Naive ophiophagus lizards recognize and avoid venomous snakes using chemical cues

Area of Science:

• Herpetology
• Behavioral Ecology
• Chemical Ecology

Background:

• Monitor lizards and venomous snakes share habitats, creating a predator-prey dynamic where both species consume each other.
• Hatchling monitor lizards lack prior experience with snakes, making their initial prey assessment critical for survival.

Purpose of the Study:

• To investigate how naive hatchling monitor lizards (Varanus albigularis) respond to venomous and nonvenomous snakes.
• To determine if chemical cues from snake skin influence the predatory behavior of monitor lizards.

Main Methods:

• Experiments exposing hatchling lizards to live snakes and snake skin segments on invertebrate prey.
• Observing lizard responses, including attack behavior, avoidance, and tongue-flicking (chemosensory investigation).

Main Results:

• Hatchling lizards attacked nonvenomous snakes but avoided venomous ones.
• Lizards consumed snake meat regardless of species but rejected invertebrate prey with venomous snake skin if restrained.
• Attack inhibition occurred when unrestrained prey with venomous snake skin were tongue-flicked, indicating chemical cue detection.

Conclusions:

• Chemical cues in snake skins are vital for monitor lizards to differentiate and avoid venomous species.
• The ability to perceive snake integumental chemicals is likely under strong selective pressure in species with reciprocal predation dynamics.