21 Dec 14

Priorslee Lake: 7:02am - 10:19am

6.5°C > 8.0°C  Variable cloud with some clear periods. Fresh W wind. Very good visibility.

(153rd visit of the year)

Counts of birds flying over the lake (therefore in addition to those on / around lake)
- 107 Canada Geese
- 3 (2) Goosanders
- 21 Black-headed Gulls
- c.600 large gulls
- 7 Feral Pigeons
- 4 Pied Wagtails
- 5 Redwings
- c.630 Jackdaws
- 8 Rooks
- 1 Raven

Birds leaving roosts around the lake
33 Magpies (incomplete count)
Redwings not counted
1 Starling only

The counts from the water
2 Little Grebes
4 Great Crested Grebes
2 Grey Herons
2 Swans
6 (3) Gadwall
10 (5) Mallard
1 (1) Pochard
49 (27) Tufted Duck
11 Moorhens
179 Coots
>200 Black-headed Gulls
59 Lesser Black-backed Gulls
21 Herring Gulls
7 Great Black-backed Gulls

Other notes
A manic period when scattered parties of several hundred Jackdaws were on the same flight line as c.100 large gulls flying over and then met up with c.100 Black-headed Gulls spiralling down to the lake. Counts were ‘best effort’!
The Lesser Black-backed Gulls included the leucistic bird last seen at Trench Lock on 2nd December.
Male Pheasant heard calling from the old Celestica grounds. First record since early April. For the previous few years this species has been regularly heard here and even bred in the Ricoh copse: scarce this year with the building work for the new school.
2 Song Thrushes singing this morning.
Cetti's Warbler not heard this morning despite two visits to all likely areas.
Yellowhammer calling from hedge on E side of Castle Farm Way.
Two more Mottled Umber moths.

“what’s this then? Barn Owl? Nope – the leucistic, presumed Lesser Black-backed Gull put an appearance at the lake this morning.

Perhaps just an effect of the light but is there some dark on the underside of the outer primaries?

This shot appears to show that it was shadow – there is no dark evident here, though the low winter sun could ‘blow it out’

An aerobatic pair: an adult Herring Gull with our bird. The Herring Gull is actually quite interesting(!) It shows some dark on the primary coverts suggesting it is a 3rd winter bird, but there is no dark in the tail and the ‘mirrors’ (white-patches) on the outer two primaries are like a full adult. As usual the birds have not read the book and don’t know what they are supposed to look like.

An action shot of our bird with two adult Lesser Black-backs and a 1st and 2nd winter Herring Gull in the background. Note the size difference between the two adult Lesser Black-backs – likely male / female. A Great Black-back would show a mantle the same tone as the folded wing-tip and also a more massive bill. The two Herring Gulls are also very different sizes, the smaller 1st winter bird also appearing smaller than the smaller of the Lesser Black-backs. On average Herring Gull is slightly larger than Lesser Black-backed Gull, the key word being ‘average’.

And here the underside of the wing tip is most definitely dusky.

As is the tail?

(Ed Wilson)


Priorslee Flash: 10:23am - 11:07am

(125th visit of the year)

No Little Grebe seen today.
Now 5 Great Crested Grebes (but one was ‘missing’ from the lake).
Big increase in Tufted Duck numbers: did not see any arrive but some may have come from the lake as the yacht club were about to take to the water as I was leaving there.
No counts of gulls flying over: these were all mixed up and impossible to separate from the birds being put up from the lake by errant banging of a stick on metal posts to flush off the Goosanders. This done by one of the fishermen who regrets that the Goosanders are better fishermen than he is.

The counts from the water
4 Great Crested Grebes
1 Grey Heron
2 Swans
5 Canada Geese
1 all-white feral goose
39 (28) Mallard
1 all-white feral duck
3 (3) Pochard
80 (28) Tufted Ducks
36 (11) Goosanders
9 Moorhens
19 Coots
c.200 Black-headed Gulls
7 Lesser Black-backed Gulls
11 Herring Gulls

(Ed Wilson)

On this day in 2005 and 2009
Priorslee Lake
Black-necked Grebe present with Little Grebe
Huge mass of gulls with around 8000+
2 Yellow-legged Gulls present.
(Martin Adlam / Jim Almond / Ed Wilson)
C.2000 Lesser Black-backed Gulls
C.500 Black-headed Gulls
5 Great Black-backed Gulls
11 Herring Gull.
(Martin Adlam)