Are Yellow Spots a “Red Flag”? Testing the Potential Deterrence of Nocturnal Mammalian Predators of the Spotted Salamander, Ambystoma maculatum.

Abstract

Aposematism is an evolutionary tactic used by animals across many phyla in which they display bright colors, distinctive patterns, or other features to warn predators of their potential threats, such as toxins. Studies have shown that predators of aposematic organisms learn to recognize their warning signals, so aposematic signals reduce predation risk. The vertebrate class Amphibia includes many species with toxic or distasteful skin secretions that also possess aposematic characteristics. For example, Ambystoma maculatum, the spotted salamander, has 2 lines of bright, yellow, or sometimes cream-colored spots on their dorsal side against a black or blue-black blue body. Although spotted salamanders have been described as aposematic, few studies test if their color pattern induces predator avoidance, as predicted for an aposematic trait. For this study we used clay models, a common method for testing predator responses to variation in prey coloration, to determine whether nocturnal mammalian predators preferentially avoid the color pattern of the spotted salamander.