An Odd Case of Common Gull

Gull season started a tad early this year – and with a bit of a bang. Bruce Mactavish first reported an adult Yellow-legged Gull in Pleasantville (east St. John’s) on September 7. Alvan Buckley upped the ante by photographing a presumed third-year Yellow-legged Gull on the same field on September 11 (relocated and photographed again by Bruce a few days later).

However, the star of the show turned out to be an odd-looking gull that Alvan photographed on September 16 while trying to relocate the Yellow-legged Gulls. Most of the features pointed to it being a Common Gull (Larus canus), which in itself is not that unusual in Newfoundland. We get a few every winter. But this one was a headscratcher because, compared to nearby Herring Gulls, it appeared too big and dark for our typical Common Gull (the nominate canus race that originates in western Europe). The size, dark mantle shade, relatively bulky structure and wingtip pattern seemed to suggest that this Common Gull was not so common — in fact, it may be a member of the kamchatka race that occurs in east Asia (Siberia, Japan). See Alvan’s blog for some more discussion.

Those of us looking failed relocate this gull over the next ten days. Yesterday morning, after a solid morning of birding around Signal Hill, Bruce Mactavish and I checked the regular gull locations in that area of town – unable to find it (or anything else exciting) yet again. Switching gears, we decided to head out to Goulds where a flock of American Golden Plover, and tons of gulls, had been hanging out in a freshly plowed field. After a few minutes, I spotted a mid-sized gull with a dark grey mantle sitting on the field — it hadn’t been there moments before. I could easily have passed it off as a Lesser-Black-backed Gull (of which there were several around), but something about the pattern of head streaking gave me pause. Then the dark eye. And the bill. There it was — the “odd” Common Gull!! (Note – this was 20+ km from the original spot, so it wasn’t really on our radar for this location).

While the bright, poorly angled sunlight makes it difficult to photograph and accurately represent mantle shades, this unedited photograph still illustrates just how dark this Common Gull was compared to Herring Gulls in the background. It was darker and unlike any other Common Gull I've seen in Newfoundland. It also looked very different than Common Gulls that I saw during the nine months I spent living in Finland, which included both nominate canus and heini races.

While the bright, poorly angled sunlight makes it difficult to photograph and accurately represent mantle shades, this unedited photograph still illustrates just how dark this Common Gull was compared to Herring Gulls in the background. In life, it was darker and structurally unlike any other Common Gull I’ve seen in Newfoundland. It also looked very different than Common Gulls that I saw during the nine months I spent living in Finland, which included both nominate canus and heini races.

Fortunately, Bruce was just as excited as me to have found this bird, and we quickly organized so that he could photograph the heck out of it (he having the far better lens & camera!). Light was really harsh with bright sunlight and poor angles, but the gull did cooperate by approaching fairly close to our position, parked on the side of a busy road. Over the next hour it made its way to the south end of the field, where we were able to reposition for better (though still very bright) light, and I even snapped off a few mediocre pics of my own.

COGO(Kam)_Sept282014_8752

Bright sunlight made it hard to capture the real tones and mantle shade, although these came out fairly well. Note the dark grey saddle, which in life was closer to that of Lesser Black-backed Gull (graellsi) than Herring Gull, and notably darker than what we expect in nominate Common Gulls that show up here each year. In fact, the mantle was similar in shade to that of Yellow-legged Gull (atlantis)– a colour we have trained ourselves to recognize!

COGU(Kam)_Sept282014_8756

This gull also had a darkish eye (which at closer range was found to be brown with a visible pupil rather than completely dark). This feature is found in all races of Common Gull, although the texts suggest that Kamchatka Gull often (but not always) shows a paler eye than other races. The head and bill shape was completely unlike that of other Common Gulls we see here – appearing larger headed with a more sloped forehead and notably longer, more substantial bill. Our “typical” Common Gulls tend to have rounder, gentler looking head shapes with shorter, daintier looking bills – resulting in a very different look.

COGU(Kam)_Sept282014_8810

Overall, this bird was much larger than the typical Common Gull we see here. In fact, this one was clearly larger than nearby Ring-billed Gulls and at times approached smaller Herring Gulls – similar in size to some Lesser Black-backed Gulls. Our “typical” Common Gulls (presumed canus) more closely match Ring-billed Gull, sometimes appearing slightly smaller and daintier. The literature indicates that Common Gulls tend to be larger and darker the further east you look, with the east Asian (kamchatka) race being the biggest and darkest of the lot.

AU142237-wings-#1

There were not many opportunities to photograph the spread wings on this bird, and I managed to miss them all. Fortunately, Bruce Mactavish nailed a few and has kindly given me permission to post a couple here. Here we can see that this gull is in the processing of growing new flight feathers. The outermost primaries, P10 & P9, are still growing in while P8 may or may not be completely grown. In any case we can see a wingtip pattern here that, according to the literature, would be considered typical of the kamchatka race, extreme for heini and likely very unusual or out of range for canus. – Photo: Bruce Mactavish

Another of Bruce's fine photos, this one gives us a better look at the primary pattern. Importantly, P8 is almost entirely black. In fact, all of what we can see is black, all the way up to the primary coverts (note, though, that this feather may not yet be fully grown). There is a full and substantial black band across the tip of P5 and a solid black mark across the outer web of P4. The white "moons" on P5-8 are relatively large, producing an obvious "string of pearl" effect - which is also more characteristic of kamchatka than other races. I sure hop we see this gull again in a few weeks when the primary growth is complete and we can get an even better picture of this intriguing wingtip patter. - Photo: Bruce Mactavish

Another of Bruce’s fine photos, this one gives us a better look at the primary pattern. Importantly, P8 is almost entirely black. In fact, all of what we can see is black, all the way up to the primary coverts (note, though, that this feather may not yet be fully grown). There is a full and substantial black band across the tip of P5 and a solid black mark across the outer web of P4. The white “moons” on P5-7 are relatively large, producing an obvious “string of pearl” effect – which is also more characteristic of kamchatka than other races. I sure hope we see this gull again in a few weeks when the primary growth is complete and we can get an even better picture of this intriguing wingtip pattern.
– Photo: Bruce Mactavish

Check out Bruce Mactavish’s blog for more of his excellent photos and further discussion. Alvan Buckley also posted some excellent discussion on his blog following his original discovery of the gull two weeks ago.

The jury is still out while we do a bit more research — gull identification, especially to subspecies level, is never as straightforward as we’d like. But all things considered, this certainly appears to be an excellent candidate for Kamchatka Gull.

While it certainly wasn’t on our radar, there have been a few other claims from the northeast (some of them rather convincing) to set a bit of a precedence. And hell – if we can get Slaty-backed Gulls, which originate in the same part of the world, then maybe a Kamchatka Gull isn’t so far-fetched afterall!

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One thought on “An Odd Case of Common Gull

  1. Awesome that you guys refound it and got the great photos! Must admit that I am a bit jealous :p

    Don’t forget that we’ve got Black-tailed Gull too, along with all those slaty-backeds…
    Definitely looking forward to seeing this thing again when I’m back on the avalon.

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