Sunday, 3 March 2013

3rd March 2013 Birling Gap NE3 Overcast 7am - 9am & Arundel

Burgess Hill
Tawny Owl 1

Great Northern Diver 1E w/p ex.
Red-throated Diver 37E, 2W
Great Crested Grebe 2E, 1 on sea
Gannet 20E
Scoter 9E
Bonxie 1E
Yellow-legged Gull 1 ad. ex.
Lesser Black-backed Gull 10 on beach
Black-headed Gull 70E, 10 on beach
Razorbill 11E
Auk sp. 92E

Adult summer Yellow-legged Gull at Birling

Yellow-legged, Common, Herring & Lesser Black-backed Gulls at Birling

Yellow-legged, Herring & Common Gulls at Birling
 

Adult summer Yellow-legged Gull at Birling
More extensive white on p10 is more frequent in E populations (Larsson 2004)
 
Arundel, Burpham SF & Amberley
Greylag Goose c.25 including 2 or 3 showing some characters of A.a. rubrirostris
Red Kite 1 ex.
Barn Owl 3
Chiffchaff 2
 
Greylag showing some characters of A.a. rubrirostris at Arundel
The Siberian form of Greylag Goose A.a. rubrirostris is described as being larger, pink-billed, paler grey and typically with broader pale fringes to the upperparts. However, it has yet to be added to the British List due to birds perhaps occuring from the reportedly wide intergrade zone between nominate anser and rubrirostris and further muddied by introductions of rubrirostris and interbreeding with anser on the near continent albeit described as genetically swamped (RIACT BB 99 December 2006). Whilst clearly the Arundel duo are pink-billed, paler grey and have pale fringes to the upperparts they appeared certainly no larger, if anything slightly smaller, than the accompanying Greylags. I also found the smooth grey face and very pale grey forehead of the above bird surprising - whilst watching it I considered it bore an uncanny resemblance to the head pattern of a Blue Crane!

Greylag showing some characters of A.a. rubrirostris at Arundel
Revealing the full extent of the barring to the flanks. Van Duivendijk (2010) notes A.a. rubrirostris as having stronger barred rear-flanks.


Greylag showing some characters of A.a. rubrirostris at Arundel
The second individual, whilst lacking the very pale grey forehead, in good light showed an almost horizontal narrow pale line across its face that was present on both sides of its head. It showed far less of a dark grinning patch and its bill gave the impression of showing some orange.

Greylag showing some characters of A.a. rubrirostris at Arundel
Perhaps just my perception of them, but at times, they had a peculiar look about them!

Greylag showing some characters of A.a. rubrirostris at Arundel
Some of the pale fringes to its upperparts do appear broader than on the Greylag in the background, that being further away, explains the apparent overall size difference of the birds in this image...

Greylag showing some characters of A.a. rubrirostris at Arundel
RJF raised the possibility of a third bird being present showing characters of rubrirostris in his SOS posting and it seems likely that this is the 'third' individual being difficult to reconcile with either of the above birds.



Same image enlarged showing orange and pink tones to its bill colour
 
A scanned slide of an Eastern Greylag A.a. rubrirostris at Bharatpur, India in December 2005