del Val E.,Behavioural and Evolutionary Ecology Associate Research Unit CSIC |
Negro J.J.,CSIC - Donana Biological Station |
Garrido-Fernandez J.,CSIC - Instituto de la Grasa |
Jaren M.,CSIC - Instituto de la Grasa |
And 3 more authors.
Journal of Ornithology | Year: 2014
Carotenoid-based ornamentation shows great variability in Common Crossbill (Loxia curvirostra) males. Plumage colour ranges from dull yellow to bright red, but the majority of birds tend to be reddish-orange. It has been suggested that moult in this species is bimodal and that the extent of red feathering depends on the period in which feather development occurred. In this study, we analysed the relationship between timing of moult and male plumage colouration in a Common Crossbill population from the Catalonian Pyrenees (NE Spain). Our results demonstrate that the concentrations of dietary carotenoids necessary for the development of red colouration in this species vary significantly within seasons, and that the main time of feather development is apparently well adapted to the period of highest pigment availability in the environment. The intra-specific colour differences between males might be related to the ability to find food resources rich in red carotenoid precursors and to overcome the physiological processes involved in their metabolism, strongly suggesting that red colouration in Crossbills functions as an honest signal of condition and health status. © 2013 Dt. Ornithologen-Gesellschaft e.V.