Hi Mick
Sure flight style is important - it's often how we pick up something
different. But even ignoring human subjectivity, flight style is
obviously not a fixed character. See how much wind strength can affect it!
So should it be relied upon to identify a rarity? I'm a skeptic. It
doesn't constitute any useful evidence in my view. It may be the bird is
genuinely different in flight for some perfectly rational (but unknown)
reason, or it may just be that people think it looks different due to
some illusion, or worse, because someone else said it did. Often it
comes down to the question of whether a bird looks different because it
is a different species, or for some other reason. It might be just
hungry or fat!
If you had a conflict of identity between what a photo showed and what
people said a bird looked like in the field, who would you believe? The
photo of course! Which is why digital cameras are so great. For the
first time in the whole of history we have a situation where there is a
very good chance that a rarity will be very well documented, and it
raises the bar away from the subjectivity of the past.
As for those pesky Shearwaters, the best way to learn them is to do it
yourself and totally avoid being led by others. Listen to the experts
because you can learn a lot, but stay skeptical and you will learn even
more! Even if the experts are right, which they usually are, everyone
sees things in different ways, and you have to work out what works for
you. Very good birders can see the same bird, but describe it quite
differently. This may not be contradictory, as it can be just a question
of how words are used.
The good news is that most birds will be agreed upon by everyone if they
get a good view. When it comes to Sooty and Short-tailed, there may be
lots of disagreements (if you can get over the tendency to follow the
leader), but that's because these species are genuinely very difficult.
There are differences, which may be obvious in the right situations, but
many should go unidentified. And isn't that the nature of nature? Some
species are always easy to identify, most are usually easy, some are
only identifiable if seen very well, and for a few you need DNA.
Cheers, Chris.
On 01/30/2012 06:26 PM, Mick Roderick wrote:
Hi all,
Yes a great discussion and timely for me too, as I was sitting next to
Nikolas on the way out on the weekend's Wollongong pelagic and
commented how the Port Stephens trips were going well...but that I was
still not on top of the Sooty vs Short-tailed identification thing! It
has always fascinated me how it seems to be something many observers
take for granted but I have always grappled with it. Chris's comments
below make me feel a lot better! I have been on pelagics where some of
the most experienced sea-birders around have argued the ID of a
shearwater that was confidently called as "Sooty" or "Short-tailed".
Unfortunately I didn't see the bird in question but I do have to
back-up what Nikolas said about flight pattern etc being important.
Sometimes being there on the day can make all the difference and I
think that the filtering-in-the-brain that Chris talks about is more
likely to be confused by lighting than behavioual traits observed in
situ. Maybe I'm wrong? Identifying from photos can be fraught with
danger I guess is my point (not always, but I've seen numerous birds
misidentified in images, especially Jaegers and Terns). I'm just not
sure if I would agree that photos provide an unbiased view but I know
what you mean by that Chris. But often any comparisons can be useful,
even if the birds aren't necessarily very similar.
Currently a few of us are sorting out Swifts and Swiftlets from
Christmas Island and I have to say that although it is a daunting
group, being in a situation where there are clearly 'different'
species above you flying around, having the luxury of comparing
relative sizes and flight patterns etc gives a big headstart, ahead of
what can often be picked up in photographs of birds like that.
Mick
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