10 May 26

Priorslee Balancing Lake and The Flash

7.0°C > 10.0°C: Early low cloud lifted and broke to give a few sunny intervals. Chilly, moderate north-easterly wind, ameliorated somewhat. Very good visibility.

Sunrise: 05:22 BST

* = a species photographed today
$ = a new species for me in this area

Priorslee Balancing Lake: 05:20 – 06:35 // 07:25 – 09:45

(112th visit of the year)

Bird notes:
- all seven Greylag Geese goslings present and correct.
- drake Gadwall seen first thing only.
- no Mallard ducklings seen.
- just three Tufted Duck, all drakes, noted.
- no visiting gulls albeit two of the ten over-flying Lesser Black-backed Gulls had a serious look at the football field before moving on.
- a Grey Heron by the dam-face early only.
- more changes in the warblers:
just eight singing Reed Warblers. Perhaps too breezy to hear all of them.
no Garden Warbler heard.
a Lesser Whitethroat was singing from scrub behind the sailing club containers at c.05:35 only. Whether this was a late arrival still looking for a territory or one of the previous songsters re-establishing its territory between broods is hard to say, though it would seem rather quick to have raised a brood already
*just the one Common Whitethroat: only singing while I was on my second lap.
- after several days with no Reed Buntings seen or heard along the South side one was heard sporadically singing along the North side.

Also of note is that there seem to be two pairs of Moorhens on the lower pool between the lake and The Flash, one pair with at least two juveniles. This is in addition to a pair (at least) on the upper pool – this is very overgrown and birds can usually only be seen when out on the grass. I cannot recall noting more than one pair in either pool previously.

Bird(s) noted flying over here:
- 1 Canada Goose: a single flew East.
- 3 Greylag Geese: a pair and a single flew West.
- 10 Lesser Black-backed Gulls
- 3 Wood Pigeons only

Counts from the lake area:
- 2 Canada Geese: a pair arrived and departed
- 2 + 7 (1 brood) Greylag Geese
- 2 Mute Swans
- 1 (1♂) Gadwall: departed?
- 10 (8♂) Mallard
- 3 (3♂) Tufted Duck
- 3 Moorhens
- 19 Coots
- 6 Great Crested Grebes
- 1 Grey Heron

Hirundines etc. noted:
Minimum numbers: I waited to do a full count when I was able to see the whole of the lake area. Before I could get in to position the sun came out and many of them departed.
- 8 Swifts
- 4 Sand Martins
- 10 Barn Swallows
- 2 House Martins

Warblers noted (the number in brackets refers to birds singing):
- 13 (12) Chiffchaffs
- 8 (8) Reed Warblers
- 13 (12) Blackcaps
- 1 (1) Lesser Whitethroat: see notes
- 1 (1) Common Whitethroat
- no Garden Warbler

On the West end street lamp poles post-dawn:
Another blank morning

Noted around the area later:
A cool breeze and little sun to temp much in to view:

Butterflies:
- none

Moths:
- *1 Plain Pollen-moth Micropterix calthella [was Plain Gold]: moth species #19 for me here this year

Bees, wasps etc.:
- *Early Bumblebee Bombus pratorum
- *unidentified ichneumon sp.

Hoverflies:
- *Buttercup Blacklet Cheilosia albitarsus
- also Buttercup Blacklet-type: either Cheilosia albitarsus or C. ranunculi.
- *Common Spotted Field Syrph Eupeodes luniger [Lunuled Aphideater]
- Chequered Hoverfly Melanostoma scalare [Long-winged Duskyface]
- Syrphus sp. S. ribesii / S. vitripennis / S. torvus

Dragon- / damsel-flies:
- *Azure Damselfly Coenagrion puella [Azure Bluet]

Alder and other four-winged flies:
- none

Other true flies:
- *dagger fly Empis tessellata
- *Yellow Dung Fly Scathophaga stercoraria
- *Tachinid fly: "flies in this Tachinid fly genus are difficult to identify" [NatureSpot]
- *other unidentified flies

Bugs:
- *Red-and-Black Froghopper Cercopis vulnerata

Beetles:
- 7 Spot Ladybird Coccinella 7-punctata
- Harlequin Ladybird Harmonia axyridis var. spectabilis
- also var. succinea

Spiders, harvestmen etc.:
- *Nursery Web Spider Pisaura mirabilis

New flowers for this year:
- *Spindle-tree Euonymus europaea

In the distance two Magpies try to move a Common Buzzard out of their territory.

Another trio of photos of the Common Whitethroat.

 Still singing away...

 ...with the wind ruffling his throat feathers.

Feeding in a buttercup flower is a Plain Pollen-moth Micropterix calthella. It has a small matching yellow tuft on its head. It used to be known as Plain Gold which is true only for fresh specimens with the light at the correct angle. It is moth species #19 for me here this year

It seems many days since I saw any bumblebees. This is my first Early Bumblebee Bombus pratorum of the year.

And like buses in London two come along together. This paler one is likely a male: the other probably a worker.

An unidentified ichneumon – as most specimens of this huge family will remain

A Buttercup Blacklet Cheilosia albitarsus with the decency to show it white front leg – the "albitarsus" that separates it from several similar species.

 A Common Spotted Field Syrph Eupeodes luniger (or Lunuled Aphideater)

A Syrphus species from one of S. ribesii / S. vitripennis / S. torvus

My first Azure Damselfly Coenagrion puella of the year. I recognise this species by the U-shaped mark on the top body segment. On Common Blue Damselfly Enallagma cyathigerum the mark is club-shaped. There is also a difference in the width of the pale areas on the thorax but I can never remember which is which. I cannot see any difference in the "blue" between the two species.

The best I could do to get a side-elevation view of the dagger fly Empis tessellata. The long "dagger" mouthpiece is reasonably clearly seen here.

A Yellow Dung Fly Scathophaga stercoraria a day keeps the... away. A male.

As yesterday there were a number of flies that I have not been able to or not had the time to identify. This one is hardly well camouflaged. Likely a Muscid fly.

The wing shape suggests this is a fly from the Muscid family in the genus Phaonia.

I am sure I have seen photos of this grey and hairy fly on the internet but I cannot locate them now. Probably a Tachinid fly.

Another Tachinid fly: "flies in this Tachinid fly genus are difficult to identify" [NatureSpot]

A two-fer. On the right a Greenbottle Lucilia sp. No idea about the other.

Another "greenbottle" but from a different family.

A smart Red-and-Black Froghopper Cercopis vulnerata

Sitting quietly on vegetation waiting for a meal to blunder by is a Nursery Web Spider Pisaura mirabilis, identified by the white line down the cephalothorax.

Another. The head shape is also distinctive.

These are the flowers of a Spindle-tree Euonymus europaea

(Ed Wilson)

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Noted in the Priorslee Avenue tunnel:

Flies:
- 4 midges of at least two species
- *2 craneflies Limonia nubeculosa
- 4 unidentified craneflies

One of two craneflies Limonia nubeculosa: the other four craneflies were not well-marked and remain unidentified.

(Ed Wilson)

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The Flash: 06:40 – 07:20

(109th visit of the year)

Bird notes:
- a pair of the visiting Mute Swans have departed.
- no Tufted Duck again.
- the pair of Coots with three well-grown juveniles seen again.
- only the Great Crested Grebe on the nesting platform seen.

Bird(s) noted flying over here:
- 4 Herring Gulls: all immatures
- 1 Lesser Black-backed Gull: (near?) adult

Noted on / around the water:
- 15 Canada Geese: other(s) heard from inside the island
- 3 Greylag Geese
- *5 Mute Swans: (assuming the resident pen hidden on the nest): see notes
- 22 (17♂) Mallard: almost all these were sitting on roofs
- 3 Moorhens again
- 17 + 3 (1 brood) Coots again
- 1 Great Crested Grebe

Hirundines etc. noted:

None

Warblers noted (the number in brackets refers to birds singing):
- 4 (4) Chiffchaffs
- 5 (4) Blackcaps

Notes around the area:

Moths:
- *1 Chocolate-tip Clostera curtula. moth species #8 here this year. My previous record was 08 May 22.

Flies:
- *1 possible dance fly Rhamphomyia crassirostris
- 1 midge
- *unidentified mayflies?

Spiders, harvestmen etc.:
- *1 Long-jawed Orb-web Spider Tetragnatha sp.

This is the immature Mute Swan, part of the visiting trio. It is still showing some grey feathering. Probably a first year bird.

From this angle this is not obviously a moth! It is a Chocolate-tip Clostera curtula.

It is only slightly better from this angle – the best I could get from its location between foliage in front of a street lamp pole. You can see the chocolate tip to the turned up tail sticking up between wings tightly rolled around the body. The furry front legs stick forward at rest.

This is possibly the dance fly Rhamphomyia crassirostris

Not sure what to make of these. Toward the top of just one of the street lamp poles where the path is adjacent to the water were at least 25 flies looking "splot" against the pole. My suggestion is that they are mayflies. But why so many in one spot is unclear.

A Long-jawed Orb-web Spider Tetragnatha sp.

(Ed Wilson)

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2013
Priorslee Lake
Great White Egret
(Ed Wilson)

2006
Priorslee Lake
2 Ruddy Ducks
(Ed Wilson)