4 Aug 19

Priorslee Lake and The Flash

Priorslee Lake:  04:20 – 06:05 // 07:00 – 09:20
The Flash:  06:10 – 06:55

16.0°C > 19.0°C:  Scattered cloud to start; clouded later. Light E breeze. Moderate visibility.

Sunrise: 05:32 BST

Priorslee Lake:  04:20 – 06:05 // 07:00 – 09:20

(191st visit of the year)

Bird notes from today
- Now two Greylag Geese on the dam top throughout.
- A Tufted Duck heard calling in flight at 04:55 and then seen on the water. Not seen again.
- One Grey Heron flew off W at 05:15. Perhaps the bird seen at The Flash later. Perhaps also the bird that flew E at 07:10.
- Two of the resident adult Great Crested Grebes not located: the newly-arrived juvenile (should really call it an immature as it has fledged) was present again.
- The three Common Terns arrived c.07:15 and flew around making a lot of noise. All seemed to be adults. All were fishing at times but also sitting on buoys / the boat platform. At one point two birds were chasing and calling with mouths full of small fish, likely Perch.
- 78 Black-headed Gulls (4 juveniles) counted on the ‘football’ field at 05:50 – a most unusually high number. Never more that 16 birds on the water – same?
- 3 Swifts noted VERY high over 09:00.
- House Martins first heard high overhead at 05:25 apparently approaching from the E. Perhaps they no longer all fit in their nests and have taken to roosting elsewhere (the reeds at Bayliss Pools perhaps?). Later at least 18 were overhead the usual areas of the lake, football field and estate.
- A loose group of at least 250 Wood Pigeons flew W at 08:35. Plenty of others around.
- A Chaffinch heard calling. My first log since 7th July when this species stopped singing.

Bird totals:

Birds noted flying over or flying near the lake:
- 4 Greylag Geese (4 outbound)
- 15 Canada Geese (2 groups outbound)
- 1 Grey Heron
- 1 Lesser Black-backed Gull
- 1 Herring Gull
- 5 Feral Pigeons (3 groups)
- 2 Stock Doves
- c.315 Wood Pigeons (see notes)
- 1 Jackdaw
- no Rooks
- 1 Raven

Hirundines etc. noted:
- 3 Swifts
- 5 Barn Swallows
- 18 House Martins

Warblers noted (singing birds):
multiple feeding groups: accurate numbers hard to ascertain
- 11 (3) Chiffchaffs
- 1 (1) Willow Warblers
- 3 (0) Blackcaps
- 4 (0) Common Whitethroats again
- 3 (0) Sedge Warblers
- 7 (1) Reed Warblers

Counts from the lake area:
- 2 + 6 (1 brood) Mute Swans
- 2 Greylag Geese (throughout)
- 15 (?♂) Mallard
- 1 (?♂) Tufted Duck
- 1 Cormorant again
- 2 Grey Herons again
- 4 + 4 (3 broods) Great Crested Grebes
- 3 + 4 (2 broods) Moorhens
- 38 adult and juvenile Coots: also both small juveniles from the newest brood
- 3 Common Terns
- >78 Black-headed Gulls: 4 juveniles

On the lamp poles pre-dawn
- 1 Common Grass-veneer (Agriphila tristella)
- 1 White Plume (Pterophorus pentadactyla)
- 1 Common Plume (Emmelina monodactyla)
- 1 Common Footman (Manulea lurideola)
- 1 The Clay (Mythimna ferrago)

The following logged later:
The bat sp. noted seemed rather different from the usual pipistrelle / noctule-types I log. It was feeding over the SW grass. It seemed more robust and less fluttery than a pipistrelle. It was not flying direct with occasional sharp deviations that characterise the higher-flying noctule.
- Butterflies (in species order : no totals)
- Speckled Wood (Pararge aegeria)
- Meadow Brown (Maniola jurtina)
- Gatekeeper (Pyronia tithonus)
- Painted Lady (Vanessa cardui)
- Peacock (Aglais io)
- Moths (in species order):
- only many unidentified grass moths noted.
- Damselflies etc:
        - Blue-tailed Damselfly
- Common Blue Damselflies
- Hoverflies:
- Marmalade hoverfly (Episyrphus balteatus)
- Tapered Drone-fly (Eristalis pertinax)
- Common Drone-fly (Eristalis tenax)
- Chequered Hoverfly (Melanostoma scalare)
- presumed Long Hoverfly (Sphaerophoria scripta)
- Syrphus sp. perhaps both Syrphus ribesii and Syrphus vitripennis
- Pellucid Fly (Volucella pellucens)
And other things:
- 1 Crab Spider, probably Misumena vatia
- 1 Bat sp. (see above)
- 1 Grey Squirrel: once again eating Hazel nuts

A colourful sunrise today.

In mid-summer the sun is a bit too far N of E for decent reflections of the actual sunrise in the lake. Here across the ‘football’ field to the trees the other side of Castle Farm Way.

One of the noisy trio of Common Terns with a fish – likely a Perch.

A Common Plume moth (Emmelina monodactyla)

Contrast that slightly brown plume moth with neat rolled wings with this typically rather feathery-looking White Plume moth (Pterophorus pentadactyla).

A portrait of a Tapered Drone-fly (Eristalis pertinax). 

And here the rather more rounded ‘tail’ of a Common Drone-fly (Eristalis tenax). The body marking on these species is variable and the difference shown here is not a identification aid.

These two hoverflies are superficially similar, though the greater size of the upper individual is readily apparent. On neither specimen do the eyes meet so they are both the same sex and we can rule out sexual dimorphism. I can only think that the smaller individual is a Syrphus vitripennis; and the larger a Syrphus ribesii. As we cannot see the hind femur of either this will have to remain conjecture.

Two hoverflies for the price of one again. The lower species has the typical markings of a Marmalade hoverfly (Episyrphus balteatus). That makes the other species really tiny and thin – it is almost certainly a Long Hoverfly (Sphaerophoria scripta), though a plan view of the back markings would have clinched the ID.

Why do bees never look like they should? From the markings it appears to be a Honey Bee (Apis mellifera) and I think that is indeed what it is. But why has it no pollen sac?

Another slight puzzle. I am sure this is a Common Carder Bee (Bombus pascuorum). But where are the antennae? As there is no hoverfly species that closely resembles this then it must have the antennae tucked out of sight.

Butterflies are a lot easier! A splendid Painted Lady (Vanessa cardui). 

I had hoped we would see the long tongue unfurled and feeding on the Buddleia: but no. Still a close look at the face (and a bit of the tongue) is different. (Sorry about the distracting background pale leaf).

A Crab Spider, probably Misumena vatia. Note the hairs which appear to be only on the outer and front part of the paired legs. This group of spiders sit stationary and pounce on insects that arrive. Normally they would sit where they are camouflaged. This one has not read the book telling it what it is supposed to do.

(Ed Wilson)

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The Flash:  06:10 – 06:55 again

(184th visit of the year)

Notes from here:
- Low count of Mallard – hiding inside the island again? Yesterday’s ducklings not seen.
- The Herring Gull was unexpected on this date. Not the bird seen flying over the lake earlier – that was a first-year bird, this was an adult.
also
- 1 Single-dotted Wave moth (Idaea dimidiata) on a lamp pole
- 1 Red-legged Shieldbug (Pentatoma rufipes) also on a lamp pole

Birds noted flying over / near The Flash:
- 2 Black-headed Gulls
- 1 Lesser Black-backed Gull

Hirundines etc. noted:
- 2 House Martins again

Warblers noted (singing birds):
- 1 (1) Chiffchaff only

Counts from the water:
- 3 Mute Swans
- 4 Greylag Geese
- 11 Canada Geese
- 16 (>8♂) Mallard
- 15 (9♂) Tufted Ducks
- 1 Grey Heron
- 2 + 2 (1 brood) Great Crested Grebes
- 3 Moorhens
- 19 adult and well-grown juvenile Coots
- 8 Black-headed Gulls: no juveniles
- 1 adult Herring Gull

A Red-legged Shieldbug (Pentatoma rufipes), sometimes called a Forest Bug. 

(Ed Wilson)

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Between the lake and The Flash:

- 2 Little Grey moth (Eudonia lacustrata) on different lamps near the upper pool.

(Ed Wilson)

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

2017
Priorslee Lake
Today's Sightings Here

2015
Priorslee Lake
Today's Sightings Here

2013
Trench Lock Pool
4 Common Terns
(Dave Tromans)

2012
Priorslee Lake
Green Sandpiper
(Ed Wilson)

2011
Priorslee Lake
3 Common Terns
(Ed Wilson)

2008
Priorslee Lake
Black-tailed Godwit
Little Grebe
(Ed Wilson)

2008
Priorslee Lake
Black-tailed Godwit
Little Grebe
(Ed Wilson)