Wednesday, 4 March 2015

Walk: Daventry - Newnham - Daventry

The weather forecast promised a dry day, dull at first with sunshine breaking through later. The prediction was correct. It could promise temperatures no higher than about 7 degrees Celsius; unfortunately that was correct too.

I walked to the edge of Daventry and followed the A45 south-east towards Northampton for about three quarters of a mile and then set off on a minor road going south-west. It was a relief to get away from the thundering traffic of the busy main road. The first part of the journey involved a steady climb of 40 metres; the climb I welcomed (I need to get fit) but the walking was less than exciting. I turned around, anticipating fine views of Daventry but all I got was a landscape of industrial units set in a drab winter landscape (yes, I know meteorologists claim that spring started on 1 March but 20 March is a more generally accepted date). 

Anyway, I pushed on until I was almost at the edge of Newnham before turning NNW across sheep pastures. There were some fine oaks dotting the hillsides together with a rather picturesque Scots' pine.

Pines are not native to Northamptonshire or, indeed, anywhere in England but they are very commonly planted. I am told that sheep drovers on their way from Wales to Northampton or London would plant pines to indicate places where they would get a friendly reception, good accommodation, pasture, etc. But in this present case I am sure the pines are simply there to enhance the landscape.

A little further on a couple of trees had been felled and their trunks lay on the ground. Hopefully they will simply be left to moulder away. Already some wildlife was taking advantage of the habitat.

Amaurobius fenestralis was found beneath bark.
Near Newnham, Northants. 4 March, 2015

A spider, Amaurobius fenestralis, was concealed beneath loose bark, accompanied by several woodlice, Porcellio scaber (to the left of the picture). The woodlice need have no fear for spiders generally ignore them. However Dysdera species are woodlouse specialists, injecting them with a venom so powerful that the victim can be dead within seven seconds. These amber-coloured spiders occasionally find their way into houses and, with their large sinister-looking jaws, can cause some alarm. I seldom record Dysdera species in Britain but frequently note them in Mediterranean regions.

Polydesmus angustus. Perhaps our commonest millipede.
Near Newnham, Northants.  4 March, 2014

A short distance away a flat-backed millipede was revealed as I lifted another section of bark. These creatures are much neglected in general but, with about 65 species present in Britain, they are not too daunting a group to study. This one turned out to be Polydesmus angustus - no surprise really as it is probably Britain's commonest millipede; certainly it is our most common Polydesmus species. 

These slow-moving creatures appear vulnerable to predators but they secrete cyanide in the form of hydrocyanic acid (with benzaldehyde). Some people have claimed to detect an almond scent as they handle these creatures but I have never noticed it. Despite this defence they have been found in the stomachs of frogs and toads.

Heterogaster urticae, with the membranous wing-tips appearing
white with reflected light. Near Newnham, Northants

Finally the loose bark yielded a bug - my first bug of the year. In fact there were dozens of them. Disappointingly the species turned out to be Heterogaster urticae. This is extremely common but I generally find them on nettles. Clearly they must overwinter somewhere and loose bark seems as good a place as anywhere. The membrane at the wing tips is glossy and in the picture they are reflecting light and so appear white.

Usually loose bark will yield a snail or two but, although slugs were present it was a snail-free zone. I replaced the bark as carefully as possible.

I had already noticed that the soil thrown up by moles was distinctly sandy and, combined with the snail clue, I suspected that the soil was rather acid. Obviously snails require lime in their habitat for the development of shells.

A little further on I came across some gorse bushes and this more or less clinched the acid soil theory. As I have remarked elsewhere, gorse doesn't demand an acid soil but it tends to avoid lime.

I soon found myself on the Newnham-Byfield road. The walking was unpleasant, not just because the narrow, winding road was rather busy with traffic but a disgraceful amount of litter was present on the verges. Much of the discarded material consisted of wine bottles! It was good to get to the margins of Daventry and a relatively litter-free environment.

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