Smithsonianus discussion

    The two "possible " 2nd w. smithsonianus on the Hayle this winter did not fulfill all the necessary  criteria  to remove all doubt about their identification. However this is not so much due to their  deficiency in smith features as to the unknown extent to which argenteus ("gents" hereafter) of the same age can show them too! Second winter/ 3rd calendar year large gulls of any taxon are worse than the rest of the morass! As well as showing arguably more variation in basic patterns at least 2 moult cycles can be underway and the effects of wear and bleaching can be thrown into the mix. Smiths are probably not as bad, but gents can look like anything from Yellow-leggeds through to smiths at the other extreme!
    Both birds showed the stereotypical smith "look"; unusually smooth, dark underparts and hind-neck "shawl", relatively dark coverts and scapulars contrasting with pale head, pale new scapulars, and- although the most over-rated/least useful characteristic- pale based "Glaucous-like" bill (see fig 6 and sketch of ind.2). These features should only serve to attract attention before looking for the key identification criteria- tail pattern, upper- and under-tail coverts. All of this is covered by the excellent paper first published in Dutch Birding by Pat Lonergan and Killian Mullarney and this is well worth downloading from the Gull Research Organisation website (which also carries additional photographs).

2nd w. L.a.argenteus- 2 birds superficially resembling smithsonianus; the left hand bird with better head, bill and coverts, that on the right with better "shawl" and underparts, though both had typical argenteus tail and tail-coverts. Sennen Cove, Cornwall, 25/1/2011

2nd w. L.a.argenteus, Marazion, Cornwall, 13/12/2012. Again superficially resembling smithsonianus  with the tail and upper-tail coverts comparable to a "poor"/atypical bird. However the "shawl" and underparts, though dark, are blotchy, and again the under-tail coverts were sparsely barred thus typical of argenteus. 

2nd w. Larus sp  Hayle, Cornwall  5/2/2015. The head, bill, "shawl" and uniform dark body were perfect for smithsonianus, but almost unbelievably neither the tail nor it's coverts were even close! The upper-wing coverts should be darker, but would arguably not have been enough on their own to rule out smithsonianus. If this is a "normal" argenteus then the head and body pattern are extremely worrying!
  

2nd w. Larus sp. (possibly smithsonianus) Cowloe, Sennen Cove, Cornwall 31/1/2011. As well as the features visible here this individual had typical smithsonianus under-tail coverts, but the spread tail and upper-tail coverts were not noted (see discussion below) before the bird disappeared. A perfect smithsonianus at face-value , but un-confirmed!
  

2nd w. Larus sp. (possibly smithsonianus, hereafter "ind.1") Hayle estuary, Cornwall, 21/2/2015. Arguably less impressive at first glance than the bird on the 5th , or the Cowloe bird above, this bird nevertheless possessed an almost perfect suite of smithsonianus features with the exception of the outermost tail feathers! (see discussion below). 

    My field experience of smith is limited  to one week in California 15 years ago, so I will welcome comments from anyone out there with more field-time (though I'd consider anything less than a year inadequate!), but I have devoted most of my winter-birding for the last 20 years looking for them in this country. I have found 4 accepted 1st winter birds so far, seen two more in Cornwall, found an adult and 4th winter type I am happy with (though did not submit), but until finding a 2nd w.bird at Ditchford, Northants in December 2013 I went through a 5 year drought (not including the Sennen individual above) and had never seen a bird of this age I was happy with in this country. So now I have seen Mush's Jericho bird the two Hayle 2nd winters would seem to be a bit of a glut, and I am far from happy with it! However, I have lived amongst breeding argenteus since the '90s and have obsessively grilled them ever since so I hope the following discussion has some use.

Tail pattern

    As previously mentioned "ind.1"'s tail was it's worst feature; classic 2nd w. smith should have a "wrap-around" almost completely dark (blackish when fresh) tail and those outside the range of variation in argenteus show no white on the outer web of r6. Any white is usually confined to fine peppering at the bases of the outer webs of the outer 1-3 ff, distal fringes (fresh), and some shaft-streaks- again only in the basal half. It is not uncommon (?) for the outermost ff to have a complete white fringe, broadest at the base, and usually peppered blackish. From above there should be no white showing at the bases of the inner-webs as the ff need to be unnaturally widely spread to expose this and the upper-tail cov.s hide their bases, but from below the pale inner webs of the outer ff can be obvious. Unfortunately gents routinely show broader dark tail bands in 2nd w. than is typical of 1st years, and- not too rarely- can be even darker than ind.1 at least (see below).

"ind.1" Hayle, 2/2/2015

"Ind.2" Hayle, 28/3/2015. As can be seen from the sentiment, this bird also showed a disappointing tail-pattern, and that I can't count as I have clearly shown pale slivers at the base  of  r4-6. Even so this pattern is marginally better than ind.1's!

Sketches of 2nd w. L.smithsonianus  Ditchford g.p. Northants, 14/12/2013. This bird showed a much better r6 than those above, but even this can be matched by European Herring Gulls- particularly argenteus . The longest under-tail covert shown is not perfect for smithsonianus in having a narrow brown centre but see below. 

      Although my photo.s are pixelated (thanks to the distances at the Hayle forcing the "stacking " of converters!) the outermost tail f. (r6) of ind.1 is mostly white with a sub-terminal band and black spotting on the inner-web. Although I have never seen it myself, and have no idea of the frequency smiths can show this, there are images in another excellent paper by Andreas Bucheim in Limicola (sorry there are no propoer ref.s here - I have lent both publications and still await their return, but I will cite them properly later) of birds with similar r6. Ind.2 appeared to have a slightly better tail, but the only view I had was during a brief period of preening  before the bird took off so it could possibly have been worse! In either case the tail is not enough to settle their identification- though smith is looking second best so far!

Upper and under-tail coverts

     Again smith should be much more heavily/densely barred dark in these tracts than in argentatus or argenteus, but although this is a reliable feature in 1st years moult in 2nd years can produce ff showing patterns from reduced barring to pure white. This seems to be more common in the upper-tail coverts, but I do not know if the "paler" ff are 2nd generation- i.e. produced in the bird's first complete moult to 2nd w.("2nd basic"), or isolated 3rd gen. ff replaced as part of a suspended pre-"breeding"("pre-alternate") moult .The latter is almost certainly the case in late winter (Feb./March), but because smith are relatively late/high latitude breeders this is probably rarer in early winter(?). Whatever the case any typical, or at least distinct smith upper-tail coverts (the longest ff over-laying the bases of the tail ff) should be more than 50% dark, and show at least 4 dark bars which reach the outer edges of the ff. There are many variations and it is common for the barring to be narrower or fainter basally which can be revealed when ff from the "2nd row" are displaced or missing. Feathers with dark centres or intricate patterns reminiscent of "white-winged "gulls are shown by more distinctive smiths and- although one should never say "never" in regards to any aspect of LWHG identification- possibly never shown by (pure) European Herring gulls- but see below!

2nd w, L.a.argenteus, Sennen, Cornwall, 26/1/2011. Tail pattern better than ind.1 apart from more extensive pale flecking, but sparsely barred upper-tail coverts typical argenteus, and upper-rump/ back mostly grey.

2nd w. (presumed) L.a.argenteus, Marazion, Cornwall, 13/12/2012. The underparts on this bird were reminiscent of smithsonianus, but the bird took off almost immediately so the under-tail coverts were not noted and this is my only image. It could be argued that argenteus cannot be confirmed from this shot; the tail is better for smith, and the upper-tail coverts show 4+ dark bars, though they do not quite reach the fringes.

2nd w, (presumed) L.a.argenteus, Sennen, Cornwall, 22/2/2010 (same individual below). It might seem  surprising that I do not consider this at least as likely to be smithsonianus as ind.1. However, although the tail pattern is better on this bird, and the upper-tail coverts have up to 6 bars, the underparts are probably too blotchy or coarsely marked and there was no solid neck"shawl". More important the possibly diagnostic almost solid-dark longest under-tail coverts of smith ( in Lonergan and Mullarney ) are not shown, despite being more closely barred than in most argenteus.

2nd w. (presumed) L.a.argenteus, Sennen, Cornwall, 22/2/2010. The 6-8 narrow dark bars on the longest upper-tail coverts are more typical of smithsonianus, and to date I have not seen "typical" argenteus matching this pattern. The white areas are presumably new ff apart from the inner web of the left/central longest  covert.

 

     The under-tail coverts in smith should be similar to the uppers but there are some differences; central coverts and vent are frequently white or sparsely marked, and any dark bars are often broader distally, irregularly or untidily patterned on the longest. Crucially Lonergan and Mullarney suggest that "solidly" dark centred under-tail coverts may be a pattern "..never found in European Herring Gulls.", whereas- in the longest ff- this may be the norm in smithsonianus!
    In their under-tail coverts at least the two Hayle individuals are far closer to smith and if Lonergan and Mullarney are correct then this feature alone could clinch their identification. Both birds showed a varying suite of supportive features so this seems reasonable but the problem is most of these can be shown to some degree by European birds, and until more is known about the significance of the "pale" outermost tail ff and dark under-tail coverts as anti- and pro-smithsonianus criteria respectively doubts will remain.

"Ind.1" possible L.smithsonianus, Hayle, Cornwall, 2/2/2015. The almost completely dark longest central under-tail coverts are just visible as this bird preens. The only pale marks on these ff were paired spots at the extreme tip, and another pair hidden here by the next longest coverts. It is possible this feature alone may be enough to identify this individual as smithsonianus but a single diagnostic feather pattern in any age or taxon of LWHG is at best extremely rare!

Detail of sketch of the under-tail coverts of "ind.2" -possible L.smithsonianus, Hayle Cornwall, 28/3/2015. Again the longest  under-tail coverts may be enough to make this bird- which was arguably more "impressive" overall than ind.1- an acceptable smithsonianus. The problems in this case stem from the lack of corroborative photographs and the brief and incomplete views obtained before the bird flew off to join the ranks of the "semi-mythsonianus"!!