Thursday, 29 December 2016

Bough Beech

Lots of Greylags, Shoveller, Mallard, Teal, Coot, Moorhen, Cormorant and some Mandarin Duck on the main lake. Possibly some Wigeon as well.

The smaller lake was largely iced over, with only a couple of Carrion Crows.

Monday, 26 December 2016

Milton Creek

A really nice walk out at Sittingbourne today in warm (for December) breezy weather with weak sun. Targets were the long-staying Long-tailed Duck, Clangula hyemalis. The drake is at the back with its longer tail, and the next one is perhaps a youngster, behind two lighter coloured females. I must say that they are remarkably pretty birds:


There are supposedly 11,000 or so wintering in the UK every year, but the distribution is much more Northern in distribution, generally north from Northumberland with high numbers off the East of Scotland. Most birds probably come from the Iceland/Greenland breeding population, but there may also be some from the Russian/North West European population. There are some records in Kent, but not a huge number. According to the RSPB they eat mainly mussels, cockles, clams, crabs and small fish.

The species is of European Conservation Concern, and appears subject to risk from oil spill in the relatively small Finnish/Scandinavian population. The UK wintering population, at the southwestern limit of its range, is therefore subject to protection and at least three Scottish estuarine shores are SPAs in part consequence.

On the tundra breeding grounds the males are highly territorial, and are reported to return to their territories year after year. Nests, with a down covering on a shallow depression in the ground, may be placed among Arctic Tern nests, affording some protection against predators. Nesting takes place from late June, usually close to a pond. The 5 - 9 eggs are brooded for 4 weeks or so, the males leaving early in the process to moult on the coast.

There were plenty of other birds to be seen, particularly at the height of the tide. There were quite a few wigeon about, although they were not particularly vocal today.


There were quite a few Redshank around.


I got a couple of shots of a Black-Headed Gull flying conveniently past, in classic winter plumage. The wing pattern is just so wonderful, both under and over.







Thursday, 22 December 2016

Uplees Marshes

Very briefly at the East Flood, two Greenshank flew in, one of which I got a good view of.

There were thousands of Golden Plover on Horse Sands, in among many other waders and gulls.

Scanning the edges of the Swale, I found Redshank, Dunlin, Lapwing, Shelduck, Curlew and a few Grey Plover on the shoreline mud.


I walked as far as the Fieldfares in the copse beyond the old dock. On the sheds there were Stock Doves, Rooks, Crows and one Green Woodpecker. There were several Grey Herons and Little Egrets. I saw two Buzzards, one of which came to rest on a gatepost.


Looking over towards Mocketts I thought I could (just) see a Ringtail Hen Harrier - just a guess really, quite orange/warm brown on its chest.

Tuesday, 20 December 2016

Willow twigs and aphid eggs


Here are some views of Salix viminalis twigs and buds, showing the greyish hairs on the twigs and buds. The buds have just one outer bud-scale, and are flattened against the twig, as is characteristic of the genus.


In this closer view you can see the placement of the lenticels on the "shoulders" of the buds - perhaps a very useful place for them to be metabolically? It is also interesting to see the "lipped" appearance of the buds, which may, or may not, be somewhat characteristic of the species - they may have dried out a bit of course. And, is it genuinely S. viminalis?

The other thing is the three small horns on the leaf scar - the two outer ones are smaller and "sharper" and sometimes appear to have a circular scab just to the outside of the horn, and I am finding it difficult to interpret this pattern. One possibility is that the circular scab results from the abscission of a stipule - as suggested on this webpage. The horns would therefore perhaps be "now blocked off" veins? If so the two outer ancillary ones may join with the central main one to form the midrib of the leaf, but perhaps branching off again in the lower quarter or third of the blade. Or could they be for stipule venation?


Several of the twigs had aphid eggs on them, quite glossy black by now.


Here are two more eggs


This is a twig from one of the yellow-orange Crack-Willows, Salix fragilis, on the Southern side of the Ocean lake. The stipule scar is very obvious and the bud itself is quite solid-looking, almost thorn-like at this angle. So many of them seem quite sharply colour-banded.


This is another twig of Crack Willow, this time with one partly diseased bud, a not uncommon sight in my limited experience.


This is a Dogwood twig, showing the spiky opposite unscaled buds that look to me like "witch's fingers"



Saturday, 17 December 2016

Snow Buntings at West Beach, Llanddulas.

Started off at Wern Road, Llandulas at about High Tide with about 400 Common Scoter, a Guilllemot, a possible Diver, 2 Great Crested Grebes, innumerable Gulls and Cormorants offshore, with 2 Cormorants, 16 Great Black-Backed Gulls, 9 Herring Gulls and 7 Black-Headed Gulls inshore.

At Penrhyn Bay there were 7 Wigeon (5 males, 2 females) and 3 Red-breasted Mergansers (2 males, 1 female) fairly close-by on the sea. Further out there were innumerable gulls, with at least 5 Great Black-Backed Gulls, 6+ Herring Gulls and 6+ Black-Headed Gulls, and many more I could not identify. Also 40+ Cormorants, flying and feeding.

There were also 13 Oystercatchers, 10 Redshank, and 2 Turnstone roosting on the offshore rocky spit towards the Little Orme,

At West Beach, Llandudno, I walked down to the spit towards Deganwy where there were 3 Snow Buntings, 84 Common Gulls, Larus canus, 20+ Black-Headed Gulls and 25+ Herring Gulls, together with 30+ Oystercatchers.

Conwy


Wednesday, 14 December 2016

Ambling around Leybourne

At the first bend on the Ocean path, there was a small group of Long-tailed and Blue Tits, and luckily I spied a Chiff-Chaff in with them, mainly by its different movements. Wonderful. I saw several similar groups of Tits on my way around, but didn't see any sign of any other Chiff-Chaffs, or indeed that one again.

On the causeway I spied two Redwing, and quickly realised that I had already seen one earlier, flying over the water towards me and the small group of Tits, noting its pale face and chin.

A lovely sunny afternoon, and I tried to look for aphid eggs, but failed (almost) entirely. Right at the last minute, by the door to the toilet I did find an oval egg of some sort on Field Maple, quite likely an aphid egg.

However, despite this failure it was so interesting to see the aphids hanging from the Grey Willow over by the West Scrub. Probably dead individuals of Tuberolachnus salignus, the Giant Willow Aphid.


Adult aphids are supposed to remain active over the winter period, through January and February. There appeared to be wingless individuals attached to the twigs further along.

Incidentally, all aphids appear to have co-evolved with a bacterial partner, Buchnera aphidicola, that helps them cope with their plant phloem-sap sucking lifestyle. Aphids, being typical animals, have distinctly poor chemosynthetic ability. However their diet is very limited in amino-acid content, for example being largely (not entirely) limited to a few non-essential amino acids like Arginine in the Phloem sap. So how do aphids get the essential amino-acids they cannot synthesise, such as Trytophan for example? The bacteria embedded in their many thousands in huge mycetocytes (cells) in their bacteriosomes (organs) are very limited nowadays, as they rely for much of their structure and nutrition on their host aphids. But they CAN produce (for example) the essential amino-acid Tryptophan from the non-essential Arginine, which they do.  Buchnera over-produces the essential amino acids which are needed by its aphid host, but none of the non-essential amino acids, for which it depends on its aphid hosts, like most of its other nutrients. This partnership goes back possibly 180 - 250 million years. The bacteria in their bacteriocytes are passed by cellular migration across the ovaries into the developing embryos (or are expelled from bacteriocytes to migrate into eggs in the sexual stage?) or......