Northern or Isabelline Wheatear, Latvia (1 Viewer)

[CerambyX]

Hi,

We are struggling a bit with this bird found today at SE part of Latvia. Doesn't quite feel right for a Northern Wheatear and at this time of year Isabelline is probable... The bird doesn't really have a defined supercillum (in front or behind the eye) but the tail shows much black and kinda looks short-ish. Wing also is not as contrasting as usually Northern Wheatears have.. We don't have much experience with this species (no records in Lv) - what's your opinion?
Photos are not taken by me so can't add much more than can be seen in photos.

Thanks in advance! B

 

[CerambyX]

One more photo + few pixels of flight shots

 

[lewis20126]

With all the black in the tail, I was wondering about Desert Wheatear but the bill is huge, so I think you are right with Isabelline. The black alula stands out and the greater coverts look relatively uniform, although difficult to see much on them.

cheers, alan

 

[CerambyX]

Thanks for reply!
These autumn birds are tricky aren't they? We are also leaning towards Isabelline but, as it would be 1st record for Latvia, we wan't to be 100% sure. So more confirmations (or other opinions) are welcome

 

[P.Sunesen]

It's between Northern and Isabelline.
More inclined to the former because of long wings (projecting too far towards tip of tail), stance and quite contrasting tertials. Bill perhaps a bit short for IW too.

It could perhaps be the Greenland subspecies leuchoroa as they sometimes look more bland/uniform overall and in the face, and may be more sandy-coloured than nominate.

Peter

 

[KenM]

First impressions Northern Wheatear, certainly not Isabelline!....then I saw the tail (very short)...almost solid black with narrow white outer-tail margins. ''Mmmm'', shank appears too short, posture in all shots not particularly upright, no white contrasting supercillium...doesn't seem to compare to either suggested species. Perhaps an Oenanthe x isabellina (ranges appear to overlap?). Certainly one for ''consideration''. Herewith an Isabelline shot earlier in the year.

 

[Jane Turner]

This is a very hard bird. I had a very very pale Northern Wheatear -( below compared to the current bird,) with most of the face pattern of an Isabelline - except it to quote Cau, it had ear coverts which are pretty uniformly darkish with a relatively well defined border with the paler throat, whereas Isabelline Wheatear usually has a pale lower ear coverts area. Mine obviously had Northern structure which helped in the not pushing the panic button stakes.

This bird doesn't look as leggy or short-tailed as I'd expect, though it does look slightly short-winged - but I've had trouble seeing the structural differences on a few accepted Issy's. I don't suppose you've got an underwing shot.

Some link on the thread might help www.birdforum.net/showthread.php?t=183391

 

[CerambyX]

Thanks for your comments!
No underwing shot unfortunately and no news from today (clear sky and cold tonight here) so these pictures are all we have. The bird apparently was very tame - allowed to approach to few m distance.
The leucorhoa subspecies is interesting suggestion - but I guess females/1cy are difficult to separate from nominate oenanthe (and still should be different than Isabelline)?

Few others who have experience with both species have commented (but with varying degree of confidence) that it's a Isabelline.

 

[lewis20126]

How can a Greenland Wheater have a "nearly all black tail"? It must be Isabelline on this feature alone surely? The other plumage features seem supportive of this also. I would go with first-winter female (as there seems to be litlle hint of incipient dark lores).

cheers, alan

 

[Jane Turner]

Its presumably a 1st winter female with no dark lores. The tail pattern, rump/back interface seem better of Isabelline, I think the primary projection is in range, it does manage to look longer legged in the photo in your 2nd post.... but its its not a "brick between the eyes" bird

cross posted with Alan

 

[Valéry Schollaert]

Isabelline is usually noticeably shy. Tail is surprising (but on the photo, can't tell, for example, if outer tail feathers are missing) but rest of the bird looks like a Northern to me.

 

[CerambyX]

For comparisons sake, here's Latvian bird (left) with bird from Sweden a few years ago (picture from http://svalan.artdata.slu.se/birds/gallery_imageinfo.asp?imageID=445080). But Jane's bird is also very similar... Difficult bird indeed.
Seems that without picture of tail pattern and/or underwing it will be hard to prove anything 100% beyond doubt.

 

[Jane Turner]

Its not just the outer TF of Northern that should have a lot of white - its T4 T5 as well, so I think you can be sure that since your bird has most if not all of its Tail, it does have a tail pattern much more in keeping with an Issy

Isyy
http://4.bp.blogspot.com/-KGBDTgxBa...rQ/s1600/Isabelline+Wheatear+Tail+Pattern.jpg

Northern
http://2.bp.blogspot.com/-zmwmS3WGJ...9hS1oGcoaE/s1600/Northern_Wheatear_flying.jpg

 

[Kopgalis]

Hello,

For my opinion this Wheatear by coloration reminds Isabelline very much, however legs and bill aren't powerful and stout enough for the latter. Tail also should look a bit shorter and supercilium should be more vivid and whitish in front. Attaching two photos of IW taken in Lithuania last year October.

 

[P.Sunesen]

Leaning more towards IW now. Did not initially find the quality of the flight shots adequate for judging the tail pattern, but the bird does appear to show this clinching field mark well enough after all.

Another, more variable character than I thought is the relative lenght of the tail to the primary tips.

After having compared photos of IW's on breeding grounds with stragglers, birds from the latter group are more variable, and some are very 'short tailed' and identical to most NW's.

This could well be explained by birds in poor condition having shorter body lenght, the more curved back causing tail to appear shorter because the wings junction to the body is a constant.

I have noticed this variation on photos of waders as well, some emaciated/dying individuals have very 'short' tails compared to obese individuals where even the leg position may be altered due to huge amounts of subcutaneous fat preventing flexibility of spine and leg bones.

Jane, did your bird show typical NW tail pattern?

Peter

 

[Xenospiza]

It reminds me of this bird, one of two Isabelline Wheatears in the Netherlands this autumn: http://waarneming.nl/foto/view/7508568
I do not have the experience of them being shy...

 

[Jane Turner]

Jane, did your bird show typical NW tail pattern?

Peter

Yes - thoug I didn't get a photo of it. It got worse and worse for IW the more I looked at it.

 

[Kopgalis]

In general, what I see from photos I would vote for Isabelline - uniform wing pattern, overall plain buff body colour, indistinct but visible uniformly whitish "eyebrow", ear coverts warm colored, but not dark, much black can be seen on the tail of fly away bird. Lithuanian bird also didn't display upright posture frequently. I guess this is more characteristic for territorial birds. Legs and bill can look more slender due to the puffy plumage.

 

[Valéry Schollaert]

uniform wing pattern

I find it too contrasted, better for NW...