Are these Gt Northern Divers (3 Viewers)

[deborah4]

GND is a fairly common winter species in hebridean waters (& is probably also in Ulster waters). A winter ferry trip to Mull or any of the other islands should yield a good number of sightings including birds in small groups. East coast birders more commonly encounter singelton GNDs.

I have to agree with this Steve. Although my experience of Divers is probably less than many on here in terms of years spent studying them, when the best part of one's learning curve is spent daily (on the west coast) intensly observing an abundance of winter divers, often with all three species together in the field, in poor weather where visibility isn't particularly good, a general jizz of shape/structure, behaviour and plumage pattern tends to emerge and it can help Iding birds without relying on clear and detailed views. Having said that, I still wouldn't call 100% on a 'still' photo image (but 90% here!), as everyone has said, the confusion in that respect is evident.

 

[TWM]

I'm still going with Black-throated (especially after seeing the photo posted by Stu Reeves) !

 

[deborah4]

I'm still going with Black-throated (especially after seeing the photo posted by Stu Reeves) !

Then we'll have to beg to differ based on percentage likelyhood from inconclusive photos

 

[gerdwichers8]

There is nothing but admiration for Stuarts input from Netfugl but the birds there are sometimes more likely to be mistaken for eel rather than for GND.
The features shown on several birds in Pluvius' pics are not only persistent but consistent as well.
Note that at the rearend of several birds the feathers stick up typically and that stains are found at the bird in the back at the last partypic. All over its white flank.
Not to mention their headpattern because I am out now; I ll too have a haircut in half an our (honest)

 

[timwootton]

This is a fascinating thread and probably the only conclusive outcome will be that the two, if seen from any great distance, are pretty tricky to seperate. The one thing I would like to point out, however - is the pitfalls associated with trying to id from photographs (particularly ones which, through magnification, will 'bleed' into the background and create shapes and colours which may not actually exist in reality) - try to 'do' the bird in the field - photos can and do lie (regardless of the saying) and colours and shapes can be altered beyond all recognition.
In this photo we are discussing - the very fact that it is indistinct makes for the enigma - whichever side of the fence you stand on, there is enough 'inferred' evidence to support your argument. There simply isn't enough visual information to catagorically state one or the other (or both as has been suggested) - In my humble opinion.
Great fun though!

 

[hannu]

Pluvius's pic in post 28 : left bird's age seems to be 1st winter, the age of 3 birds in the right 2nd winter or older..
the border of black area in the head seems to be under the eye in these adult birds,
> there seems to be white area around the GND's eye very often
GND in netfugl...
http://www.netfugl.dk/pictures.php?id=listpictures&species_id=4&page_nr=1

 

[Gavin Haig]

Sorry I haven't carefully read every post (bit pushed for time) but my two pen'orth is this:
I vote Black-throated - firmly - and feel the perceived head shape in some of the pics is simply misleading. A real clincher for me in good light (which we seem to have here) is how contrasty BTD look, with virtually auk-like coloration. In fact, when BTD is relaxed, resting and riding high in the water I have almost overlooked them as Guillemots in the past - don't laugh, they were rather distant! For me, the head is way too dark for GND. There are a couple of other things, but that'll have to do for now. Gotta go.............

 

[Chris Benesh]

Hi All,

I have been watching this thread on the sidelines for a while, but finally decided to jump into the fray. I agree that it is always a challenge to identify birds from distant images (not to mention distant lands), but what the heck. I can understand that the quality of the images may be such that not everyone will feel comfortable coming to any firm conclusion. Pretending for a moment that we use the same terminology for divers, I would be inclined to see these as Great Northern Divers. That was my impression from the initial photo based primarily on subtle shape and apparent neck markings. But Pluvialis's additional photos seem to me all the more compelling that these birds are indeed GNDs. To me, these birds look too short necked and big headed for BTD, and none show a classic BTD waterline pattern (though I know this can be obscure at times). This impression was only strengthened by me after checking Stuart's linked photo. On the other hand, there has already been a good analysis of pro GND features. I have attached one of Pluvialis's images again, a la Deb's, though I went ahead and put pointers to features as described in the Collins Guide as being pro GND features which I had always assumed to be diagnostic. I am interested to see and hear more about the variability of neck patterns in basic plumaged Black-throated Divers, particularly if supported by photos (in addition to Tim's exquisite paintings). A good head-scratching debate!

Chris

 

[HH75]

Hi all,
At the risk of trying to teach people how to suck eggs, my initial reaction on opening the first thumbnail was that these birds were Great Northern Divers, based mainly on the head shape, white indentation into the dark hindneck (an extremely good indicator of Great Northern, and diagnostic vis-a-vis Black-throated) etc.
Of course, Great Northern is common around the Irish coast, whereas Black-throated is found in a handful of areas, with only singles or very small groups anywhere else.
To my mind, there is nothing unusual about seeing so many GNDs close together: where the species is common, as in Ireland, such gatherings are perfectly normal.
Regards,
Harry

 

[deborah4]

LOL well in the light of the previous two posts, one from (hope he doesn't mind me saying) a very experienced bird IMV, another from one very familiar with the locality, I'm pushing my % upto 95!!! Good debate though.

 

[hannu]

If there are both species ???? ... :bounce:

 

[HH75]

Hi Hannu,
In my opinion, all of the birds photographed in Northern Ireland on this thread are Great Northerns, including one in what appears to be more or less full breeding plumage in the first pic.
Regards,
Harry

 

[hannu]

You're more experienced, fellow Harry ....

 

[HH75]

Hi Hannu,
That doesn't necessarily make me right!
Mind you, I am very confident that these are Great Northerns.
Regards,
Harry

 

[Jane Turner]

Hi all,
At the risk of trying to teach people how to suck eggs

Always happy corrected, by one as gentlemanly and skilled as you!

I only do Divers in flight - when GND look like they are Greylags trailing parachutes, or at 10m range on marine lakes!

 

[hannu]

Hi Hannu,
That doesn't necessarily make me right!
Mind you, I am very confident that these are Great Northerns.
Regards,
Harry

I know that,....
By the way,.. Chris Benesh's added bow-up lead me to think that at least that bird looks enough good to be GND....

 

[lou salomon]

Hi Hannu,
In my opinion, all of the birds photographed in Northern Ireland on this thread are Great Northerns, including one in what appears to be more or less full breeding plumage in the first pic.
Regards,
Harry

i must confess that the one with black head and neck got me quite irritated... , especially as i had the initial feel they were BTD. chris and you convinced me of the opposite. to the contrary i've seen far more BTD than GND...and i think all in that group are of that species.

 

[TWM]

I must admit Debs 4 my call is not looking very good, however the photos still shout B-t to me!! There is no doubt that photos at long range, etc can be difficult I think I shall retire (gracefully?) from this thread and follow it from a distance.

 

[Jane Turner]

I would still call that first pic BTD... even knowing its a wrong call! I console myself that I could never make that mistake in the field *cough*

 

[Th_SQ]

I'm too lazy to read everything and I may well break opened doors but from what we are given to see (i.e. a bit fuzzy and distant shots) it looks like more Great Northern Divers.