4 Sep 19

Priorslee Lake, The Flash, Trench Lock Pool and Trench Middle Pool

Priorslee Lake:  05:10 – 07:00 // 07:50 – 09:25
The Flash:  07:05 – 07:45
Trench Lock Pool:  09:35 – 09:40 // 10:15 – 10:45
Trench Middle Pool:  09:45 – 10:10

15.0°C > 14.0°C:  Initially broken cloud after overnight rain. Several heavy showers c.07:00 and then clear and cooler. Light showers again by 10:45. Light NW wind becoming moderate W with clearance. Very good visibility.

Sunrise: 06:24 BST

Priorslee Lake:  05:10 – 07:00 // 07:50 – 09:25

(214th visit of the year)

Bird notes from today:
- The Canada Geese all flew to the NNE and somewhat behind the tree-tops. Again none of these was noted returning.
- Single Little Grebe seen in two locations. Same bird? Neither was close-enough to reliably age.
- I yet again despair over the Great Crested Grebes! The two broods in close proximity in the NW area have two and three juveniles respectively. Again I could only find three adults sharing the workload here. One of the unattached adults seems to have left since yesterday.
- A single small juvenile Coot from the last-but-one brood noted.
- A juvenile Common Gull was likely the bird seen on Monday (2nd)
- Only a ‘small number’ of House Martins was heard over the ‘football’ field at 06:45. Just six, probably these, were then seen heading away from the incoming shower at 06:50.
- This morning’s ‘football’ field count gave me 197 Black-headed Gulls, 3 first-winter Lesser Black-backed Gulls, 16 Wood Pigeons, one Jay(!), five Magpies, two Carrion Crows and 49 Pied Wagtails. There were another 41 Black-headed Gulls on the school playing field at this time. I did the count just, and only just, ahead of a heavy shower when it was very dark and some of the less well-marked juvenile Pied Wagtails may well have been overlooked. What are they finding to eat? Spiderlings?

Bird totals:

Birds noted flying over or flying near the lake:
- 266 Greylag Geese (145 outbound in 12 groups; 121 inbound in seven groups)
- 73 Canada Geese (73 outbound in eight groups; none inbound)
- 1 Grey Heron
- 15 Lesser Black-backed Gulls: 11 of these first- winter birds
- 98 large gulls (too dark to ID)
- 33 Wood Pigeons
- 5 Jackdaws
- 86 Rooks

Hirundines etc. noted:
- 1 Barn Swallow again
- 6? House Martins

Warblers noted (singing birds):
- 11 (0) Chiffchaffs
- 5 (0) Blackcaps

Counts from the lake area:
- 2 + 6 (1 brood) Mute Swans
- 9 (?♂) Mallard
- 2 (0♂) Tufted Ducks again
- 1 Grey Heron again
- 1 Little Grebe
- 8 + 4 +9 (3 broods) Great Crested Grebes (see notes)
- 4 + 4 (3 broods) Moorhens
- 73 + 1 (new-ish brood) Coots
- >250 Black-headed Gulls
- 1 Common Gull: first-winter bird
- 45 Lesser Black-backed Gulls : 43 of these first-winter birds
- 2 Herring Gulls: both first-winter birds
- 1 Kingfisher

On the lamp poles pre-dawn and after rain:
- 1 dew-covered micro moth, likely a Bryotropha sp.
- 1 unidentified crane fly
- 2 unidentified flies
- 1 Leiobunum rotundum harvestman
- 1 probable White-lipped Snail (Cepaea hortensis)

The following logged later:
- No moths
- Butterflies:
- Painted Lady (Vanessa cardui)
- Dragonflies etc
        - Common Darter
- Hoverflies:
- Common Drone-fly (Eristalis tenax)
And other things:
- 1 Grey Squirrel

Here are two of the well-grown but still immature Great Crested Grebes with one of the ‘spare’ adults (with head plumes). They look sufficiently different to suggest they come from separate broods.

Another extreme range shot and the only time I located what seems likely to be the same juvenile Common Gull that I photographed almost as badly on Monday. Note that it – the bird on the right – is only slightly larger than the winter-plumaged Black-headed Gull, it has the distinctive rounded head profile and, at this age, the rather weak bill is all black (not easy to see against the background).

Two first-winter Lesser Black-backed Gulls show off their dark upper wings. I have no idea why one of the feathers in the tail of the closer bird is not solid black – it is not supposed to look like this at any age!

Compare here with a first-winter Herring Gull at the same angle. The upper wing is not as dark and particularly the inner primaries are noticeably pale – the so-called ‘pale window’. I am not sure about the bird we can see only the underside of: I am none too confident of ID-ing immatures from underneath.

Here we see the very dark wings of the first-winter Lesser Black-backed Gull (upper bird) contrasting with the paler wings of a first-winter Herring Gull. The difference is somewhat accentuated by the angle of the light.

A while since we had a Long-tailed Tit photo. Remedied today!

Another chance to get familiar with juvenile Goldfinches. This one is easy as the yellow in the wing is diagnostic.

Same bird, different angle. Not so easy. The pointed bill is perhaps the best clue. ‘In the field’ the twittering call is likely to be a better feature.

This micro-moth is the size and shape of a Bryotropha sp. but covered in too much dew to be able to specifically confirm that or specifically identify it.

This is rather a puzzle. It is obviously a crane fly and a male (females have pointed abdomen). It is resting with its wings at 90° to the body and they are either very narrow or somehow rolled up. I can find no photos of crane flies sitting like this. Also unusual are the apparently long antennae, even though the angle of the camera’s flash has tended to exaggerate this feature. In the genus Rhipidia males have long and pectinate antennae. Only one of the three UK Rhipidia species is illustrated on the web and it does not match this. I read they have recently found seven new Rhipidia species in China to add to the 50+ in this genus!

Trying to hide from the camera is this snail with a rather attractive shell. Its strategy has succeeded as we cannot see the lip of the shell and so tell whether it is a White-lipped Snail (Cepaea hortensis) or a Brown-lipped Snail (Cepaea nemoralis). In my experience the former is the more common here.

(Ed Wilson)

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The Flash:  07:05 – 07:45

(204th visit of the year)

Notes from here:
- Where were some of the Mallard hiding today?
- All the usual Great Crested Grebes relocated
- Three Common Buzzards were circling the hill to the SE. One was a calling juvenile and they were likely a family party. I think a different family from those that nested in the Ricoh copse near Priorslee Lake as the juvenile from that nest was calling from inside the trees both before and after I visited here.
- At least 40 Starlings seen in group flying low E to the N. Unusually large number here?
- Two wagtails seen flitting about on the island seemed to be Pied Wagtails: I would have expected it to be Grey Wagtails doing this. I did not get a good look at them, neither did I hear them call so I will have to pass.
and
- 1 Red Underwing (Catocala nupta) on a lamp pole.

Birds noted flying over / near The Flash:
- 3 Common Buzzards
- 2 Black-headed Gulls: no juvenile / 1st winter birds
- 4 Feral Pigeons
- 7 Wood Pigeons
- >40 Starlings

Hirundines etc. noted.
None

Warblers noted (singing birds):
- 5 (1) Chiffchaffs again: the only Chiffchaff heard singing today.

Counts from the water:
- 3 Mute Swans as usual
- 1 Greylag Goose
- 3 Canada Geese
- 27 (12♂) + 1 (1 brood) Mallard
- 36 (15♂) Tufted Ducks
- 1 Grey Heron
- 2 + 2 (1 brood) Great Crested Grebe
- 1 Moorhen
- 18 Coots
- 6 Black-headed Gulls: no juvenile / 1st winter birds

This is not a copper underwing moth as I initially ID-ed but a Red Underwing (Catocala nupta). I see this most years and often find it resting on the walls of the Priorslee Avenue tunnel.

(Ed Wilson)

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Between the lake and The Flash:

Nothing of note.

(Ed Wilson)

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Trench Lock Pool:  09:35 – 09:40 // 10:15 – 10:45

(40th visit of the year)

This location continues to disappoint. While it is always best in Winter / early Spring the low number of Coots this year and continuing poor number of, especially large, gulls is rather worrying. The success of the Great Crested Grebes and presence of Cormorants suggest there are fish. I wonder whether lack of vegetable matter might contribute to the absence of diving ducks and poor Coot counts? Perhaps related to last Autumn’s partial draining of the water.

Other notes from here:
- I think we must assume that the long-term rather large and pale feral Mallard is no more. I never saw it in flight in all the years (>10?) it was here. I have not seen it since 15 July.
- The usual Great Crested Grebe puzzle. A pair seems to have three juveniles with these now often separated by some distance from their meal-providers, one in particular usually well away. An extra lone adult has been here for several months. Today there was a fourth juvenile that I would judge as a fledged bird new in. But ....
- A rather late date to see a Sand Martin amongst the House Martins – this species is first to arrive in Spring, sometimes as early as late February, and usually early to leave. Perhaps the mid-summer flooding that washed out the nests in local river banks caused late re-nesting? The Barn Swallow was more to be expected.
Also
- 1 Green-veined White butterfly (Pieris napi)
- 1 Painted Lady butterfly (Vanessa cardui)
- >10 Drone-flies (Eristalis sp.)
- 2 Common Carder Bees (Bombus pascuorum)
- 1 wasp sp.
NB: Somewhat amazingly the Painted Lady appears to be my first-ever log of this species here.

Birds noted flying over / near here [other than local Wood Pigeons and Jackdaws].
None

Hirundines etc. noted:
- 1 Sand Martin
- 1 Barn Swallow
- 8 House Martins

Warblers noted (singing birds):
- 3 (0) Chiffchaffs

Counts from the water:
- 2 Mute Swans
- 18 Canada Geese: departed
- 6 (2 drakes) Mallard
- 2 Cormorants: 1 departed; different bird arrived
- 3 + 4 (? broods) Great Crested Grebes
- 2 + 1 (1 brood) Moorhens
- 13 Coots
- 6 Black-headed Gulls: 4 of these juvenile/first winter birds

(Ed Wilson)

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Trench Middle Pool:  09:45 – 10:10

(40th visit of the year)

Work continues on the N-side embankment with continued impact on number of geese etc. expecting handouts

Notes from here:
- There are certainly three juvenile Great Crested Grebes here, all old-enough to do their own fishing. Probably not yet fledged.

Birds noted flying over / near here:
- 1 Common Buzzard

Hirundines etc. noted.
None

Warblers noted (singing birds):
- 4 (0) Chiffchaffs

Counts from the water:
- 2 Mute Swans
- 3 Greylag Geese: arrived
- 15 Canada Geese
- 7 (6 drakes) Mallard
- 11 (3 drakes) Tufted Duck
- 2 + 3 (1 brood) Great Crested Grebes
- 2 + 1 (1 brood) Moorhens
- 31 Coots
- 9 Black-headed Gulls again

(Ed Wilson)

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On this day..........

2015
Priorslee Lake
Today's Sightings Here

2014
Priorslee Lake
Today's Sightings Here

2012
Priorslee Lake
Kingfisher
(Ed Wilson)

2011
Priorslee Lake
Common Sandpiper
(Ed Wilson/ John Isherwood)

Nedge Hill
2 Hobby's chasing Swallows and martins
1 Common Redstart
2 Meadow Pipits - first autumn birds
(Ed Wilson/John Isherwood)

2010
Priorslee Lake
Teal
14 Cormorants
(John Isherwood)

Nedge Hill
Hobby chasing Swallows
1 Wheatear
2 Raven
(John Isherwood)

2009
Priorslee Lake
Little Egret
Kingfisher
(Ed Wilson)

2006
Priorslee Lake
Kingfisher
2 Swifts
1 Meadow Pipit - first autumn bird
(Ed Wilson)