Fig. 4.

Conspicuous toxic poison frogs achieve equal protection from predation with different combinations of warning signal components. Skull-and-crossbones icons represent toxicity; sun icons represent conspicuousness. Protection from predation is measured as the ratio of pre- to post-learning time spent with the stimulus frog. (A) E. parvulus achieves equal protection from predation with high toxicity and moderate conspicuousness as E. bilinguis achieves with moderate toxicity and high conspicuousness. Relative toxicity, conspicuousness, and protection are scaled to a maximum of 1.00 (data are mean ± SE; n = six chicks per treatment). (B) The comparative benefits of warning signal components, conspicuousness, and toxicity support alternative strategies for an effective and efficient warning signal. Measured (nonrelative) data for toxicity, conspicuousness, and protection from predation are shown.