American Herring Gull L.smithsonianus
I am treating this taxon first as, thanks to M. Ahmad "(Mush") finding a 2nd winter briefly at Drift reservoir, and then relocating it at Jericho Farm outside St Just last week, and now having seen another possible 2nd w. on the Hayle (28/3/15) this is more topical. Mush's bird is a classic "smith" and provides a perfect bench-mark against which to judge the Hayle birds!
The initially distant views and poor light (low evening sun was burning out detail and producing deceptive deep shadows) made ageing tricky when I saw the Jericho bird thanks to a timely lift from Bob Hibbett. The bird looked remarkably like a typical 1st w./2nd calendar year; smooth or "clouded" brownish underparts and hind-neck shawl contrasting with pale head, extensive dark greater covert bar, apparently solid brown tail, dark centered rear scapulars contrasting with newer pale grey ff in the mantle and upper scapulars, and particularly the dense, broad dark-barred (arguably dark ff with pale notches!) upper tail coverts and single generation upper-wing coverts.
Bare-parts were inconclusive as the (apparently) dark eye and extensive blackish running along the cutting-edges towards the bill base could be shown by 2nd or 3rd calendar years, and- added to the distance- wear and bleaching at this time of year make it impossible to use fine ff pattern details to help ageing. Pattern distribution is of some use; 1st w. birds should still have uniformly patterned upper/under wing and tail coverts, being all retained juvenile ff, so no "breaks" or moult contrast should show until spring when new ff would be obvious. There are a couple of problems with this as more "northern" taxa such as smithsonianus (hereafter just "smith"- I don't want to keep on typing anus!) breed and therefore moult later, so 2nd w. (2nd basic) birds are less likely than argenteus to begin another moult (usually a few median cov.s etc.) before winter suspends it.
2nd w. smithsonianus (upper mid. showing underwing) Jericho farm 20/3/2015
The Jericho bird looked better for 1st w. on the upper wing and tail cov.s but crucially the corresponding undersides were too messy and- on the underwing- too pale, thus better for 2nd w. In addition the bird had a more blotchy body, the newest grey scap.s looked plain, it lacked the dark sub-terminal marks on the inner pp typical of 1st w. and had a clean white outer edge to r6 all favouring 2nd w. (M.Ahmad pers.com.).
2nd w. smithsonianus Jericho farm. My sketches made 20/3 (after returning from field). Note
depicted in low sun from left.
Now I have to deal with the Hayle birds- I don't like discussing my own records as the bird's should stand on their own merits. The problem is I know both birds are flawed in that they don't have the full suite of characteristics for 2nd w. smith- unlike the Jericho bird- but given the infamous variability of L.W.H.G. at this age the question remains are they smiths?
2nd w. Larus sp. (pos. smithsonianus) Hayle; top 31/1, lowest 21/2, rest 2/2/15.
Sketches from notes of 2nd w. Larus sp. (pos. smithsonianus) Hayle, 28/3/15