Caspian Gulls in Peterborough

I'm back in Lincolnshire for Birdfair weekend and have been able to sneak in a couple of fairly brief sessions at Dogsthorpe Tip over the past two days - one on my way back home yesterday and one before work this morning. In total I've seen five Caspian Gulls: two 3cy and juvenile yesterday and then two of those birds plus a second juvenile and a near-adult (4cy) this morning.

Scope views of the pit are pretty good at present but both yesterday and today have been very warm, with an abundance of heat haze making photography difficult. It's a stretch for my 400mm lens to produce anything decent at the best of times here and so the efforts below are really just for documentation. Unfortunately the near-adult wasn't photographed despite doing a brilliant fly-past at about 30m range - I should have nailed it but my camera was on the wrong settings and so all I have are blurs.

Bird #1: juvenile, 17-18 August

I'm a bit sceptical about whether this is a pure Caspian Gull. Plumage is a little on the dark side - not out of range for a juvenile Casp but, when combined with the fairly Herring-like structure (quite big-headed and short-billed) plus quite heavily marked uppertail and undertail coverts, alarm bells sound. However it possesses the typical mouse-brown basal colour as well as the long, drooping lower tertials of a juvenile Casp and does kind of just look like one - if you don't stare too hard! The underwing is pretty pale, too, if not as pale as it can be in cachinnans. Perhaps it's from Germany.

Bird #2: juvenile, 18 August

Unlike the other youngster, no doubt about this one! First shot is with the DSLR, second with my iPhone 5.

Bird #3: 3cy (2s/3w), 17 August

Structurally quite obvious and also showed a small white mirror on retained p10.

Bird #4: 3cy(?), 17-18 August

I didn't realise this was a different bird to the above until I reviewed images this evening! Present almost next to the other 3cy on 17th, hence the confusion.

At least eight Yellow-legged Gulls were seen over the two sessions with the commonest age class being juveniles (four) followed by 2cy (three) and a single 4cy. Weirdly no adults; traditionally I've found them to be the commonest age class here in past summers.

Juvenile Yellow-legged Gull, 17 August

Gulling in the boro'

LBBs @ Tanholt

Back in Lincs this weekend so headed over to Peterborough to check the gulls out this morning. Absolutely nothing at Dogsthorpe, with no tipping activity happening either. However, Tanholt was a different story, with at least 500 large gulls - mainly Lesser Black-backed - gobbling up detritus on the new landfill cell there. I eventually found a good place to view them, and had nine Yellow-legged Gulls (3 adults, 2nd-summer, 1st-summer and 4 juveniles). Some photos below.

Juvenile; note the presence of several moulted upper scapulars (with anchor markings) already.

Juvenile; same bird as above. A classic in every respect.

Adult (or near-adult) with Lesser Black-backed and Herring Gulls. I always find that older michahellis look much
 grottier facially than Herrings at this time of year, presumably because they moult their head feathers earlier.

Comparison of juvenile gulls: Lesser Black-backed (left), Yellow-legged (above centre) and Herring (bottom right).

In other news, I flushed a Quail on my patch this afternoon as I searched for the recent Black-necked Grebe (no sign). This is the first time I've seen a Quail without hearing it; really surprised me and burst out of the undergrowth Jack Snipe-stylee. Got great views of the facial markings, too - top stuff.