A very rare spider found in Fingle Woods

A couple of days ago I received an email from Matt Parkins who works for the Woodland Trust in Fingle Woods. He sent me a couple of photographs of spiders he had found whilst checking the wooden dormice boxes which have been set up in the woods as part of a research and monitoring project of that species.

Spiders can be notoriously difficult to identify from photographs – often you need to put a specimen under the microscope and look at features which are invisible to the naked eye. However these two species looked identifiable just from the photographs. As a result I sent a tweet asking for help – I knew the ID of one of the species but was uncertain of the other. Kevin Rylands and Matt Prince (both of whom are top Devon naturalists) came to the rescue. The species I was unsure of turned out to be very rare nationally and quite a find. I have since done a little research so that the species and the record can be put into context.

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This is the rare one – it is the Running Lichen Spider Philodromus marginatus – it is very distinctive. This is a male and its body is around 4.5mm long – however if you add in its legs, it is around 1.5-2cm (over an inch) in extent depending on how it is settled. Photo copyright Matt Parkins.

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Here is the national distribution, courtesy of the British Arachnological Society – as you can see it is a very localised species,

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And here is the tetrad data, again courtesy of the BAS.

The Devon records are as follows:-
SX78 Coleridge Woods – part of Fingle Woods
SX77 Valley just to the east of Yarner Woods
SX76 Hembury Woods
SX55 Heddon Woods
SX56 south of Shaugh Prior woods (pre 1980)
SX78 Hall’s Cleave Wood – Fingle Woods (the most recent record i.e. this blog)

Nationally there are are now 57 records from 25 10km squares for this species. Only 15 (10km records)  of these are post 1992 records. So Devon has over 25% of the post 1992 records in terms of distribution. 4 out of the 5 sites are on Dartmoor or their very near fringes.

Surprisingly all the records, except for the Matt Parkins records, are for June to August which is in December.

So, the question that hangs in the air …. is the Running Lichen Spider more common on Dartmoor than the records suggest? In theory there are many more place places where it could be.

philodromus-marginatus-robertsThis illustration from Michael Robert’s book ‘The Collins Guides to Spiders of Britain and Northern Europe’ (a must have book for naturalists – see here) shows how cryptically camouflaged the species is. The fact that it has now been been found in constructed nest boxes might imply that this is an additional survey technique.  As a result we should try and ensure that dormouse workers and bird nest ringers are aware of this spider and keep an eye out for it when they are carrying out their nest box checks.

The other species which Matt photographed was this one.

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This is the Toad Spider Nuctenea umbratica which I know well from my time in the East of England, I have now discovered that it is less common in the South West.  Photo copyright Matt Parkins

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The 10km square appears to show it is well distributed

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The tetrad data shows that it is not that common

Keep an eye out for both these species and let me know if you find them.

 

 

 

 

 

 

 

Maize grown for AD plants increase by 55% in a year

Figures just release by Defra (see here) show that the area of land in England used to grow maize for use in Anaerobic Digestion plants to produce electricity rose to 52,280 ha – a 55% increase on 2105.

29% of all maize grown in England now is for AD plants. This accounts for 1% of all arable land in England.

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As I, and many others, have repeatedly said maize can be implicated with increased flood risk (see here and  here for my collection of blogs on the topic).  Maize is harvested late in the year and the heavily compacted soils are left bare all winter. During periods of high rainfall these soils do not absorb the water to any great extent – instead the water rushes off the fields, particularly when they are on slopes and quickly overwhelms stream and river systems. When this happens extensive soil erosion can also occur.

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Here is an example of the phenomenon from Herefordshire  last month following Storm Angus as reported by the Environment Agency

Prior to its abolition earlier this summer, following Theresa May’s appointment as Prime Minister, the Department for Energy and Climate Change had issued a consultation paper which included two options to reduce the incentives for farmers to grow maize for AD – see here.

I haven’t heard the outcome of that consultation and I’m not sure which government Department is now responsible for it – Defra maybe? Does anyone else know?

The 55% increase in maize grown for AD announced today would not have been influenced by the DECC consultation as the seeds would have been already sown. It would however be helpful if an announcement is made soon as it would potentially influence sowing intentions next spring and I don’t think anyone (other than the maize farmers concerned) want to see a further increase in the area of maize grown in England with its attendant increased flood risk and heightened soil erosion potential.

 

A blue jellyfish at Orcombe Point

A friend of mine sent me this photograph of a large blue jellyfish that had washed up yesterday on the beach near Orcombe Point at Exmouth.

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Apparently it is about 2 feet across.

I think it is a Barrel Jellyfish which can be up to 3 feet across and can occur in a variety of colours ranging from white through to blue.

We are quite used to seeing jellyfish on our beaches and in the sea during the summer months and into the autumn but I wonder whether a December record is unusual?

Thanks for the picture and the tip off Caroline.

25 December moths in the trap this morning!

This morning there were 25 December moths in my trap – I’ve never seen that many before! The milder weather has certainly brought the moths out.

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Four December moths on the egg box in the trap (this gives the moths somewhere to rest / hide)

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Close up of a December moth

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A Winter moth (perhaps a Northern Winter moth – they are very similar)

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One of 6 Feathered Thorns

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A Dark Chestnut

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A Red-green Carpet

December and over 40 individual moths in the trap!

Three Tors and an optical illusion

Lots of people know that the huge TV mast on Dartmoor is located at North Hessary Tor – it is one of the major features we use when navigating on the moor.

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It can however prove to be a bit of an optical illusion – here is the mast with a Tor at its base – so this must be North Hessary?
south-hessary-1Stand back a bit and slightly change the angle and you can see that North Hessary is further back – to the left is Rundlestone Tor – so the Tor in the picture above is Rundlestone Tor.

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Standing at the Hamlet of Rundlestone  you can see this Tor on the slopes up to Rundlestone Tor and Hessary Tor – this is Hollow Tor.

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Standing a bit to east under Great Staple Tor you can put all three Tors into perspective. Rundlestone Tor to the left, Hollow Tor in the middle and North Hessary (with the mast) to the right.

Our 10 Tors Christmas Walk

Yesterday was our last 10 Tors  training walk of the year – not a long walk just around 4 hours which culminated in our traditional Christmas lunch in the car park below Great Staple Tor.

Earlier in the day we had been over to Fice’s Well to checkpoint our 45 and 55 mile teams. As the morning progressed the wind picked up and it was bitterly cold.

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A horse shoe on a granite wall on the way down from Great Mis Tor

great-mis-tor-posterI used this photo in my blog yesterday – I’ve had a play in Photoshop and I quite like this version too.

xmas-pastyIn total there were nearly 80 of us out yesterday and at the end of the walk we had warm pasties, warm mince pies and hot ‘mulled’ fruit juice. A feat of hard, work, timing and improvisation – thanks Karrie

xmas-treeWe even had a Christmas tree!

vixen-torLooking down from the car park is Vixen Tor – one of the very few on Dartmoor you can’t visit.

pew-torAnd looking across to the west is Pew Tor with a herd of galloway grazing the Common below

 

Up to Great Mis Tor

This is my favourite picture from our walk on Dartmoor today

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The path up to Great Mis Tor with Little Mis Tor on the left – it was might cold in the wind when we weren’t walking and even then it wasn’t great !

The newtakes with the moor beyond.

Out of shot to the left all the ewes (female sheep) are in the fields for ‘tupping’ – i.e. mating with the ram (the male sheep) – soon they will be back on the Commons