LAUSR

Constriction is an evolutionarily and functionally important behavior that many snakes use to subdue a variety of prey. However, little work has examined the effects of prey size on constriction performance. Furthermore, many snakes are known to feed even while previously consumed prey remain in the stomach. This temporary increase in mass may place constraints on subsequent performance. To test these effects, I investigated constriction performance in eastern kingsnakes Lampropeltis getula handling different sizes and quantities of rodent prey in two experiments by measuring coil length and peak constriction pressure. In the first experiment, constriction coil length and peak constriction pressure did not differ significantly between snakes feeding on either ‘small’ (5% relative prey mass, RPM) or ‘large’ (15% RPM) rodent prey. However, there was a significant interaction between prey size and repeated feeding. Snakes that had previously consumed large meals had significantly shorter coil lengths and lower peak constriction pressures when fed for a second time (reductions of 60 and 51%, respectively). In Experiment 2, snakes offered five sequential, similarly sized prey (@ 7% RPM), showed a regular decrease in coil length and peak constriction pressure across sequential feeding trials. During the final (fifth) trials, snakes used 45.7% shorter coils and exerted 50.1% lower peak constriction pressures. Thus, prey size alone did not affect constriction performance, but predation performance was significantly affected by the prior consumption of prey ≥7% RPM, and performance was further reduced during additional feeding trials.