A couple of days ago, I saw this gull at McDonalds hoping for handouts. Although the colors seemed basically right for a Thayer’s Gull, its bulk did not. It seemed very comparable in size/shape to other Glaucous-winged Gulls that were nearby, and qualitatively it struck me as significantly larger than I tend to associate with Thayer’s Gulls. I tried to get photos of it with other birds for comparison, but was unable to do so as there was a particularly aggressive bird that appeared to me to be a second-cycle Glaucous-winged Gull. It chased several birds away from the car, presumably to keep the potential food source itself (of course, while chasing the other birds away, it typically missed opportunities to grab a bite). On a number of occasions it chased this particular mystery gull.

For now I am thinking this bird is probably a Glaucous-winged x Herring Gull hybrid due to the large bulk, dark eyes, and dark wingtips. I am definitely not completely confident with this choice, and would be interested to hear alternative suggestions.

Unidentified Gulls

Mid-February seems to bring the arrival of mystery gull season. I’m not sure if it’s just an impression, or actually true in practice, but it seems like around this time more large gulls show up around town where they are easy to observe. For them, it’s the lean time of year, and the food available around town certainly plays a role in the gathering. Once the herring really move in during late March or early April, they are very abundant, though not always as easy to observe closely, and gradually numbers thin out a bit as spring heads into summer.

I recently took pictures of three different gulls which are giving me a little identification trouble. I also realized that I have some photos of gulls from last year around this time that I have yet to get conclusively identified. Rather than cram them all into one post, I think I’ll let this be the start of a series of mystery gull posts.

Unidentified Gulls

Last summer while coming down Verstovia in early July, I happened to catch some nice light at the first view point. There were some lichens that were illuminated in a manner that I found to be quite striking, so I stopped and took some pictures. As is my wont, I tried to figure out what I saw after I had a chance to sit down a look at the pictures.

I am by no means anything approaching competent when it comes to the identification of lichens. I am also not likely to become any sort of expert, as I am not particularly fond of making collections and even when I do, my motivation to do the chemical testing necessary for identification is minimal. However, I knew enough to tell that this was a Cladonia (which I also knew is a particularly challenging group), but not much beyond that. A little thumbing through the appropriate section of Macrolichens of the Pacific Northwest, led me to Cladonia transcendens as a likely candidate.

The description for C. transcendens seemed to match my photos quite well, even down to the yellowish tinge (as these were growing in a relatively open area), so I felt reasonably comfortable with this choice. I was also reassured by the fact that similar species mentioned in the notes had (or lacked) characteristics that would seem to rule out the possibility that what I photographed was one of them. Some time later, I happened to notice that the prefered growth substrates indicated were not quite such a good fit.

Macrolichens of the Pacific Northwest indicates C. transcendens grows on bark and wood. The Lichen Inventory for Southeast Alaska indicates the species is present in the Sitka area, but also suggests it grows on “bark and lignum of conifers.” While I cannot rule out the possibility that the lichens I photographed were growing on a root or some woody debris, I’m pretty sure they were actually growing on the ground.

Given the difficulty of identifying Cladonia lichens to species, even though I felt pretty comfortable with the description, I decided that it’s best to leave this as Cladonia sp until such time as I decide it’s worth getting a collection and subjecting it to some chemical tests.

SitkaArea.bib bibtex file not found
SitkaArea.bib bibtex file not found

These three gulls were all photographed in February of this year, the first one was at Starrigavan, the other two at Swan Lake.

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Unfortunately I neglected to get a whole body shot of this gull, so it may not be possible to identify it. My best guess is Thayer’s Gull, but I’m not sure I can rule out a Glaucous-winged Gull with dark wingtips. The eye and head/bill structure suggest Thayer’s Gull to me. The wingtips seem very light. Perhaps pale wingtips are not too unusual in Thayer’s Gulls, however. I’m really not sure.

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Structurally this gull strikes me more as a Thayer’s Gull, but the coloring seems more typical of a Glaucous-winged Gull. Unfortunately I did not get a picture of this gull with other gulls of known identification, so it’s may be a little difficult to judge size.

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If I were just looking at the head, I would say my best guess is Thayer’s Gull. If I were just looking at the body, I would say Glaucous-winged Gull. As it is, I am uncertain. One striking characteristic of this bird is how bright yellow the beak is (that stood out at the time compared to other gulls as well).

More Gull Identification Challenges