Strange state of moult? Med Gull, SE England (1 Viewer)

[deborah4]

Hi

What I presume was a Med Gull moving out of 1w plumage has me stumped for a number of reasons. I'm very familiar with BHG and Med Gull are also seen quite regularly when birding locally. However, the moult pattern and some structural anomalies had me a little perplexed. I didn't have a camera so it may be difficult to comment and have uploaded some rough field notes which may be more a hindrance than a help! The Gull was the size of a large range Med (about the size of a Common Gull but longer winged and much longer legged). However, the bill looked far too long for Med (being easily as long as BHG, perhaps longer, about a length and quarter x width of head. Bill was better shape for Med just longer than BHG! The neck was thick and long with a sloping forehead. The legs were long, consistent with Med, very dark reddish brown. Bill almost black. (colours not being inconsistent with 1w bird of either species) The advanced almost full hood did not fit with the wing pattern. It was almost solid (views through binos) black but coverage consistent with Med extending to occipital area rather than ending on crown. However, the wing pattern looked more like 1w BHG except it was very long winged. No windows/white on primaries at rest and which were long. Tertials/coverts retained some brown consistent with a first year bird and in flight, the whole wing looked very 1w, giving general dark appearance with obvious black inner secondaries on trailing edge. I didn't have time to note the extent of primary black in flight. Overall, it looked structurally ok for Med, with the exception of the long bill in particular. The bird was solitary, foraging in mud flat, continously walking while feeding. No calls were made. Comment on variation, age, moult anomalties would be appreciated as would some links on 1cy and 2cy Med Gulls during spring moult.

Many thanks.

 

[Jane Turner]

What was the mantle colour like? You could do with ruling out Laughing gull

 

[deborah4]

Hi Jane

- there was a 1w LG hanging around for some time at Arlington several miles away about November time I think. However, although the mantle was darker than I'd expect for BHG or Med, (it was closer to HG between nape and top of mantle) I didn't think it darker enough for at least Adult LG/or other BH variety at least according to Collins having checked in retrospect. I only had good views of the side of the gull which certainly appeared darker than the top and good views in flight, but the top of the mantle (in full sunlight), didn't look exceptionally dark (not as dark as GBBG anyway) and in flight, I was too struck by the 'unusual' moult on wing cf. to head, to notice mantle colour but overall it all looked darker rather than lighter, if that makes sense - Don't have any experience of LGs obviously. The other consideration to be fair to those that help me now, I didn't have a camera and my field notes are rather inadequate, so any 'record' is a non-starter. ID would be academic either way. Perhaps the moult complex might help with ID? Not exactly sure what would show what and when exactly!

 

[J Jones]

Somewhat perplexed by your description of the bird Deborah - as you say hard to nail down without photos, especially the wing moult.....

Hybrid Med X BHG are fairly unusual but far from being unknown, so it could be this.

 

[deborah4]

Somewhat perplexed by your description of the bird Deborah - as you say hard to nail down without photos, especially the wing moult.....

Hybrid Med X BHG are fairly unusual but far from being unknown, so it could be this.

It's more likely I think that it's a Med gull with rather out of sync moult and a large bill (which presumably is variable with all gulls) but that's my uneducated guess. I have no more re: obs than those recorded on fieldnote unfortunately. There was nothing in structure, other than bill lenght to remotely suggest BHG.

My description is fairly accurate but it's the moult that's causing major confusion for me here. I would expect a 1s Med not to have a full hood, and a 3cy, to have red bill and brighter red legs as well as clean tail and less brown on wings.

Hopefully Jan might have some comment re: moult sequences.

 

[deborah4]

Comment on variation, age, moult anomalties would be appreciated as would some links on 1cy and 2cy Med Gulls during spring moult.

Many thanks.

Well I don't seem to be making any head way here! Surely there are some gull experts who can offer some constructive comments on this? I'm familiar with both Med and BHG gulls and although there's no photo, my notes are pretty accurate overall. I've spent hours trying to find links of moult variation in 2cy Med gulls that have an almost solid black head, or 3cy that have retained the brown covert/tertial patterning in open wing and thin black band on tail but having no luck. If it's any help the general jizz of the wing in flight, including scaps, was dark.

 

[J Jones]

What was unusual about the moult? 2CY meds can have almost full hoods.

Size, bill length etc is very variable - these are gulls!

 

[JANJ]

Hi Deborah.

A lot of variability in moult - timing - some more advanced than others!
Regarding the development of a hood in first summer BHG & MG there´s great variability and fewer MG develope full hood comp. to BHG, which also depends on which time in spring - the further ahead in spring the more hood so to speak. Usually the hood isn´t fully complete there´s white flecking to variable degree. Partial moult in both is limited to head, body. some wing coverts, tertials and one or a few outer tail feathers. As mentioned MG is usually less advanced when it comes to hood development. One should bear in mind the variability in gulls!

Your gull Deborah could be an aberrant individual - difficult to say from here, but if it didn´t have a 'window' being a 2cy it´s either a very advanced individul or not a MG, I belive 'the not MG'

http://www.gull-research.org/melanos/mediterraneans.htm

http://www.gull-research.org/ridibundus/ridibundus.htm

http://cyberbirding.uib.no/photo/l_melanocephalus_02.php

Nice note taking!

JanJ

 

[deborah4]

Hi Jan

Many thanks for your help here and thanks for the comment on fieldnotes (they're getting more detailed slowly ).

The bird did have an obvious window, which I referred to rather amateurishly as a ''white patch'' - but the sketch is probably unreliable regards how far it extended lengthways across primary trailing edge and I think it included some of the prim covs too, but can't be sure. The gull certainly wasn't BHG on size, structure, so 'if not Med' then I'm truly stumped and will have to put it down to more experience needed in all the variables unless I can get back out there later in the week with a camera and catch up with it

As Josh said 'they're gulls'

Thanks again for your time. Much appreciated.

 

[Jane Turner]

I've seen a number of Gulls, most frequently 1st summer Kittiwakes with a "window" caused by an absence of greater coverts and or primary coverts. Its the bases of the flight feathers that appear white.

 

[deborah4]

I've seen a number of Gulls, most frequently 1st summer Kittiwakes with a "window" caused by an absence of greater coverts and or primary coverts. Its the bases of the flight feathers that appear white.

'patch' was probably a better description then - seriously can't remember noting specifically extent/lack of black on primaries/tips below covs - just remember black trailing secondary edge ending abruptly at beginning of primaries - anyway, have a lot more work to do on my topography both in recording and describing, so a graceful withdrawal might be more sensible. Cheers for your help Jane.