Longhorn moths' dances curtailed by breezy weather

 Over the last couple of weeks I've seen a lot of these male yellow-barred longhorn moths, which have extraordinarily long antennae. They are at their most fascinating when the males congregate and perform aerial dances to impress females, rising and falling in the air, as if attached to invisible bungee cords. 

This one was resting on a bramble leaf in Backstone Bank wood, in the Tunstall valley in Weardale, where I suspect the breeze blowing through the trees prevented it from dancing. Those long antennae make the insects aerodynamically unstable on windy days, but do allow them to detect the scent of females, which have shorter antennae, from a long distance.

Backstone Bank wood

Thursday's Guardian Country Diary is about this fledgling tawny owl that we found comfortably ensconced in the crevice formed by the roots of an oak tree in Backstone Bank woods in Weardale. 

Here it is on the day that we found it .....

.... and here it is a few days later, although this might not be the same bird; it most likely had siblings, which the parents had distributed around the wood and would come back to feed at dusk.

Backstone bank is an ancient woodland SSSI and part of the forest that once clothed Weardale. It's a lovely sessile oak wood on acid soil, covering the hillside on the eastern edge of Tunstall reservoir.It's a popular spot for birders, not least because ....

...pied flycatchers nest there. Above, a male, below, .....

..... his consort, who is nesting ....

... in this nest box.

While we sat and watched this long-tailed tit caught caterpillars ...

... and this robin paid us a visit.

The woodland has lots of fallen wood that is left to decay, gradually sinking under a blanket of moss and woodland wild flowers.

There are some nice stands of wood horsetail and lots of ...

... bilberry.

Yellow pimpernel, an indicator species of ancient woodland, is plentiful here.

The trees are mainly sessile oak, with ash, hazel holly and birch and some scattered bird cherry and rowan.

All in all, a lovely place for a tawny owl to raise a family.

Boletus

I found this beautiful bolete amongst the old oaks in Backstone Bank wood, near Wolsingham in Weardale, this morning. Think it might be an oldish specimen of the cep or penny bun Boletus edulis, judging by the whitish edge to the cap - but not sure.

Vegetable Vampires 1: Common Cow-wheat

Backstone Bank wood near Wolsingham in Weardale has an interesting ground flora - one factor that qualifies it for SSSI status - and it includes this attractive little plant that blooms amongst the bilberry around the western edge of the wood. This is common cow-wheat Melampyrum pratense and although it looks harmless enough it's a partial parasite (hemiparasite) on the roots of bilberry. Its green leaves carry out photosynthesis and produce sugars but its roots invade those of the bilberry, siphoning off water and mineral nutrients.

Specialist hemiparasites like this thrive in soils with low fertility where there is intense competition for essential but scarce minerals, like nitrogen and phosphorus, because they are the botanical equivalent of vampires, tapping into the internal plumbing system of their host to supplement their own nutrition.

This is common cow-wheat but for pictures of its much rarer cousin small cow-wheat Melampyrum sylvaticum take a look at Mark's Beating the Bounds blog.

Some plants (holoparasites) have taken parasitism one step further, losing their chlorophyll and becoming totally dependent on their host for all their nutritional requirements - you can find a common example here and an extremely rare and beautiful example here.

Backstone Bank Wood

Today's Guardian Country Diary describes a late winter walk from Salter's Gate, high on the moorland above Tow Law in County Durham, down to Tunstall Reservoir and Backstone Bank wood. The most picturesque way to approach the wood is to first follow the route of this old railway line, part of the old Stockton and Darlington railway that was opened in 1845 to carry passengers and coal to the ironworks at Consett. The line closed in 1939 but it must have been a great train ride in its day ....

... with wonderful views down to the reservoir, built in 1879, .....

... and across wild moorland of Wolsingham Park Moor.

When you leave the rail track and follow the stony path downhill it takes you down past larch and spruce plantations, that have a wonderful scent of resin on a winter's day.

After heavy rain, all the way down you are never far from the sound of water cascading down from the hillside in the feeder streams that drain into the reservoir

...until you reach Backstone Bank wood, an ancient semi-natural woodland of oak, holly and birch that's now an SSSI.

The path through the woodland skirts the edge of the reservoir and is popular with birdwaters. There are sandpipers here in summer, geese and ducks on the reservoir and woodland birds that include redstarts and pied flycatchers. This, incidentally, is the point where we crossed paths with that magnificent pheasant that I mentioned in an earlier post.

At this time of year the brightest green is confined to the woodrushs - still flattened from the winter snow - and new growth of mosses.

The humidity makes this a good spot for lichens like this Cladonia...

... and in late winter many mosses, like this Polytrichum species, produce new growth before the leaf canopy develops in spring and casts them into shade.

The oaks are rooted in poor soil in a severe climate so growth is very slow. Near the end of the walk through the wood we came across this stump that had been cut, presumably to remove a tree that had blown down in the recent gales. We gave up counting the annual rings after we got to 100 but they are each notably narrow - testament to the short growing season.

When you emerge from the wood the path crosses the dam wall, with this view of water overflowing and cascading down the spillway into Waskerley Beck, which must have extraordinarily well oxygenated headwaters. It eventually flowers into the River Wear at Wolsingham, at the bottom of the valley.