Evolutionary Ecology

, Volume 13, Issue 6, pp 579–589

Experienced chicks show biased avoidance of stronger signals: an experiment with natural colour variation in live aposematic prey

  • Gabriella Gamberale-Stille
  • Birgitta S. Tullberg
Article

DOI: 10.1023/A:1006741626575

Cite this article as:
Gamberale-Stille, G. & Tullberg, B.S. Evolutionary Ecology (1999) 13: 579. doi:10.1023/A:1006741626575

Abstract

An important factor for understanding the evolution of warning coloration in unprofitable prey is the synergistic effect produced by predator generalisation behaviour. Warning coloration can arise and become stabilised in a population of solitary prey if more conspicuous prey benefit from a predator's previous interaction with less conspicuous prey. This study investigates whether domestic chicks (Gallus gallus domesticus) show a biased generalisation among live aposematic prey by using larvae of three species of seed bugs (Heteroptera: Lygaeidae) that are of similar shape but vary in the amount of red in the coloration. After positive experience of edible brownish prey, chicks in two reciprocal experiments received negative experience of either a slightly red or a more red distasteful larva. Attacking birds were then divided into two treatment groups, – one presented with the same prey again, and one presented with either a less red or a more red larva. Birds with only experience of edible prey showed no difference in attack probability of the two aposematic prey types. Birds with experience of the less red prey biased their avoidance so that prey with a more red coloration was avoided to a higher degree, whereas birds with experience of the more red prey avoided prey with the same, but not less red coloration. Thus, we conclude that bird predators may indeed show a biased generalisation behaviour that could select for and stabilise an aposematic strategy in solitary prey.

aposematismdefenceGraptostethus servusLygaeus equestrispredationstimulus generalizationsynergismTropidothorax leucopterus

Copyright information

© Kluwer Academic Publishers 1999

Authors and Affiliations

  • Gabriella Gamberale-Stille
    • 1
  • Birgitta S. Tullberg
    • 1
  1. 1.Department of ZoologyStockholm UniversitySweden