Tuesday 29 December 2009

Japan day 2: Vega and Slaty-backed Gulls

This post shows various age classes of Vega and Slaty-backed Gull. I hope to upload a full sample of birds in the fullness of time, once I am home and can process all my pictures, but for the moment here are some example birds. Images 1-11 are Vega, while 12-15 are Slaty-backed. If you are interested in the field identification of Vega, you might find this article I put on surfbirds a few years ago of some use (http://www.surfbirds.com/ID%20Articles/JapanGulls/index.html); it contains various frequency statistics for wing tip patterns etc.

1. Eye pigmentation varies a lot in Vega; this is a very dark-eyed individual

2. A paler-eyed bird. Most Vegas, like this one, have not yet completed primary moult. This is a little behind the majority, with most birds having full new Primaries 1-9, with the new P10 approx 75% of its full length.

4. Note that the outer primaries are not properly visible as they are regrowing (e.g. P10 is not visible in the far wing)

5. Primary pattern varies a lot in Vega. This is a very typical individual; note the michahellis like P10 and 5 patterns. Some birds have P10 identical to cachinnans, With a long tongue and fully white tip; many also have black on the outer web of P4.

6. 2cy (second winter)? There has been some useful discussion of the age of this bird on Surfbirds Forums (advanced ID). Given the small white tips to the primaries, and the deep white secondary skirt, it may be a 3 cy (third winter). But its general plumage (heavy and extensive head and body blotching, limited grey in the wing coverts and tertials) and bare parts (bill colours, still wholly dark brown eye), are more consistent with a second winter; so if it is a third winter it is very retarded compared to the majoriy of Vega's of this age. I need to look for some other pics of this bird in case I have any flight shots than can resolve this issue properly.
7. 1cy
8. 1cy

9. 1cy
10. 1cy
11. 1cy
12. Slaty-backed Gull, showing off its 'string of pearls'

13. This may not be fully adult; note black on bill and tail.

14. 3 cy
15. 1cy

Japan day 1 (28 December): a selection of small gulls

Choshi, Japan, is of course famous for its gulls. I arrived on 27 Dec for a 9 day visit. This post shows some small gulls seen on my first day. The image above shows Vega and Black-tailed Gulls.
Black-tailed Gull; a stunner

Black-tailed Gull

Black tailed Gull

Black-tailed Gull - a nice dark 1cy

Black-tailed Gull. For a moment I thought this bird was carrying a fish! But actually it proved to be a fishing weight and hook attached to its foot.

Pacific Kittiwake

Tuesday 22 December 2009

More Herring Gulls and some ducks

A rather pale (presumably a northern argentatus type) bird in the snow of Peterhead (19 December). The primaries have clear pale fringes and are distinctly brown, rather than black. I guess these features may be interpreted as suggesting some Glaucous influence, but birds like this are part of a continuum from dark to pale Herrings and confidently drawing a dividing line (at least for me) is difficult. Notably, this bird seems to have renewed one inner greater covert.

A few more typical argenteus type birds are shown here.

I came down to my home town of Sunderland on 21 December. The perfect combination of bright sunshine, snow and a partially frozen lake encouraged me to play around taking some duck pictures.

The same Mallard

Female Pochard

Male Tufted Duck

Male Pochard

Female Pochard

... and another Tufted Duck.

Sunday 13 December 2009

A dozen Herring Gulls (Peterhead, 13 December)

The weather has been mild and there are few gulls at Peterhead. So, yesterday I kept myself amused by getting some images of a variety of Herring Gulls. This post illustrates the range of plumage, moult and structural variability that it is possible to encounter in a sample of Herring Gulls. The colour tones in some images are rather odd - this is because some photos (the latter ones) were taken at dusk, with light coming from the spotlights of the fishing boats and the harbour streetlights (I was shooting on ISO 1000, with shutter speed of 1/30th sec).

This individual has rather odd, pale greater coverts

Presumed argentatus; e.g. note the retained first generation scapulars
This is a rather strange, pale bird. It has a gentle facial expression and a jizz not unlike Iceland Gull. I always struggle to decide whether birds such as this are simply extreme, pale Herring Gulls or sufficiently pale and odd they they are likely to be hybrids.
This bird has a rather odd (extensively grey) pattern on the second generation scapulars.

Very unusual to see covert moult in first winter Herring Gulls. This bird seems to be dropping many feathers simultaneously, without replacement; perhaps this suggests some problem rather than being moult sensu stricto.

The plumage of this bird is very like Great Black-backed Gull, so much so that I waited to hear it call before confirming that it was actually a strangely marked Herring.

Sunday 6 December 2009

Herring Gulls, Peterhead (6 December)

I spent the whole weekend at Peterhead. There were no white-winged gulls but plenty of 'argies' to look at and photograph. These images are not great (very grainy), as the light was very poor and I was shooting on ISO approx 1600-2000.

L.a.argentatus (with nice cachinnans type pattern on P10)

L.a.argentatus; the angle makes the outer-primaries appear more extensively white than in life

Several of the adult argies have yet to complete their wing moult.

L.a.argentatus; a very dark one.
L.a.argentatus. Unusually dark nape and breast sides.

1 cy Herring Gull

Herring Gull. Presumably from the far north (i.e. no scapular moult yet).

1 cy Herring Gull.

1 cy Herring Gull.

1 cy Herring Gull.