Cliffe Pools

Walked up to Flamingo Pool where there were dozens of Great Black-backed and Black-headed Gulls roosting, together with a possible Whimbrel (very short bill, something of a central forehead stripe), Oystercatchers, Little Egrets, Coot and Great Crested Grebes.

At the start of the path there were perhaps a hundred Goldfinches on the bushes by the side of the track. I could hear Little Grebes calling across the central pool, where there were Redshanks and Lapwings roosting on the islands, and some Coot in the water.

Along the path I think I identified Bastard Cabbage, Rapistrum rugosum, with its clusters of small pale yellow flowers leaving behind long strings along the stems of double-chambered fruit, with the top segments abruptly narrowed into (0.8) 1 - 3.5 (5) mm styles, reminiscent of Chianti bottles. Rose has an amazing clear description - "Fruit with two joints. The upper globular, 3 mm wide, with a long beak like an old Chianti bottle, lower joint like a stout stalk".

Stace has it as subspecies linneanum with long thin appressed pedicels (1.5 - 5 x 0.3 - 0.7 mm) and seedless lower fruit segments. He also states that the fruits are also very variable in hairiness and degree of sculpturing, and these were not noticeably hairy.

It is an erect but well-branched annual, to 1 m., said to be hispid at least below. The leaves are dentate and a little fleshy, and in these plants today quite grey, possibly due to mildew. It flowers May to September.

The plant is introduced/naturalised from S. Europe, casual in waste and arable land, on tips, waysides and open grassland, frequent and increasing in C. and S. Britain. It has been introduced to N. America and it is classed as a noxious weed in Texas at least. It seems to smother other seedlings with its basal rosettes in the early phases but these do die off, as they have in these plants at this stage.

Lots of Bristly Oxtongue and other late summer flowers out.

White-rumped Sandpiper at Oare

Back to Oare, and I THINK I saw the Sandpiper in among the Dunlin on the far side of the ponds - somewhat darker speckles stretching lower down the breast. It was too far away to get a good photo but I thought the bird was a bit slimmer/sleeker and the tail was more pointed, fitting in with the primaries extending beyond the tail. However I didn't see the white rump itself!

I think this might be it, most easily seen, looking at the smaller birds to the back, and, hopefully, the slightly thinner bird with a shorter bill, below and to the right of the Dunlin:

There were a few Knot around, which I particularly enjoyed, here with one Redshank and some Golden Plover,

And there was a seal out in the Swale, popping its head out over the waves.

Oare Marshes - but still no Bonaparte!

Lots of varied Black-headed Gulls, Chroiocephalus ridibundus, though! A Snipe by the tussocks.

At least one Curlew Sandpiper in the middle distance, still with noticeable rusty underparts markings. I think there is one Common Redshank, behind and to the right, with apparently at least one albino feather.

Oare Marshes

A Wood Sandpiper, Tringa glareola, on passage, almost the first bird I saw at Oare today! There were also birds at Reculver and Elmley on the same day, presumably birds moving south from Scandinavia, rather than from the tiny breeding population in North Scotland. Nice to see the slim gawky movements, the bold white speckling on the back, the strong white eyestripe, prominent even behind the eye, the gradual merging of the streaking of the neck and throat into the whitish belly. I thought it was quite whitish in front of the wing, and I could not see any barring on the flank, so probably already properly in winter plumage. Not a tiny bird, but a little smaller than the Redshank, with a shorter bill.

Leybourne Lakes

Lots of Cabbage Whites, hopefully mostly Large Cabbage Whites, Pieris brassicae, on the long walk around the lakes. This is I think the height of their numbers. We unfortunately killed a couple who wandered in on to the moist concrete as it was laid in the extension two days ago.

These ubiquitous insects are incredibly successful because they are so well adapted. They don't lay too many eggs on a particular plant or a leaf. Larval feeding or leaf damage, or the number of eggs already laid, as set out in research from Miriam Rothschild among others no doubt, are all cues not to lay any more eggs.


The work described in this paper forms part of an investigation into the conditions which influence the breeding of Pieris brassicae (L.) in captivity. Observations have been made on the behaviour of the females at the time of oviposition, on factors which influence oviposition, on the appearance and weight of the eggs and on their fertility and hatching.

Females which are ready to lay seek out green surfaces and, as they respond eagerly to plants from which they are separated by glass, it seems that plant odour plays little part in the attraction. Once they have alighted, however, the insects drum on the surface with their fore legs to test its suitability. Normally they lay only on plants which contain the mustard-oil glucosides, but they have been observed to oviposit on broad bean (Vicia faba), on which the larvae do not survive. Sinegrin applied to green paper stimulates the female to lay. Provided she is standing on an acceptable surface she will oviposit on any other surface, for example, filter paper or glass. The eggs are normally deposited on the under surface of the leaves. This is largely due to a preference for the physical underside but the insects also seem to prefer the morphological under surface of the leaf to the upper surface. When laying an egg, the female locates one previously laid with the tip of her abdomen and so builds up the regularly arranged batches.

The females lived and oviposited as well in small cages as in large cages. They laid more eggs per day, and more eggs in a batch, at 30°C. than at 20°C. Both numbers increased until the female was about six to seven days old and then declined. Oviposition occurs at low light intensities. Fertilised females laid very many more eggs than virgin females. Oviposition occurred two to three days after copulation, and most females oviposited six or seven times in eight days. The number of eggs laid by starving insects is low: it is higher for insects given water or one per cent, honey solution and very much higher for insects given ten per cent, honey solution. Sucrose solutions are as satisfactory as honey solution.

When first laid, the eggs of P. brassicae are yellow in colour and become more orange as they develop. Some batches of newly laid eggs are of a distinctly darker yellow than others but, as it is believed that the eggs are fertilised only just before oviposition, it seems that this colour difference cannot be due to the eggs being in somewhat different stages of development. The number of ribs on the shells seems to vary in different cultures.

Batches of eggs which are laid within an hour of each other may begin to hatch several hours apart, and the time taken for all the eggs in one batch to hatch was found to range from two hours to about seven. A fertilised female lays scarcely any infertile eggs. The fertility after one mating falls below 100 per cent, after about 14 days, but normally the female mates again before this time. Temperature naturally affects the time taken by the eggs to hatch. The shortest time was about 3¾ days at 28°C.; the longest observed was 17 days at 12·5°C.

The eggs cannot be stored for more than ten days at 3·5°C. and 50 per cent, relative humidity. Eggs will develop and hatch at very low humidities. If the eggs are detached from the surface on which they are laid by the use of acetone their capacity to develop and hatch in air dried over phosphorus pentoxide is substantially reduced.


As part of development of an IPM programme for cabbage crops in the Netherlands the possibilities for biological control of lepidopteran pests by means of inundative releases of Trichogramma species was examined. The studies involved pre-introductory research to select effective Trichogramma species/strains. This paper dealt with laboratory research on the host-selection process. They examined whether strains of Trichogramma evanescens Westwood prefer one of the three most harmful lepidopteran pest species in cabbage, Mamestra brassicae, Pieris brassicae and Pieris rapae when these are offered simultaneously to the parasitoids. The most important aspect of this paper was the development of a fast and reliable method to determine host preference. It appeared from the evaluation of the different methods used in this study that direct observation of the parasitization behaviour of the wasp is necessary to determine preference in a reliable way. Differences were found in host preferences between strains of one Trichogramma species. The differential acceptance and preference of the three host species is now used to select Trichogramma strains as potential biological control agents.

Great Crested Grebes with Coots on the water, and lots of young Greylag Geese, Anser anser, by the feeding area.

Lakenheath Fen - The Reserve

Plenty of Ruddy Darters along the track towards Fen View. I do not THINK I saw any Common Darters, which was quite a surprise to me!

Here is an immature male rather, perhaps, than a female, I think, on balance. However, this is just based on my impression of the tail shape:

It is definitely a Ruddy Darter, as it has the frons side line, the blackish T-mark back from the collar, and entirely black legs, and more solid black markings along the middle of S8-9. I think my memory was was that it was also quite small, with a fairly short abdomen. 

Picking up Simon from Heathrow

Nice Jay crossing the A21 by the "high" Bridge on the outward journey, and a Buzzard circling over the Downs escarpment by the A22 on the way back.