Well to respond to your main concern, Paul, I didn't ask any questions
on the boat because the questions didn't occur to me until I got home
and looked at the pictures. As you will recall, the birds were a bit
stand-offish and didn't settle on the slick to provide nice close-up,
'live' views.
I find it useful to examine photos from field trips, and the bird that
piqued my interest was very pale in the body - off-white with brown
flecks. I could see that this colouration was not simply an artefact of
the light as the white of the face and brown of the head were as
expected, and the off-white was apparent on both the shaded and
unshaded portions of the belly. This was considerably lighter than any
illustrations I came across, including HANZAB's drawing of a Providence
Petrel in worn plumage [that I was subsequently able to access].
Yes, you did respond to my initial post to the effect that "all those
shots are of stock standard Providence Petrels, which are now strating
to show varying degrees of plumage wear".
My approach when dealing with conflicting opinions [treating field
guide drawings as opinions] is to seek information from multiple
sources [I don't regard any individual source as being infallible]. So
I invited comment from a dozen or so people, a process that is normal
practice for me.
Yes, the four people experienced enough to make a call [including
yourself] all said "Providence", and those who weren't experienced had
something to look and discuss, which is useful for their birding
development. Two of the other experienced respondents also provided a
range of helpful pointers in relation to body and wing shape, underwing
pattern, colour pattern of the belly feathers and colour of museum
specimens etc. [I suspect that the people who draw the illustrations
of seabirds aren't looking at them in lighting conditions that exist
over water]. In addition, in relation to the underparts HANZAB notes
that "With extreme feather wear, concealed white bases sometimes
revealed".
So I can now see how a bird that has underbody plumage more inline with
the drawings of a Herald Petrel [in both the field guides and HANZAB]
can in fact be a Providence Petrel. I don't perceive this process of
puzzle-solving as "being in a bind".
As for the pterodroma comment, yes, what I would have said if I was
being more precise was that the white chin, forehead and lores made it
obvious that the bird was a pterodroma. One thing I noticed in my
literary travels is that pterodromas seem to be the only "brown
seabirds" with that pattern of white on their faces.
I hope that resolves the issues in relation to my posting, and am happy
to forward the pictures of the petrels in question to anyone who is
interested having a gander at worn petrel plumages.
Regards, Laurie.
On Monday, July 19, 2004, at 07:00 PM, Paul Walbridge wrote:
Hi Birding-aussers, I'll be posting a trip report of the Southport
pelagic in the next day or so but first let's see if we can sort out
Lauries dilemma. First of all Laurie, you frequent flyer you, you
should have realised by now that I don't use the general Aussie field
guides at sea & in fact discourage others from doing so. The plates
from guide to guide vary far too greatly and also generally are
inaccurate. Secondly, all the pelagic venues that I know of carry at
least one experienced guide with a wealth of knowledge borne of many
years of field observations. It is the job of that (those) guide(s) to
answer any queries, in the course of a day at sea many people do so
but you Laurie rarely seem to & get yourself into a bind.
Laurie sent me four images, from the trip, of Providence Petrels and I
explained to him that they were of fairly standard appearence for this
time of year, ie; in various stages of plumage wear. If he had asked
me this at the time I could have cleared this up for him. Thank
goodness a real white-bellied Providence or Great-winged Petrel didn't
turn up. Something else Laurie, quote "That the birds were pterodromas
was obvious with their white chins". Where on earth did you get that
little gem from, surely not from a field guide!
I now find Laurie, that you have sent two images to people, some of
whom would have very limited field experience with such birds, if any,
getting yourself further into a bind. The moral of the situation is
that Laurie had legitimate questions (queries) but chose (given his
limited field knowledge) to ignore a readily available resource at
hand. I acknowledge Laurie, that you are a scientist & have certain
skills acquired from tertiary studies & I also understand your
concerns re; general field guides but I've already broached that
subject.
Pelagic organizers spend (waste ?) a good deal of time (and money)
both studying in the field & researching, so don't waste 'em. I'll now
get back to writing up a rather boring trip report for Southport
17/7/04. Cheers - Paul W.
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