Biology Notes

Wednesday, February 04, 2015

Rainbow Plumage on Parrots

Rainbow Plumage on Parrots
JD O’Dea PhD

Abstract: Several parrot species from different continents and subfamilies share a remarkable feature of their plumage. The colours of the visual spectrum appear in order on their bodies, in the same order as in a rainbow. The observation is discussed.

Parrots are renowned as colourful birds, but some deserve to be described as “flying rainbows.” These parrots have many of the colours of the spectrum in their plumage, and even more remarkably, they appear in the same order as in the visual spectrum (red, orange, yellow, green, blue, indigo, violet).

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The following are some of the parrot species that show this rainbow plumage effect:

Ara macao (scarlet macaw). Family Psittacidae. Subfamily Arinae. Neotropical.
Aratinga solstitialis (sun conure). Family Psittacidae. Subfamily Arinae. Neotropical.
Aratinga jandaya (jandaya parakeet). Family Psittacidae. Subfamily Arinae. Neotropical.
Platycercus eximius(eastern rosella). Family Psittaculidae. Subfamily Platycercinae. Australia.
Neophema chrysogaster (orange-bellied parrot). Family Psittaculidae. Subfamily Psittaculinae. Australia.
Psephotus varius (mulga parrot). Family Psittaculidae. Subfamily Platycercinae. Australia
Cyanoramphus malherbi (Malherbe’s parakeet ). Family Psittaculidae. Subfamily Platycercinae. New Zealand.
Hapalopsittica fuertesi (indigo-winged parrot). Family Psitticidae. Subfamily Arinae. Neotropical.
Amazona oratrix (yellow-headed amazon). Family Psittacidae. Subfamily Arinae. Neotropical.
Conuropsis carolinensis (Carolina parakeet). Family Psittacidae. Subfamily Arinae. North America (now extinct)
Eunymphicus cornutus (horned parakeet). Family Psittaculidae. Subfamily Platycercinae. New Caledonia.
Agapornis lilianae (Lilian’s lovebird). Family Psittaculidae. Subfamily Agapornithinae. Africa.

Among parrots in general, it is common to find adjacent areas of green and blue plumage, and adjacent areas of yellow and green are also often observed (Forshaw, 2010). These colours are also adjacent in the visual spectrum of course.

The nature and function of parrot plumage colours has attracted recent attention (Berg and Bennett, 2010; Tinbergen et al., 2013). Both pigmentary and structural colours are present and the parrots’ visual system is sensitive to colour. It is thought likely that plumage colouration is important in sexual signalling and mate choice.

The common juxtaposition of areas of plumage in colours that are also adjacent in the visual spectrum and the occurrence on a number of parrots of most of the colours of the spectrum in order could simply be a random, if noteworthy, effect. On the other hand, it may have some role in mate choice. One possibility is that having colours adjacent on the body that are close on the visual spectrum might make the perception of colour patterns more difficult and therefore more of a selective challenge for potential mates.

References

Berg, M. L. and Bennett, A. T.D. (2010). The evolution of plumage colouration in parrots: a review. Emu : austral ornithology, vol. 110, no. 1, pp. 10-20.
Forshaw, J.M. (2010). Parrots of the World. Princeton University Press.
Tinbergen, J., Wilts, B.D. and Stavenga, D.G. (2013). Spectral tuning of Amazon parrot feather coloration by psittacofulvin pigments and spongy structures. The Journal of Experimental Biology 216, 4358-4364.

# posted by Karna O'Dea : 10:43 PM

Thursday, December 12, 2013

Did Tyrannosaurus rex use its forelimbs in bird-like feathered threat displays?

I have previously discussed the possibility that T. rex, which is now thought to have likely had feathers, could have used its relatively small forearms in a feathered display:

http://julianodea.blogspot.com.au/2013/07/did-tyrannosaurus-use-its-vestigial.html

These two videos show the kind of threat displays involving wings seen in the descendants of dinosaurs, the modern birds:

http://www.youtube.com/watch?v=Dnq9bq_JuB4

http://www.youtube.com/watch?v=eKfteGYOBAM

# posted by Karna O'Dea : 8:40 PM

Tuesday, November 05, 2013

Process of evolution of birds from dinosaurs

http://blog.hmns.org/2010/05/flat-footed-reptiles-to-high-stepping-chickens/

# posted by Karna O'Dea : 1:39 PM

Monday, November 04, 2013

Interesting critique of classical ethology

http://academic.brooklyn.cuny.edu/biology/jbasil/documents/LehrmanQuartRevBiolCritiques1953CLASS1.pdf

# posted by Karna O'Dea : 1:09 AM

Thursday, September 26, 2013

A further reference to my idea on African lips

http://teakdoor.com/speakers-corner/128449-racism-can-justified-i-think-so-9.html

Note the reference to human eye sensitivity to wavelengths at the blush colour.

# posted by Karna O'Dea : 5:37 PM

Friday, September 06, 2013

A Selection Model of Molecular Evolution Incorporating the Effective Population Size: Ellegren

http://onlinelibrary.wiley.com/doi/10.1111/j.1558-5646.2008.00560.x/full

# posted by Karna O'Dea : 7:03 PM

Wednesday, September 04, 2013

The Maintenance of Sex: Ronald Fisher Meets The Red Queen

http://www.biomedcentral.com/content/pdf/1471-2148-13-174.pdf

# posted by Karna O'Dea : 6:56 PM