Daniel Hanley, Mark E Hauber, Mandë Holford, Collins Moya, Claire N Spottiswoode, Tanmay Dixit
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引用次数: 0
Abstract
The precise mimicry of host eggshell colours and patterns by some obligate avian brood parasites provides a powerful study system for understanding co-evolutionary arms races. However, most attention has focused on host behaviour in response to mimicry, rather than the proximate mechanisms that give rise to mimetic eggshell colours and patterns. In Africa, the cuckoo finch Anomalospiza imberbis produces a wide range of eggshell colours that largely match those of one of its hosts, the tawny-flanked prinia Prinia subflava. Here, we use chemical analysis and avian visual modelling to determine how cuckoo finches and prinias produce this wide array of perceived eggshell colours. Although both species incorporate similar proportions of the two main egg pigments (biliverdin and protoporphyrin) into their eggshell matrix, the cuckoo finch deposits greater concentrations of pigments. Proportions of pigments predicted eggshell coloration only in bluer eggshells, whereas there was no statistical relationship between pigments and colours in browner eggshells. Possible explanations include that brown pigments are involved in maculation and/or strengthening the eggshell. Overall, variation in the deposition of eggshell pigments results in complex relationships between eggshell chemistry and avian-perceivable coloration, both within and across species in this system.
期刊介绍:
Previously a supplement to Proceedings B, and launched as an independent journal in 2005, Biology Letters is a primarily online, peer-reviewed journal that publishes short, high-quality articles, reviews and opinion pieces from across the biological sciences. The scope of Biology Letters is vast - publishing high-quality research in any area of the biological sciences. However, we have particular strengths in the biology, evolution and ecology of whole organisms. We also publish in other areas of biology, such as molecular ecology and evolution, environmental science, and phylogenetics.