Wednesday, 6 July 2016

South Moreton and the Mill Brook

There is an area between Britwell-cum-Sotwell, Didcot, Blewbury and Cholsey that is low and flat; it was formed in the late Ice Age when the Thames was blocked and formed a large lake. Up until fairly recent times the area was a marshy quagmire. It acted as a good line of defence for the Iron Age people who lived on the Wittenham Clumps (Sinodun Hills). When the area was drained it became very fertile agricultural land. The main water flow is the Mill Bourne that flows from the chalky Springs around Blewbury east to join with the Thames at Wallingford. I decided to explore the marshy banks of the Mill Brook hoping to see a range of wetland flora and fauna. I started from South Moreton which is an old village which had an old mill on the Mill Brook. 'Moreton' refers to its place in the wild 'moor' or 'marsh'. The first part had many butterflies - and this time of year it is the Meadow Browns that are in great numbers - so much so that I became rather sick of the sight of them!

On the field edges were arable weeds such as Common Field Speedwell, one of these bright flowers has an extra petal - they normally have four.

Close to the mill was a pretty little flower that I think is a garden escape - a cultivated form of a bellflower.

The village of South Moreton has a few old buildings strung along the High Street. It was for a while the home of the writer Hilaire Belloc while at Oxford - his son Peter's name is on the WWI memorial here.

I followed a path that goes under the main Bristol-Paddington railway line and into a pleasant meadow. Here were many plants in flower including Lady's Bedstraw (Galium verum) which was brought into houses to impart its fresh scent.

Another plant that had enjoying the cool and moist early summer was Self heal (Prunella vulgaris). It was a valued medicinal plant for treating small wounds, enabling people to heal themselves without needing a herbalist - hence 'self-heal'.

The meadow led down to the Mill Brook which I then followed for a few miles towards Wallingford where it joins the Thames. One of the first signs of water were lots of damselflies, principally Banded Demoiselles (Calopteryx splendens) this was a good male specimen.

This is a typical scene along the whole of this stretch - lots of wild-flowers hugging the banks of the brook. Unfortunately, as it it turned out, there were not many places where you could get a good view of the stream. Water figwort, water crowfoot and water fern are some of the many aquatic plants I saw.

Walking around the area gives you intimate acquaintance of different types of stile. These are all being gradually being replaced with rather ugly 'kissing gates' to improve accessibility. This one I thought was a good, elegant design - entirely made from welded box steel.

As well as many Meadow Brown butterflies there were good numbers of Ringlets, Small Tortoiseshells, Large Skippers. Unlike a fortnight ago there were relatively few Marbled whites and no blue butterflies at all.

I saw and heard a few warblers along the way. I am no expert on distinguishing them and will have to seek guidance on identification. I think this little one is a Marsh Warbler.

Retracing my steps and crossing to the northern bank I caught sight of a few flashes of red in the distance. Thinking it might be a Painted Lady butterfly I carefully sneaked up close. It turned out to be one of the most colourful moths you can hope to see. It is a Scarlet Tiger moth (Callimorpha dominula) and is quite at home in marshy areas like this.

I then made it back to the meadow where I had seen the Lady's bedstraw and Self heal. At the far end I saw two Pyramidal Orchids (Anacamptis pyramidalis) - compared to my last walk on chalk downs a fortnight ago a poor tally.

Near the village White Bryony (Bryonia alba) was entwining itself along the hedgerow. It is the only native wild species from the Cucumber family (Cucurbitaceae).

I then walked west to follow the upper stretches of the Mill Brooke. In the distance was the impressive terracing of the Iron Age hill fort at Blewburton Hill emphasizing the flat, originally marshy land that separated it from the Sinodun Hills to the south.

This western section was very hard to navigate - the footpath was overgrown and unmarked and the margins of the brook were now lined with large trees. In compensation on the field margin I spotted one attractive flower. It was Sainfoin (Onobrychis viciifolia). Whether this is a true 'wild' flower is debatable. It has been used as a fodder crop for millennia - as a member of the pea family it added valuable nutrition to grass meadows. Sainfoin comes from the Old French meaning 'healthy hay'. It is now quite often sown by farmers so I am not sure how long the plant had been here.

Retracing my steps to South Moreton I saw a roe deer in the distance (as I had on the last walk) - this time much more interested in feeding on freshly mown hay than the photographer.