American Zoologist · 1983 · 113 citations · 0 references
Life SciencesPhysiologyZoologyHerpetologyMammalogySensory PhysiologyPerception In AnimalsSensory BiologySensory ProcessingSensory SystemsThermal PhysiologyThermal SensationHeatHierarchyPrey Capture MechanismsReptile Foraging EcologyReptile Sensory BiologyReptile ThermoregulationTemperature CuesThermal Cues
Snakes rely on multiple sensory modalities, with visual or chemical cues dominating pre‑strike behavior, but in low‑visibility settings heat radiation guides species with pit organs while substrate vibrations guide others. This review examines how heat sensing complements vision, smell, and mechanoreception in snake feeding, proposing that heat information replaces mechanical cues in pit‑organ snakes. The authors analyze the role of heat sense in feeding behavior through a comparative review of sensory hierarchies across snake taxa. Sensory hierarchies differ between heat‑receptor and non‑heat‑receptor snakes during pre‑strike phases, yet all species rely on chemical cues for post‑strike behavior.
Behavior can be regarded as a result of various processes of decision based on the information provided by the sensory organs. In this review the role of the so-called additional heat sense, next to vision, smell and mechanoreception is discussed with respect to the feeding behavior of snakes. The hierarchy of the sensory information in various phases of the feeding behavior differs between snakes possessing heat receptors (e.g., species of the Crotalinae and Pythoninae) and those without (e.g., species of the Viperinae and Colubrinae). Probably depending on the influence of ecological demands, visual or chemical cues are the main information in the behavioral phases before the strike However, in situations with little visual input, e.g., in darkness, rodents' burrows, etc., hunting behavior is guided in the first place by radiation of warm objects in Crotalus, Python and Trimeresurus flavoviridis, and by substrate vibrations in Vipera aspis, Pituophis melanoleucus and Boa constrictor. I suggest that in the sensory hierarchy, heat information functionally replaces the mechanical information which is utilized by snakes without pit organs. Poststrike behavior on the other hand is mainly guided by chemical cues in all snakes.