Bold Tail Coloration Protects Tadpoles from Dragonfly Strikes
Some amphibian larvae develop brightly colored or black tail fins when reared in ponds with predaceous insects. The conspicuous tail has been proposed to lure predator strikes toward the tail and away from the more vulnerable head/body region. We tested this hypothesis by presenting model tadpoles that differed only in coloration to Aeshna dragonfly larvae. The models had either a dark body and pale tail, a dark spot in the middle of the tail, or a dark spot near the tip of the tail. Almost all models with plain tails were struck on the head/body, whereas those with dark spots in the tail were struck significantly more often on the tail. Because living tadpoles survive better when attacked on the tail than on the head, our results show that tail coloration can protect tadpoles from predators at close range.Abstract

Distributions of labial strikes by Aeshna dragonfly larvae along the long axis of model tadpoles having three kinds of coloration. The vertical dashed line signifies the transition from the head/ body to the tail, and the heavy dark bar represents the location of a dark spot on each model. Dragonflies struck the head/body most often, but were frequently deceived by the tail spot

Estimated probability of surviving a dragonfly attack for living tadpoles that have color patterns represented by the three models. The relationship between strike location and survival came from observations of Rana temporaria tadpoles attacked by Aeshna larvae (Van Buskirk et al., 2003). Bars indicate mean ± 1 SE
Contributor Notes
Institute of Zoology, University of ZÜrich, CH-8057 ZÜrich, Switzerland. Present address: (JVB) Department of Zoology, Melbourne University, Victoria 3010, Australia. (JVB) joshv@unimelb.edu.au Send reprint requests to JVB.