That would be easily settled by having a close look or feel. Not so easy just
from a photo. I don’t have access to a darter in my room. An analogy I know of,
is from the ornamental feathers of pheasants (Golden & Lady Amherst as I
recall) they feature black bars. If you run your fingers along them, it is very
obvious that the black bars are much thicker than the colour background. Like
as though the pigment is laid on so thickly that the feather is much thicker on
the bars. Possibly the same here. Actually at a microscopic level more
pigmented parts of feathers are often sturdier than the pale parts, which leads
to seasonal changes, as pale parts of feathers wear away e.g. white spots on
starlings, white tips to bib of House Sparrows, and several cases among sea
birds.
Philip
From: Harry Nyström
Sent: Sunday, 9 September, 2018 4:27 PM
To: Philip Veerman
Cc: Birding-Aus
Subject: Re: [Birding-Aus] Two "ladders
Hi,
Sorry about my error in terminology: not inner secondaries but of course
tertials.
But for me they appear ribbed as in corrugated or waved, not just as a color
pattern. And I'm quite sure that was what Jack was also referring to. Is it so
or is it just an illusion?
Cheers,
-Harry
pe 7. syyskuuta 2018 klo 2.17 Philip Veerman <> kirjoitti:
I wonder what aspect you are referring to as "ribbed" I see them as barred.
Barred feathers are entirely normal in a whole range of birds, many raptors,
waders, black-cockatoos, cuckoos, etc. Maybe Jack was referring to the shape
and Harry referring to the pattern, or both. I am not sure.
Philip
-----Original Message-----
From: Birding-Aus On Behalf Of
Harry Nyström
Sent: Thursday, 6 September, 2018 6:47 PM
To: Birding-Aus
Subject: Re: [Birding-Aus] Two "ladders
Hi,
Those are the innermost secondaries.
But maybe someone else could know or have an educated guess on why they are
ribbed?
Cheers,
-Harry
to 6. syysk. 2018 klo 11.17 kirjoitti:
> Hi
>
>
>
> Just looking at an image of an Australasian Darter (male, breeding I
guess)
> photographed a couple of weeks ago in the Botanical Gardens in Cairns.
> Photographed from behind with wings drying. Can any ornithologist tell me
> what the two "ladder-like" feathers are next to its body? I cannot find
the
> answer anywhere.
>
>
>
> Thanks in advance
>
>
>
> David in Blackheath
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