Changes in the foraging mode of the lizard Acanthodactylus schreiberi at Caesarea and Nizzanim sand dunes

Lizards forage actively or from ambush and anywhere between these extremes. Little is known about the ultimate factors that determine the tendency towards one of these two foraging modes (FM). Many studies correlate species. FM with environmental conditions, but species may be constrained to a FM by their taxonomy-dictated morphology. As an alternative, we studied ultimate factors that determine lizards FM by looking at a single species with flexible FM in diverse environments. We examined whether the FM of the lacertid Acanthodactylus schreiberi differs with age and among habitats. We conducted the study at Caesarea and Nizzanim in stabilized, semi-stabilized, and shifting dunes, and, in Nizzanim, also in dunes whose vegetation was partially removed. We measured moves per minute (MPM) and percent of time spent moving (PTM)
in 15-min-long observations. We found that juveniles are significantly more active (higher PTM) than adults. A. schreiberi modifies its foraging, so that it is more active (higher MPM and PTM) in shifting than in semi-stabilized and stabilized dunes. In addition, MPM and PTM values on manipulated dunes were intermediate between stabilized and semi-stabilized dunes, thus the removal
manipulation created a habitat that is treated by the lizards only partially as the target dunes.