Green Sandpiper at Cliffe

A good all the way round walk of just over four miles certainly tired Monty out, and my knees felt it as well.
The new camera lens worked excellently and gave me as good detail at long distance as I think I could have hoped for. I tried to do a count of some of the waterbirds, and got good numbers of coot, tufted, mallard, teal, shoveller and some pintail duck, and a good group of greylag geeses, together with lapwing and godwits, at least some of which (probably all) were black-tailed. although the RSPB website claims high numbers of Dunlin can be seen at the reserve I have only seen the occasional handful.

On the far side of the radar pool, a gull was beating up the coots on the water, and then I got a long-distance snap of it as it wheeled away:

It is a Common Gull, but I am pretty sure it is a second winter bird, because of the dark brown patches at the front and back of the upper wing just to the inside of the black wing tip patches, and also the reduced white mirrors at the very tips of the wings.

Other gulls were wheeling around and they might also have been common gulls at a guess, young ones mainly. I got one shot at the precise moment that an adult wheeled close to the surface of the water, its wingtip apparently only an inch or two from cutting into the surface:

I missed most of the ships coming in and out of the Thames but here is a shot of the relatively small dredger "Marieke" coming up river across the Marsh, and then another shot, closer to.

As we went around the Mead wall I shouted at Monty rolling in some muck by the side of the path and thereby put up a smallish dark wader with a very distinct white rump. According to the sightings board, Green Sandpipers have been around for several weeks, so it was probably a Green Sandpiper, Tringa ochropus, my first ever properly identified -  However I am now quite certain that I had misidentified the two waders I saw in the autumn which I had called Curlew Sandpipers on the basis of their white rumps alone - in my ignorance - they were almost certainly my first Green Sandpipers. So what made me think the bird today was definitely a Green Sandpiper on the spot this time? It was the very dark colouring to the upperparts, the very distinct white rump, the sandpiper-like look to the bird in flight, the sandpiper call just like the Green Sandpiper on Xeno-Canto (a three note whistle), and of course the fact that the Sightings Board predicted that Green Sandpiper was there!

This is from the Itchen birds website (I hope they don't mind!

The Green Sandpiper actually nests in old nests of other species of birds, such as a Fieldfare (Turdus pilaris) or a woodpigeon (Columba palumbus) or a squirrel (Sciurus) drey in trees (!), or on stumps or mounds where trees are unavailable. Separate nesting and feeding territories are thought to be held. little extra nesting material will be added to the existing structure, although some may be re-arranged. This nesting style is rather like the related Solitary Sandpiper in North America and the two together are thought to be quite close to the ancestral Tringa type.

The Green Sandpiper lays 2–4 cream with brown or purplish blotches eggs in a clutch, which take about three weeks to hatch. Incubation is by both parents, starting with the last egg, and hatching is synchronous. The young are precocial and nidifugous.

The species is generally said to be one of the darkest on the upper-side in its group, and in non-breeding plumage, there are none of the myriad small light spots that grace the breeding plumage. Although the upperparts are therefore darker, in contrast the underparts are whiter at this time of the year.

The birds breed in areas such as the Sweden and Finland. The range is quite wide, and extends through the Sub-Artic region North to the Low Artic, and through the Boreal region South to the Temperate, with a montane outlier in Transcaucasia. Females tend to leave the breeding grounds first, perhaps before the young are fledged, followed later by the juveniles and the males.

They winter in Western Europe (a few), around the Mediterranean, in Africa or across Asia, to avoid the snow and ice that would cause them to starve on their breeding grounds. In Britain most over-wintering birds are found in Southern Britain.

Feeding is relatively secretive, regularly entering ditches, stream beds and enclosed ponds, shunning wide horizons and open coastal habitats. In such habitats the only waders likely to be seen are Snipe, Common Sandpiper and Green Sandpiper. The only one of these with a bright white rump is the Green Sandpiper. Food is small invertebrate items picked off the mud (it isn't a great "prober") as the bird works steadily around the edges of its chosen pond. The picture below shows the somewhat sheltered ditch that my particular bird was seen at - doesn't seem to exactly fit.

As the light faded, I tried to see the gulls behind a large ship going out, but failed to get much detail. Possibilities of a couple in the crowd, where the dark wings and whitish tail were caught by the sun, included Black-Backed Gulls, either Lesser or Greater. Others could have been Herring Gulls.

As I looked, a large cloud of waders (at least 150) flew rapidly upriver, too fast and small for curlews. The beaks I thought looked relatively small, so my best guess would be Grey or Golden Plovers, but they could have been a lot of other things as well.

Mum didn't go to Iceland after all!

At the end of an afternoon down by the gravel pits I couldn't resist the temptation of going to look for the Icelandic Gull seen the day before on the Dartford Marshes area, and drove off down the M20 with the sun steadily sinking ahead of me! I thought there was a possible second winter Icelandic Gull at the front of the small group - an immature Gull drably brown overall and streaky (a bit too streaky probably), although it was a bit darker on the belly (mud perhaps, it did seem to spend time preening its breast), but clearly there were a lot of other options. In the ground photos, it was not possible to see whether there was a dark wingtip/tail as would be seen in a second winter Herring Gull Larus argentatus, or whether there wasn't, in which case the possibility of a second winter Icelandic, Larus glaucoides, might actually still be on the cards! Eventually the immature gull took off and surprisingly I did manage to get a couple of shots, one of which very surprisingly turned out to have some detail in it! Sadly, however this photo showed that there was a very clear darker training edge to the secondaries, and according to Malling-Olsen and Larsen this makes it a second year Herring Gull.

I was therefore very glad to get this photo - its so nice to have an answer with some degree of confidence, as opposed to a complete "don't know", even if the answer you get is the less exciting of the options! I think I could fairly well exclude junior Lesser Black Backed because of the overall colour pattern,and the bill having a dark tip and paler base, and what appear to be very pink legs. However the photo isn't very clear and a new lens would be an ideal purchase at some stage - a 300 mm is really the entry level lens length for bird photography and I am not really getting close enough to the birds to get good images.

Windy Whetsted and some Herring Gulls

Quite breezy today, rocking and rolling my quite lightweight tripod. Mild though for the time of year, all things considered.

On the eastern pit on the central roost there was an interesting looking gull - I thought at first from its size and general colour pattern that it must have been a Herring Gull, Larus argentatus. In the UK these are almost always the smaller, less formidable and lighter in colour subspecies argenteus. The adults have a yellow bill with a red spot on the angle of the bill that is known as the gonys. However this bird had no red spot, but a black vertical bar across the bill which is just subterminal. This is likely therefore to be a third winter young bird,

This bird is quite light grey with only a hint of darker streaking on the head. This doesn't look as dark overall especially around the head and neck or as brown in the wing as most of the pictures of the species but ssp argentatus would generally tend to be much darker on the head, and browner on the wing coverts, etc and as this is almost certainly argenteus, it should still be a righteous identification. It certainly isn't dark enough on the hood or in the grey on the wings to be a young Lesser Black-backed Gull, and it is very unlikely to be a rarity. The picture below shows it a long way away, still on the central roost, amongst the smaller black-headed gulls:

You cannot see the black band on the bill very clearly in the picture above, but it shows up rather better below:

This next picture gives a good impression of the squarish head said to be characteristic of Herring Gulls in general although ssp argenteus and females both tend to have somewhat rounder and smaller heads in general in comparison to ssp argentatus and males respectively. It just goes to show the usefulness of taking many photos of the same bird!

There was some degree of darkening to the feathers on the head/neck region (although not as much as in the guidebooks and internet pictures) and this was visible in some of the pictures of the gull with its head facing forward. This is also a good chance to (possibly) agree that the eye is light coloured rather than black, as in the first two years of life:

The grey back of the neck is slightly more visible in this picture where the head is pointed backwards. You may also see a hint of brown on the wings, although this certainly isn't visible in all the photos:

In this photo as the bird is flapping its wings and about to take off, there is a definite impression of brown in the primary and secondary coverts (or scapulars?). In this picture you get a good view of the black bar on the end of the tail, and the streaking around the neck as well:

While in flight the patches of brown on the coverts are quite clearly visible, and maybe there is a hint of light brown on the overall wings. The pattern of black wing tips with white primary tips and a white mirror on P10 fit really well with a third year argenteus bird.

The main problem with the above id is that the bill certainly looks like a third year winter bird, but the overall plumage is still actually a little bit more like an adult winter bird. But in the end I may just have to think this was an issue of the flat light available, and the limited camera lens and usage that I have, and leave the issue until I am more experienced! I should also check all the rarity possibilities!

Here are a couple of younger herring gulls, again Larus argentatus argenteus. These could be first winter or second winter birds, I really can't get the detail at this distance.

This is another photo of the same pair - again you can see the dark fleck on the back of the head of the gull on the left.

Here the gull on the left bends down to pick up something that might be food. The eyes do look dark, as is said to be true for both first and second year birds:

and here is the successful result

and here is the adult common gull, Larus, on the very right, compared in size to several black-headed gulls and the first/second winter herring gull.

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Blistering barnacles!

Barnacle geese migrate very large distances very quickly. However the fantastic group of 44 that I saw at the Gravel Pits today were certainly feral and non-migratory - although that itself raises a number of questions! Why is the migratory pattern so strong and consistent in wild birds - and how do feral birds "lose" this tendency?
As a species that is increasing its feral population worldwide as well as undergoing significant expansion and establishing new breeding areas in the wild (in the Baltic increasing from zero to over 17,000 birds in 27 years) it is noteworthy that there is a new Dutch breeding population over 4,000 birds already, apparently also non-migratory (???).
In nature barnacle geese don't exercise particularly more to practice flying in the periods before migrations of thousands of miles at a time. However they do spontaneously increase muscle mass (how?) and may undergo a number of other physiological changes before setting off. Their heavier mass itself may mean that they have to work harder in these periods.
Wild birds tend to trial pair in their first year or two, but then pair more or less for life. They tend to migrate in family groups, and sisters of the same year group tend to nest close to each other, while males tend to disperse a bit more. Do they break out from the family migration groups?
The Greenland birds winter in Ireland and Western Scotland, especially the Hebrides, the Svalbard birds winter in the Solway/Southern Scotland area, while the Novaya Zembla birds (and the newer Faroes population) winter mainly in the Netherlands. The last population is bigger than the other two together.
In the Solway population, the birds always arrive in Caerlaverock and then depart from Rockcliffe, both areas of which are traditional over-wintering grounds. They also now use two further areas around the Solway, in Southerness and in Morecambe Bay, as numbers increase. To indicate the scale of this over-wintering, numbers dropped to about 400 in the 40s, apparently due to disturbance, but are now up to about 25,000, with very significant support!
Populations in the Netherlands are also on the increase, due again to nature conservation measures, although West Germany in contrast has lost most (all?) of its original over-wintering habitat. The increase in over-wintering numbers presumably increases numbers/density on the breeding grounds, potentially having multiple effects on the Artic ecology. Increasing pink-footed goose numbers may increase grubbing and digging, affecting soil temperature and type and amount of plant regrowth, thus possibly affecting barnacle goose and other herbivore numbers indirectly as well as directly. The barnacle geese may however be able to compete relatively better on the short grass swards around the nests, so its not all a one-way street.
The increase in winter protection and feeding opportunities is likely then to be partly responsible for increased populations on the breeding grounds, which may impact on the artic ecosystems primarily via effects on the artic flora and ecosystem functioning. The Svalbard population used to be mainly confined to islands to avoid predation, but has now "spilt over" to mainland cliff sites, presumably less than ideal from the goose's point of view. As the bird is relatively small it is more subject to artic fox predation than other goose species, which are able to breed more freely on the valley bottoms and repel the foxes. Foxes are a major predator, but gulls are mentioned in Russia, and Polar bears, skuas and eagles may also be involved.
It may share breeding grounds with other species such as the pink-footed goose, but at least on the mainlands the barnacle nests on the steepest ground, and needs watery refuges against predation following hatching, while the pink-footed goose is more free to nest and feed on better vegetated areas. As a smaller goose the barnacle is also less able to dig up plant parts such as rhizomes, at any time in the breeding cycle, thus leading to at least some partitioning in resources.
Branta leucopsis is present on its breeding grounds from May or June to August or September where it breeds in small but often closely packed colonies of 5-50 pairs, occasionally singly or in groups of up to 150 pairs. It uses the same nesting sites year after year and sometimes nests among seabird colonies. The females incubate and must not wander too far from the nest to avoid egg predation. They must use a large amount of energy up, and may use all their food items immediately around their nests.

After the young hatch the adults undergo a flightless moult period near the breeding grounds between mid-July and mid-August that lasts for 3-4 weeks. The species then migrates to autumn staging areas in September from which it travels via regular stop-over sites to the wintering grounds, arriving in late-September (??) The Svalbard birds may fly generally fairly directly (?). The return migration begins in April or May, the species moving to spring staging areas where it may be present for 20-30 days before migrating northwards. This spring stop is generally more important because (at least) the females have to have reserves to go virtually into non-feeding incubating mode as soon as the snow melts and nesting can begin (this is of course a fine judgement, dependent upon that year's weather conditions). Such careful judgements may benefit from the social structure and group migration strategy being (generally?) used, ensuring the benefit of experience from the older birds is used.

The species is highly gregarious outside of the breeding season, often feeding in dense concentrations on coastal grasslands during the winter. In winter habitats it roosts on water or on sandbanks near saltmarshes and pastureland.

The species is herbivorous, on the winter grounds apparently preferring well fertilised grass that perhaps has been cut for silage and then grazed, on medium to large sized fields (4 - 10 hectares). Upon landing the group is tight and easily spooked for the first ten minutes at least but may then relax. Larger groups may tend to spread out a bit more to reduce competition for food. The geese may graze cyclically, encouraging a grass regeneration of young plants with a high protein concentration.

Feral groups appear to move about quite a lot in winter presumably consisting of individuals having escaped from collections, with perhaps some resulting offspring. A new small population of Icelandic breeding birds are said to have possibly developed from escapes.