Wing patterns of Black-headed Gulls

This Black-headed Gull, Chroicocephalus ridibundus, clearly shows the white triangle on the far wing. This is supposed to only cover four feathers. However - it does look as though the outer web of P6 (as well as P7) is actually white rather than grey. Most books talk about the white triangle only extending over P10-7, the four feathers stated above. Note however the wide spread of the wing - normally the grey portion of these webs might be hidden? 

This bird also looks as if P6 is at least half white. It doesn't look too rare to me?

Here again the outer half of P6 looks white to me, at least on the right hand wing. And I still haven't understood how the underside of the wing can differ from the upperside:

This bird on the other hand appears to be entirely white on P10-P7, and nothing after that!

Birthday bash at Barden

I managed to get a few more pictures at Barden today, and I was a bit luckier with flying birds. Here is an adult that doesn't seem to have started its head moult at all yet.  The wings are quite blurry - I'm not sure if this is due to a shallow depth of focus, or to the speed of the wing movement:

Here is another, still at roughly the same stage of moult. The bill is also still quite orangey, or at most a medium red, rather than the breeding dark red. There could just be a black line along the outside top of P8, and see the picture a further two down for possible confirmation.

Moving on to another bird now, this one partly through the head moult

This is another bird, at about the same stage of the head moult, but one of the best candidates for a second winter bird that I have seen, with really clear black lines along parts of the edges of P7, P8, P9 and P10:

And here is a first winter bird for comparison - note the almost complete black lines along the edges of the outer primaries, together with the typical patches of brown and sooty black along the coverts. Note the very yellow orangey bill:

This first winter bird below (different to the one above) is showing two white tail feathers, T1 and T2. This can occur, according to Olsen, as an early part of the spring moult to summer plumage, although in this case this would be an early example, and apparently prior to any head moult in this particular individual. Morg of Morgithology mentions seeing something like this in 2010, but was also unsure of a definitive explanation. These particular white feathers look as though they are projecting out further than their dark-tipped neighbours.

Trying out the long lens at Barden

This is a first winter Black-headed Gull, Chroicocephalus ridibundus and you can see the typical black lines extending forwards on P10 and P9, and the brown carpal/tertial splodges. 

This is the same bird a moment later, this time at the point of landing a second time, showing incredible wing angles as the bird slows down, as well as the obviously orange bill and legs.

Here is a Common Gull, Larus canus, facing up to an adult Black-headed Gull on the left. Intriguingly on the Black-headed Gull, the P7-P5 black wingtips are showing white tips themselves on the upperwing, said to be a feature of fresh feathers, and thus indicating a survival from last autumn's moult. These are rather parallel to the white tips of the corresponding feathers seen in the Common Gull. Behind the adult Black-headed Gull is what MIGHT be a second winter Black-headed Gull, showing the black lines running along the edges of P6 and P7 - unless this is actually an "angle" thing, and maybe even bit of a snare and a delusion.

The bird below is a first winter, with two completely white newly moulted feathers in the middle of the tail (T1) , breaking the juvenile pattern of the brown-black sub-terminal tail bar extending across most of the width of the tail. The central feathers also seem longer - because they are fresh and not worn? Some birds do include these two central tail feathers in the partial moult to first summer plumage (Olsen and Larsson). All the other tail feathers have to wait until the full moult in summer-autumn! You can also see some white on the underside of P7 and P8, and the clearly orange colour of the bill at least.

As in one of the photos above, this Black-headed Gull shows the small white tips to the primaries still showing from last autumn's main moult, despite the very blurry photo. Quite a few birds are still showing these, but this may change over the rest of the year as these feathers wear away slightly, until we reach next year's moult (in July - October).

Here are the white patches within the dark of the underside of primaries again, but I think it would be useful to look at some specimens in the hand to fully understand these colour shifts and the variation within them. The white tips to the feathers from last autumn's moult can also be seen again!

These two adults below are respectively nearly at the end, and nearly at the start of the head moult, which is proceeding rapidly at the moment. You can quite clearly see how the moult starts at the back of the head, as in the bird of the right, and may be nearly complete across 90% of the head before the last areas at the front start to go dark, as in the bird on the left. The white "eyelids" become increasingly prominent of course as the background of the rest of head goes dark.

Two further stages in the head moult! The moult to the summer breeding plumage is a partial moult, only involving the feathers of the head and body.

This is a better shot than some of the above, with an adult showing the upper wing pattern really quite clearly. Note the "ruffle" of possible back-thrust (about to stall?) along the inner shoulder as the bird breaks abruptly to a halt ready to land.

This first winter shows the upper wing pattern beautifully, with the left hand wing sitting neatly over an adult wing just behind it, giving a great comparative shot! See how the first winter wing has a dark trailing edge almost all the way along it, until the wing nearly reaches the body , brown splodging all along the lesser coverts, and sooty markings on the front edge of the wing particularly at the median coverts and greater primary coverts. The dark lines along the outer primaries are also quite clearly visible.

The bird swimming in front (and the bird to the near left?) is also a first winter from the brown on its lesser coverts, and its orange bill.

Here is another view of the upperside of a first year wing, with rather more brown lines along the coverts perhaps - its all very variable of course! Again notice the orange bill. And yes, it is the head and yellow bill of an adult Common Gull in the front of the photo, trying to get into the act.

Barden

Chroicocephalus ridibundus, the Black-headed Gull in flight has such an amazing pattern of black, grey and white on its wing. Here you can see the obvious black on most of the primaries as viewed on the underwing, but the highly contrasting bright white of 90% of the underside of P10 and P9 apart from their jet black tips, with perhaps very small white patches on P8 and P7.

The rest of the underwing is mainly a contrasting dark grey, shading lighter towards the base of the wing, with maybe also a greyer patch nearer the front of the wing, but you generally also see a bright white front line to the front of the wing at the shoulder. 

The last two pictures are of the same bird, and its only in the first of these that you see a suspicion of the white flashes of P8 and P7. This could therefore be the angle of the feathers, with the white from above showing through when the feathers are opened or at a certain angle.

The upperwing is not the same pattern, with a much larger wingtip white triangle for a start, although there are a lot of general similarities.

To learn more, I'd better take lots more, and better, photos! This should enable me to recognise second winter patterns for example.

Here's an old photo from Cliffe - note how the primaries further in from P10 and P9, are both black and white!

The Bourne meanders

This was one of the nicer afternoons of February, although not as warm as the previous two days.  So I took the footpath through the College's equine unit until I reached the meadow just upstream through which the River Bourne meanders. The beautiful meadow and the river meanders edged with alders are just gorgeous, even in the thin winter sunshine of a February afternoon.

The occasional clump of snowdrops brightens the banks. Here you can also see the "witches broom" of some of the alder bases - a few have this dense thicket effect that may be physiological.

Saturday gulls at Barden

Lots of black-headed gulls on the lake today - is it because its Saturday? Several more now wearing their brown hoods. Two Common Gulls as well. Usual Mallard (the rufus-sided one included), several mating season flights going on, Tufted Duck, and the two Farmyard Ducks with a cormorant flying overhead twice (or two birds?) and a pair of Great Crested Grebe showing very well indeed.

Canada Geese (looking as though things are moving along) and I was glad to see the Greylag hybrid back again. One Mute Swan. Coot, including the regular mottled bird, and several pairs of Moorhen.

Robins and Great Tits singing. Chaffinches, Blackbirds and Blue Tits around.

Scandi readiness

Several hundred fieldfares, Turdus pilaris, with a couple of redwings, Turdus iliacus iliacus, a dozen or so blackbirds, Turdus merula, and about 70 starling, Sturnus vulgaris, were on Gipsy and Rhubarb fields this afternoon. Overall it was quite a sight!

 Looked as though the fieldfares are going for a protein rich diet before heading off back to Scandinavia. Warren reported over a hundred on the sheep field at Migrant Alley in the morning.

Breeds in small colonies.

A pair of greylag flew together over Gipsy, one mainly white on the body with really only a grey neck and the pair were later seen on the ground in Great Court. A kestrel flew low over Rhubarb, putting the fieldfares up into the trees.

A small group of great tits were noisy in the newer trees along 123 towards Victoria Road, and later through the ash trees between the two fields.