Multiple achromatic plumage signals of male quality in the snow bunting (Plectrophenax nivalis)

摘要

Although males can produce many ornaments, the evolution of multiple ornaments is not well understood. We investigated achromatic plumage traits in the context of multiple ornaments in Arctic-breeding snow buntings ( Plectrophenax nivalis ). We examined whether multiple ornaments: are providing multiple messages, are redundant, are unreliable signals or are aimed at different receivers. We measured plumage reflectance and pigmentation patterns that are differentially, but conspicuously advertised during male inter- and intra-sexual displays. Our results indicate that although several signals are redundant, different body regions appear aimed at different receivers. The wings of males--displayed during courtship--indicate male expected reproductive performance. Conversely, melanin reflectance displayed during intra-sexual threat displays signals territoriality. Different information provided by distinctive aspects of plumage may have differential importance in inter- versus intra-sexual communication. This study demonstrates that even relatively simple plumage traits can serve in complex communication.