The Godwits return to Cliffe Pools

Hundreds of Black-tailed Godwits, Avocets and dozens of Great Black-backed Gulls, Black-headed Gulls, Coot, Redshank, 1 Peregrine. The peregrine was standing quietly on the sand spit the other side of Flamingo, not significantly disturbing the other birds close to it as long as it stayed on the ground.

White Butterflies, 4 Gatekeepers, 5 Meadow Browns, 4 Holly Blues, 2 Commas, 1 Small Heath, 1 Small Tortoiseshell, 2 Red Admirals.

Common Blue Dragonflies.

Round the reservoir and back via the Victoria Road bridge

On the reservoir banks there was a huge change in the obvious vegetation patterns. The lush mix of colour of a wide range of flowers in June has been replaced by a an almost complete cover of brown seeding grass, with dominating white Wild Carrot, Daucus carota, interspersed with a few plants of Bristly Oxtongue, Picris echioides. This is a view of the "Wild Carrot landscape" that clothed the whole of the top of the banks and the outer slopes.

On the internal banks themselves there was a bit more diversity with an apparent ecological zonation, of Common Fleabane, Pulicaria dysenterica, then Mayweed, Matricaria, and finally Grass and Wild Carrot, Daucus carota. It is interesting to speculate on the mix of physical, biological and temporal factors that created this pattern.

There was one very smart male Common Blue Butterfly on the Eastern bank of the reservoir, with great colour on the upperwing, but I only caught the undersides with the camera. Still it looked very fresh, fairly newly emerged.

Gatekeepers galore!

Several Gatekeeper "faces":

The scales of a butterfly or moth are extremely varied in form and function. Some of course are upright and fringed, the better to release the scent pheromones, such as those found in the male "sex-brands" mentioned in previous blogs or in tufts in some other species, but some are developed into extremely long hairs, as seen on the body and in these patches on the wings in this Gatekeeper. This explains why where on the insect you see the hairs you get fewer coloured scales (whether genuine pigment colours or refractive colours), a feature that I had noticed previously but never stacked up properly to draw the correct conclusion. The function of hairs is presumably primarily insulation - but I wonder how the presence of the hairs affects other things such as flight, and specifically drag, for example.

This should be a male, as it has the wide dark marks in the middle of the forewings.

The hairs on the underwing often appear more vertically orientated away from the wing - is this gravity or not? It doesn't look like it. If it's a deliberate difference, then could it be for aerodynamic purposes?

This is a fairly typical upper forewing, and again I think this should be a male with a wide dark smudge as a sex-brand in the middle of the forewing!   It is nice to see the clear brown brand around the outer edge of the wing shared by both sexes, with a neat tiny fringe of hairs at the wing edge.

Very late at Dene Park

Far too late in the day, no camera, just a walk for Monty, maybe 35 minutes on site.

Only butterflies seen in the dank drear evening with thunderstorms threatening were one Meadow Brown, Maniola jurtina, and One Green-veined White, Pieris napi.

The Green-veined White, may have been one of the first of the second brood, according to Thomas and Lewington.

The other insect tentatively identified was a Green Shieldbug, Palomena prasina, in its brown winter colours - a bit early I would have thought, and its definitely not a confirmed ID.

Bourneside Meadow

The butterflies were superb at Bourneside Meadow today. It was particularly nice to see the Small Copper, Lycaena phlaeas, although Warren also saw it today at Pittswood and at the Nursery of Ashes Lane, so I suspect it may be more widespread across the parish than I had realised.

I saw several male Common Blue, Polyommatus icarus, males but they were moving too quickly to be photographed. These must be early representatives of the second generation of this summer, which has started just this last week, after a break of about a fortnight from the first generation. Singles or pairs are regularly seen by Warren every summer, so this suggests adults of this species should also be fairly well spread across the parish. This butterfly forms reasonably discrete colonies measured in tens or hundreds, with individuals occasionally wandering some distance.

This species is most active in sunshine and is a frequent visitor to flowers. Males are the more active of the two sexes and set up territories which they patrol in search of females. The female is less conspicuous, spending most of her time nectaring, resting and egg-laying. When egg-laying, the female makes slow flights, low over the ground, searching out suitable foodplants on which to lay. When a suitable plant is located, a single egg is laid on the upperside of a young leaf (UK butterflies), which should be fairly clearly visible.

In dull weather this species roosts head down on a grass stem. As for similar species, such as the Brown Argus, this species roosts communally at night, with several individuals occasionally found roosting on the same grass stem.

The chrysalis is attended by ants, which may take it into their nests, feeding off the honeydew it may excrete.

One of the clues as where the Common Blue breed is going to be the location of the larval food plants. I checked some of the Birds-Foot Trefoil plants in the meadow and I thought most of them were Greater Birds-Foot Trefoil, Lotus pedunculatus, but at least some definitely looked like Common Birds-Foot Trefoil, Lotus corniculatus, as in the relatively hairless plant with (only 3) orange flowers below. Both are included in the fairly wide ranging list of trefoils and medicks that are used as larval foodplants, so this species of butterfly should do well on this particularly rich patch of wild flowers.

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I also spotted (I think) a Brown Argus, Aricia agestis, picking it out from the Small/Essex Skippers as it fluttered past me, found where it had settled, and grabbed a very poor photo just to confirm the record of the colony. The wings are a good chocolate colour and there are good orange spots around the edge, with no blue dusting towards the body, so I do not think it is a Common Blue female. From the rather rounded wings and the full extent of the orange spots it is possibly a female rather than a male Brown Argus. As it seems quite fresh this might be one of the first of the second generation this year.



On one of the Hogweed heads there was a Crabronid wasp, Crabroninae. The wings lie flat across the abdomen. It is very likely to be an Ectemnius species. Sometimes you find Cerceris species in Philanthinae but these are quite easily distinguishable, by the unevenly ridged segments of the abdomen, the head shape, the yellow face and the overall jizz,  http://www.ispotnature.org/node/281557  and http://www.ispotnature.org/node/280405. The yellow proximal sections of the antennae suggest Ectemnius rather than the otherwise very similar Crabro, where the antennae are black overall.

Another confusion possibility is Mellinus arvensis, generally late in the season, and without the yellow on the bottom of the antennae, or the silver or gold hairs on the clypeus, and with more orange rather than yellow legs.

As to getting down to species, this is very difficult - useful notes from Ardea:

"For female ID you need to get a clear view of the shape of the clypeus (basically upper lip) which you can only see well from the underside of the head, against the light. The clypeal hairs obscure the shape from the front. WIth your photos, long Mesonotal hairs, golden clypeal hairs = either lapidaries, ruficornis (scarce), cavifrons and sexcinctus."

Dene Park

I was glad to see butterflies that I was fairly sure were Large Whites, Pieris brassicae (L.),  rather than Small Whites, Pieris rapae (L.),  today. I was even more convinced when I saw the photos in close-up. The dark blotches that I can see on the upperside of the wing are rather on the large side and the patch at the tip of the wing tracks down both edges of the wing from the tip. The impression of size also helps.

This will be one of the second brood, in which males and females are pretty indistinguishable when seen from the underside.

There was also a Peacock, beautifully coloured on both its hind and forewing underside:

Tudeley Woods

Plants were looking particularly good. This Spear Thistle, Cirsium vulgare, was attracting Bumble Bees in particular, and is a useful ecological component despite being classified as a noxious weed under the Weeds Act 1959. .

This is a close-up of the tubular flowers from the infloescence above, with pollen being pushed out of the tips. In at least one I think I can see a y-shaped stigma just protruding. The purity of the colours is just wonderful!

This next photo was taken just at the edge of the inflorsecence - I am unsure of the nature of the more tendril shaped structures.

Looking lower down the inflorescence, the slight cottony fibres covering the surface interspersed with the green bracts somewhat recurved and ending in yellow spines were fairly clear.

The stem is slightly cottony as well.

and the leaves are also notoriously spiny.

Queensdown Warren late in the day

Lots of Meadow Browns and Two Marbled White Butterflies between 4:30 and 7:30 this evening.

This is a Marbled White, Melanargia galathea. This is a female, recognisable by the yellowish tinge on the underside of the wings, the males are more monochrome black and white. There are only four functional legs in both males and females in the family of Brush-footed Butterflies, Nymphalidae, the Browns, subfamily Satyrinae, the front pair of legs being converted into a small pair of "brushes". Incidentally, the stem behind is an Agrimony, Agrimonia eupatorium, stem going to fruit, remarkably beautiful.

This is the peak month for this butterfly and they should be dropping their eggs over the potential grass larval food plants from around this weekend onwards. This is a typical pose for these butterflies in the afternoon, either on grasses or their nectar source flowers. In the morning they tend to rest with their wings spread to warm up, and for the rest of the day of course they are generally much more active. Unimproved tall grassland is their typical habitat, particularly chalk downland, but even small patches of verge with tall grass will sometimes support small colonies. The Marbled White is a strong flier and a good disperser, so should be fairly good at surviving in the patches of grassland still available on the North Downs, according to research in Belgium and Germany. However the more patches there are, the easier that survival should be.

The Butterfly appears to be spreading slowly North and has most likely recolonised most of Europe from different glacial refuges around the Mediterranean. North Africa and specifically the Maghreb may also have been involved. There are two sibling species, Melanargia galathea that is thought by some to have expanded back into Europe after the last glaciation from two separate refuges in Italy (Western population) and the Balkans (Eastern population) and Melanargia lachesis that is currently found only in Spain and Southern France. The species split itself may have occurred much earlier in the glacial/interglacial cycles, but the mutual interactions of the two species raise several interesting questions about competition, dispersal and evolution. It is interesting to note that the form known as ssp serena is distinguished as the form found in Britain, which derives from the Western population of Melanargia galathea and which must also be a founder effect at the time of the cutting of the land bridge.

The subspecies include serena in Britain, galathea in Europe and the South Urals, donsa in the Caucasus, satnia in the Caucasus major and minor, lucasi in North Arfrica, and tenebrosa.  However I know little about the rest of the species' populations spread across Asia as far east as Japan.

The high genetic diversity and the relatively strong differentiation of the four African populations sampled in a
comparatively limited area of the Atlas Mountains indicate that the most probable origin of the species Melanargia galathea is northern Africa, with its sibling species, M. lachesis, evolving in parallel in Iberia. Most probably, M. galathea colonised Europe first during the Eem (last before this one) interglacial, some 130 ky ago. Since M. lachesis must have existed on the Iberian peninsula during that period already, M. galathea should have reached Europe via Italy. The genetic differentiation to distinct groups in Europe most probably evolved during the following (most recent) Wu¨rm glacial period.

There is a lot of genetic diversity in Melanargia galathea, but this is well mixed within its habitat patches and amongst the wider populations, due to the species' movement ability. The genetic diversity may have arisen partly as founder effects of the small populations isolated in refugia at the time of previous, and in particular the last, glaciation. The species may now in theory require this continuing diversity and intermixing and may be vulnerable to further habitat isolation if the genetic diversity is consequently severely reduced.

The distribution on the chalk in Kent is primarily Eastern according to Thomas and Lewington, and admittedly these are the most Westerly ones that I have seen so far in this county. On the other hand I have seen them in good numbers at Oxford services, so its not all about latitude! Other observers in Kent have also seen numbers to the West, at Darland Banks, Borstal, Lullingstone and Cobham, so the distribution in Kent may have evened out a bit.

This on the other hand is a male, not so well focussed sadly, seen a few moments later on a Large Knapweed, Centaurea macrocephala, flower.

Red Fescue, Festuca rubra, is thought perhaps to be an essential larval food plant, and it picks up some toxins from a fungal infection of that plant, which are apparently carried through into the adult body. However the larvae do feed on a range of other grasses.