File(s) under permanent embargo
Do glucocorticoids or carotenoids mediate plumage coloration in parrots? An experiment in Platycercus elegans
journal contribution
posted on 2019-04-16, 00:00 authored by Mathew BergMathew Berg, Ben Knott, Raoul RibotRaoul Ribot, Kate BuchananKate Buchanan, Andy BennettConspicuous coloration can indicate phenotypic quality, and may reflect exposure or vulnerability to stress, or access to essential nutrients such as pigments. Although the production of pigmented colours is well understood, much less is known about how structural colours are affected by physiological state. In this study, we tested whether glucocorticoids (corticosterone) predicted expression of plumage coloration in an Australian parrot, the crimson rosella (Platycercus elegans). Parrots provide an interesting and unique test, as they possess conspicuous coloration produced by distinctive pigments known as psittacofulvins, in addition to structural coloration. We have previously documented that coloration in P. elegans is condition-dependent and responds to dietary manipulation. Here, n = 21 P. elegans underwent a dietary manipulation (including food restriction or carotenoid supplementation) during which they moulted, and the change in reflectance was measured for three structural and three pigmentary plumage patches. Stress-induced corticosterone (10 min after handling) measured at the start of the experiment predicted change in coloration in two pigmentary patches (crown and front). We also found that change in stress-induced corticosterone during the experiment was associated with the change in coloration of the crown and two structural patches (cheek and epaulette). Baseline corticosterone (<3 min after handling) was not associated with any measure of coloration. We found no effects of dietary manipulation on baseline or stress-induced corticosterone, but carotenoid supplementation was associated with an increase in a measure of chronic stress (heterophil/lymphocyte ratio), and the corticosterone response to handling decreased over the course of the study. Our results suggest that corticosterone may be linked to colour expression more broadly than previously recognised, including psittacofulvin and structural coloration in parrots, and they confirm the independence of plumage pigmentation in parrots from carotenoid accumulation. Moreover, our study provides new insight into the stress responses of Psittaciformes, one of the most highly threatened avian orders.
History
Journal
General and comparative endocrinologyPublisher
ElsevierLocation
Amsterdam, The NetherlandsPublisher DOI
ISSN
0016-6480eISSN
1095-6840Language
engNotes
In PressPublication classification
C1 Refereed article in a scholarly journalCopyright notice
2019, ElsevierUsage metrics
Categories
Keywords
CorticosteroneCrimson rosellaH\/L ratioImmunocompetencePsittacofulvinsStructural colorationScience & TechnologyLife Sciences & BiomedicineEndocrinology & MetabolismZoologyPSITTACOFULVIN-BASED COLORATIONOXIDATIVE STRESSCORTICOSTERONE LEVELSSTRUCTURAL PLUMAGEBURROWING PARROTSRESPONSESFEATHERSPIGMENTSSIGNALSCOLORSPhysiologyZoology
Licence
Exports
RefWorks
BibTeX
Ref. manager
Endnote
DataCite
NLM
DC