Repair work at the Heronry Pond

The Heronry Pond is being refilled from the borehole after the recent draining of the lake.

The lake was drained in order for repair work to be carried out on the concrete lining at the east end, where tree-roots had broken through and destroyed parts of the existing lining. Apparently this work was necessary to comply with the Reservoirs Act, for the lakes in Wanstead Park come under that category.

I felt it a shame that millions of gallons of water had to be drained out at this time of year, albeit the water was transferred into the adjacent Perch Pond so was useful in keeping that and the Ornamental Waters topped-up. It was the time of year that dismayed me - a time when many birds, particularly Coots and Moorhens were nesting. The Coot's nests in particular provided a strange sight, left high and dry - really high! Little Grebes did not do so well with their breeding this year, and perhaps this didn't help?

The fish in the lake were stunned and removed to another lake, but of course that is only the larger fish. Smaller ones - of which there would have been many fry at this time - were left to ever-decreasing areas of water and shallows. One positive result of this aspect was the remarkable sight of up to seven Little Egrets at a time having a feast. I suspect the fish and other creatures weren't quite so happy about things, and I suspect that possibly MILLIONS of creatures perished because of the changes in their environment.

It was interesting to be able to observe crayfish in the shallows (unfortunately the invasive North American ones - not our native species) as well as Great Pond Snails, and - distressingly, I thought - Swan Mussels lying high and dry on the drying mud and algae. I even went to the trouble of rescuing one that I thought still may be alive and depositing it in some remaining water.

swan_mussel_hp_0650Swan Mussel in Heronry Pond

The repair work is complete - you can see the lighter-coloured cement between the Northumberland Avenue gate and the refreshment Kiosk - but considering the considerable expense that this must have involved and the damage - as I see it - to the wildlife, I have to ask why when the lake was drained was the opportunity not taken at least to clear some of the accumulated debris from the pond - particularly along the east bank? An opportunity missed, I think.

Paul Ferris 4th September 2009

Water supply work near the Shoulder of Mutton Pond in Wanstead Park

 

Recently digger and tree-felling activity has taken place at the west edge of the Shoulder of Mutton Pond where the stream from Reservoir Wood flow in. This is a lovely area of reed-beds and overgrowing vegetation. There is a large poplar tree that had fallen to bridge the Reservoir Stream which had re-rooted and put up a lot of new growth - a phoenix tree!

Reservoir StreamReservoir Stream

This gives rise to a remarkable area, not too disturbed by people so great for visiting and nesting birds. The area has recently been cleared to allow more ready access for the water supply from the stream, making the ditch wider. The lake system certainly needs all the water it can get. However, a reed-bed filter is not too bad an idea - it helps filter out unwanted materials and chemicals before they get into the lake. It is perhaps unfortunate that so much of the regrowth of the tree has had to be cut away presumably to allow the machinery through, but the vegetation will recover and should regain something of its previous character.

 

Paul Ferris, 3rd September 2009

Migration Excitement on Wanstead Flats

Anyone visiting the Flats on the last Saturday of August 2009 could have been forgiven for thinking they had been transported to one of the UK's coastal bird migration hot-spots. As I was walking towards Jubilee Pond just after 8 a.m. I received a text message from Jonathan Lethbridge - at the other end of the Flats - telling me he'd just seen a Spotted Flycatcher, a Redstart and three Whinchats. Minutes later I was watching four Whinchats in one tree, while a group of distant pipits flitted between trees. Unfortunately, I couldn't get close enough to make up my mind whether they were the Tree or Meadow variety, and I didn't hear them call. However, my suspicion is that they were the former species and - like the Whinchats - on the move from breeding sites unknown. Evidence of a good breeding season, and the great importance of this tract of the Flats, I saw at least 12 Common Whitethroats in the area just south of Lake House Road.

The combination of the time of year, with many of our summer visitors beginning their long migrations south, and a spell of overnight rain which had probably encouraged many to pitch down in the nearest suitable habitat, had clearly produced something very exciting.

When I reached the broomy area south of Long Wood I couldn't believe my eyes. Wheatears and Whinchats seemed to be everywhere I looked! I counted four Northern Wheatears in one hawthorn, while another three hopped around on the dusty track. In the broom itself there were at least five more Whinchats - but it was difficult to be sure of the number because of their constant flitting from plant to plant.

I joined Paul Ferris near Alexander Lake, where we searched in vain for the Redstart and the Spotted Flycatcher. Just after I left Paul I found another Wheatear on the edge of a football pitch.

It is notoriously difficult trying to accurately assess numbers of small migrating songbirds, but piecing together the evidence from my own observations and those of Stuart Fisher, Jonathan Lethbridge and Paul Ferris, the migrant 'fall' involved at least three Yellow Wagtails, three Redstarts (two of these being males), eleven or twelve Whinchats, eight Wheatears, one Lesser Whitethroat, a dozen or more Common Whitethroats, several Chiffchaffs, three Willow Warblers, a Spotted Flycatcher and up to eight Tree Pipits.

Expecting the migrants to have departed overnight, imagine my surprise when the following morning there were still five five Whinchats (a mixture of adults and young birds) south of Long Wood. And on the bank holiday Monday a 'new' female Redstart was near Jubilee Pond, with seven Whinchats nearby and another four of the latter species to the east of Centre Road.

It's weekends like this that local patch-watchers live for. Eat your heart out, Cley!

Tim Harris, 1st September 2009

Little Egrets at Wanstead Park

Following a visit to the Heronry Pond in Wanstead Park of a Little Egret on 9th July 2009 and on subsequent days, a number of people including Jennifer Charter and Kathy Hartnett reported seeing two of these birds on on 20th July.

Little Egret, Heronry PondLittle Egret feeding at Heronry Pond, Wanstead Park

They were apparently making use of the low water-levels in the lake as it was being drained for some concreting work to take place at the eastern end. As water levels dropped, numerous small fish and other creatures would have been easy prey for Egrets. It is amusing to watch them agitate the water with a foot (often a bright yellow foot!) to stir up creatures that they might find tasty. Quite tolerant of man and dog, they are easy to view either perched in a tree or feeding in the water.

These very attractive almost pure-white small herons are birds of the Mediterranean and North African area, who not long ago were rare visitors to Britain. Increasingly over the years they have visited the south coasts, eventually breeding and spreading northwards. Now they are a common sight on the Essex coast, and have occasionally been seen as short-stay visitors to our area.

Either one or two Little Egrets became a common sight over the next week or so, but on 3rd August, seven birds were present, making a quite spectacular sight as the either fed together, perched in trees or particularly when they all took flight at the same time.

A nice addition to our species, they don't seem to have any serious adverse effects on our present wildlife.

Paul Ferris, July 2009

 

The Slender Groundhopper Tetrix subulata in Wanstead Park

On 24th April 2009 I had a look at one of the very overgrown outcrops of land that form the sculpted south edge of Heronry Pond. On what is left of a track that leads almost un-noticeable off the Northumberland Avenue Strip, an insect flew across my feet and landed nearby - apparently a grasshopper. I couldn't understand why a fully-grown grasshopper was around at this time of year, so determined to take a photograph as a record. It was from the photograph that I later identified it as a ground-hopper, an insect closely related to grasshoppers and crickets.

There are only four species of ground-hopper to be found in Britain, and they are found in a variety of places where there is some grass cover. However, they don' t favour extensive grass cover so tend not to be found in the same type of habitats where we would expect to see grasshoppers.

Slender Groundhopper Tetrix subulata

They are active by day, and their activity depends on the temperature. 24th April wasn't a cold day, but it was April and I wouldn't have expected to find grasshoppers so early in the year. However, a major difference in behaviour between grasshoppers and groundhoppers is that the latter survive the Winter as adults and may be active all the year.

In Essex only two species are recorded on the Essex Field Club's database: the Common Groundhopper Tetrix undulata and the Slender Groundhopper Tetrix subulata, so it was likely to be one of these.

Two major differences became apparent: groundhoppers differ from grasshoppers in that their pronotum extends to the tip of the abdomen, whereas in grasshoppers it is much shorter. The Common Groundhopper has relatively short hind wings and is flightless, whereas the Slender Groundhopper wings reach right to the tip of its longer pronotum. That fact was clear from the photographs, and the fact that it flew across my feet helped too! The Common Groundhopper also favours somewhat drier situations, whereas the Slender Groundhopper is often found in damper ones; tangled vegetation next to Heronry Pond meets that criteria. The creature was then a specimen of the Slender Groundhopper Tetrix subulata.

Finally, it is interesting to note that this is the only record of this species in the whole of Epping Forest. I hadn't seen one before, and I haven't seen one since.

Paul Ferris, 25th April 2009