and moving the concealed predator. When I touched the snake, the through soft sand reminiscent of those in the sandfish lizard was released and immediately ran away, which skink Scincus mitranus Anderson, 1871 (Gardner, suggests that not much time had elapsed since its 2013). While it is quite a common species in suitable capture. Other Arabian toad-headed agamas, typically habitats, it may remain unnoticed even during extensive diurnal reptiles (see Kooij, 2000), were also active at surveys (see Kooij, 2001). This snake usually burrows that time. Meteorological conditions may have favoured quite deep in the sand during the day, but rises to the diurnal activity of the snake. The locality (20.97291°N surface at night to hunt (Egan, 2007). A recent study 58.62674°E) is not far from the sea, from which at that of prey remains in stomach contents revealed mainly time (Figure 1b) the south-east monsoon was bringing lizards, rodents and beetles. Diurnal lizards (Schmidt’s relatively cool moist air. The nocturnal Arabian sand fringe-toed lizard Acanthodactylus schmidti Haas, 1957) boa may opportunistically become a diurnal predator in the stomach contents were considered due to snakes under circumstances unfavourable for night ambushing. foraging at night for inactive prey (Al-Sadoon and Al- Its elliptical pupils may serve in this respect, too, as Otaibi, 2014). However, this snake has the most upward expandable pupils are common in animals that are facing eyes in its genus, and oblique elliptical pupils, active during both day and night, though slit pupils apparent adaptations to detect prey moving behind and are usually vertical, instead of oblique, in snakes (e.g., beside the snake’s head. This strongly suggests that Werner, 1967). active hunting in this species may be less important than lying in ambush in the sand with just the eyes above the Acknowledgements. My sister Raffaella draw my attention to surface. The following observation gives some evidence “that impressive sight”. Giuliana Marzi provided the photograph for Figure 1b. Andrew S. Gardner, Roberto Sindaco and an that active prey is ambushed not only at night but also anonymous reviewer offered useful suggestions to improve the in daytime. manuscript. On 13 August 2014, 8:18 a.m. local time, near my night camp in Wahiba Sands, Oman, I observed an References Arabian sand boa constricting an Arabian toad-headed Al-Sadoon, M.K., Al-Otaibi, F.S. (2014): Ecology of the Sand Boa, Eryx jayakari in Riyadh Region of Saudi Arabia. Saudi Journal of Biological Sciences 21: 391-393. Egan, D. (2007): Snakes of Arabia: A field guide to the snakes of the Arabian Peninsula and its shores. Dubai, Motivate Publishing, 208pp. Via San Vincenzo 20, 20123 Milano, Italy Gardner, A.S. (2013): The Amphibians and Reptiles of Oman and E-mail: [email protected] the UAE. Frankfurt, Chimaira Press, 480pp . 156 Tiziano Londei Figure 1. (a) Arabian sand boa with Arabian toad-headed agama; (b) location of the encounter in the Wahiba Sands, Oman, 13 August 2014. Kooij, van der, J. (2000): The herpetofauna of the sultanate of Oman. Part 1: The amphibians, worm lizards, agamas and chameleons. Podarcis 1: 70-102. Kooij, van der, J. (2001): The herpetofauna of the Sultanate of Oman: Part 4: The terrestrial snakes. Podarcis 2: 54-64. Werner, Y.L. (1967): Dark adaptation of the vertical pupil in a snake. Herpetologia 23: 62-63. Accepted by Zoltán Nagy.