Baraba-type Gulls, Oman

[JanJ]

Take a look a this then...
http://www.flickr.com/photos/neubauerg/ ... 508214870/

Hi Ruud.

I have seen Neurbauergs photos. I´m not disputing what´s been said and is a common belive! Just speculating - wrong or right? Otherwise I´m a strong beliver in scientific values and when it comes to gull taxonomi and such, I´m a fanatic for the correctness . Sometimes you cross that border and makes things easier than it really is, a human thing, just hoping you don´t blow it Much more to learn!

Cheers
Jan

[marsmuusse]

Without disputing the interesting value of the colony visited by Gregory and the bird seen in Stockholm (which I don’t think is barabensis btw), it may be interesting as well to continue discussing the birds photographed in Oman, by Hans.
The outlined strategy above (first try to group birds in Steppe Belt and Tundra Belt breeders) combined with the upperpart grey tone, immediately lead to problematic birds.

In Hans’ section ‘barabensis type gulls’, there are a few birds probably too dark to fall in the range of barabensis. They also show a late moulting scheme, which together should better fit heuglini. Some examples are maybe these:
http://www.pbase.com/hans_larsson/image/120150305
http://www.pbase.com/hans_larsson/image/120150379
http://www.pbase.com/hans_larsson/image/120150329 (2cy!)

But this bird is a real bugger:
http://www.pbase.com/hans_larsson/image/120150337
as is this one:
http://www.pbase.com/hans_larsson/image/120150344
Obviously too pale to fall within the limits for heuglini, but with an extraordinary late moult scheme. Hopefully Hans has another picture, showing strong neck-streaking and bloching on the side of the breast, which would fit taimyrensis. But what if (some) bababensis also show a late moult scheme?

There are some more birds which have not finished the complete moult, and are pale enough to call barabensis (also on jizz):
http://www.pbase.com/hans_larsson/image/120150349
http://www.pbase.com/hans_larsson/image/120150303 (bird on the foreground, compare with dark backed heuglini -?- in the background, but also mind relative possition to photographer).
http://www.pbase.com/hans_larsson/image/120150317

Difficult to analys these birds, I’m afraid… But fun to go through this set, one by one maybe?

[marsmuusse]

And, two images of which I think involve barabensis, as we called them in Bahrain. It was in the early days of digiscoping, way back (grandfathers voice), so sorry for poor quality... But to compare grey tones barabensis-heuglini, maybe of interest. Location: Bahrain. date: 1st week March 2001.

[JanJ]

As Mars, I found his examples to and would agree to his suggestion, although difficult judging from pic. in difficult light. However, maintaining such recomendations is not easy, the eye see what it sees - and wants to see, which might not be wrong all of the time, especially when seen in company with paler species/ssp and then in several pic of the same individuals in different positions. In Hans pic, with the examples given - picing heuglinis is rather straightforward if you add structurally differences - when seen well and the villingness to accept that it might be wrong.
Are there any heuglini among these (revealing that I think most of these are barabensis, which I´m of course not 100% sure of), if so, are they possible to pic out. Also note moult scores.

http://picasaweb.google.com/mark.seawat ... GullsNov08#

Jan

[Hans Larsson]

"The outlined strategy above (first try to group birds in Steppe Belt and Tundra Belt breeders) combined with the upperpart grey tone, immediately lead to problematic birds."

Yes, we probably have to deal with the presence of "intermediate" birds in the Middle East too.. But, being invaded by various hybrids in everyday-gulling up here, it should be bareable, but nonetheless challenging.

It seems the moult stage is highly overlapping, but generally there should be a notable difference between the two. And, for the paler end early-moulting barabensis, there should be a nice pot with cachinnans/barabensis types as well... Theoretically a mess, but in the field I think that many should be straightforward to label, when having the invaluable help of the live observation.

"In Hans’ section ‘barabensis type gulls’, there are a few birds probably too dark to fall in the range of barabensis. They also show a late moulting scheme, which together should better fit heuglini."

http://www.pbase.com/hans_larsson/image/120150305
http://www.pbase.com/hans_larsson/image/120150379
http://www.pbase.com/hans_larsson/image/120150329 (2cy!)

Structurally, I would label these barabensis, but as Mars points out, moult is late, and also, in the adult bird the primary pattern may not be as expected in barabensis (black on p10-p4/p3 & "cachinnans-tongues"). I find the mantle shade very hard to assess exactly in these photos, at least without any good comparison objects side by side, so in my view they may well be ok. Also, I feel that I may have under-exposed quite a few pics during the sunny conditions.
But, these odd ones should preferrably be put in a separate section. I will create a new gallery for the freaks mentioned, and put some others there as well...

http://www.pbase.com/hans_larsson/image/120150337

This one looks a bit over-exposed, but seems like a barabensis to me. However, I have no knowledge on the moult of subadult birds more than that they "probably" approaches heuglini in this respect. That sounds reasonable however, given the long distance migrancy of barabensis...

http://www.pbase.com/hans_larsson/image/120150344

This looks fine for barabensis, I think, jizzwise as well as in mantle shade. My biggest concern is the freshness of the old primaries, they seem not worn at all, with really nice white tips... When were they moulted?

http://www.pbase.com/hans_larsson/image/120150349
http://www.pbase.com/hans_larsson/image/120150303 (bird on the foreground, compare with dark backed heuglini -?- in the background, but also mind relative possition to photographer).
http://www.pbase.com/hans_larsson/image/120150317

They all look ok to me. If Santa could only bring me a new cumputer with some nice video-editing software, I may be able to put out some footage of a number of gulls from Oman, wich would make assessing of structure and shape a whole lot easier.

All in all, I have the feeling that many "difficult" cases usually suffers from poor documentation in some way. If I had only taken the time to sort out and thoroughly study and document a fewer number of birds, they may all have been readily ID´d from photos. Next time...

Hans

[JanJ]

It´s interesting to note the freshness of the outer primaries, especially p6, in this one as noted by Hans:

http://www.pbase.com/hans_larsson/image/120150344

If it wheren´t for the fact that p5 is growing I could have sworn that it had completed it´s primary moult quite recently. Could some kind of irregular moult or accidental cause be the explanation?

A possible rather similar situation but with a missing p5 (or is it p6), might be happening on this one, although not a fully adult:

http://www.pbase.com/dophoto/image/89527398

This one is a late moulter, most probably barabensis:

http://www.pbase.com/hans_larsson/image/120150388

Jan

[Hans Larsson]

I have added a new gallery with oddies or kind of intermediate birds. However, some should be possible to ID, I think. Some birds in the other sections may have to be moved here, as well..

http://www.pbase.com/hans_larsson/barab ... i&page=all

Also, earlier I forgot some additional images of baraba-types, I have now updated this gallery (you´ll find the new ones at the bottom of the page):

http://www.pbase.com/hans_larsson/barab ... _&page=all

Hans