13 Sep 21

Priorslee Lake and The Flash

13.0°C: Overcast with light rain at times. Light ESE wind. Moderate visibility.

Sunrise: 06:40 BST

* = a photo today

Priorslee Lake: 05:00 – 09:10

(202nd visit of the year)

It was a Monday: it was wet: it was the 13th. What could possibly go wrong? Well: actually something went right. As I was leaving the Priorslee Avenue tunnel having found very little lurking there I heard the wavering call of a Tawny Owl from the Ricoh copse. It is two months since the last addition to my 2021 bird list for here! This makes #105.

Other bird notes:
- The Mute Swan cygnets took themselves on several fast taxiing runs, wings and legs flailing, as they prepare for flight. The fourth cygnet joined in on at least one occasion. Usually it is the adults that coax them to try though last year the cygnets at The Flash taught themselves.
- Many fewer Black-headed Gulls than yesterday – I thought c.105 at most.
- Conversely a higher number of large gulls were noted – 277 logged flying from the W after 06:10. A significant proportion of these passed to the SW though some circled back to join the main group having a wash and drink. My view was blocked by trees to get an accurate count of birds that did not stop.

Overhead:
- 1 Greylag Goose: outbound
- 7 Racing Pigeons: together
- 258 Wood Pigeons
- 2 Black-headed Gulls
- 3 Herring Gulls
- 26 Lesser Black-backed Gulls
- ? large gulls: see notes
- 3 Jackdaws
- 1 Pied Wagtail

Hirundines etc., noted:

None

Warblers noted:
- 8 Chiffchaffs: four in song
- 1 Blackcap

Count from the lake area:
- 2 + 4 (1 brood) Mute Swans
- 16 (9♂) Mallard
- 4 (1♂) Tufted Duck
- 5 Moorhens
- 56 Coots
- 10 + 5 (3 broods) Great Crested Grebes
- >100 Black-headed Gulls
- *11 Herring Gulls: all immatures
- *1 Yellow-legged Gull: first-winter
- *48 Lesser Black-backed Gulls: various ages
- 277 'large gulls': see notes
- 1 Grey Heron

Moths at the lamps pre-dawn:
- *1 Garden Rose Tortrix (Acleris variegana f. asperana?)
- *1 Common Plume (Emmelina monodactyla)

Other things:
- *1 mayfly sp.
- 1 crane fly
- 2 Bridge Orb-web Spiders (Larinioides sclopetarius)
- 1 unidentified spider
- 2 Dicranopalpus sp. harvestmen
- *1 Leiobunum rotundum/blackwalli harvestman

Noted later: too damp and dull for much.
- 1 Pipistrelle-type bat echo-locating the rain-drops
- many White-lipped Snails (Cepaea hortensis)

"Life Gets Teejus, Don't It" © Carson Robison 1948. A first-winter gull agrees. Both these gulls show notching on the folded tertials which suggests they are both first-winter Herring Gulls despite their very different appearance.

However... this is the left hand bird showing that the inner primaries are not significantly pale – mainly on the inner webs. That in combination with the secondary coverts being patterned rather than dark, matching the exposed secondaries, suggests this is a Yellow-legged Gull.

This is what I would expect a first-winter Herring Gull to look like – more extensively pale inner primaries, not just the inner webs.

And with their wings spread here are two first-winter Lesser Black-backed Gulls with the merest pale on the inner webs of just three inner primaries and mainly dark secondary coverts.

As the wings starts to close they shows no pale whatsoever on the inner primaries.

After one yesterday I found this different Garden Rose Tortrix (Acleris variegana) in vegetation under a lit street lamp. Whether this qualifies as having "no dark patch on the dorsum" and hence of the form asperana is a moot point.

It is almost six months since I logged my first Common Plume moth (Emmelina monodactyla) of 2021 here. This is a fresh specimen which will, unless predated, over-winter as an adult and become active again in the Spring. So my first records of this species this year related to moths that had hatched in 2020.

Perhaps I have just 'got my eye in': this has been a bumper year for mayflies. Identification relies on a combination of wing venation (not apparent here) and number of tails (this does not seem to have any!). So mayfly sp. it is. Note the horizontally-striped eyes.

I am still finding these Grouse Wing caddis flies (Mystacides longicornis) almost daily pre-dawn in the sailing club shelter. They do not seem willing to dance over the lake-side vegetation at the moment. This one is holding its left antenna at a jaunty angle.

With an almost circular body this is a male Leiobunum rotundum/blackwalli harvestman. I can't decide whether the white of the eyes is from the camera-flash or whether it is the 'white-wall tyre' feature around the eyes of L. rotundum and not L. blackwalli.

(Ed Wilson)

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In the Priorslee Avenue tunnel pre-dawn:

Moths

None

with:
- 3 Common Rough Woodlouse (Porcellio scaber)
- several craneflies of different species
- 1 Garden Spider (Arameus diadematus)
- various other unidentified spiders as usual

(Ed Wilson)

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The Flash: 09:15 – 10:00

(182nd visit of the year)

Bird notes:
- Some of the geese had returned before I arrived and more flew in. Some quickly disappeared inside the island so my counts are likely incomplete.
- Many more Tufted Duck than in recent days when the numbers thinned out.
- A drake Tufted Duck was consorting with the main group of Mallard. Possibly the bird that spent the breeding season as part of a ménage à trois with a pair of Mallard.

Birds noted flying over here:
- 3 Wood Pigeons
- 1 Black-headed Gull

Hirundines etc., noted:

None

Warblers noted:
- 6 Chiffchaffs: no song

On /around the water:
- 94 Canada Geese: many of these arrived
- 23 Greylag Geese: most of these arrived
- 3 + 2 (1 brood) Mute Swan
- 24 (16♂) Mallard
- 32 (?♂) Tufted Duck
- 3 Moorhens only
- 29 Coots
- *2 + 3 (1 brood) Great Crested Grebes again
- no Black-headed Gulls
- 1 Grey Heron

On a lamp pole:
- 1 Dicranopalpus sp. harvestman

Two of the three juvenile Great Crested Grebes. They are growing fast though at this age they still show bare skin in front of their real eyes giving them a 'big-eyed' look. At least the pink colouration has faded.

The other sibling.

(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

2007
Priorslee Lake
Shoveler
Redwing
(Ed Wilson)