Color as an assessment signal in the black-winged damselfly

Abstract

Background: - Signals are a form of animal communication important in intraspecific interactions. An assessment signal conveys information about the condition of a conspecific. - There is a selective advantage for males that can accurately assess an opponent’s relative fighting ability during a contest, and for females that can choose the most fit male to mate with. - Reliable assessment signals evolve due to the mutual benefits of avoiding the high energetic costs of fighting. Life History: - Adult male damselflies defend streamside territories to attract mates, a strategy known as resource defense polygyny. - Aggressive encounters between territorial males include chasing, face-off displays, and spiral fights. Previous Studies: - Fat reserves in damselflies are a good predictor of fight outcomes (Marden & Waage 1990, Marden & Rollins 1994). - The published data is divided on whether damselflies can assess relative fighting abilities in a contest. - Fitzstephens & Getty (2000) proposed abdomen color as a possible mechanism for assessment, and found that males with high fat contents were significantly more likely to be blue.