26 Nov 25

The Flash and Priorslee Balancing Lake

0.0°C > 3.0°C: Clear skies until c.10:30 when cloud encroached from the West. Light south-easterly breeze. Mostly very good visibility.

[Sunrise: 07:52 GMT]

I decided on another "Winter schedule" visit to avoid the early chill. A fortuitous choice as the Balancing Lake had been fogged-in early and was only beginning to clear as I was heading to start at The Flash.

Priorslee Balancing Lake: 09:25 – 10:30

(288th visit of the year)

Mostly from the dam-top area. I did walk all around without anything interesting entering the log.

Bird notes:
- the model boat club were using the West end of the lake. Some ducks may have departed as a result.
- none of the three Pochard was an adult drake: neither did they seem to be immature drakes. It is most unusual for duck Pochard to outnumber drakes. But then, not quite so unusual, the duck Tufted Duck also outnumbered the drakes.
- a dead Moorhen was seen. Just the head and scattered feathers remained. Exactly what killed it is not clear. The plucked feathers might suggest a Sparrowhawk but I would be surprised that one would have taken anything right alongside the water. I would not have expected a Fox to pluck its prey. No bones were noted.
- I took gull counts as I arrived and again as I was about to depart. It is likely that different birds were involved as there was a steady stream of arrivals and departures. The two totals are presented as <total_1> || <total_2>.

Bird(s) noted flying over here:
No specific counts were taken. Approximate numbers...
- >10 Wood Pigeons
- >1 Herring Gull
- c.40 Lesser Black-backed Gulls
- 2 Jackdaws

Counts from the lake area:
- 7 Canada Geese
- 15 (9♂) Mallard
- 3 (0♂) Pochard
- 30 (10♂) Tufted Duck
- 6 Moorhens: one dead: see notes
- 55 Coots
- 6 Great Crested Grebes
- 27 || 34 Black-headed Gulls
- 28 || 32 Herring Gulls
- 108 || 132 Lesser Black-backed Gulls
- 2 Cormorants
- 2 Grey Herons

I checked all the street lamp poles and found nothing.

One of three duck (female) Pochard here. The eye looks white because the protective translucent membrane is covering the pupil allowing some vision against danger. Just about visible of the pale eye ring with a pale line running behind the eye.

Here are the other two. Pale eye-rings and streaks behind the eye more easily seen.

A first-winter Herring Gull departs.

The back gull of these two immature gulls looked different somehow. Smaller and more compact that the first-winter Herring Gull in front of it. I wondered what Obsidentify would make of my photo. "Harbour porpoise". Well I know the photo is not very good! Google Lens said "Iceland Gull". Wrong again as that species at all ages lacks any black feathering and this bird shows unrelieved black on the folded wing-tips. A "different-looking" first-winter Herring Gull is my conclusion.

A typical adult-winter Herring Gull, the pale eye and the head streaking giving it an evil look.

I did a double-take on this adult Herring Gull. There is so little dark on the wing-tips that at first glance it looked like an Iceland Gull which has no black. The camera reveals all. Looking at the right wing it shows that several of the outer primaries are still re-growing. Thus when viewed from above it appears as a thin line of black where these feathers are overlaid on each other.

An adult-winter Lesser Black-backed Gull with several unusual features. There looks to be no contrast between the inner wing and the always black wing-tips. The head is about at densely streaked as any I have seen. And the usual wide white trailing edge to the wing is narrow and uneven. I can't turn it in to anything more exciting.

(Ed Wilson)

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The Flash: 10:40 – 12:15

(281st visit of the year)

c.90% ice. Apart from many of the gulls happily standing on the ice most birds were concentrated in a small area between the island and the Wordsworth Way turn.

Bird notes:
- no (Common) Teal seen.
- most of yesterday's Pochard gone. Just a trio of drakes remain.
- a single brownhead Goosander noted.

Bird(s) noted flying over here:

None

Noted on / around the water:
- 6 Canada Geese
- 31 (19♂) Mallard
- no (Common) Teal
- 3 (3♂) Pochard
- 34 (17♂) Tufted Duck
- 1 (0♂) Goosander only
- 7 Moorhens
- 45 Coots
- 3 Great Crested Grebes
- 74 Black-headed Gulls
- 12 Herring Gulls: ages not determined
- 4 Lesser Black-backed Gulls: all (near) adults
- 2 Cormorants
- 1 Grey Heron

Nothing noted around the area:
I was not surprised to draw a blank. The Ivy bank was in full sun but with a temperature of just 1.0°C nothing was venturing out.

Taken from the pull-in in Derwent Drive The Flash was ice all the way to the island.

Here from one of the footbridges with ice all the way to the top end. The Flash always freezes quickly. Nevertheless I was surprised how extensive the ice was after just one below freezing night. The incoming cloud is lurking to the West and North.

One of the three drake Pochard asleep on the patch of open water between the island and Wordsworth Way. Note the fine vermiculations on the flanks of this bird.

Another one pretending to be asleep. Note the red eye. I can find no information on why the eye colour varies between bird species. What may be relevant is that Pochard often dive at night to feed on vegetation and spend the day loafing. Tufted Ducks with yellow or orange eyes dive during daylight.

Two first-winter Herring Gulls probably encountering their first ice and slip-sliding about.

Four immature Herring Gulls looking for food on the ice. The left-most three are all first-winters with dark bills. The right-hand bird with only a small amount of black on the bill and a pale eye is a second-winter bird.

I paused over this gull. Rounded head and dark eye. These are Common Gull features. Not so: the bill is too robust and would be two-tone on a Common Gull. And anyway as a two-year (to maturity) gull a Common Gull would show extensive pale grey on the back and wings. This bird is a first-winter Herring Gull, most likely a female which average smaller than males.

(Ed Wilson)

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2012
Priorslee Lake
22 Tufted Ducks
143 Coots
Nuthatch
34 Redwings
1 Fieldfare
228 Jackdaws
98 Rooks
(Ed Wilson)

2006
Priorslee Lake
1 Little Grebe
11 Greylag Geese
27 Pochard
70 Tufted Ducks
1 drake Ruddy Duck
70 Coots
>400 Black-headed Gulls
315 Lesser Black-backed Gulls
5 Herring Gulls
221 Wood Pigeons
22 Blackbirds
45 Fieldfares
38 Redwings
264 Jackdaws
71 Rooks
5 Siskins
(Ed Wilson)

2005
Priorslee Lake
1 Pochard
40 Tufted Duck
1 Goldeneye
2 Ruddy Duck
C.700 Lesser Black-backed Gulls
16 Herring Gulls
2 Yellow-legged Gull
2 Great Black-backed Gulls
Caspian Gull
Sparrowhawk
c.628 Jackdaws
c.358 Rooks
(Martin Adlam)