'Caspian' Gull revisited

22nd June 2014 - Topsham

As I'd hoped, our mystery gull turned up again, this time under rather more favourable viewing conditions at Topsham Rec. The same slightly odd shape and the same wing pattern as the BGM bird of Friday, and no real surprise, it's a Herring Gull.

Herring Gull 2nd Summer/3cy 22/6/2014 - Topsham

Herring Gull 2nd Summer/3cy 22/6/2014 - Topsham

Herring Gull 2nd Summer/3cy 22/6/2014 - Topsham

The bill is quite hefty and with a strong gonys. The primary projection is standard Herring Gull length and the legs don't look that thin after all. The breast is an odd shape for Herring but this may be due to a full crop, or perhaps it's eaten something it shouldn't have. The mantle is definitely too pale for cachinnans and there are a few remaining 2nd winter/3rd generation scapulars showing a Herring type anchor mark pattern. The median coverts are fresh (still with buff-brown ground colour) so, if I've interpreted its age correctly, must be recently grown 3rd generation. They do have the appearance though of 2nd generation feathers (which are more usually plain grey at this stage) but this may be down to the health/hormonal condition of the bird? The iris, although rather darker than usual for this age argenteus, is starting to lighten.

Apart from a slightly odd shape (still not right for Caspian though) and unusual median coverts it probably wouldn't draw a second glance if seen well. I can't quite believe how much time I've spent on it, I suppose once it was claimed as a Caspian (still don't know who by) I really wanted to figure out: is it? and if not, why not? It's all educational, after all.

Thanks to Matt Knott and Gavin Haig for their comments on Friday's appearance.

Caspian Gull...maybe

20th June 2014 - Topsham

No matter how many times I insist I'm no gull expert (I'm not just being modest, I'm really not, I prefer to think of myself as an enthusiast) I still get asked for an opinion on difficult birds. Over the years I've learned, through listening to real experts, to talk the talk about scapulars and tertials, mirrors and tongues, and I can count primaries. But when faced with a tough one, I generally rely on the Father Ted response, 'ah now, that would be an ecumenical matter'. Of course, it also pays to get as many photos as possible and show them to someone who really does know their arse from a hole in the ground.

On Friday lunchtime I got a call from Dave Stone about a claimed Caspian Gull at Bowling Green Marsh, I hopped on my bike and popped down for a look. The bird was distant across the pool and the heat haze was bad but it looked to me rather like a 2nd summer Herring Gull so I spent a while admiring the Bonaparte's Gull and looking for the apparently now resident Ross's Gull. A little later I had another look at the large gull in question and started having doubts, the bird's posture had changed and now looked a little more interesting. Soon after it flew off, nothing useful being seen due to the bright sun, and reappeared on the near shore at half the distance. I took a few photos.

Larus sp. 20/6/2014 - Topsham

Larus sp. 20/6/2014 - Topsham

Larus sp. 20/6/2014 - Topsham

Larus sp. 20/6/2014 - Topsham

Larus sp. 20/6/2014 - Topsham

Larus sp. 20/6/2014 - Topsham

Larus sp. (with Herring Gull) 20/6/2014 - Topsham

And a here's a digiscoped photo taken By David Boult (thanks) showing a little more detail on the wing.

Larus sp. 20/6/2014 - Topsham (David Boult)

News of a possible Caspian (a rarity in Devon) was put out and a few people got down in time to see it. Quite a few more will have been interested but couldn't make it so I thought I'd post some photos and give my opinion - for what that's worth. Let's hope it's seen again with better views or photos.

It's a second summer bird (third calendar year) halfway through moult to third winter, this is most clearly seen on the spread wing, P1-4 are new adult type feathers, grey with white tips, P5 is growing and shows a black band and white tip, the old P6 is missing (new P6 just starting to grow and not visible) and P7-10 are old second generation brown feathers. Unfortunately this is just about the worst age for identification purposes, there are no known diagnostic characters to look for, though there may still be clues.

First the structure: at times it did look quite convincing as a Caspian, small pear-shaped head and a long bill, long and fairly thin legs, prominent crop/breast and a suggestion of a hanging belly behind the legs. At other times it looked less good, the bill seeming to be less 'peg-like' with a stronger gonys and the primary projection really didn't look too long. It was a warm day and and this always makes gulls look sleek, small-headed and long-legged.

As for plumage there appear to be no diagnostic characters to look for, however there are a few points to make. The mantle is the same pale grey as the adjacent Herring Gull (or even the Black-headed Gulls), on a Caspian it should be slightly darker. There are a few older scapulars visible and these show hints of barring rather than the finer shaft streaks typical of Caspian. The wing coverts are mostly very faded and pale and show fine faint barring or vermiculation, the darker row of median coverts are a real problem though, these seem to be fresher than the lessers and greaters (or else why are they darker). A Caspian should show a fair number of plain grey coverts at this stage, particularly on the medians.

The bare part colours are not terribly informative at this age but I did notice a dark grey iris (I could distinguish the black pupil from the surrounding colour at least) through a scope on high magnification, a Caspian would be expected to show a rather darker iris.

So what was it? I really don't know, it certainly looked very Caspian-like at times and I don't think there's anything to rule it out but there are just to many things that don't look quite right. Maybe 'not-proven' is the only sensible verdict.

Many thanks thanks to the ever helpful and knowledgeable Martin Elliott for his input, also thanks to David Boult for sending me his photos, and to Dave Stone for the call.

As ever, I'd love to hear other views.

Mediterranean Gulls - a 3rd summer and an 11th winter plus

20th June 2014 - Topsham

While most of the the rare gull action is currently at Bowling Green Marsh, I'm still regularly  checking the situation at the Recreation Ground. There's usually a couple of hundred Herring Gulls, a dozen or so Lesser Black-backed and a couple of Greater Black-backed on the big gull spit on an afternoon low tide. A presumed hybrid - the broken P9/10 bird - occasionally drops in and impersonates a Yellow-legged. Small gulls are few and far between this year, severely limiting my chances of seeing either of the two rarities at the Rec. However, I see signs of numbers increasing with 20 or so Black-headed yesterday (including a juvenile) and a couple of Mediterranean Gulls also visiting. This looked like an adult, presumably the bird seen at BGM over the last few days, then I checked my photos. That black line on P9 indicates that this is a 3rd summer bird. Non Gull fans can skip this next bit - in fact it's in its 4th calendar year, the outer primaries are 3rd generation feathers and, as it's begun primary moult, it's now in it's 4th moult cycle.

Mediterranean Gull 3rd S - 19/6/2014 Topsham

Mediterranean Gull 3rd S - 19/6/2014 Topsham

 Some more photos of the same individual from this morning, they really are beautiful gulls and it's always a pleasure to see them.

Mediterranean Gull 3rd S - 20/6/2014 Topsham

Mediterranean Gull 3rd S - 19/6/2014 Topsham

 On the subject of Med Gulls, I finally got news of a colour-ringed bird I saw in November 2012 - the code was a little hard to read so I guess it took time to sort it out.

Mediterranean Gull adult PAJ7 - 14/11/2012 Topsham

This bird - Red PAJ7 - was ringed as an adult on 10th May 2005 in central Poland (to be precise near the village of Radyczyny which lies about 40 miles north west of Łódź - I just had to look that up, apparently it's pronounced something like 'Wootj').

So it was at least three years old (3rd summer at least) in 2005, therefore in 2012 it was ten years or older and in November it was an 11th winter at least (if my always shaky maths is correct). I did a bit of digging around and it appears to have been first recorded in Devon in 2008 - and several times since.

The Tubenose Handbook - Great Shearwater

16th June 2014 - Topsham

Here's one I made earlier: this is a recently painted plate from the 'Tubenose Handbook' - by Hadoram Shirihai and Vincent Bretagnolle, and illustrated by yours truly (still can't quite believe my luck to be working on this project). Occasionally I find myself working on a species I think I know fairly well, back in the late 80's and early 90's I had many good days at Porthgwarra watching big passages of Great and Cory's Shearwaters. Having said that, it's only after sorting through hundreds of photos that I really appreciate just how variable Great Shearwater is and that juveniles are often identifiable.

Great Shearwaters - underside variation

And here's the whole plate - with provisional captions and before corrections.

Great and Cape Verde Shearwaters

In the book this plate will be faced by one showing Cory's and Scopoli's Shearwaters.

Microlarids

7th June 2014 - Topsham

Late morning Friday I'm looking over Bowling Green Marsh from the lane when Russ Eynon stops to say hello. The Ross's Gull is lying low and well hidden in the grass so he heads for the hide for a better view and promptly finds a 1st summer Bonaparte's Gull! To be fair, I hear it was on the far side of the pool so, as I'm currently scope-less, I wouldn't have bothered checking anything that distance, still a very good find. I missed the Bonaparte's on Friday but it came in again at high tide on Saturday, joining the now long-staying Little and Ross's Gulls for a convention of the World's Smallest Larids.

Here's the 1st summer Bonaparte's; slightly smaller than Black-headed, thin blackish bill, distinctly grey nape and hind neck and, just visible, blackish centred tertials and coverts.

Bonaparte's Gull 2cy - 7/6/2014 Topsham BGM

Bonaparte's Gull 2cy - 7/6/2014 Topsham BGM

Bonaparte's Gull 2cy - 7/6/2014 Topsham BGM

Bonaparte's Gull 2cy - 7/6/2014 Topsham BGM

Here's the Bonaparte's and the Ross's together (almost), the small white-headed Ross's is fairly obvious at the left and the Bonaparte's is towards the right with its head turning away.

Ross's Gull (left) and Bonaparte's Gull (right) - 7/6/2014 Topsham BGM

I managed to get a few more flight shots of the Ross's Gull, hard to pick out when the whole flock went up. All the primaries are extremely worn, I count only nine on the right wing so I presume primary moult has started with P1 growing.

Ross's Gull 2cy - 7/6/2014 Topsham BGM

Ross's Gull 2cy - 7/6/2014 Topsham BGM

The Little Gull is rather more advanced in its moult, all three inner primaries dropped and/or growing as is the new white central tail feather.

Little Gull 2cy - 7/6/2014 Topsham BGM

Little Gull 2cy - 7/6/2014 Topsham BGM

And finally a fluke shot of Little and Ross's - the World's two smallest gulls - together.

Ross's Gull 2cy and Little Gull 2cy - 7/6/2014 Topsham BGM

And the three all together in the same photo? There's still a chance.

Ross's Gull

7th June 2014 - Topsham

 

In between working on a plate of Great Shearwaters for 'The Tubenose Handbook' and cycling to and from to BGM and just missing the 1st summer Bonaparte's Gull, I took a break to do this pencil drawing of the Ross's Gull.

Ross's Gull - Topsham BGM 3/6/2014

Meanwhile, back at The Rec

4th June 2014 - Topsham

 

The Ross's Gull is spending plenty of time at Bowling Green Marsh but it's proving difficult to get the bird on my Recreation Ground patch list. While waiting at the BGM hide for the Ross's to arrive I got a call from Martin Elcoate who was watching the bird on the large gull spit at the Rec - actually from his back garden but I'm trying not to be jealous. So myself and Martin Elliott - stopping off on his journey back to Penzance to see the gull - legged it through Topsham as the Ross's Gull promptly left the Rec and flew down to BGM. So, no patch tick and Martin missed his train.

I decided to go back to checking the Rec more regularly and dropped back in for low tide later that afternoon. No Ross's predictably but I did find this familiar face.

Larus hybrid? 4/6/2014 Topsham Rec

Anyone paying attention (?) will immediately recognise a similarity with my possible Yellow-legged Gull of 25th May and it certainly ticks a few boxes: mid-grey mantle shade, yellow legs and even a red orbital and gape and the red on the bill bleeding onto the upper mandible - next photo.

Larus hybrid? 4/6/2014 Topsham Rec

You can probably guess there's going to be a catch; as you can see, this time the bird flew and I got a good look at the spread primaries.

Larus hybrid? 4/6/2014 Topsham Rec

Larus hybrid? 4/6/2014 Topsham Rec

Right P9 and 10 both broken as on the bird of the 25th May so presumably the same individual. The black band on P5 is not quite complete and there's rather too much black - reaching or almost reaching the primary coverts - on P9 and 10. This and the fairly unimpressive bill all count against it being a pure michahellis, in combination I think it more likely a hybrid - though not necessarily 1st generation - Herring x LBB.

Meanwhile my Ross's Gull stakeout at the Rec continues...

More Ross's Gull

2nd June 2014 - Topsham

Still can't get enough of this bird, I've dropped in at least once a day since last Wednesday in the hope of more and closer views. It's very loyal to the site, arriving at high tide with the regular flock of Black-heads plus the somewhat less reliable Little Gull.

It's not showing a typical 1st summer plumage - according to the books - and shows no obvious signs of moult. There's still a few dark juvenile feathers on the crown and has no apparent dark necklace. The flight feathers - especially the outer primaries - are extremely worn and surely it should start to replace them soon.

There's been plenty of photos about over the last few days, here's a few sketches.

Ross's Gull - Topsham 29th May 2014

Ross's Gull - Topsham 30th May 2014

Ross's Gull - Topsham 31st May 2014

Ross's Gull - Topsham 2nd June 2014