The effect of stimulus features on the visual orienting behaviour of the salamander Plethodon jordani.
The effects of the visual features of prey-like objects on the orienting behaviour of the salamander Plethodon jordani were studied. Two stimuli (cricket dummies, rectangles), moving in opposite directions, were presented simultaneously on a computer screen. They differed in size, contrast, velocity and movement pattern of the entire body or the body appendages. Size and velocity appeared to be the dominant features; shape was of lesser importance. Contrast and movement pattern were of intermediate importance and local motion of little importance. This rank order was the same when the probability of a response to the different stimuli was estimated by means of the maximum-likelihood method. Cluster analysis revealed that in all animals stimuli could be grouped into five clusters. Among individuals, the rank order of stimuli was similar for high- and low-ranking stimuli and varied for those of intermediate rank; stimuli could be grouped into 3-5 clusters. Our findings favour the view that, in amphibians, prey recognition is guided by a number of visual features acting either alone or in combination and depending on internal motivational or attentional states and individual experience.
Schülert
Niklas
N
Brain Research Institute, University of Bremen, 28334 Bremen, Germany.
Dicke
Ursula
U
D000818:Animals; D001522:Behavior, Animal / Q000502:physiology*; D009068:Movement; D011187:Posture; D011235:Predatory Behavior; D014562:Caudata / Q000502:physiology*; D014785:Vision, Ocular