ML21482531

Age

Not specified

Sex

Not specified

Observation details

**VERY RARE. Still would really like to have some other observers get good look at this bird and photos. However, excerpt of OBRC report included below: We found this bird and watched it for 75 minutes through scopes at ranges of 200-500+ m. 2) Description This was a medium-sized gull in it's first calendar year. It was most directly comparable in the field to Herring Gull, from which it was noticeably smaller. Overall this was a very dark brown gull, with extremely dark wings, particularly the primaries and secondaries which all appeared to be black. The inner primaries, when seen in flight were slightly lighter brown than the outer primaries and secondaries. The bird's legs were never seen well. The bill was rather long, and not as heavy as a Herring Gull's; it was distinctly bicolored with the inner 2/3 greyish-pink and the tip black, contrasting sharply. The head shape appeared rather oval/flattened, not rounded like a Ring-billed or Iceland tend to appear (and more elongate than most Herring Gulls appear). The bird's tail was black, with very faint barring on the brownish rump/uppertail. The bird's mantle had molted so as to be a grey colour, contrasting markedly with the brown body and wing feathers. The shade of grey was difficult to assess: at times it appeared to be slightly darker than the Herring Gulls which were near it for comparison but this was hard to judge as to whether it was real or imagined. The bird's face was uniformly brown, with distinct darkening around the eye, almost forming a bit of an eye patch. The sides of the neck appeared to have vertical streaking. The general impression that this bird gave in flight was a very dark-winged bird, recalling Lesser Black-backed Gull. However, when perched it did not jump out as such a dark bird, but was still darker than most first year Herring Gulls nearby. 3) How were similar species eliminated? Being a first winter gull, there are many species that have to be eliminated but which are relatively similar. I will only focus on the common gull species: -The dark brown plumage overall and size (slightly smaller than a Herring Gull) eliminates Ring-billed and Mew/Common Gull. -The chocolately-brown colouration as well as the bill pattern eliminates Lesser Black-backed Gull. -Our main issue was whether a runt Herring Gull could be eliminated. I would really like to have good photos of this bird to fully satisfy this possibility but without that I am left with the following points: 1. The bird was very dark-winged. I believe the bird's primaries/secondaries were too dark for any Herring Gull 2. The bird was noticeably smaller than Herring Gulls beside it. There is a possibility for a Herring Gull to be this small (though rare). 3. I don't think a Herring Gull this dark (i.e. a "northern" Herring Gull) would be this advanced in molt (having replaced most of its mantle feathers). 4. The bill pattern, as well as size and shape fits California Gull better than Herring Gull. 5. The face pattern with the dark smudge around the eye is also a character that should not be shown by Herring Gull. -I suppose a Herring x Lesser Black-backed Gull could look similar to this bird as could many other hybrid combinations but without photos for a detailed analysis (and probably DNA for a first winter large gull!) this is probably beyond the scope of this report. For what it's worth (not much!) here are pics taken from about 500 m away:

Technical information

Model

Nexus 4

ISO

200

Focal length

4.6 mm

Flash

Flash did not fire

f-stop

f/2.6

Shutter speed

1/120 sec

Dimensions

2448 pixels x 3264 pixels

Original file size

806.29 KB