6 Aug 25

Priorslee Balancing Lake and The Flash

10.0°C > 17.0°C: Mostly clear with thin high haze layer. Very light south-westerly wind. Very good visibility.

Sunrise: 05:38 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

For those of you who use the Merlin bird song app I have another cautionary tale. It is not uncommon for it to report "Spotted Flycatcher". Since that species no longer breeds in the area and is even unusual on passage then it has to be something else. But what? I tracked it down this morning to calls made by a Robin, the song and many of which it correctly identifies.

Priorslee Balancing Lake: 05:05 – 06:25 // 07:35 – 09:50

(190th visit of the year)

Bird notes:
- no Canada Geese on the water at dawn. 45 seen flying outbound in three groups. Eight inbound in two groups ahead of 54 flying in.
- the usual single Greylag Goose was again present throughout. A group of seven were also present at dawn, these briefly feeding on the dam-top before flying off East. Later four flew in with Canadas.
- a trio of late Swifts again c.05:50 only.
- a single House Martin was over the football field c.09:40.
- a higher total of Jackdaws and Rooks as they passed over from their roosts.
- a Cetti's Warbler sang once around dawn. No juveniles seen or heard.
- a Common Whitethroat was noted sitting silently on one of its favourite song-perches.
- a lone Starling was on the roof of the academy at 06:00: my first here for several weeks – since the last of the juveniles fledged.

Bird(s) noted flying over here:
- 53 Canada Geese: 45 outbound in three groups; eight inbound in two groups
- 4 Stock Doves: two duos
- 163 Wood Pigeons
- 11 Lesser Black-baked Gulls
- 112 Jackdaws
- 90 Rooks

Counts from the lake area:
- 54 Canada Geese: see notes
- *>8 Greylag Geese: see notes
- 2 Mute Swans
- 41 (♂?) + *2 (1 brood) Mallard
- no Pochard
- 10 + 4 (2 dependent broods) Moorhens
- 90 Coots
- 8 + 5 (3 broods) Great Crested Grebes
- *34 Black-headed Gulls: two juveniles
- 1 Herring Gull
- *5 Lesser Black-baked Gulls
- 1 Grey Heron

Hirundines etc. noted:
- 3 Swifts
- 1 House Martin

Warblers recorded (the figure in brackets is birds noted singing):
- 1 (1) Cetti's Warbler
- 11 (0) Chiffchaffs
- 7 (0) Reed Warblers
- 4 (0) Blackcaps again
- 1 (0) Common Whitethroat

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

Moths
*1 Common Grass-moth Agriphila tristella [previously Common Grass-veneer]

Spiders, harvestmen etc.:
1 Bridge Orb-web Spider Larinioides sclopetarius
3 harvestman Dicranopalpus ramosus/caudatus
1 harvestman Paroligolophus agrestis

Noted later:
A significant drop-off in insects now there are few flowers around. Also my fourth sighting of a European Hornet suggested I should not venture too far "off piste"!

Butterflies:
Large White Pieris brassicae
Speckled Wood Pararge aegeria
Gatekeeper Pyronia tithonus

Moths
*6 Straw Grass-moth Agriphila straminella [previously Straw Grass-veneer]

Bees, wasps etc.:
Red-tailed Bumblebee Bombus lapidarius
*Common Carder Bee Bombus pascuorum
Common Wasp Paravespula vulgaris
European Hornet Vespa crabro

Hoverflies:
*Common Dronefly Eristalis tenax
*Tiger Hoverfly Helophilus pendulus [Tiger Marsh Fly; Sun Fly]
*Common Twist-tail Sphaerophoria scripta [Long Hoverfly; Common Globetail]

Damsel- /Dragon- flies:
*Common Blue Damselfly Enallagma cyathigerum [Common Bluet]
*Blue-tailed Damselfly Ischnura elegans [Common Bluetail]
*$ Migrant Hawker Aeshna mixta

Other flies:
Greenbottle Lucilia caesar or similar
*phantom cranefly Ptychoptera contaminata
*Sarcophaga sp.
otherwise as usual many unidentified fly species

Bugs:
7 Spot Ladybird Coccinella 7-punctata

A hazy sunrise with no cloud to add interest.

A group of seven Greylag Geese were on the dam top around dawn (hence the less than clear photo). I was struck by the white patches shown by some but not others. I am presuming it is to do with the timing of their annual moult. Where not all the feathers have regrown the white bases to the underlying feathers are visible.

I am assuming these are the same two Mallard ducklings that have been around for over a week with never any sign of a parent. They seem to be doing OK. There were as many as 41 other Mallard around today – they were scattered all around the lake in small groups which may well have been family parties. As previously noted very few show any sign of adult drake plumage. It seems we have had bumper success in breeding here this year.

Another dawn dam-top photo, this of a juvenile Black-headed Gull (with two Carrion Crows). The darkest of the immediate post-fledging plumage has already begin to tone down.

Also on the dam-top around the same time was this second year Lesser Black-backed Gull showing an unusually white and unmarked head. An adult Black-headed Gull moulting out of breeding plumage is in the foreground.

 A Common Grass-moth Agriphila tristella on a street lamp pole before dawn

A very pale Straw Grass-moth Agriphila straminella. I am not sure whether it is just "worn" or whether it has a pigment deficiency.

A Common Carder Bee Bombus pascuorum on one of the few Common Knapweeds Centaurea nigra still with a few flowers that were in the sun with nectar flowing.

And another.

I noted very few hoverflies around. One Common Dronefly Eristalis tenax.

Just one Tiger Hoverfly Helophilus pendulus.

And a single Common Twist-tail Sphaerophoria scripta.

A male Common Blue Damselfly Enallagma cyathigerum.

And a male Blue-tailed Damselfly Ischnura elegans.

Full marks if you can identify this. I knew it was the head and legs of a hawker dragonfly but I was not going to identify it from this view through a tiny gap in the foliage.

I managed to change position slightly without flushing the insect.

I moved slightly further, and here it is looking at me. Because there are blue dots at the bottom of every abdominal segment it has to be a Migrant Hawker Aeshna mixta.

And away it goes.

The phantom cranefly Ptychoptera contaminata.

I am not sure whether this fly Sarcophaga sp. is resting or drowning in the flowers on a spike of a Butterfly-bush Buddleja davidii

If I get time I might further investigate this fly with wing markings. It was on a street lamp pole before dawn and I was unable to reach higher to obtain a shot without a confusing shadow.

(Ed Wilson)

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In the Priorslee Avenue tunnel:

Moths: [37 species here before today; no additions]
*1 Single-dotted Wave Idaea dimidiata

Flies:
7 moth flies Psychodidae sp. [Drain Fly or Owl Fly]
13 midges of various species.

Arthropods:
no White-legged Snake Millipede Tachypodoiulus niger

Spiders, harvestmen etc.:
2 Missing Sector Orb-web Spiders Zygiella x-notata [Silver-sided Sector Spider]

Yet another Single-dotted Wave moth Idaea dimidiata here.

(Ed Wilson)

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The Flash: 06:30 – 07:30

(187th visit of the year)

As I arrived there was a commotion going on with the gulls all leaving, Jackdaws calling as they passed overhead, more that 30 Wood Pigeons flying in all directions and the local Carrion Crows sounding very upset. I could not locate the source of their concern.

Bird notes:
- very few Mallard seen and no ducklings noted.
- a family party of Goldfinches seen: the juveniles without the red faces.

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

Noted on / around the water:
- 12 Canada Geese
- 2 Greylag Geese
- 8 Mute Swans
- 12 (?♂) Mallard only
- 14 (?♂) Tufted Duck
- 4 Moorhens again
- 88 + 2 (1 dependent brood) Coots:
- 4 + 5 (2 broods) Great Crested Grebes
- 6 Black-headed Gulls: departed
- 1 Lesser Black-backed Gull: departed
- 1 Grey Heron

Hirundines etc. noted:

None

Warblers recorded (the figure in brackets is birds noted singing):
- 5 (0) Chiffchaffs
- no Blackcaps

Noted around the area:

Moths:
*1 Ermine sp., probably one of Yponomeuta padella / malinellus / cagnagella [Orchard / Apple / Spindle Ermine]

Spiders, harvestmen etc.:
21 (!!) harvestmen Dicranopalpus ramosus/caudatus
*1 harvestman Leiobunum rotundum
*1 harvestman Opilio canestrinii

There are three species of Ermine moth that are almost impossible to separate from photos, especially when the moth is less than pristine as is this one. So Ermine sp., probably one of Yponomeuta padella / malinellus / cagnagella [Orchard / Apple / Spindle Ermine] it will stay.

A harvestman with seven legs: a Leiobunum rotundum. It seems that harvestmen easily lose legs, often deliberately so to avoid predators. Although some spider species can regrow lost legs harvestmen cannot.

Positioned well against the dark background of a handrail on one of the footbridges is a harvestman Opilio canestrinii, also with only seven legs.

(Ed Wilson)

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2012
Priorslee Lake
Green Sandpiper
(Ed Wilson)

2011
Nedge Hill
1 (imm/fem) Common Redstart
(John Isherwood)

2009
Priorslee Lake
Dunlin
(Ed Wilson)

2006
Priorslee Lake
2 Common Tern
(Merv)