Lip-curling in redbelly snakes (Storeria occipitomaculata): functional morphology and ecological significance

Abstract

Redbelly snakes Storeria occipitomaculata have a characteristic agonistic display involving conspicuous lip-curling and head distortion. The lip-curling and head distortion display is similar to head shape-changes during feeding. Storeria occipitomaculata produced mouth secretions while displaying. Micrographs of maxillae and observation of changes in head configuration showed that the lip-curling behaviour of S. occipitomaculata is related to the presence of carina-bearing maxillary teeth, which are protruded from the mouth during the display. I compared the behaviour and morphology of this species to other gastropod-eating snakes and suggest that these behavioural and morphological characteristics have a two-fold role: in prey capture they aid the capture, the handling, and perhaps the digestion of prey; in predator deterrence they may act as delivery agents for mouth secretions.