Post-cranial prey transport mechanisms in the black pinesnake, Pituophis melanoleucus lodingi: an x-ray videographic...

Most previous studies of snake feeding mechanisms have focused on the functional morphology of the highly specialized ophidian jaw apparatus. Although some of these studies have included observations of post-cranial movements during feeding, the functional roles of these movements have remained poorly understood. In this study, we used x-ray videography to examine post-cranial prey transport mechanisms in a colubrid snake, Pituophis melanoleucus lodingi. We found that prey transport in this species progresses through four distinct phases, three of which are characterized by either undulatory or concertina-like movements of the anterior portion of the trunk. In the first phase of transport (the oral phase), unilateral movements of the jaws are used to pull the head forward around the prey. In the second phase (the orocervical phase), unilateral jaw movements continue, but are augmented by concertina-like movements of the anterior portion of the trunk. In the third phase (the cervical phase), prey transport occurs exclusively through concertina-like movements of the neck. Finally, in the fourth phase (the thoracic phase), prey is transported to the stomach via undulatory movements of the trunk. Our observations of feeding behavior in a phylogenetically diverse sample of fourteen other snake species demonstrate that similar post-cranial transport mechanisms are used by a wide variety of alethinophidian snakes that feed on large, bulky prey.