Teesmouth Bird Club

Apparently the name has been changed from "Black throated Diver" to "Arctic Loon". Thanks to Neil, Ray and Shirley Crabtree for the info and the crack at dinner time.

(Not forgetting the pied piper of Billingham)



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Well done catching it in flight Dave.

It's amazing what a bit of sun will do to bring them out. I reckon we spotted over 15 Northern Loons (photographers), showing well all round the marina, while we were there. Great weather, great birds, great company.

The bird had just finished dancing on the water before it reached me and passed on to you. Ray or JB must have a good shot.

Cheers, Neil

My contribution to the 'Loonies' day out.

Hi Neil, your picture nicely captures the complete vent strap on this bird - a feature not, therefore, that unique to Pacific Diver.

Quote from: Gary Sharples on February 04, 2010, 09:45:09 AM
Hi Neil, your picture nicely captures the complete vent strap on this bird - a feature not, therefore, that unique to Pacific Diver.

Hi Gary, i also thought a complete vent strap was only shown on Pacific Diver, this has been quoted as a diagnostic feature of Pacific as recently as 2007. Further reading in Martin Garners book "Frontiers In Birding" research has shown that 93.5% of Juvenile Pacifics examined do have a Vent strap and "limited" research of Western Europe Black-throated Divers indicates that a complete vent strap is not unusual and perhaps should no longer be considered a Key feature of Pacific!

It's worth remembering of course that Britains first Pacific Diver was as recent as January 2007 and just down the road at Farnham GP in North Yorkshire! I think there's now being about four British records and Ireland, Channel Islands and Spain (i think) have recently also recorded this species for the first time so a Cleveland record would not be that out of the question! I'm sure from now on all inland or easily viewable B.T.Divers will be getting a grilling and Superb photo's like the above can only help the identification process...

Cheers Ian.

Hi Gary and Ian,

The visible white flanks while swimming, slightly peaked head shape and bill size left me not even considering that the bird might have been a Pacific Diver... and I'm still pretty sure it was a BTD.  I didn't consider checking the vent strap which, as you say, is often given as a diagniostic for a PD.  Also the size is similar to that of the GND and, therefore, almost certainly too large for a PD.

With all that said it would have been interesting to identify the bird from the flight pictures alone where gizz, size and head shape are difficult to pick up. Is there a diagnostic other than bill size/shape vs. vent strap that would have identified this as a BTD?       ... just in case I happen to come across a PD and photograph it taking off !!!  I can dream.

Cheers,

Neil

Another flight shot - a bit distant - to add to the pool of photos

Enjoyed the crack, on the day, and a few bonus photo's.
The noise from the cameras, was like listening to a typing pool, when the Loon took off .

Hi Neil,

From what gather without going into too much detail i dont actually think there is any one diagnostic feature to identify Pacific Diver (although i'll probably be proved wrong)! It's one of those species that's id'd using a combination of features...Any B.T.Diver type that shows a lack of white thigh patch, has a more smooth rounded head profile, smaller more gentle bill shape/size and with any luck a clear cut chin/throat strap along with the vent strap would almost certainly be a Pacific! Most of these, if not all would need to be seen for a record to be accepted. Anyone claiming a Pacific Diver on a flight view would be a brave man but with digital photography the way it is these days who knows whats possible?

Hope this helps

Cheers Ian.