28 February 2020

Winter is coming

..but it hasn't arrived yet. This "winter" has consisted of plenty of wind and rain but we are still waiting for a cold snap, consequently there haven't been a great number of species from the lands to the north. This report covers November through to March, spring is coming.

Significantish winter sightings

Goldeneye November 10th
Caspian Gull 11th January, the first twitch of the year (for me) was to see a 2nd winter Caspian gull that Tony found on Jubilee. A very nice bird, even if it is a gull.

Yellow-legged Gull 12th January a huge hulking great beast found by James on Alex and subsequently seen about for a few weeks. This was a bit of a puzzle and has been blogged already.
Rook 20th January, Nick found our regular juvenile Rook perched in the same spot, more on this later.
Redpoll 13th February, Nick heard one flying over the broom. 
Mediterranean Gull 23rd February found loafing on the Flats by Tony, but didn't stay long enough to be twitched, probably a migrant passing through.
Chiffchaff ! 27th February. Getting desperate here, but Nick finally had one for the patch. Unlikely to stay a blocker for long though Nick.

The only addition to our site list for 2019 in November and December was the Goldeneye Nick saw flying West over the the Park on the 10th. This year has been somewhat underwhelmimg, but we have reached 79 species.Most of the goodies so far have been the above gulls.

We have very few Siskin, usually to be found in the Dell and about 20 Redwing and a few elusive Fieldfare around the Fairground, along with ten or so flighty Linnet. Two Woodcock can be seen flying onto the goldf course if you wait for dusk on the Roding path. If asked don't be too explicit about what you are waiting for. Although the ground is sodden we have no confirmed Snipe reported. Things have not been very exciting so far this year, but Spring is coming.

Enough of this meagre feast, on to meatier (or quornier) stuff.

The Rook

Rook is a difficult bird on the patch, it is usually seen in the spring with one or two birds flying through, heading elsewhere. However for three years now we have had a single solitary juvenile Rook sitting in a group of trees, almost on the same branch next to Alex, early in the year. It is tolerated by the permanent murder of crows presumably because it's bill is still dark. It raises a few questions:
Why just one - it may be we can't be bothered to sort through the others?
Why always in the same place - it may be we only look there?
Where are it's parents?
Do other patch workers see solitary juvenile Rook amongst their Crows?
I don't think it is anything other than a Rook, and I don't think it is a bird in arrested development. It is a bit of a puzzle.

A dearth of ducks
In 2017 the Basin lake on the golf course next to Wanstead Park had the weed cleared, mostly from the central island. This appears to be a responsibility delegated to the fishermen as part of their licence to fish. Up until that time the Basin was a good place for ducks, we often had Wigeon drop in and tens of Gadwall, Mallard and Tufties fed there. The result was that these ducks more or less disappeared and we thought this was due to the lack of cover and things would improve. They didn't and we noticed that the water looked a very dark blue. Enquiries made it clear that a food dye had been added to the water to supress weed growth. The literature indicates food dye is safe for fish and insects, but our duck do not seem to like it.

We are also concerned with the recent low numbers of duck in the other Park lakes as charted above. We had nationally significant numbers of Gadwall (in orange) on the lower lakes in 2013-6, but the numbers have tailed off recently along with Shoveller, Pochard and Tufted Duck. Resident Mallard seem to have stayed fairly constant. The overall numbers will of course fluctuate year by year but the last two years have been a cause for concern. The supply of water to the lower lakes is a problem in hot summers and both Heronry and the Ornamentals were dry last summer. This is not unusual and although this could affect the amount of food, this year seems to be particularly poor for duck numbers with the duck numbers on Wanstead Flats higher than in the Park for the first time we are aware of. We know that the water flow through the Park is from the Basin through the other lakes to the Roding. We are suspicious that the food dye in the Basin may be seeping through to the lower lakes and having a detrimental impact on duck numbers. To counter this idea numbers of Odonata seem to be fine, though without a proper survey.
One way of eliminating immediate local climatic factors is to look at the total peak numbers of duck in Wanstead  Park and compare that to the lakes on Wanstead Flats, where numbers have been traditonally lower.

I think this is quite dramatic, though thereasons are unclear!
We don't know whether out loss of duck numbers is a local or more general problem of course. Ducks may be staying in Europe as a consequence of warmer continental weather or in protest at Brexit? We will continue to monitor and investigate.

Comments on either of the above topics welcome.

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