5 Aug 22

Priorslee Lake and The Flash

11.0°C > 15.0°C: A few clouds from late overnight showers moved away to leave an almost cloudless morning until c.08:45 when cloud started to form again. Moderate W wind and feeling brisk. Excellent visibility.

Sunrise: 05:35 BST

* = a photo from today

Priorslee Lake: 04:50 – 06:00 // 07:05 – 09:15

(166th visit of the year)

Bird notes:
- No idea why some of the adult Great Crested Grebes were 'missing'. All four nest locations were active.
- There were no Black-headed Gulls on the football field at 05:50.
- A female Sparrowhawk flew low across the West end of the lake and in to the trees. None of the birds in the area seemed to notice.
- A Cetti's Warbler was again calling continually at the West end, but only before 06:00. Again I did not see it but I was close-enough to be sure that only one bird was calling.
- This was my first early morning visit this year when I did not hear a Song Thrush in song.

Birds noted flying over here:
- 24 Canada Geese: 20 outbound in four groups; four inbound as two duos
- 4 Greylag Geese: duo outbound; duo inbound
- 49 Wood Pigeons
- 9 Black-headed Gulls
- 9 Lesser Black-backed Gulls
- 88 Jackdaws
- 4 Rooks

Hirundines etc. noted:
None

Warblers noted (figures in brackets relate to singing birds):
- 1 (0) Cetti's Warbler
- 8 (0) Chiffchaffs
- 6 (0) Reed Warblers
- *6 (0) Blackcaps

Counts from the lake area:
- 8 Canada Geese: two arrived and were shortly followed by a group of six
- 2 + 4 (1 brood) Mute Swans
- 20 (?♂) Mallard for a change
- 4 adult / juvenile Moorhens
- 73 adult / juvenile Coots
- 1 Little Grebe
- 6 + 3 (two broods) Great Crested Grebes
- c.60 Black-headed Gulls
- 3 Lesser Black-backed Gulls: adults, all briefly
- 1 Grey Heron
- 1 Kingfisher

Noted on / around the street lamp poles pre-dawn:

Moths:
None

but:
- *1 green sawfly sp.
- *1 Tephritid fly probably Anomoia purmunda
- *1 caddis fly sp.
- *1 Dicranopalpus ramosus/caudatus harvestman
- 1 Leiobunum rotundum harvestman
- *1 Paroligolophus agrestis harvestman

Noted later:

New for this year
In a continuing dearth of insects:

- *Hornet Hoverfly (Volucella zonaria) [aka Hornet Plumehorn]

Repeat sightings:

Butterflies:
- Speckled Wood (Pararge aegeria)
- Gatekeeper (Pyronia tithonus)

Moths:
- Satin Grass-veneer (Crambus perlella)
- Common Grass-veneer (Agriphila tristella)

Bees, wasps etc.:
- Honey Bee (Apis mellifera)
- Common Carder Bee (Bombus pascuorum)
- Buff-tailed Bumblebee (Bombus terrestris)

Hoverflies:
- Tapered Dronefly (Eristalis pertinax)
- *Common Dronefly (Eristalis tenax)
- *Dead-head Hoverfly (Myathropa florea) [aka Batman Hoverfly]

Dragon/Damselflies
- Common Blue Damselfly (Enallagma cyathigerum)
- Brown Hawker (Aeshna grandis)

Other 'flies':
- Greenbottle Lucilia sp.
- *Yellow Dung Fly (Scathophaga stercoraria)

Beetles:
- *pollen beetle sp.

A female Blackcap peering at me. Juveniles of both sexes also sport brown caps. I would expect a juvenile to look rather 'fuzzy' due to its new feathers and would expect its wing-feathers to be more strongly pale-edged.

A rather different sawfly that I found resting on one of the street lamp poles. I cannot recall seeing a green-bodied species before. This is a female with a relatively long ovipositor. It was waving its antennae but it is just possible to see they are banded.

A different view of the same insect.

A Common Dronefly (Eristalis tenax) confirmed by the extensive pale yellow on the legs.

I have not seen very many of these Dead-head Hoverflies (Myathropa florea) this year. Here is one feeding on the tight, rounded umbels of Wild Angelica (Angelica sylvestris). Stephen Falk calls this species Batman Hoverfly. Neither name seems apposite to me.

This nearly confused me in to thinking I was looking at a real hornet. It is a Hornet Hoverfly (Volucella zonaria), called by Stephen Falk a Hornet Plumehorn
.
 Certainly the 'insect of the day' and my first this year.

Here its tongue is sticking in to a Common Knapweed flower (Centaurea nigra). I don't think my camera has enough resolution to show the 'plumehorn' - the antennae are slightly plumed.

One more look at this splendid creature.

A Yellow Dung Fly (Scathophaga stercoraria) accompanies a number of pollen beetles on a flowering Common Hogweed (Heracleum sphondylium). [As an aside the Giant Hogweed (Heracleum mantegazzianum) that had been missed when most of the plants were destroyed now seems to have been dealt with.]

I have mixed feelings about this fly. It does a useful if somewhat nasty job. It is rather attractive in its own way.

Another insect on one of the street lamp poles was this Tephritid fly. probably Anomoia purmunda. The eakringbirds website warns against total reliance on wing marking to identify individuals in this group of flies.

I found this caddis fly also resting on one of the street lamp poles. There is very little to aid identification here. As previously noted it is the number and arrangement of the spurs on each pair of legs that is the primary identification feature. They are not all clearly visible here but anyway I do not have the key to decode them.

The action part of a Dicranopalpus ramosus/caudatus harvestman. The very long palps are unique to this species pair.

This is the last of the common species of harvestmen I have recorded this year. The relatively short legs, especially pairs one and three, help identify it as a Paroligolophus agrestis harvestman.

Aircraft of the day. This is a rather elderly (nearly 23 years old) long range version of a Boeing 777 200 series of United Airlines. It is on the descent in to London's Heathrow Airport after a flight from the International Airport at Houston in Texas. I can tell from the colour on the tail-fin that United thought it worthwhile repainting it in to their latest livery using a different shade of blue. They have eschewed the current fashion for Billboard airline tiles under the fuselage or wrapping the tail colour around the rear fuselage. The scheme looks better on the ground than it does in the air.

(Ed Wilson)

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The Flash: 06:95 – 07:00

(162nd visit of the year)

Bird notes:
- I did not see the duck Mallard with any ducklings today.
- An unknown number of juvenile Coots from a very recent brood was heard begging from behind vegetation and could not be included in my count.
- The Little Grebe was in with one group of Tufted Duck. I did wonder whether it had been here since I last saw one on 12 July but I had overlooked it. I suspect not as a very poor photo I managed suggests it is a juvenile whereas my previous record was of a breeding plumaged adult.
- A Cormorant looked to be flying in but disappeared in to shaded area and I am not 100% sure it did not fly on.
- *A Stock Dove was, most unusually, calling while sitting on a roof in Westcroft Walk. This species normally only sings from the cover of wooded areas.

Birds noted flying over here:
- 8 Jackdaws

Hirundines etc. noted:
None

Warblers noted (figures in brackets relate to singing birds):
- 2 (0) Chiffchaffs

Noted on / around the water:
- 28 Canada Geese
- 5 Greylag Geese arrived together
- 6 + 4 (1 brood) Mute Swans
- 32 (?♂) Mallard
- 1 all-white duck (Aylesbury Duck)
- 34 (?♂) Tufted Duck
- 10 adult / juvenile Moorhens
- >33 adult / juvenile Coots
- 1 Little Grebe
- 2 + 4 (1 brood) Great Crested Grebes
- 9 Black-headed Gulls
- 1 Lesser Black-backed Gull: adult, briefly
- 1 Cormorant: arrived: see notes

Noted on / around the street lamp poles:
- 1 Swallow Prominent moth (Pheosia tremula)
- 1 Dicranopalpus ramosus/caudatus harvestman

This Stock Dove was in very difficult lighting conditions, most unusually sitting on the roof of the houses in Westcroft Walk. The lack of white both on the neck and at the bend of the wing means that it cannot be a Wood Pigeon. There are really no features visible here to separate it from one of the many Feral Pigeons in the area. Luckily it was calling and this is distinctive.

I did promise to revisit the flowering Purple Loosestrife (Lythrum salicaria). I am not sure this is much better, this patch hanging precipitously over the water and still in shade at the time I was visiting.

(Ed Wilson)

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Between the lake and The Flash:

- Moorhen(s) heard at the upper pool only again.
- A Chiffchaff was calling beside the lower pool.

and
- A Dicranopalpus ramosus/caudatus harvestman was on one of the street lamp poles

(Ed Wilson)

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In the Priorslee Avenue tunnel:

- *7 owl midges Psychodidae sp
- 5 White-legged Snake Millipedes (Tachypodoiulus niger)

One of the, at least, seven owl midges Psychodidae sp. on one wall of the tunnel. I have no idea about the origin of the crimson marks.

(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

2012
Priorslee Lake
Common Sandpiper
(Ed Wilson)

2010
Priorslee Lake
A female Teal
(John Isherwood)

2009
Priorslee Lake
30 House Martins
(Ed Wilson)

2008
Priorslee Lake
Little Grebe
Common Sandpiper
(Ed Wilson)