Feeding behaviour of the Madagascar leaf‐nosed snake, Langaha madagascariensis (Serpentes: Colubridae: Pseudoxyrhophiinae), with an alternative hypothesis for its bizarre head structure

Abstract

Feeding behaviour of the Madagascar leaf‐nosed snake (Langaha madagascariensis) is described and an alternative use for its unusual nasal appendage is hypothesized. Langaha madagascariensis employs a sit‐and‐wait foraging strategy and stalking prey is initiated once a snake is conscious of potential prey. Stalking is preceded by hooding, swaying anterior portion of its body laterally, tongue flicking, and advancing toward prey. Strikes are typically made at an extremely close distance, sometimes while a snake places its nasal extension directly onto the back of the prey's head. Prey was always grasped anterior to the pectoral girdle behind the head or neck region. Once prey is seized, it may be coiled around and is usually pulled off its perch and left to dangle in mid‐air, while being worked into the back of the mouth toward the snake's rear fangs. Langaha madagascariensis also exhibits hooding while stalking prey. These hooding and swaying behaviours along with its cryptic colour patterns, might allow L. madagascariensis to mimic a vine swaying in the wind. Because of the many behavioural and ecological similarities between L. madagascariensis and other arboreal snake species, I hypothesize that the nasal extensions in L. madagascariensis serve as an extension of its narrow head and is used as a point of reference during prey stalking.