19 Aug 21

Priorslee Lake and The Flash

14.0°C > 15.0°C yet again: Low overcast began to break after 06:15 with some sunny spells before more cloud after 07:30 with light drizzle as I was leaving. Light SW wind. Good visibility.

Sunrise: 05:58 BST

* = a photo today

Priorslee Lake: 04:35 – 06:25 // 07:30 – 09:45

(179th visit of the year)

Bird notes:
- I could not find an eighth adult Great Crested Grebe. As the juveniles grow they can be left safely on the water and the adults are ranging more-widely and I wonder whether I ever did see an eighth yesterday.

Overhead:
- 120 Canada Geese: all outbound as 21 singles/duos/groups
- 107 Greylag Geese: all outbound in 12 groups
- 12 Feral Pigeons: single and one group – probably not Racing Pigeons
- 3 Stock Doves: single and duo
- 88 Wood Pigeons
- 1 Herring Gull
- 25 Lesser Black-backed Gulls
- 1 Sparrowhawk
- no Jackdaws
- 1 Rook

Hirundines etc., noted:
- 2 House Martins: singles at 06:05 and 07:40
- >1 Barn Swallow: single flew E 08:15; as yesterday possibly the same seen over the lake three more times

Warblers noted:
- 11 Chiffchaffs again: one of these noted in song
- 6 Reed Warblers
- 2 Blackcaps
- 1 Common Whitethroat

Count from the lake area:
- 2 + 4 (1 brood) Mute Swans
- 14 (?♂) Mallard
- 2 Moorhens again
- 52 Coots again: adults and immatures
- 8 + >3? (3 broods) Great Crested Grebes
- 141 Black-headed Gulls: apparently just one juvenile
- 4 Lesser Black-backed Gulls: all juveniles; arrived separately but briefly present together
- 1 Cormorant: arrived
- 1 Grey Heron: departed

On / around the street lamps pre-dawn:

Moths:
- *1 Dark-triangle Button sp.' (Acleris laterana/comariana)
- 1 Common Roller (Ancylis badiana)
- 3 Common Grass-veneer (Agriphila tristella)
- *2 Barred Grass-veneer (Agriphila inquinatella)
- *1 Single-dotted Wave (Idaea dimidiata)
- *1 possible Triple-spotted Pug (Eupithecia trisignaria)
- 1 Common Footman (Eilema lurideola)

and
- *1 unidentified caddis fly
- 1 Bridge Orb-web Spider (Larinioides sclopetarius)
- *2 Cucumber Green Orb Spiders (possibly Araniella cucurbitina)
- 4 Dicranopalpus sp. harvestmen.
- 2 Leiobunum rotundum harvestmen

In the sailing club shelter pre-dawn:

Spiders:
- the usual Bridge Orb-web Spiders (Larinioides sclopetarius)
- *Walnut Orb Weaver (Nuctenea umbratica)

Things seen later in dull conditions again:

Moths:
- *Horse-chestnut Leaf-miner (Cameraria ohridella)
- Pale Straw Pearl (Udea lutealis)

Bees / Wasps etc.:
- Honey Bee (Apis mellifera)
- Common Carder Bee (Bombus pascuorum)
- Buff-tailed Bumblebee (Bombus terrestris)
- Common Wasp (Paravespula vulgaris)

Hoverflies:
- Marmalade Hoverfly (Episyrphus balteatus)
- *Chequered Hoverfly (Melanostoma scalare)

Damselflies:
- *Common Blue Damselfly (Enallagma cyathigerum)

Bugs:
- Common Green Shieldbug (Palomena prasina): instar

Molluscs:
- White-lipped Snail (Cepaea hortensis)

Mammals:
- 6 Pipistrelle-type bat: did not check all areas
- 2 Grey Squirrels

Yes: another photo of a Horse-chestnut Leaf-miner moth (Cameraria ohridella). Note to the left of its head is the hole where it has emerged from the brown patch – the leaf mine. Having only just emerged probably explains why this moth was unusually still though I am sure the dull conditions also played a part.

A different specimen of 'Dark-triangle Button sp.' (Acleris laterana/comariana) from yesterday. This one has a small pale area in the dark triangle but this does not help clinch the identity.

A different species of grass moth for a change. It is a Barred Grass-veneer (Agriphila inquinatella) and a moth I do not record every year – probably because I get fed up with logging Common Grass-veneers and stop looking!

An identification challenge was this worn moth. The smudging on the inner edge of the forewing is enough to make it a Single-dotted Wave (Idaea dimidiata).

I could convince myself that this is a Triple-spotted Pug moth (Eupithecia trisignaria) but.... I find pug moths very challenging to identify and my Field Guide notes that this is a Local species (to where?) with a flight period of June and July. I will take advice.

Another immature Common Blue Damselfly (Enallagma cyathigerum). It is a male – the female has all body segments mostly black apart from having the same thistle-shaped mark as the male on the second segment.

Angled like this shows the triangular yellow markings of a female Chequered Hoverfly (Melanostoma scalare). On the male these would look rectangular.

This unidentified caddis fly was running round and around a lamp post giving me little chance of an identification.

I wasn't sure about this at the time and enlarging the photo does not entirely help. I think this is a tiny aphid-type fly on a bird-dropping though there seems to be a few strands of a spider's web involved. Also I don't think it can be a real aphid as the head looks too separated from the thorax.

A Cucumber Green Orb Spiders possibly Araniella cucurbitina though there is another species which cannot be separated from a photo. Not all specimens have the red markings.

This spider is a Walnut Orb Weaver (Nuctenea umbratica). It seems to have caught a grass moth for its meal.

Another spider victim. This bluebottle fly has had its head neatly amputated. The legs are scattered about.

Yet another exciting-looking spider!

(Ed Wilson)

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Between the lake and The Flash:

- Adult Moorhen seen with two young between a gap in the vegetation at the lower pool. The young are smaller than all but one of the broods extant at The Flash.
- Single Chiffchaffs calling beside both pools again

(Ed Wilson)

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In the Priorslee Avenue tunnel:

- 1 Common Green Lacewing (Chrysoperla carnea) [probably this species though there are similar...]
- 1 unidentified caddis fly

(Ed Wilson)

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The Flash: 06:30 – 07:25

(165th visit of the year)

Bird notes:
- One of the arriving Greylag Geese was a strange white-headed bird I have not seen before.
- The Tufted Duck or her ducklings are getting hard to spot as the youngsters are almost full-size. Luckily they tend to stay together and away from other birds so any group of five is worth examining.
- *A Grey Wagtail, presumably the same, was seen in three different locations.

Birds noted flying over here:
- 1 Canada Goose
- 3 Feral Pigeons: together
- 7 Wood Pigeons
- 1 Collared Dove
- 1 Lesser Black-backed Gull again

Hirundines etc., noted:
- 3 House Martins again: one a juvenile

Warblers noted:
- 7 Chiffchaffs: no song heard
- 1 Blackcap

On /around the water:
- 9 Canada Geese
- *12 Greylag Geese: all arrived together
- 3 + 2 (1 brood) Mute Swan
- 46 (?♂) Mallard
- 40 (?♂) + 4 (1 brood) Tufted Duck
- 3 + 3 (3 broods) Moorhens
- 8 juvenile Coots (4 broods)
- 2 + 3 (1 brood) Great Crested Grebes
- 26 Black-headed Gulls: one juvenile
- 1 Grey Heron

On various lamp poles:
- 1 Scalloped Hook-tip moth (Falcaria lacertinaria): same place as last two days, possibly dead in spider's web?
- *1 Plumed midge (Chironomus plumosus)
- *1 possible sawfly, perhaps of the genus Machrophya

Also
- many Grouse Wing caddis flies (Mystacides longicornis) dancing over waterside vegetation
- 1 Grey Squirrel

Yes well! In flight all the 12 geese that came in together looked like Greylag Geese. On the water this did not! Apart from the white head (with a black crown) the bill is more pink than Greylag-orange and what little can be seen of the leg looks very orange rather than the Greylag's dull pink. The back is darker too. My only suggestion is that this hybrid has Farmyard Geese genes. These geese were originally domesticated Greylags. But where has this individual come from?

The first Grey Wagtail I have seen on he ground around The Flash for a while. I have heard several recently, usually from the island or flying over. This is a juvenile.

Not often I find a Plumed midge (Chironomus plumosus) at eye-level in the day to show off the plumed antennae that only males have – for detecting the female's pheromones.

A rather striking-looking fly with white areas on all its legs. I think it is a species of sawfly and it bears some resemblance to those of the genus Machrophya. However....!

(Ed Wilson)

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On this day can be found via the yearly links in the right-hand column.

Sightings from previous years without links are below

2011
Priorslee Lake
4 Common Sandpiper
Female Ruddy Duck
(John Isherwood)

2006
Priorslee Lake
A male Cockatiel
1 drake Ruddy Duck
(Ed Wilson)