Inter-annual variation in American redstart (Setophaga ruticilla) plumage colour is associated with rainfall and temperature during moult: an 11-year study.

摘要: Carotenoid-based colouration plays an important role in sexual signaling animals as honest indicator of individual quality during mate choice and competitive interactions. However, few studies have examined how natural variation weather conditions influences inter-annual the expression ornamentation, potentially through affecting dietary availability carotenoids. In this study, we examine carotenoid-based plumage relation to temperature rainfall pre-moulting moulting period over 11 years a population American redstarts, Setophaga ruticilla, breeding eastern Canada. We used reflectance spectrometry tail feathers collected from male female redstarts relate feather colour with previous season months which are likely moult (June–September). At level, birds expressed higher red chroma lower brightness following high July low August temperature. The pattern was stronger males, but generally consistent across ages sexes. Analyses repeatedly captured indicated that above patterns could be explained by change colour. suggest may increase insect abundance This is among first show effects on signalling trait, consequences for selection, choice, reliability putative signals.