If you check out the link provided below, you will find a substantial error in the reporting of this subject (although that is not necessarily included in the
actual study ? I don’t know about that)- , as pointed out by myself and another contributor to Birding-aus 1 and 2 days ago. As below.
Well sort of. The text makes the mistake of first writing of "an iconic Australian species, the rosella" (suggesting ignorance maybe, that rosella is more than one species), only later identifying that it is describing just one species:
"The crimson rosella (Platycercus elegans), comprising several subspecies across its range in the southeast of the continent." The other mistake is plonking in a photo of an Eastern Rosella, probably because whoever composed the publication have no idea what
the other forms of the species look like. This is a typical sloppiness of this sort of media release.
It also seems to me to ignore the likely genetic component of the variation.
From: Birding-Aus [ On Behalf Of Anthea Fleming
Sent: Monday, 18 February, 2019 9:25 PM
Subject: Re: [Birding-Aus] The impact of climate on rosella plumage colours
And this publication doesn't know the difference between a Yellow Rosella and an Eastern Rosella. Note picture!
being pedantic as usual.
On 18/02/2019 7:38 PM, Laurie Knight wrote:
From: Robin Hide [
Sent: Wednesday, 20 February, 2019 9:28 AM
To: Canberra Birds
Subject: [canberrabirds] 'Plumage coloration follows Gloger's rule in a ring species' - Crimson Rosellas
Of interest to some - unfortunately not open access.
Journal of Biogeography (Early view 2019)
Plumage coloration follows Gloger's rule in a ring species
F. H. Ribot,
Mathew L. Berg (Corresponding
Author E-mail address: m("deakin.edu.au","mathew.berg");" title="
Link to email address
T. D. Bennett
Animal coloration is expected to differ between populations in different habitats according to Gloger's rule, with darker animals found in more
humid, vegetated or warmer environments. Yet despite considerable support across the globe, the mechanisms behind this biogeographical rule are currently still unclear. Exploiting a ring species with plumage coloration from crimson to pale yellow, we test
Gloger's rule and the mechanisms behind phenotypic divergence.
Major taxa studied
Crimson rosellas (Platycercus elegans).
We combined three modelling approaches (spatial regression; random decision forest species distribution and conditional inference tree) to test
the association between 10 environmental variables (based on long?term
climate data and remotely sensed reflectance of the land) and plumage coloration across the distribution of
P. elegans. We also took in?situ
measurements of background coloration of dominant vegetation to examine the relationship between (a) background coloration measured locally and remotely, (b)
P. elegans coloration and (c) known differences in visual sensitivity of the subspecies using species?specific
On both a continental and a local scale, the distribution of yellow?red
plumage coloration was strongly predicted by average rainfall, summer temperature and the Earth's reflectance between 620?670 nm. Remotely sensed radiance measures correlated strongly and positively with reflectance of the leaves of the dominant tree species
at sites across the P. elegans distribution. Visual modelling indicated that differences in background colour could affect signalling efficacy in dim?light
Our study shows that the highly variable plumage coloration conforms to Gloger's rule, and indicates that background coloration of the vegetation
and thermoregulation are likely to be important mechanisms. Our results also show that Gloger's rule can explain variation in pigmentary systems other than melanin, and highlight that selection from environmental variation could be an important force behind
the geographic diversity found in ring species.