26 Sep 25

Priorslee Balancing Lake and The Flash

6.0°C > 12.0°C: Clear skies which was a surprise as many local areas were foggy and the lake area is often the worst. Almost calm. Good visibility.

Sunrise: 07:03 BST

* = a species photographed today
$ = my first sighting of the species for this year
$$ = my first ever recorded sighting of the species in the area

Priorslee Balancing Lake: 05:35 – 09:20

(234th visit of the year)

Update
Firstly an update from Wednesday courtesy of eagle-eyed Tom Lowe – to whom many thanks. My photo of what I noted as 27 departing ducks that I surmised were all Eurasian Wigeon has been re-identified as showing 15 Eurasian Wigeon and 14 Common Teal – the smaller birds on the right that I assumed were just further away. Tom points out that these smaller birds are "beakier". So there were 29 birds – seems I cannot count as well as identify ducks! Oops.

Today's bird notes:
- a duck Common Teal was with a small group of Tufted Duck. Most of the Tufted Duck departed.
- some Moorhens have taken to feeding on the dam-top and are therefore more are visible. I doubt the higher number being logged indicates any arrivals.
- another large arrival of gulls with the numbers in the log almost certainly underestimated. The Black-headed Gulls were difficult to see through light mist on the lake. Big numbers of large gulls came in from both the South and, slightly later, the East. This is different from recent years when early arrivals were from the north-west: I was told that birds were roosting on the roofs of the industrial units in Hortonwood (they may of course switch to doing so when the weather becomes colder). Large and small gulls were flying around all the while and both were often on the south-west grass. Later arrivals may well have been returning birds though a few Herring Gulls appeared only at this time which suggests some of them were new birds.
- a very poor showing of passing Jackdaws and Rooks. It is just possible that on this clear and bright morning many passed before I was in position. However I would have expected to have at least heard some of the usually noisy Jackdaws. Their roost site was possibly fogged in and their passage either delayed or re-routed to avoid the fog.
- what I assume was the same Cetti's Warbler that was singing from lake-side vegetation around dawn was heard persistently calling alongside the West end public footpath c.09:00. Could I see it? Nope!
- many of the Chiffchaffs seemed to have departed. Two of those noted singing were doing so from locations where I have not noted the species recently.

Bird(s) noted flying over here:
- 1 Stock Dove
- 17 Wood Pigeons
- no gulls confirmed as passing over
- 12 Jackdaws
- 37 Rooks
- 2 Pied Wagtails

Counts from the lake area:
- 2 Mute Swans
- 16 (9♂) Mallard
- *1 (0♂) Common Teal
- *9 (4?♂) Tufted Duck
- 17 Moorhens
- 46 Coots
- 4 Great Crested Grebes
- *>250 Black-headed Gulls
- 8 Herring Gulls
- *>300 Lesser Black-backed Gulls
- 2 Cormorants: arrived separately
- 1 Grey Heron

Hirundines etc. noted:

None

Warblers recorded (the figure in brackets is birds noted singing):
- 1 (1) Cetti's Warbler
- *5 (3) Chiffchaffs

Noted on the West end street lamp poles pre-dawn:

Moths:
- none

Springtails:
- 1 springtail Pogonognathellus longicornis

Four-winged flies:
- 1 Common Green Lacewing Chrysoperia carnea

Other flies:
- *2 plumed midges Chironomus plumosus
- 6 Spotted-winged Drosophila Drosophila suzukii

Spiders, harvestmen etc.:
- *1 Stout Sac Spider Clubiona sp.
- 1 Noble or False Widow Spider Steatoda nobilis
- *1 unidentified spider
- 1 female harvestman Leiobunum blackwalli
- *2 harvestmen Paroligolophus agrestis

Noted on the walls of the sailing club HQ pre-dawn:

Spiders, harvestmen etc.:
- 24 spiders: usual suspects

Noted later elsewhere:

Bees, wasps, etc.:
- European Hornet Vespa crabro: at least 5 around the nest site

Flies:
- *1 cranefly Tipula confusa
- a very few other unidentified flies

Spiders, harvestmen etc.:
- *1 harvestman Dicranopalpus ramosus/caudatus

This sunrise through distant mist with many gulls flying in the foreground.

From the left a duck Tufted Duck; a duck Common Teal (smaller with a very different bill shape); and a drake Tufted Duck. It is not common to see dabbling ducks (as the Teal is) in the company of diving ducks.

Another view with the Teal with two duck Tufted Ducks. Note the white flash down the side of the Teal's tail, only visible after I edited this in-to-the-light photo.

Around 07:00 there was already a mix of gull species on the south-west grass. Mostly Black-headed Gulls with at least 13 Lesser Black-backs. Just four Coots (and a Moorhen). Normally I would expect up to 100 Coots on the grass but not this year. Are the gulls there because the Coots aren't? Or are the Coots not there because of all the gulls?

An unprecedented number of gulls on the south-west grass.

Here leaving the south-west grass!

A Chiffchaff peering at me through vegetation. A few birds may hang around for two to three weeks yet after which any that overwinter will stop calling and be hard to locate.

"Look out!". A plumed midge Chironomus plumosus is being threatened by a harvestman Paroligolophus agrestis. A harvestman with all eight legs!

 Resting on the Teece Drive fence a cranefly Tipula confusa.

It must be "that time of the year". My first Stout Sac Spiders Clubiona sp. for a while were noted yesterday and here is another. Two eyes are showing eyeshine from the camera flash. I guess that means that the spiders eight eyes are typically not pointing in the same direction.

I can't get an identity I am happy with for this small spider. Obsidentify suggested a crayfish! Google Lens gave a slightly more believable suggestion of Missing Sector Orb-web Spider Zygiella x-notata which I dismissed as the light and dark areas are almost the obverse of the photos on the internet.

Spiders are capability of tackling prey larger than they area. I am not sure what the Walnut Orb Weaver spider Nuctenea umbratica has ensnared.

Also resting on the Teece Drive fence was this harvestman Dicranopalpus ramosus/caudatus. Two harvestmen with all eight legs on the same day!

I wonder what this was before it met its end? Looks beetle-like. I also looked at an inverted image: it did not help.

(Ed Wilson)

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In the Priorslee Avenue tunnel:

Another morning with few spiders

Moths: [46 species here before today; no addition]
- none

Flies:
- 1 moth fly Psychodidae sp. [Drain Fly or Owl Fly]
- 49 midges of various species

Arthropods:
- 10 White-legged Snake Millipedes Tachypodoiulus niger

Spiders, harvestmen etc.:
- 3 spiders only

(Ed Wilson)

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The Flash: 09:25 – 10:20

(225th visit of the year)

Bird notes:
- ten Mute Swans again/still.
- I was not able to sex the Tufted Ducks or age the Great Crested Grebes as many of them were silhouettes against the bright sun (shouldn't complain!).
- two Skylarks passing overhead were my first of the year here – I did not note any on Spring passage this year. Bird species #75 for me here in 2025.
- a Grey Wagtail again flying around.

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

Noted on / around the water:
- 7 Canada Geese: of these two arrived together
- 6 Greylag Geese: more inside the island?
- 10 Mute Swans
- 31 (18♂) Mallard
- 15 (?♂) Tufted Duck
- 13 Moorhens once again
- 93 Coots
- 6 Great Crested Grebes: see notes
- 6 Black-headed Gulls
- 8 Cormorants
- 2 Grey Herons

Warblers recorded (the figure in brackets is birds noted singing):
- 1 (1) Chiffchaff

Noted around the area:

Moths:
- none: the Brindled Green Dryobotodes eremita has gone

Bees, wasps etc.
- Common Wasp Paravespula vulgaris: just the one

Flies:
- *$ caddisfly Stenophylax permistus

I think this caddisfly is, as suggested by Obsidentify, Stenophylax permistus. I was very slightly concerned by the white marks in the wing. I think these are just "wear and tear" visible as the sunlight streams behind the insect. This species is known to be attracted to lights and here it is at the top of a street lamp pole.

(Ed Wilson)

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2011
Priorslee Lake
115 Greylag Geese
420+ Canada Geese
Shoveler
Common Sandpiper
Kingfisher
3 Blackcaps
12 Chiffchaffs
(Ed Wilson)