GULLS smithsonianus
Western
Slaty-backed

first cycle

older ages

Temp 1
Temp 2

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VEGA GULL IN CALIFORNIA ?

Here are photos of a couple of birds which I think are Vega Gulls, or at least very good candidated from California. I would appreciate any comments folks might have. These pages are under construction, but the end goal is to have a set of photos showing what gulls in California look like.

Jump to 2005 first cycle bird.

Jump to 2003 first cycle bird.

Adult - winter. Feb. 20, 2005.

The Vega Gull is not yet confirmed from California. For a general introduction to the problem and some resources see the first shot of the immature bird below. A source that is most useful for understanding what Vega Gull adults look like is:

Chris Gibbins site on the topic on surfbirds.com

The bird in question is the adult in the center. Effectively this bird looked structurally like a smithsonianus Herring Gull, and in size it was comparable. The birds around the bird are mainly Glaucous-winged Gulls, with a Western to the left, and a second cycle smithsonianus preening up and to the right. What made this bird stand out was the dark mantle colour, it was picked out through binoculars due to the very dark upperparts. Other features noted that suggested this was not a smithsonianus included a heavily dark speckled eye, a reddish orbital ring, and perhaps differences in the primary pattern.

Vega 2 shows the dark speckled eye, not a bright yellow eye as on a smithsonianus. As well, you can see the reddish orbital. When zoomed up to 60 power on the scope, the orbital could be seen to have orange tones, I hope this was not colour shift due to the scope, but at lower power it looked reddish. The head was well streaked, hooded even. This pattern is not uncommon in smithsonianus, but it is not typical. This is a pattern that is also not classic for Vega, but it is not rare either. The bill had a greenish colour, reminiscent of Thayer's Gull. The red gonys spot reaches to the cutting edge of the bill. The dark mantle is apparent here, the mantle colour of the second cycle Glaucous-winged Gull behind the bill of this Vega candidate is obvioulsy paler.

Vega 3 Shows the bird with an adult Western Gull to the right, and a preening third winter Glaucous-winged x Western hybrid. Below the bird is a first cycle Glaucous-winged Gull. The photos do not do the mantle shade justice, but we thought it was roughly intermediate between occidentalis Western Gull and Glaucous-winged Gull, hence relatively similar to the hybrid Western x Glaucous-winged.

I have seen Herring gulls in the gull flock which appeared to have dark eyes and have thought Vega Gull was a possibility. However careful looks at these birds have suggested to me that they have been Glaucous-winged x Herring hybrids. These confusing individuals do not show a darker mantle shade than Herring or Glaucous-winged, they also show reduced black on the underside of P10, but they do show the dark eyes, pinkish orbitals, and moderate 'string of pearls' pattern on the primaries. This Vega candidate is not a Glaucous-winged x Herring hybrid as the mantle shade is darker than either parent species, the primaries are blackish, and extensively dark below.

Vega 4 - Here is the bird behind an adult "Puget Sound Gull" a hybrid Western x Glaucous-winged Gull. The other birds around the possible Vega are first cycle Glaucous-winged Gulls. This shot shows the slightly darker mantle colour of the possible Vega compared to the hybrid. In the field, the mantle colour was similar to California Gull.

Vega 5 shows the bird with Western Gull above and to the right. You can see that the primaries are black and quite fresh. Interestingly P10 is still growing in on the near wing! P10 was also growing in on the other wing, and I have shots that show this. Active wing moult in late February is not anything I have seen on the local gulls. The Herring Gulls here are one of the latest moulters, and are often finishing up in December. I have never knowingly noticed active wing moult here in February on any gull. Vega Gull is a late moulting species, with many finishing up in early January (according to Olsen and Larson 2004). They note mout extending to February in some. The late moult is definitely off for our local gulls, a bit on the late side for Vega, but on the whole suggests Vega. Looking at the Gibbin's article on Surfbirds.com, his sample showed that nearly 10% of Vega Gulls he looked at in Japan were growing in P10 in late February. His data strengthens the importance of the observed late mout of this bird, our locals just don't moult this late!

The pattern on the far wing is difficult to decipher, but it seems to show that there is a tiny bit of black on P4, and only on the outer vane. The tip of P6 is the last tip you can see before the Glaucous-winged Gull obscures the longer primaries. There is also some evidence of internal white crescents or tongues at least to P6. I have enlarged the wing tip below to see patterns a bit more clearly.

Here the wing tips are enlarged, and the pattern is...well...only a bit clearer. What I think I see on the near wing is P10 growing in, with its tip just beyond the tip of P7 currently. On the opposite wing the longest primiaries are covered up by the sitting Glaucous-winged Gull. The last obvious white tip is that of P6, the innermost primary with a good amount of black near the tip. There is a thin ribbon of black near the tip of P5, and then a little black wedge on the outer edge of P4. Gibbin's sample showed that over a quarter of his Vega had some black to P4, although this is more typical of mongolicus. I am not sure how many smithsonianus show black to P4, I can't say that I have studied this feature closely on the local gulls. However, the dogma is that it goes to P5 only.

Part of the complication of the pattern of that opposite wing is due to white crescents or tongues interior of the black subterminal bands. These can be seen on P4-P6, and I must admit that it is very difficult to describe where they are as the primary tips and white crescents are blending in and look like solid masses of white in this photo. But at least I think they are clearly there once you determine where the primary tips are. These white crescents would create a "string of pearls" pattern on the wing as on a Slaty-backed Gull, but less noticeable in extent and due to the paler colour of this gull. This is a feature I have noticed in Vega Gull adults in Alaska, and in photos from Japan. How is that for reading a lot into a bunch of folded primaries!

Vega 6 shows a nice profile of the bird, but concentrate on the primaries. To help in this discussion I have enlarged the primaries below and adjusted contrasts to hopefully better see what is there. I had originally thought that the underside of the primaries showed a large white mirror separated from the white tip. The realization that P10 on the near wing was growing in allowed me to see that in fact what I am seeing is that P10 is growing in, and the white mirror is united with the primary tip, creating a large entirely white tip to P10. It seems like P9 may also be growing in. See the blow up below, and check out what I mean.

Another feature that can be seen in this photo, and several other photos I have of this bird is a thin white bit just above the black of P6. This is in fact a bit of the white crescent or tongue on P7, immediately below P6. So I think that this bird shows a string of pearls pattern at least to P7, something that would be highly unsual in our smithsonianus.

This is a blow-up of the above image, concentrating on the primaries.

smithsonianus for comparison. I had a look at my smithsonianus photos from
California and noted that the most consitent difference between the Vega candidate and the smith series was how much black there was at the base of the outer primares. The Vega photo #5 above shows that there was extensive black at the base of the primaries on that bird. At least inward to P8 there was a substantial amount of black at the primary bases. On my sample of California smithsonianus inward of P9, there is little black on the primary bases. I think this shows up well in this photo of a smthsonianus taken minutes after the Vega type showed up. Olsen and Larson (2004) write that West Coast smithsonianus have more black and less white than East Coast smithsonianus. I agree that they have less white (smaller mirrors etc) but I am not so sure that they have more black. Here I find that smithsonianus usually shows a relatively small amount of black on the primaries, due to large intrusions of grey along each primary. I will admit that I need to look at smithsonianus more closely to adequately determine what is normal and what is not, keep in mind that at least on the coast we see a good number of Herring x Glaucous-winged, and all the backcrosses, making the determinatioon of 'normal' somewhat of a fantasy.

First cycle - Juvenile/first basic.

Feb 2005 bird.

VEGA1. Feb 7, 2005. Half Moon Bay, SM, California. A. Jaramillo

The Vega Gull is not yet confirmed from California. The taxon (species? subspecies?) is common in summer in Alaska, more so than the Slaty-backed Gull. Therefore it is logical that the Vega Gull probably occurs in winter along the Pacific coast where there are many records of Slaty-backed Gull. However, birders have had few resourced to refer to in order to understand what the Vega Gull looks like, particularly in non adult plumages. Two great resources are:

Nial Moore's summary of the Herring complex in Korea, on the Birds Korea site.

The Ujihara's Japanese Gulls Site.

OK, so on to our bird. This individual appears to be the same bird found by Dan Singer on Tuesday Feb. 3, 05, and in turn it could be the same individual observed by Steve Howell, Ryan Terrill, myself and several other birders on Sat. Jan. 29, 05.

This individual is structurally like a smithsonianus Herring Gull, but much more well marked above. This checkered appearance appears to be typical of the paler end of Vega Gulls. Note that it has black primaries, not brownish or dull primaries which would suggest a Glaucous-winged x Herring hybrid, or even the equally well marked Thayer's Gull. The general pattern of this bird reminds of a European Herring Gull (at least from a North American perspecitive) or even a Lesser Black-backed Gull, although very different structurally from that species.

PHOTO2 shows the bird nearly in profile. Note the fact that the upperparts are still fresh and are retained juvenas feathers, suggesting an Arctic origin for this bird. The retention of juvenal upperparts late into the season is not a pre-requisite for Vega Gull, but it is typical and unlike most smithsonianus Herring Gulls at this time of year. The head, neck and breast are pale with moderately blurry streaking. Most importantly notice the well patterned coverts, specially the greater coverts. They are widely barred with pale to their bases. Typical smithsonianus Herring Gull shows a dark base to the greater coverts. As well, the undertail coverts are largely white with few bold dark bars, giving a spoted look.

PHOTO3 shows the distinctive tail band, typical of Vega Gull and other Palearctic Herring Gull taxa. Not all Vega gulls show the tail band, some have largely dark tails like smithsonianus, but here in California the tail band is a major feature used to separate from smith. Looking at the rectrices in detail, one can see that even the central rectrix has pale markings at its base. Does this feature ever occur on smith? Also typical of Vega is the white rump and uppertail coverts with sparse dark spotting. The rump and lower back contrast well with the darker mantle, smithsonianus tends to be much more evenly coloured. Not visible on any of my photos, but clearly seen in the field was the pale inner primaries (P1-5 or so) which contrasted well with the darker outer primaries. The pale inner primary window is important in separating this taxon from Yellow-legged Gulls, Caspian Gulls, and Lesser Black-baked Gulls. Also the tertials were well marked, unlike the largely dark and crisply fringed tertials of Lesser Black-backed Gull. The tail pattern, very black primaries, and structure separates this bird from Thayer's Gull which can be similarly well checkered on the upperparts, and which similarly retains juvenal plumage late into the winter.

PHOTO4 shows another view of the same bird. The bill has an extensively pale base, which is ok for Vega, although retention of a blackish bill may be more typical for this time of year. In my experience smithsonianus which are very pale in their first cycle tend to have a well developed pink bill base, clearly demarcated. In this respect, this individual is no different than smithsonianus, except that pale based smith often has a crisper division of pink and dark base. If this individual has first basic upperpart feathers, they would be expected to be pale grey with a crisp black anchor pattern, a pattern rarely shown by smithsonianus, but typical of paler Vega Gulls. The conbination of retained juvenile plumage, widely white barred greater coverts, checkered mantle, tail band, whitish head and neck, pale inner primary window, contrasting whitish rump and lower back, sparsely marked undertail coverts, and blackish primaries lead me to believe that this bird is a Vega Gull rather than an odd smithsonianus Herring Gull. Comments welcome.

Dec 2003 bird

PHOTO1 This individual has moulted some of the upperparts, so it shows a mix of first basic mantle, and juvenile lower scapulars. Note that the new upper scapulars show the dark anchor pattern mentioned above. The juvenal scapulars are well checkered, not unlike the 2005 bird. The tertial pattern of both birds is quite similar. Also similar is the whitish head, neck and breast with blurry streaking. Again note the black primaries, and rather dark centered tertials - quite unlike what one sees in assumed hybrids with Glaucous-winiged Gulls. Structurally last year's bird was a bit smaller billed, and stockier.

PHOTO2 shows a profile, the bird somewhat alert and drooping wings. The well checkered upperparts are nicely shown, as is the whitishs head and neck. This individual has a blackish bill with only slightly paler base, unlike the 2005 individual. Looking at the greater coverts, they show wide white bars, right to the base of the coverts. In Vega the typical barring pattern is for white bars to be as wide as dark bars, sometimes they are wider than dark bars similar to similar aged "Mongolian" Gull. Smithsonianus rarely shows white bars as wide as dark bars. In fact pale barring on smithsonianus tends to be buffy rather than whitish, and the greater coverts typically have dark bases.

PHOTO3 This image shows the pale inner primary window well. Also you can see the pale rump and uppertail coverts, as well as a small amount of the white at the base of the tail. In fact it is interesting to note that this more boldly marked individual shows a wider tail band than thte 2005 bird. However, when spread, the tail of the 2003 individual was clearly pale based. The well banded coverts are also visible here. While the outer greater coverts are not crisply barred to the base, there is no dark base as expected on a smithsonianus.