File(s) under permanent embargo
Avian retinal oil droplets : dietary manipulation of colour vision?
journal contribution
posted on 2010-03-22, 00:00 authored by Ben Knott, Mathew BergMathew Berg, E Morgan, Kate BuchananKate Buchanan, J Bowmaker, Andy BennettAvian vision is highly developed, with bird retinas containing rod and double-cone photoreceptors, plus four classes of single cones subserving tetrachromatic colour vision. Cones contain an oil droplet, rich in carotenoid pigments (except VS/ultraviolet-sensitive cones), that acts as a filter, substantially modifying light detected by the photoreceptor. Using dietary manipulations, we tested the effects of carotenoid availability on oil droplet absorbance properties in two species: Platycercus elegans and Taeniopygia guttata. Using microspectrophotometry, we determined whether manipulations affected oil droplet carotenoid concentration and whether changes would alter colour discrimination ability. In both species, increases in carotenoid concentration were found in carotenoid-supplemented birds, but only in the double cones. Magnitudes of effects of manipulations were often dependent on retinal location. The study provides, to our knowledge, the first experimental evidence of dietary intake over a short time period affecting carotenoid concentration of retinal oil droplets. Moreover, the allocation of carotenoids to the retina by both species is such that the change potentially preserves the spectral tuning of colour vision. Our study generates new insights into retinal regulation of carotenoid concentration of oil droplets, an area about which very little is known, with implications for our understanding of trade-offs in carotenoid allocation in birds.
History
Journal
Proceedings of the Royal Society B-biological sciencesVolume
277Issue
1683Pagination
953 - 962Publisher
The Royal SocietyLocation
London, EnglandPublisher DOI
ISSN
0962-8452eISSN
1471-2954Language
engPublication classification
C1 Refereed article in a scholarly journalCopyright notice
2009, The Royal SocietyUsage metrics
Categories
No categories selectedKeywords
avian visionretinal oil dropletscarotenoidscolour visionvisual ecologyresource allocationScience & TechnologyLife Sciences & BiomedicineBiologyEcologyEvolutionary BiologyLife Sciences & Biomedicine - Other TopicsEnvironmental Sciences & EcologyVISUAL PIGMENTSPLUMAGE COLORATIONSPECTRAL SENSITIVITYZEBRA FINCHPHOTORECEPTORPREFERENCETETRACHROMACYMETABOLISMSONGBIRDS
Licence
Exports
RefWorks
BibTeX
Ref. manager
Endnote
DataCite
NLM
DC