The male Shining Flycatcher could be construed as being "duller" than the
female. Though they share the breeding duties with the female. I think it is
another interesting example of 'irregular' dimorphism.
Mick
----- Original Message ----
From: L&L Knight <>
To: Birding-aus <>
Sent: Tuesday, 13 May, 2008 4:52:01 PM
Subject: Re: [Birding-Aus] Land of Parrots & comment on Eclectus Parrot
behaviour.
As far as I can see, the rule of thumb for evolution is that organisms
that are better suited to the environment they exist within are more
likely to survive to sexual maturity and hence tend to produce more
offspring. The rub is that in the case of species with sexual
dimorphism, the gender making the decision doesn't always make its
decision on the basis of characteristics that enhance an individual's
survivability [eg excessively long tails, predator-attracting colours
etc].
The thing that is unusual about Eclectus Parrots is that the brooding
gender is the brightly coloured one. I think there are a couple of
dimorphic species where the male does the breeding and is less
conspicuous - eg Plains Wanderer?
Ultimately you could say that Eclectus Parrots are unconventional - a
bit like people who misplace apostrophe's.
Regards, Laurie.
On 12/05/2008, at 11:33 PM, Philip Veerman wrote:
> I too liked that doco and all the raptor bits as well. But no need
> for me to at this late stage add to what others have mentioned. The
> one thing that I didn't like though was the statement made that the
> Eclectus Parrot "breaks all the rules of evolution". That is a
> nonsense. There are an infinite number of "rules of evolution" that
> relate to every feature of every organism: genetics, physiology,
> biogeography, structure, behaviour, all the rest. The Eclectus
> Parrot adheres to them as much as everything else. The point they
> were making is that the bird appears to contradict only one "rule",
> which is only a general trend, as there are many other species that
> outwardly show the same aspect, albeit for different reasons. That
> relates to the reversed sexual dimorphism (brighter coloured
> females). Having made that wrong remark, they then proceeded to
> outline why it is not true, the particular nesting behaviour of the
> bird allows that difference. The bird is indeed not breaking that
> "rule of evolution". It is just that it has adopted a particular and
> unusual strategy that allows it to adhere to the rule in a different
> way from most birds. It is damaging to suggest in such loose manner
> that any organism "breaks any of the rules of evolution" because the
> comment can easily be taken out of context. It is simply that we
> should not take the unusual adaptation as somehow being inconsistent
> with the well documented trend without properly seeing the evidence.
>
> Philip
> www.birding-aus.org
> birding-aus.blogspot.com
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