16 Sep 21

Priorslee Lake and The Flash

12.0°C > 18.0°C: Area of cloud to E initially and then cloud to W later: stayed sunny until after 09:30. Light SW wind. Very good visibility.

Sunrise: 06:45 BST

* = a photo today

Priorslee Lake: 05:15 – 09:15

(205th visit of the year)

Bird notes:
- One of the two pairs of Great Crested Grebes that were without a nest or juveniles seems to have left
- Different behaviour from the gulls this morning:
*** the first Black-headed Gull arrived at 06:05. No more until 18 arrived at 06:30. These soon departed back to the W. I counted 116 in the mist on the football field at 06:40 with a few more on the academy paying field. Some of these were presumably the c.40 on the lake later.
*** the first large gulls dropped in from the overhead at 06:20. As it became lighter I could see large gulls passing S to the E, some at considerable range. Some from the closer groups were peeling off and coming for the usual wash and brush up. None arrived from the E today.
*** later arrivals and birds passing were also all heading S.

Overhead:
- 2 Canada Geese: cross-bound (if there is such a word) together
- 2 Feral Pigeons: together
- 3 Stock Doves: together
- 147 Wood Pigeons
- 1 Black-headed Gull
- 1 Herring Gull: adult
- 5 Lesser Black-backed Gulls
- 57 large gulls: see notes
- *1 Cormorant
- 1 Common Buzzard
- 7 Jackdaws
- 1 Pied Wagtail

Hirundines etc., noted:

None

Warblers noted:
- 11 Chiffchaffs: five in song
- 1 Blackcap

Count from the lake area:
- *2 + 4 (1 brood) Mute Swans
- 16 (>7♂) Mallard: some flew off while still too dark
- 5 (?♂) Tufted Duck: departed
- 8 Moorhens
- 78 Coots
- 2 Little Grebes
- 8 + 5 (3 broods) Great Crested Grebes
- c.125 Black-headed Gulls
- *4 Herring Gulls: all immatures
- *18 Lesser Black-backed Gulls: various ages
- 43 'large gulls' only: see notes
- no Grey Heron
- 1 Cormorant

Moths at the lamps pre-dawn:
- 1 Common Marbled Carpet (Dysstroma truncata)
- *3 Snout (Hypena proboscidalis)

Other things:
- 2 Common Wasps (Paravespula vulgaris)
- 2 Bridge Orb-web Spiders (Larinioides sclopetarius)
- *3 other spider sps. - one Clubiona sp., one Metellina sp. and one possible M. segmentata
- 3 Dicranopalpus sp. harvestmen
- 1 Leiobunum rotundum/blackwalli harvestman
- 1 Paroligolophus agrestis harvestman

Noted later:
- Speckled Wood (Pararge aegeria)
- *Common Blue (Polyommatus icarus)
- Common Nettle-tap (Anthophila fabriciana)
- *Common Carder Bee (Bombus pascuorum)
- Common Wasp (Paravespula vulgaris)
- Common Dronefly (Eristalis tenax)
- *Tiger Hoverfly (Helophilus pendulus)
- *Common Blue Damselfly (Enallagma cyathigerum)
- *possible Netted Slug (Deroceras reticulatum)
- many White-lipped Snails (Cepaea hortensis) as usual
- 1 Grey Squirrel
- 1 Brown Rat (Rattus norvegicus)
- 1 Pipistrelle-type bat

A strange weather effect this morning. The football field on the right was shrouded in low-level mist. The hedge on the left separating the footpath from the academy stopped the mist penetrating further.

The Mute Swan cygnets are progressing well with their flying attempts. Both feet off the 'ground' here.

But not for long – touch-down for some more paddling.

Get those wings working!

Three first-winter gulls. The very dark bird at the top is a Lesser Black-backed Gull. The one on the left with extensively pale inner primaries and pale secondary coverts is a Herring Gull. The bird on the right is more of a puzzle. You will note how the angle of the light affects the appearance of the tones in the wing as on both the lower birds. I am inclined to think it is a Yellow-legged Gull. It would have been helpful to have a clearer view of the head: this species has a whiter head at this age than either of the others. As I am unsure I have logged it as a Herring Gull.

Cormorants in flight always seen quite pre-historic to me. This is an immature with some pale on the belly.

One of three Snout moths (Hypena proboscidalis) at the lamps this morning. Easy to see how it got its name. The larvae of this common species feed on nettles and there are plenty of those in the area.

This was a surprise find, sunning itself. A male Common Blue butterfly (Polyommatus icarus) - the blue on the upper forewing of the male is just visible. This species is normally double-brooded with peaks in mid-May and mid-August. It is known that in some years there is an Autumn third brood. Whether this obviously fresh specimen is from a third brood or whether the very cold May delayed the flight periods is an interesting question.

A splendid Common Carder Bee (Bombus pascuorum).

A Tiger Hoverfly (Helophilus pendulus) has found the background to provide camouflage.

This seems to me to be another unusual sighting at this date: a male Common Blue Damselfly (Enallagma cyathigerum).

It is not just hoverflies and bees that like the flowers of Larger Bindweed (Calystegia Sepium). This slug is probably not interested in the style but will munch the petals. Slug identification is far from easy: many species come in many colour forms and their appearance varies depending on whether they are stretched out or, as here, not. My vote would be for a Netted Slug (Deroceras reticulatum): I was not motivated to investigate further.

A handsome spider: I think Metellina segmentata.

I would have had another moth to record this morning as I saw one fly in to the web of this spider. The spider was quicker than I was and by the time I had the camera raised the moth was already too wrapped up for me to have and chance of an identity. Probably also a Metellina species: these are orb-web spiders.

Not an orb-web spider and likely one of the Clubiona species. As so often separation requires more detailed examination than a photo.

(Ed Wilson)

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In the Priorslee Avenue tunnel pre-dawn:

Moths:
- 1 Common Marble (Celypha lacunana)
- *1 possible White-spotted Pug (Eupithecia tripunctaria)

with:
- 1 lacewing sp., perhaps Common Green Lacewing (Chrysoperia carnea)
- 3 Common Rough Woodlouse (Porcellio scaber)
- 2 White-legged Snake Millipede (Tachypodoiulus niger)
- plus many spiders as usual

I find pug moths a nightmare. This might (or might not) be a White-spotted Pug (Eupithecia tripunctaria). Not a species I have recorded in the area. I'll try and get it checked.

(Ed Wilson)

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The Flash: 09:20 – 10:05

(185th visit of the year)

Bird notes:

- Only two of the juvenile Great Crested Grebes noted.

- When the geese have arrived back the resting area on the edge of the island used by the Black-headed Gulls is not available. The gulls fly off elsewhere.

Birds noted flying over here:
- 1 Feral Pigeon
- 1 Pied Wagtail

Hirundines etc., noted:

None

Warblers noted:
- 4 Chiffchaffs: no song

On /around the water:
- 57 Canada Geese: some of these arrived
- 7 Greylag Geese: most of these arrived
- 3 + 2 (1 brood) Mute Swan
- 32 (19♂) Mallard
- 44 (?♂) Tufted Duck
- 8 Moorhens
- 26 Coots
- 2 + 2 (1 brood) Great Crested Grebes
- no Black-headed Gulls
- no Grey Herons

On one of the lamp poles:
- 1 Dicranopalpus sp. harvestman

Elsewhere:
- Large White butterfly (Pieris brassicae)
- Speckled Wood butterfly (Pararge aegeria)
- Common Wasp (Paravespula vulgaris)
- Common Drone Fly (Eristalis tenax)
- *Humming Syrphus (Syrphus ribesii) hoverfly
- Scorpion Fly (Panorpa sp.): my first at this location
- *unidentified gnat / midge sp.
- Grey Squirrel

This a female Syrphus sp. (S. ribesii / S. vitripennis).

Here it is feeding on the flower of a Honeysuckle (Lonicera sp.). The rear leg is clearly visible and shows that the hind femur is yellow and therefore S. ribesii which Steven Falk calls Humming Syrphus. It is worth quoting his explanation "This is the main hoverfly responsible for the mysterious hum that you sometimes hear in a wood (created by thousands of males vibrating their wings as they rest on tree foliage) and males can often be seen hovering in loose swarms beneath the woodland canopy in sunbeams".

I was inspecting the Horse-chestnut (Aesculus hippocastanum) leaves for any remnant Horse-chestnut Leaf-miner moths (Cameraria ohridella) when this tiny insect appeared. I guess a midge or gnat?

(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

2013
Priorslee Lake
Ringed Plover
(Ed Wilson)

2007
Priorslee Lake
Nuthatch
Kingfisher
(Ed Wilson)

2006
Priorslee Lake
Kingfisher
(Ed Wilson)