Friday, May 22, 2015

Knucklebone floor

We walked in the wonderful Allen Banks in Northumberland yesterday, where the spring foliage on the trees was looking almost luminous. On the way we passed .....

...... this extraordinary knucklebone floor, on the site of a former summer house. I've blogged about this before but am doing so again because there are now a few more web sites with information about these strange floors. Knucklebones were a construction material that seems to have been most popular in the early 18th. century but there are also 19th. century examples. They were were made by hammering sheep knucklebones into the ground to form a hard, durable floor. I suppose the modern equivalent is block paving.

Some knucklebone links:

A deer knucklebone floor in Devon - another picture here

Preparation of sheep knucklebones for making a floor

These bones have been worn smooth by passing feet, exposing some of their internal structure.

The Allen Banks summer house floor is circular .....

...... and it must have had a magnificent view across the river Allen gorge from this high vantage point.

Wednesday, May 20, 2015

Marsh violet

If we hadn't been caught in a heavy rain shower that forced us to shelter under a tree in Hamsterley forest yesterday morning, I probably wouldn't have noticed these delightful little marsh violets growing in a ditch.

A closer look revealed several large patches of them, which is good news because they are the food plant of the caterpillar of the small pearl-bordered fritillary, a rare butterfly in County Durham.

I'll be going back for another look at regular intervals, just in case the butterflies are around ...... unlikely, but you can never be sure .....

Tuesday, May 19, 2015

A dirty job, but someone has to do it....

We've found three of these dor beetles Geotrupes stercorarius blundering through the leaf litter in Backstone Bank wood in Weardale in the last week.

Dor beetles tunnel through animal dung and lay their eggs underneath, where their developing larvae live on a rich diet of faeces that's conveniently located just above their heads. It is said that adult and larva can both eat their own weight in dung everyday, which we should be thankful for: without them it might be piled high in the fields.

It seemed odd to find these in this patch of ancient woodland because there is no cow dung, which they often eat. The largest animal poo in Backstone Bank belongs to roe deer, although dog walkers' pets also make a contribution to the beetle's nutrition and child-rearing.

Dor beetles are ungainly insects and this one lost its footing, tumbled down the bank and landed, upside-down and helpless, at my feet. The iridescent blue-black colours areparticularly attractive, provided you don't dwell for too long on what it has just emerged from.

I turned it over with a twig and sent it on its way.

Dor beetles are also known as 'lousy watchmen' because they are usually infested ith mites. To see an afflicted individual that we found a couple of years ago, click here