17 Apr 24

Priorslee Balancing Lake and The Flash

4.0°C > 7.0°C: Broken cloud. A few sunny spells. A heavy shower c.06:30. A light hail shower c.09:00. Moderate to fresh north-westerly breeze. Very good visibility.

Sunrise: 06:07 BST

* = a species photographed today

Fewer Willow Warblers at the Balancing Lake: still plenty around The Flash.

Priorslee Balancing Lake: 05:35 – 06:15 // 07:20 – 09:50

(82nd visit of the year)

Best bird today was a *male White Wagtail seen on the south-west grass. Depending upon your taxonomic preference this is either a full species Montacilla alba separate from Pied Wagtail M. yarrellii: or they are subspecies of M. alba, respectively M. alba alba and M. alba yarrellii. Confused? Good. The folk in charge of the official British bird list, the British Trust for Ornithology (BTO), treat them as one species so I cannot count this as another species for my year list. White Wagtails breed on the Continent and are migratory though the UK is Spring and Autumn though in Autumn when they are out of breeding plumage they are more difficult to separate from Pied Wagtails. The latter are mainly sedentary and breed only in the UK.

Other bird notes:
- the sitting Canada Goose came off the nest and then the two birds went to the nest together before separating again. Whether this was a swap of the brooding bird (which I have not noted before) or whether the female(?) was taking the male(?) to view newly-hatched goslings is unclear. I know geese have goslings elsewhere in the vicinity.
- a drake Gadwall (the one seen at The Flash?) arrived with a drake Mallard c.09:00. It left a few minutes later.
- a Mistle Thrush was in full voice from the Ricoh copse, opposite the houses along Teece Drive. This is the first time for some weeks I have heard it here. It is possible a first brood has fledged and it is re-establishing its pair-bond and territory. No juveniles seen though.

Counts of birds noted flying over:
- 2 Canada Geese: a pair flew North
- 8 Wood Pigeons
- 1 Lesser Black-backed Gull
- 1 Starling

Hirundines etc. noted:
- *3 Barn Swallows

Warblers noted (the figure in brackets relates to birds heard singing):
- 1 (1) Cetti's Warbler
- 7 (7) Willow Warblers
- 15 (15) Chiffchaffs
- 17 (12) Blackcaps
- *1 (1) Common Whitethroat

Counts from the lake area:
- 4 Canada Geese: a pair throughout: *another pair visited and were chased away by the cob Mute Swan
- 2 Mute Swans
- 1 (1♂) Gadwall: arrived with...
- 1 (1♂) Mallard
- 10 (5♂) Tufted Duck
- 3 Moorhens
- 23 Coots
- 6 Great Crested Grebes
- *1 Common Sandpiper
- 1 Grey Heron: arrived

Noted on the street lamps poles pre-dawn:

A rain shower sent most things to shelter (except me)

Flies:
- *1 male plumed midge Chironomus plumosus

Beetles:
- 1 Alder Leaf Beetle Agelastica alni

Spiders:
- *1 possible Zygiella Orb-web spider

Noted later:

Bees wasps etc.:
- *Chocolate Mining Bee Andrena scotica

Hoverflies:
- Chequered Hoverfly Melanostoma scalare

Flies:
- Alder Fly Sialis lutaria
- many other miscellaneous species wherever there was sun and shelter from the wind.

Beetles:
- Alder Leaf Beetle Agelastica alni

Spider:
- *probable Four-spotted Orb Weaver Araneus quadratus

 Another depressing dawn with a shower-cloud heading in from the North.

The visiting Canada Geese decide discretion is the better part of valour and decline to take on the cob Mute Swan.

I have yet to get close to any of the Common Sandpipers this Spring. This is the best I could do this morning.

This morning's Cormorant arriving. An immature with a pale belly. Judging by the extent of the pale it is likely a first year bird. I have never previously noted a paler neck ring on any Cormorant. A trick of the light?

 Rather unusual. After flying around for a while this Barn Swallow rested in a tree – a distant tree...

...where it was joined by a second.

 I am sure I will do better! A typical pose as a male Common Whitethroat dives for cover.

And here singing from a song-perch.

This is a view of typical male with a grey head contrasting with the rufous back. I am still puzzled as to why the bird I photographed on Sunday looked so washed-out.

As highlighted this is a White Wagtail. The black head and breast confirm it is a male. On 'our' Pied Wagtails the back would also be black: here it is dark grey. The flanks are also paler on White Wagtail though this can be hard to judge. Separation of females is more tricky and can only reliably be done by the colour of the rump – black on both sexes of Pied Wagtail and grey on both sexes of White Wagtail. At rest the folded wings hide this diagnostic feature.

A cool temperature and brisk wind meant there were very few insects about even when the sun popped out. They were mostly flies of various unidentified species. This Chocolate Mining Bee Andrena scotica put in a brief appearance.

A male plumed midge Chironomus plumosus looking slightly different with the antennae looking more feather-like than the usual plumes.

I found this attractive small spider on a vertical support of the 'boxing ring'. You would think identification would be easy. It is not. My best suggestion is Four-spotted Orb Weaver Araneus quadratus, a very variable species (as are many spiders) that usually shows markings, frequently bold, on its abdomen. Not here.

A spider on a street lamp pole for which I have been unable to get a positive identity. Obsidentify suggested Missing Sector Orb-web Spider (or Silver-sided Sector Spider) Zygiella x-notata. I am not convinced but cannot offer a better alternative.

Planes of the day: top left is a Qatar Airways Boeing 777-300 series en route from New York's JFK Airport to Doha. Bottom right is another Boeing 777-300 series, this one of Air France en route from San Francisco to Paris' Charles de Gaulle Airport.

Here is the FlightRadar24 (FR24) data for the 11-plus hour Qatar flight. Note it is at 33,000 feet – flights flying 'South' cruise at odd-numbered levels.

And the FR24 data for the nine and half hour Air France flight. It is at 37,000 feet. Higher flight levels are more fuel-efficient. This aircraft is nearer its destination so it has burned through more of its fuel load. It is thus able to fly at a high altitude. Note that the lower-flying Qatar aircraft is leaving a more obvious contrail (or vapour trail). The level at which aircraft leave contrails depends purely upon atmospheric conditions just as some days you can see your own breath. It has nothing to do with the amount of fuel being burned or the composition of the exhaust gasses. It is purely condensing water vapour that is always emitted.

(Ed Wilson)

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In the Priorslee Avenue tunnel:

Arthropods:
- 1 White-legged Snake Millipede Tachypodoiulus niger

(Ed Wilson)

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The Flash: 06:20 – 07:15

(85th visit of the year)

Bird notes:
- a drake Gadwall again but see notes from the Balancing Lake.
- a Great Crested Grebe was seen at the bottom end as I arrived, where I typically see one. Later two were together at the top end and I initially they were different bird. However I then saw these two paddling fast toward the island so I am less sure they were both different birds.
- it is an unusually late date for me to record a fly-over Siskin. This species has been extending its breeding range outside its traditional conifer plantations so perhaps some are breeding more locally these days.

Bird(s) noted flying over here:
- 1 Siskin

Warblers noted (the figure in brackets relates to birds heard singing):
- 16 (16) Willow Warblers
- 7 (5) Chiffchaffs
- 8 (7) Blackcaps

Noted on / around the water:
- 21 Canada Geese: of these a pair flew off
- 7 Greylag Geese
- 2 + 4 Mute Swans
- 1 (1♂) Gadwall
- 13 (12♂) Mallard
- 24 (16♂) Tufted Duck
- 2 Moorhens
- 19 Coots
- 2 or 3 Great Crested Grebes: see notes
- *2 Herring Gulls: adults, arrived together

Noted elsewhere:

Flies:
- *1 probable Hybos dance fly

Beetles:
- 1 Alder Leaf Beetle Agelastica alni on a street lamp pole

The two adult Herring Gulls that dropped in.

A distinctively-shaped fly with the round head, almost all comprising the compound eyes, on a thin neck. It seems likely to be one of the Hybos species of dance fly. These prefer to chase-around on leaves and do not fly very often.

(Ed Wilson)

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Sightings from previous years

2014
Priorslee Lake
1 Cormorant
2 Grey Herons
8 Greylag Geese
10 Tufted Duck
1 Sand Martin
4 Swallows.
1 Sedge Warbler
10 Blackcaps
7 Chiffchaffs
191 Jackdaws
(Ed Wilson)

Woodhouse Lane
2 Red-legged Partridges
1 Whitethroat
4 Skylarks
1 Blackcap
1 Chiffchaff
1 Linnet
2 Yellowhammers
(Ed Wilson)

Nedge Hill
1 Wheatear
1 Common Whitethroat
1 Willow Warbler
3 Chiffchaff
2 Swallow
2 Blackcap
6 Skylark
1 Great Spotted Woodpecker
(Martin Grant)

2013
Nedge Hill
1 Common Redstart
5 Whitethroat
15 Wheatear
2 Swallows
Chiffchaff
2 Yellowhammer
6+ Skylarks
3 Linnet
(Ian Grant, Martin Grant)

2012
Priorslee Lake
1 Dark-bellied Brent Goose
(John Isherwood)

Nedge Hill
1 Redstart
2 Wheatear
1 Raven
(John Isherwood)

2011
Priorslee Lake
1 Common Sandpiper
2 Tufted Ducks
1 Lapwing
1 Siskin
Common Whitethroat
(John Isherwood/Ed Wilson)

Nedge Hill
1 Common Redstart
12 Wheatear
(John Isherwood)

2010
Priorslee Lake
1 Common Sandpiper
(John. Isherwood)

2009
Priorslee Lake
2 Reed Warblers
1 Pochard
17 Tufted Duck
6 Swallows
2 Reed Warblers
4 Blackcaps
5 Chiffchaffs
1 Willow Warbler
1 Jay
(Ed Wilson)

2008
Priorslee Lake
1 Little Grebe
1 Gadwall
7 Tufted Ducks
1 Common Sandpiper
111 Sand Martins
1 House Martin
4 Swallows
1 Blackcap
4 Willow Warblers
11 Chiffchaffs
1 Common Tern
(Ed Wilson)

2006
Priorslee Lake
4 Great Crested Grebes
3 Tufted Ducks
3 Ruddy Duck
9 Common Sandpiper
11 Chiffchaff
8 Willow Warbler
4 Blackcaps
1 Common Whitethroat
1 Swallow
1 Willow Tit
5 Greenfinch
1 Linnet
1 Redpoll
4 Reed Bunting
(Martin Adlam)