Abstract
Avian brood parasites lay their eggs in other birds' nests and impose considerable fitness costs on their hosts. Historically and scientifically, the best studied example of circum-enting host defences is the mimicry of host eggshell colour by the common cuckoo (Cuculus canorus). Yet the chemical basis of eggshell colour similarity, which impacts hosts' tolerance towards parasitic eggs, remains unknown. We tested the alternati-e scenarios that (i) cuckoos replicate host egg pigment chemistry, or (ii) cuckoos use alternatie mechanisms to produce a similar perceptual effect to mimic host egg appearance. In parallel with patterns of similarity in avian-perceived colour mimicry, the concentrations of the two key eggshell pigments, bilierdin and protoporphyrin, were most similar between the cuckoo host-races and their respective hosts. Thus, the chemical basis of avian host-parasite egg colour mimicry is eolutionarily consered, but also intraspecifically flexible. These analyses of pigment composition reveal a noel proximate dimension of coeolutionary interactions between avian brood parasites and hosts, and imply that alternatie phenotypes may arise by the modifications of already existing biochemical and physiological mechanisms and pathways.
Original language | English (US) |
---|---|
Pages (from-to) | 1068-1076 |
Number of pages | 9 |
Journal | Proceedings of the Royal Society B: Biological Sciences |
Volume | 279 |
Issue number | 1731 |
DOIs | |
State | Published - 2012 |
Externally published | Yes |
Keywords
- Eggshell coloration
- Host-parasite similarity
- Mass spectrometry
ASJC Scopus subject areas
- General Immunology and Microbiology
- General Biochemistry, Genetics and Molecular Biology
- General Environmental Science
- General Agricultural and Biological Sciences