Theoretical investigations of automimicry: multiple trial learning and the palatability spectrum.
We previously explored automimicry assuming that a species of prey was so unpalatable as to promote conditioned avoidance for a period of time after a predator encountered a single individual (Case 1). In this paper, we assume that the prey is less noxious and that two encounters are required. Case 2 allows the two encounters with unpalatables to be separated by any number of palatables, while in Case 3 the predator must encounter two unpalatables, consecutively.The general relationships in the three cases are similar, but the automimetic advantage is reduced moderately in Case 2 and greatly in Case 3. To attain the same automimetic advantage as in Case 1 requires an increase in the proportion of unpalatables, or in the induced rejection period, or both. Consequently, selection will tend to increase the unpalatability so that Cases 2 and 3 converge to Case 1.Species that are uniformly and highly unpalatable can afford to be more dispersed than automimetic species. Case-2 and -3 automimetic species will benefit greatly from gregariousness, while in Case-1 automimicry situations this is less important.
Pough
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FH
Cornell University, Ithaca, New York 14850.
Brower
L P
LP
Meck
H R
HR
Kessell
S R
SR