Garter snake trailing behavior: effects of varying prey-extract concentration and mode of prey-extract presentation.

In a multiple-choice maze, garter snakes were trained to follow earthworm-extract trails for worm bit rewards. In Experiment 1, they were tested for their abilities fo follow extract trails that had been dried or extract trails that were removed from direct lingual access by a perforated floor. Snakes were able to follow the dry trails and unable to follow removed trails. In Experiment 2, snakes were tested for their behavioral responses to different concentrations of extract trails. Snakes trailed more accurately, moved more slowly, and exhibited much higher tongue flick rates on the intense concentration trails. The results are interpreted in terms of the assumption that effective trails are perceived by the tongue flick delivery of odorants to the vomeronasal organs.