Differential Handling of Dangerous and Non-Dangerous Prey by Naive and Experienced Texas Spotted Whiptail Lizards, Cnemidophorus gularis

Abstract

We compared foraging behavior of juvenile and adult Texas spotted whiptail lizards, Cne- midophorus gularis, when preying on a non-dangerous species, the lab cricket Acheta domestica, and a po- tentially dangerous species, the scorpion Centruroides vittatus. When presented with scorpions as prey, both naive juveniles and presumably experienced adult C. gularis executed prolonged and violent attack sequenc- es. In contrast, when presented with crickets of similar sizes, lizards exhibited an abbreviated, less violent foraging sequence. Certain actions like head shaking with prey clutched in the jaws and throwing of prey, which were always present in the foraging repertoires of adult and juvenile lizards when foraging on scorpions, were almost never present when foraging on crickets. In addition to the effect of prey type, scorpion size also affected the attack sequence executed by adult lizards. More total attacks and more violent attacks were directed toward large scorpions than toward small scorpions. These experiments indicate that C. gularis may distinguish between different levels of risk associated with foraging on different types and sizes of prey, and that further, this ability to distinguish is present in naive individuals and is likely an innate response.