23 Sep 26

Priorslee Balancing Lake and The Flash

16.0°C: Much medium-level cloud. Two very light showers. Also a few sunny bursts. Very light winds early with a light north-westerly breeze developing. Very good visibility except in showers.

Sunrise: 06:56 BST

* = a species photographed today
! = a first sighting of the species this year
$ = a new species for me in this area

Priorslee Balancing Lake: 05:45 – 09:10

(219th visit of the year)

Bird notes:
- *a pair(?) of Mute Swans arrived from the West at 08:20 and departed back there 08:40 (and were probably at The Flash later).
- just three Tufted Duck noted.
- for the first time in many a long week as I approached the lake my ears were not assailed by the insistent begging calls of juvenile Great Crested Grebes! All old-enough to feed themselves now? Several were noted in flight though these looked to be adults rather than juveniles trying their wings.
- gull numbers around first light difficult to ascertain as two disputing Grey Herons kept them on the move.
- at least 300 Black-headed Gulls were present early. I counted 154 on the football field at 07:05.
- about 100 Lesser Black-backed Gulls were present early with at least another 50 passing South far to the East.
- later the now-usual arrival from the East comprised 132 Lesser Black-backs and eight Herring Gulls.
- no hirundines were seen again.
- as yesterday nine Chiffchaffs noted with just one of them heard singing.

Bird(s) noted flying over here:
- 74 Lesser Black-backed Gulls
- 1 Stock Dove
- 14 Wood Pigeons
- 199(!) Jackdaws
- 36 Rooks

Counts from the lake area:
- 2 *Mute Swans: arrived and departed
- 19 (>9♂) Mallard
- 3 (1?♂) Tufted Duck
- 4 Moorhens
- 45 Coot
- 13 Great Crested Grebes
- c.300 Black-headed Gulls
- 8 Herring Gulls
- c.230 Lesser Black-backed Gulls
- 2 Cormorant
- 2 Grey Heron: one departed

Hirundines etc. noted:

None

Warblers noted:
- 9 Chiffchaffs: of these one in song again

Also noted:
Very little.

Bees, wasps etc.:
- Common Wasp Vespula vulgaris

True flies:
- cranefly Tipula confusa

On the West end street lamp poles before dawn:

Moths:
- 1 *Narrow-winged Grey Eudonia angustea

True flies:
- 3 midges
- 1 *presumed gall-midge
- 1 *Root-maggot fly from the Anthomyiidae family
- 1 *Muscid fly Phaonia pallida
- 1 winter cranefly Trichocera sp.

Springtails:
none

Beetles:
- 1 presumed Cabbage-stem Flea Beetle Psylliodes chrysocephala

Spiders, harvestmen etc.:
- 1 *crab spider Xysticus cristatus
- 1 other spider, unidentified

Fungus
- unidentified fungus!

The best I could do with a sunrise worth staying in bed for.

With undercarriage down the to Mute Swans arrive....

...and then leave.

This moth is a Narrow-winged Grey Eudonia angustea. The easiest species to identify in a confusing group not least because it is the only one still likely to be flying at this date. It is my 73rd moth species at the lake this year.

The best I can do with this is to identify it as one of the many Root-maggot flies from the Anthomyiidae family.

Another red-bodied fly, more robust than the recent Dryomyza anilis and seems to be the Muscid fly Phaonia pallida.

This looks interesting: a small fly with long antennae from a well-separated and rounded head and relatively broad wings. Only Google Lens helped with one of the photos it showed rather than the suggestion. It looks to be a gall midge. NatureSpot has several pages of these but only shows the galls that have been made and not the midge responsible. So I am none the wiser.

This is the crab spider Xysticus cristatus. As with most species of spider the markings on the abdomen are very variable but this species can be separated from similar crab spiders by the two lines on the cephalothorax.

I cannot begin to get an identity for this group of fungus. They were behind a large bramble clump so I could not access to do any "gardening" and get a better close-up view.

(Ed Wilson)

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In the Priorslee Avenue tunnel:

Moths:
none

True flies:
- 10 midges of at least three species
- 3 *moth fly Psychodidae sp. [Drain Fly or Owl Fly]
- 2 *winter cranefly Trichocera sp.

Arthropods:
- 2 White-legged Snake Millipede Tachypodoiulus niger
- 6 Common Rough Woodlouse Porcellio scaber

Spiders, harvestmen etc.:
- 1 Long-jawed Orb-web Spider Tetragnatha sp.
- 13 Missing Sector Orb-web Spider Zygiella x-notata [Silver-sided Sector Spider]

A more-or-less normal moth fly Psychodidae sp., at least in shape. Somewhat unusual in that it was on the ceiling and not the easily accessible wall.

I now believe these small, plain-looking craneflies are winter cranefly from the genus Trichocera. There are several species not separable from photos.

(Ed Wilson)

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The Flash: 09:15 – 10:40

(214th visit of the year)

Bird notes:
- a most unusual sight (sound?) was a party of 18 Canada Geese flying in without making any noise! A few minutes later another trio arrived similarly silently.
- an additional two (pair?) of Mute Swans were present (perhaps the birds seen earlier at the lake). The "resident-in-charge" was giving chase to little avail.
- no Tufted Duck seen.
- 42 brownhead Goosander were on the open water; another three were inside the island; and then a group of nine flew in, heading directly to haul out on the island.
- the daily change for the Great Crested Grebes: one full adult was with the four dependent juveniles with another adult noted catching (and eating!) fish.
- *another unusual site was a flock(?) of seven Grey Herons arriving from the South and circling around. The island prevented me seeing what happened next but at least two spent some while perched on trees. The resident(?) bird sounded none too happy about the visitors.
- the two Little Egrets remain.

Bird(s) noted flying over here:
- 4 Jackdaws

Noted on / around the water:
- 27 Canada Geese; of these 21 arrived in two groups
- 8 *Mute Swans
- 43 (24♂) Mallard
- no Tufted Duck
- 54 (0♂) Goosander: see notes
- 7 Moorhens
- 18 Coot again
- 2 + 4 (1 brood) Great Crested Grebe
- 26 *Black-headed Gulls
- 3 *Cormorants yet again
- 8 *Grey Herons: see notes
- 2 Little Egrets still

Warblers noted:
- 4 Chiffchaffs: one of these in song

Noted around the area:
No sun.

Bees, wasps etc.:
- >10 Common Wasp Vespula vulgaris

Hoverflies:
- 1 *possible $ Rural Roundface Eumerus strigatus
- 1 Tapered Dronefly Eristalis pertinax
- 1 *Humming Syrphus Syrphus ribesii [Common Flower Fly]
- 1 *Wasp Plumehorn Volucella inanis [Lesser Hornet Hoverfly]

Four-winged flies:
- 1 *unidentified caddis fly

Other true flies:
- 1 *Muscid fly, perhaps Helina evecta
- 1 *Muscid fly from the Phaonia genus
- several other flies not identified

Beetles:
- 1 7 Spot Ladybird Coccinella 7-punctata

What might, or might not, be the two Mute Swans that briefly visited the Balancing Lake.

Sitting well for the camera a first-winter Black-headed Gull.

Another taking a drink. Pigeons are the only birds that can suck liquids, all other birds have to dip their bills and then use their tongue to transfer the water and swallow it.

Not something you see every day: a flight of seven Grey Herons.

Two come close.

And one even closer!

The resident Grey Heron looks on in disdain.

Visitors top left and bottom right with three Cormorants sharing the trees on the island.

I recently mentioned that most caddis fly species are all-brown. Here is an example that was at least twenty feet up a street lamp pole in squirrel alley. Such unmarked species are best identified by the arrangement of spurs on each pair of legs. I think I will have to pass!

Definite "find of the day" even if I cannot provide a positive identity. It is a hoverfly from the genus Eumerus which Steven Falk calls Roundfaces. It is a new genus for me. There are seven very similar species known from the UK. Reading his text for all seven this date suggests it is most likely Rural Roundface E. strigatus which is also one of the species with a swollen hind femur.

Another female Humming Syrphus Syrphus ribesii showing her yellow hind femur to allow specific identity.

I am 99% certain this is a female Wasp Plumehorn Volucella inanis (or Lesser Hornet Hoverfly) despite Obsidentify assuring me it is a Hornet Hoverfly V. zonaria. I think Obsidentify was confused as the folded wings provide an orange cast on the abdomen. Hornet Plumehorn has the upper band orange and the others yellow. Here they are all yellow. Also the mark at the back of the thorax is prominent, as here, on Wasp Plumehorn.

She was sitting in full sun on a street lamp pole. Here is a "down" view illustrating how hairy the upper-body is.

This Muscid fly is perhaps Helina evecta known for sunning itself on leaves (and apparently street lamp poles) in Autumn. There are of course similar species.

This fly is also from the Muscid family and appears to be a member of the Phaonia genus. Many of these too are very similar and difficult to specifically identify.

(Ed Wilson)

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2013
Priorslee Lake
2 Whinchat
3 Snipe
1 Wigeon
(John Isherwood)

2011
Priorslee Lake
Common Sandpiper
(Ed Wilson)

2008
Priorslee Lake
Water Rail
(Ed Wilson)

2007
Priorslee Lake
Ruddy Duck
Kingfisher
696 Swallows, House Martins and Sand Martin
55 Meadow Pipit
(Ed Wilson)