Diver, Fife Ness, Scotland 13/10/14 (1 Viewer)

chris butterworth · Oct 17, 2014

tittletattler said:
Fair point (and always question everything) but the bill is pale in each photo.

Winter GND's have pale ( grey ) bills.

tittletattler said:
[*]Length of the bill

There is an overlap between GND and WBD.

tittletattler said:
[*]Straight culmen

I don't think you can be 100% sure of the culmen shape, or the gonydeal angle ( a more important discriminant feature ) from the photos.

tittletattler said:
[*]Angular head shape

Both species can show equally angular head shapes. In fact all Divers, except for Red-throated, often raise the feathers over the top of the forehead / front of the crown producing an 'angular head shape'.

tittletattler said:
[*]Leg size

Both large Divers have large feet but, unless the views are ideal / the two species are seen in flight together, it's a variable feature due to how the toes are held.

tittletattler said:
[*]Head colour

The head and, more importantly, the sides of the neck, look equally as dark as the upperparts. GND can often show a fairly large pale area around the eye ( depending on the age ) which can make the 'face' look rather 'open'. Having said that juvenile WBD [/I] can have a very pale head and neck ( but it's both and would be obvious in the photos ).

tittletattler said:
The dark area at the base of the upper mandible is feathering.

Winter WBD have a dark culmen like GND. GND have a dusky tip to the bill, but this is often very difficult to see in less than ideal conditions.

Jane Turner · Oct 17, 2014

It makes a lot of difference which photo you choose with this bird (which is never a good thing when striving for certainty)

This one looks pretty nailed on GND for example

Would be good to hear from people in NE Scotland who actually see these things in flight!

Tiraya · Oct 17, 2014

tittletattler said:
If you can't be bothered to read what has been said above and/or view the links (whilst failing to provide links of your own to support your argument) then your opinion counts for nothing.

You and Silverwolf are usually better than this.

I'll just "+1" chris' comment above for my reasoning. I have seen all the points here but I am not yet convinced enough that it is white-billed diver. Any ID links helpful have already been provided in this thread. Whether you consider my and other's opinion(s) is up to you of course.

Stonefaction · Oct 17, 2014

Here's another two photos of the same bird. No idea if these are any additional help......

tittletattler · Oct 17, 2014

chris butterworth said:
Winter GND's have pale ( grey ) bills.

There is an overlap between GND and WBD.

I don't think you can be 100% sure of the culmen shape, or the gonydeal angle ( a more important discriminant feature ) from the photos.

Both species can show equally angular head shapes. In fact all Divers, except for Red-throated, often raise the feathers over the top of the forehead / front of the crown producing an 'angular head shape'.

Both large Divers have large feet but, unless the views are ideal / the two species are seen in flight together, it's a variable feature due to how the toes are held.

The head and, more importantly, the sides of the neck, look equally as dark as the upperparts. GND can often show a fairly large pale area around the eye ( depending on the age ) which can make the 'face' look rather 'open'. Having said that juvenile WBD [/I] can have a very pale head and neck ( but it's both and would be obvious in the photos ).

Winter WBD have a dark culmen like GND. GND have a dusky tip to the bill, but this is often very difficult to see in less than ideal conditions.

Links?

You guys clearly didn't look at the two links I provided. I chose the GND at Portland as it was the most WBD like. But note the down curved upper mandible, the greyish bill (not ivory), the shorter bill, the smaller feet and the darker areas on the bill.

Have a look at the feathering at the base of the upper mandible on the Brixham bird and the dark area at the base of the bill itself.

Jane's image seals the deal.

Have another look at the image selected by James (a much better birder than me). With the dark sea behind the bill you can see it's as good as it gets.

Jane Turner · Oct 17, 2014

This is illuminating (with sharper images - no criticism of the OP intended )

https://naturescapeimages.wordpress.com/tag/common-loon/

Does this "un-seal the deall" it Andy?

DarkFireFalcon · Oct 17, 2014

tittletattler said:
Links?

You guys clearly didn't look at the two links I provided. I chose the GND at Portland as it was the most WBD like. But note the down curved upper mandible, the greyish bill (not ivory), the shorter bill, the smaller feet and the darker areas on the bill.

Have a look at the feathering at the base of the upper mandible on the Brixham bird and the dark area at the base of the bill itself.

Jane's image seals the deal.

Have another look at the image selected by James (a much better birder than me). With the dark sea behind the bill you can see it's as good as it gets.

I don't get this insistence on "links or GTFO". Plenty of ID questions have been solved here, even complicated ones, without anyone linking to additional pictures. You can find links that selectively support your theory, but that doesn't mean it represents the total range of variation in a species. All of Chris's points are solid points, many of which deal with uncertainty of judging the salient ID marks in the photos..

Regardless, Jane linked to a good photo that shows that an "ivory" bill (what exactly constitutes Ivory vs pale gray, in a grainy picture of a moving bird against the sea, is obviously a tough question) with a slight upturn doesn't make this a Yellow-billed Loon (sorry, I'm American).

Personally, I don't think that Common Loon (sorry again) can safely be eliminated.

Ratal · Oct 17, 2014

OK - Why I personally see this as a White Billed Diver.

When you watch a Great Northern (AKA Common Loon) fly low across water like the original photograph, the bill really is very hard to see against the grey of the ocean unless it is in strong sunlight. Watched them all last winter off West, north west and north east coast of Scotland (Cape Wrath, Stornoway and superb up close flying no further than 100 meters away and feeding even closer at Fortrose).

The White billed Divers however appear brighter in dull conditions (exactly as the OP's photo shows). It's moving, in inclement weather, poor ocean luminosity, the cards are stacked against it really, but that says to me why it for me is a White Billed. I can see the bill clear as day.

Maybe its just me, maybe I'm barking up the wrong tree, but if I saw this bird on a sea watch it 100% would catch my eye and have me pootling along for a better closer view.

tittletattler · Oct 17, 2014

Jane Turner said:
This is illuminating (with sharper images - no criticism of the OP intended )

https://naturescapeimages.wordpress.com/tag/common-loon/

Does this "un-seal the deall" it Andy?

No.

Jane Turner · Oct 17, 2014

I'm just amazed anyone can be so certain!

tittletattler · Oct 17, 2014

Jane Turner said:
I'm just amazed anyone can be so certain!

You know it's a WBD. You're just playing along.

The culmen on each of the subsequent birds is wrong.

SteveClifton · Oct 17, 2014

My opinions, going purely from the ‘evidence’ I can see in the photos provided:

Neck looks deep & thick-set, especially towards the body (favours WBD). It also looks to be a very heavily built bird, esp in pic 3

It’s true that Gt Northern’s bill can look pale in good light, but the tip is always darker than the base. This does not appear to be the case here, and, for what it’s worth, this bird is not subject to strong directional light (eg low afternoon sun which would make GND’s bill look paler than usual) The light is flat and overcast in the OP’s images which could, conversely, make a pale bill look darker than it really is, yet the overall feel here is of a bird which consistently looks pale-billed in all images (especially towards bill-tip).

Darkest area on the neck is the half-collar at the base, and to a lesser extent the ear-coverts. The section between these dark areas is clearly paler/browner across the majority of images (again, favours WBD)

With respect to the images Jane posted, it’s all very well posting images of proven WBD in strong sunlight and comparing them with the subject bird here. That’s not really comparing like with like!
If you do a Google image search there are plenty of pictures of WBD that look darker-necked than the textbook images we usually expect to see. Importantly though, the middle section of the neck looks consistently paler than the areas either side if it. Try finding images of GNDs in overcast light with pale-looking neck-sides!

I have to conclude that the images are not 100% conclusive either way. But, to look at this from a different perspective, if this was in an area where GND was the rarer species, you’d need to make a very strong case why this was GND and not WBD.

edit: some darker looking WBD in dull light...

http://robs-birding.blogspot.co.uk/2014/01/my-birding-review-of-2013.html (scroll to bottom of page)

http://carolinabirds.org/People/RunolfssonLG/Loon,_Yellow-billedRunolfsson.jpg

http://www.simnet.is/dna/Icelandic-Birds/Svalbrusi.html

Jane Turner · Oct 18, 2014

tittletattler said:
You know it's a WBD. You're just playing along.

The culmen on each of the subsequent birds is wrong.

No I'm not playing - I'm genuinely not sure. In some photos it looks convincingly WBD in others it looks like GND.

What age do we think it is? My biggest worry is that it looks to be a juv - I can't see any spots on the wing coverts. If so why is the head so dark?

Jane Turner · Oct 18, 2014

Which of the appearances of the bill is artefact Top left or top right?

skbirder · Oct 18, 2014

Interesting and tricky bird. It looks to me like a White-billed based on the shape and form of the bill, although if I only saw top left image in Jane's collage I'd be thinking Great Northern.

Just to illustrate the difficulties involved, here are images of a bird from Sweden last autumn that was identified - using photos - first as Black-throated (the commonest of the three large divers up here), then Great Northern and then, finally, as (a dark) White-billed.

http://svalan.artdata.slu.se/birds/gallery_imageinfo.asp?imageid=530649
http://svalan.artdata.slu.se/artportalen/gallery/images/swe/birds/2013/large/530785.JPG

tittletattler · Oct 18, 2014

Jane Turner said:
Which of the appearances of the bill is artefact Top left or top right?

Top right is undoubtedly the image to use. The others are OK too but that image puts the ID beyond all doubt. Not that there should be any doubt! And yes, it's a juv IMO.

This is a species that was under recorded and on seeing the responses on here I can see why. Guys- you won't find a GND with such a long, straight, horizontal and ivory bill. End of!

In answer to 'darkfirefalcon', it's because it is the professional thing to do.

chris butterworth · Oct 18, 2014

tittletattler said:
This is a species that was under recorded and on seeing the responses on here I can see why. Guys- you won't find a GND with such a long, straight, horizontal and ivory bill. End of!

In answer to 'darkfirefalcon', it's because it is the professional thing to do.

You are still persisting with the "long" bill fallacy. Baker. K. (1993 ) Identification of European Non-Passerines, BTO Guide 24, BTO, Thetford gives ( as quotes from BWP ) GND bill length as 72 - 89mm and WBD as 83 - 96mm therefore my comment about bill lengths stands, regardless of a 'link' or not. WBD has anything but a "straight" bill, it's much more like a large RBD bill in shape, with the majority appearing uptilted due to the rather obvious gonydeal angle. I see no obvious sharp break in the line of the lower mandible in the OP's photos. All 5 Divers will hold their bills horizontally, with only RTD regularly lifting the bill above the horizontal ( both RTD and WBD can appear to be carrying their bills uplifted, but that is often because of the distinctive gonys ). The points in my last post still stand, despite your 'demand' for sausages, as valid reasons why the bird could be, and probably is, GND.

Microtus · Oct 18, 2014

After looking at the photos, and reading the posts through #24, plus DarkFireFalcon at #27, I believe that this bird is a Great Northern Diver/Common Loon. The bill does not look ivory to me (according to a recent how accurate is your monitor test I have true color display), and the neck flanks are too dark for White-billed Diver/Yellow-billed Loon. Like Silverwolf in #23, I "+1" Chris' post in #21.

tittletattler · Oct 19, 2014

There are a number of inaccuracies in the posts above from the 'antis'. The bill is 'ivory' in the object bird (see attached images) and matches other Whte-billed Divers perfectly. The flanks can be darker on WBD than on GND (Common Loon); again see attached images. The bill length is consistently longer on WBD (despite the overlap). Some of you stated that WBD doesn't have any dark on the base of the upper mandible; they nearly all do! Question; on a sea watch, what would you call the bird in the third image attached?

The object bird, in the images attached, shows a straight, long, horizontal culmen. Compare to the steely grey bills of the GNDs in the attached images. Note the GNDs also show the typical darker areas for that species.

One thing not mentioned so far is the sheer bulk of the object bird. It is broad and deep bodied.

I believe that the two images that I've attached prove the ID beyond all doubt. The problem with stating 'facts' that are non-evidenced based is that people are able to trot out any old rubbish and pass it off as fact. I work in an area where evidence is required before decisions can be made. If you stack shelves, or whatever, then you won't understand.

By all means prove me wrong. But stop saying 'the World is flat, so there'.

Stonefaction - submit this record as WBD and use my images attached and 'Roy as your expert opinion.

Cheers,

Andy.

Jane Turner · Oct 19, 2014

I'd like to see the underwings of undoubted WBDs in poor light. Your photos clearly shows pale primary shafts on WBD. Its a bit of a Scopolis/Corys type thing I suspect. I'll have a look later perhaps!

Diver, Fife Ness, Scotland 13/10/14 (1 Viewer)

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