15 Jul 19

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

Priorslee Lake:  04:10 – 05:40 // 06:40 – 06:50 // 08:40 – 10:20
The Flash:  05:45 – 06:35
Trench Lock Pool:  07:00 – 07:05 // 07:50 – 08:30
Trench Middle Pool:  07:10 – 07:45

11.0°C > 18.0°C:  Clear sky with mist over the lake and then a bank of fog at the lake only until after 07:00. Light SE breeze. Very good visibility – apart from the fog bank!

Sunrise: 05:03 BST

My now customary summer early visit to Trench with split visits to the lake.

Priorslee Lake:  04:10 – 05:40 // 06:40 – 06:50 // 08:40 – 10:20

(175th visit of the year)

Bird notes from today
- Needs good light to be able to separate the oldest juvenile Coots from adults and separation will soon not be possible.
- One Common Tern seen flying over Teece Drive towards the lake at 06:45 – probably one of the birds seen at The Flash minutes earlier. Two over the water at 08:40 until 10:20. Mobbed an over flying Grey Heron and the local Buzzards.
- A few of the small group of early arriving Black-headed Gulls left to the E today. Most still returned W from where they came at 04:30.
- Yesterday the Rook passage was more or less directly over the lake. Today there were fewer birds and they were very far to the E.

Bird totals:

Birds noted flying over or flying near the lake:
- 2 Grey Herons
- 2 Lesser Black-backed Gulls
- 33 Wood Pigeons
- 35 Jackdaws
- 72 Rooks

Hirundines etc. noted:
- 12 Swifts
- 1 Barn Swallow
- 6 House Martins

Warblers noted (singing birds):
not much song now
- 8 (3) Chiffchaffs
- 9 (4) Blackcaps
- 1 (1) Garden Warbler
- 2 (1) (Common) Whitethroats
- 3 (3) Reed Warblers

Counts from the lake area:
- 2 + 6 (1 brood) Mute Swans
- 14 (13♂) + 2 (1 brood) Mallard
- 6 + 3 (2 broods) Great Crested Grebes
- 2 + 2 (2 broods) Moorhen
- 34 + 33 (? broods) Coots
- 2+ Common Terns (see notes)
- 12 Black-headed Gulls

On the lamp poles pre-dawn:
- 2 Common Grey (Scoparia ambigualis)
- 1 Small Fan-footed Wave (Idaea biselata)
- 1 Chironomus plumosus (a plumed midge sp.)

Seen later:
The following logged
- Butterflies (in species order):
- >20 Small Skippers (Thymelicus sylvestris)
- >5 Green-veined Whites (Pieris napi)
- >20 Ringlets (Aphantopus hyperantus)
- 2 Small Tortoiseshells (Aglais urticae)
- 1 Comma (Polygonia c-album)
- Moths (in species order):
        - 1 Common Marble (Celypha lacunana)
- several Garden Grass-veneers (Chrysoteuchia culmella)
- Shaded Broad-bar (Scotopteryx chenopodiata)
- Damselflies etc. (alphabetic order of vernacular name):
- 1 Black-tailed Skimmer: ** new here for 2019
- many Blue-tailed Damselflies
- 1 Brown Hawker: ** new here for 2019
- very many Common Blue Damselflies
- Hoverflies (alphabetic order of scientific name):
- very many Marmalade hoverflies (Episyrphus balteatus)
- >4 Common Drone-flies (Eristalis tenax)
- many Syrphus sp. hoverflies
- >5 Pellucid Flies (Volucella pellucens)
And other things:
- what may be my first-ever horse-fly sp. here. As it was biting me I did not stop to ID it!
- 1 Harlequin Ladybird (Harmonia axyridis)
- one 7 Spot Ladybird (Coccinella 7-punctata)
- one 24 Spot Ladybird (Subcoccinella vigintiquattuorpunctata)
- many Hogweed Bonking beetles (Rhagonycha fulva)

The sunrise before the mist rolled in – just a hint of mist over the water at this time.

The sunrise!

The pair of Great Crested Grebes in the NW corner have been somewhat reluctant to show their one remaining offspring. Here it is, now growing fast, with a parent.

One of the local Common Buzzards passing by .... 

... and calling! 

With two of them doing a dance.

Who is leading?

Sometimes you are in the right place at the right time. A Common Tern passes by showing the black tip to its bill.

Twice in one day!

Look at that maneuverability – just coming out of the water after a fishing attempt the wings and tail are all over the place as it regains normal flight.

And this bird just landing shows some white in the forehead.

Terns are very aggressive – they attack humans that get too close to their nests. Here one chases a passing Grey Heron that looks somewhat alarmed – as well it might.

The young Blue Tits are still quite yellow-looking.

“Drawn through a hedge backwards” springs to mind. This Long-tailed Tit needs to do some serious preening to sort this out.

This moth found on a lamp pole is a Small Fan-footed Wave (Idaea biselata). Not too many moth species rest with wings pressed forward like this.

There were many Small Skipper butterflies (Thymelicus sylvestris) today. I tried to convince myself that this specimen had black tips to its antennae and was therefore an Essex Skipper (Thymelicus lineola). The camera says otherwise.

This is a male Green-veined White butterfly (Pieris napi). Male because it has only two black spots showing on the wings. And Green-veined White because we can see a hint of the veins, more prominent on the underwing. Also the black on the wing tip extends in blotches along the wing edge.

And here is the female. Four spots visible in the wings. This specimen is more strongly marked – that is not a sexual difference, just how ‘fresh’ any individual is.

A nicely posed and fresh Ringlet butterfly (Aphantopus hyperantus) showing how it got its name.

This is the very small ladybird that delights in the name 24 Spot Ladybird (Subcoccinella vigintiquattuorpunctata). The scientific name is longer than the beetle! Identify by the concolorous head and elytra. It does not always have all 24 spots. Last noted by me here on 25 July 2017.

(Ed Wilson)

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The Flash:  05:45 – 06:35

(168th visit of the year)

Two highlights this morning:
- another Common Sandpiper, continuing the bumper sightings this year
- at 06:25 two Common Terns flew in from the N, calling. One of these was already beginning its post-breeding moult. This bird peeled off and left to the NW. The other bird flew around a while and then seemed to head to the lake. From a later visit to the lake it seems they may both have ended up there. Species #75 here in 2019, equalling my species total for all of 2018

Other notes from here:
- As usual not possible to sex all the adult Mallards. No ducklings seen.
- Eight Swifts far to N. May have included the four seen overhead earlier.

and
- 1 unidentified pug sp. moth on a lamp pole in squirrel alley
- 1 probable Uncertain moth (Hoplodrina octogenaria) on a different lamp pole in squirrel alley

Birds noted flying over / near The Flash:
- 2 Feral Pigeons (singles)
- 2 Wood Pigeons
- 3 Jackdaws

Hirundines etc. noted:
- 8+ Swift
- 4 House Martins

Warblers noted (singing birds):
- 1 (1) Chiffchaff
- 2 (1) Blackcaps

Counts from the water:
- 3 + 4 Mute Swans
- 69 Greylag Geese
- no Greylag x Canada Goose noted
- 148 Canada Geese
- 35 (14+♂) Mallard
- 15 (15♂) Tufted Ducks
- 2 + 2 (1 brood) Great Crested Grebes
- 4 Moorhens
- 15 + 7 (3 broods) Coots
- 1 Common Sandpiper
- 2 Common Terns
- 3 Black-headed Gulls

A record shot only: on this, one of the Common Terns, we can just about see there is white on the forehead. Checking the literature this species, unlike Arctic Tern, starts its post-breeding moult in July and hence this is likely an adult doing just that rather than a sub-adult as I assumed at the time.

This pug moth was a long way up a lamp-pole in squirrel alley. I tried standing in the vegetation so as to shoot it more horizontally. This was the rather poor result. Not too many pug species rest with wings held slightly forward but in the end I decided there was not enough detail and I would have to pass.

This was another challenge at the top of a lamp pole at an unhelpful angle and on the vegetation-side of the lamp (the stinging nettle side!). I think on the basis of the warm tones this is an Uncertain moth (Hoplodrina octogenaria). Separation from Rustic (Hoplodrina blanda) is not easy but as the scientific name suggests Rustic is ‘bland’ and usually rather grey

(Ed Wilson)

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Between the lake and The Flash:

- Adult Moorhen on the grass at the upper pool
- 1 Blackcap calling by the upper pool
and
- 2 Grey Tortrix Agg. moths (Cnephasia sp.) on a lamp pole – not specifically identifiable in the field.

Similar to the confusing ‘grey’ species of moth this is one of the even more confusing ‘grey Tortrix’ moths of the genus Cnephasia. Without microscopic examination of the genitalia these need to be recorded as Grey Tortrix Agg. (Cnephasia agg.).

And here is the other one, also Grey Tortrix Agg. (Cnephasia agg.). Since it was about six inches away it is likely they have both very recently hatched from the same batch of eggs.

(Ed Wilson)

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Trench Lock Pool:  07:00 – 07:05 // 07:50 – 08:30

(34th visit of the year)

I visited very briefly on Wednesday 10th June. I did not do a log but I need to record that there was a Common Tern present c.11:30 – my 55th species of the year here

Notes from here for today:
- The lone juvenile Great Crested Grebe continues to thrive unaided.
- Very low count of Coots today. On my brief look at 07:00 I only found 4! More emerged later.
also
- many Hogweed Bonking beetles (Rhagonycha fulva)
- a delicate fungus species found, probably Glistening Inkcap (Coprinellus micaceus)

Birds noted flying over / near here [other than local Wood Pigeons and Jackdaws]:
- 22 Greylag Geese

Hirundines etc. noted:
- 1 Swift
- 1 House Martin

Warblers noted.
None

Counts from the water:
- 2 + 2 Mute Swans (see notes)
- 3 Greylag Geese
- 6 + 8 (1 brood) Canada Geese
- 22 (?♂) Mallard
- 1 (1♂) Feral Mallard
- 1 Grey Heron
- 2 + 1 (1 brood) Great Crested Grebes again
- 2 + 1 (1 brood) Moorhen
- 14 + 4 (2 broods) Coots
- 5 Black-headed Gull

These delicate fungus were on a log partly submerged in the water, supporting a fishing platform. They look superficially like a species of Mycena. I discounted this because the striations on the cap are too fine. The clue is in the very different-looking fruiting body that has yet to expand and these are I believe Glistening Inkcaps (Coprinellus micaceus)

A top view shows that they were brown – and still are in the centre. The outer of these very short-lived fruiting bodies is deliquescing

(Ed Wilson)

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Trench Middle Pool:  07:10 – 07:45

(34th visit of the year)

Notes from here:
- Clearly some of the geese are now flying again after their wing-moult and have gone.
- The all-white goose/duck not seen.
- The second adult Great Crested Grebe not seen today. The juvenile seemed to be feeding itself now, though I doubt it is fledged.
- Many of the young Coots getting hard to distinguish from adults here too.
- Black-headed Gulls now returned to partake in the food hand-outs.
- Two Grey Wagtails.

Birds noted flying over / near here:
- 1 Lesser Black-backed Gull again

Hirundines etc. noted.
None

Warblers noted (singing birds):
- 1 (1) Chiffchaff
- 1 (0) Blackcap

Counts from the water:
- 2 Mute Swans again
- 83 + 6 (2 broods) Greylag Geese
- 90 Canada Geese
- 24 (?♂) Mallard
- 7 (7♂) Tufted Duck
- 1 + 1 (1 brood) Great Crested Grebes
- 4 + 5 (4 broods) Moorhens
- 11 + 16 (? broods) Coots
- 6 Black-headed Gull
- 1 Kingfisher

One of the Grey Wagtails here quickly moulting out of breeding plumage.

(Ed Wilson)

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

2018
Priorslee Lake
Today's Sightings Here

2016
Priorslee Lake
Today's report Here

2015
Priorslee Lake
Today's Report Here