30th July - Old Winchester Hill

Appointments in the morning meant I only had the opportunity to get out after lunch, so decided to meet Ian at Old Winchester Hill.  There has to be an increase in butterfly numbers at some point this year and with the very hot weather this weekend I was hoping it was today.

Leaving the car park there was a good number of Red Admiral on the bramble, nothing near the numbers of last year, but at least six was huge for this year.

Walking on to the top path Brimstone once again were all over the place.

An opportunity for a close up as a male nectared on the scabious.

On reaching the hill fort we walked down the south slope.  The vegetation was quite high at first, then became a lot lower and there were plenty of Six Spot Burnets, they were liking the good number of scabious flowers around.

There a re a couple of late emerging butterflies for the year and the Chalk Hill Blue is one of them, the other the Silver-spotted Skipper.  At the bottom of the slope we suddenly found a few Chalk Hill Blues whizzing around over the grass.  At last one settled on some trefoil.

As its name suggests, the Chalk Hill Blue is found on chalk downland, although limestone downland is also used. The adult butterfly is most-often seen in bright sunshine, where the ground may appear to shimmer with the activity of hundreds, if not thousands, of males searching for a mate just a few inches above the ground, this however was not the case today, but having found one several more appeared. The distribution of this species follows the distribution of Horseshoe Vetch which, in turn, follows the distribution of chalk and limestone grassland. 

Here nectaring on a thistle head.

Another close up.

The sexes are strongly dimorphic; the males being a pale sky blue, and the females being a chocolate brown. The adults use a variety of nectar sources, and the males will also visit, often in some numbers, moist earth or animal droppings to gather salts and minerals.

The adult butterflies feed primarily on Common Bird's-foot-trefoil, Field Scabious, knapweeds, Selfheal, thistles (Carduus spp. and Cirsium spp.) and Wild Thyme.

Amongst the Chalk Hills, a female Brown Argus.

We moved back up the slope to the hill fort.  In the tall grasses at the top of the slope there was a Brown Heath Robber Fly embracing a Fly.  But the embrace is not loving.  

All Robber Fly species are fearsome predators and have piercing mouthparts that deliver the most potent toxin known of any fly (although, reassuringly, harmless to humans!). Most species hunt their prey by taking up a suitable perch and then sitting on high alert, the highly mobile head tilting and turning on the look-out for anything that might stray within range, and then darting out to capture it. Prey items vary depending on species but consist largely of other flies (including robberflies in some instances) but also parasitic wasps and sawflies, bugs, beetles and even the odd spider.  All have an elongated body and have long legs that give them a gangly appearance, often with spines on them which help them grasp their prey, much like the ‘basket’ on the front legs of dragonflies. 

Walking around the Hill Fort there were plenty of Meadow Brown moving through the grass stems and scabious.

A Small Skipper.

A Small Skipper and a typical spring away.

The flowers on the side of the north slope of the fort.

Walking around the slopes to the main hil a Painted Lady settled on the ragwort showing off the beautiful pattern on the underside of the wings.

Walking down the steep slope, I mentioned to Ian this is where I had the Dark Green Fritillary on my last visit and low and behold one appeared again.

A female, a little duller on the upper side, it still retains the green wash on the under side.

Coming out of the wood the meadow was full of Chalk Hills and Marbled Whites, but the special butterfly ironically for me was a Common Blue.  I have hardly seen any this year.

A Small Skipper on Knapweed.

And a Chalk Hill Blue on scabious.

A walk around the bottom of the car park slope couldn't find any of the Silver-spotted Skippers, but it is still early for them here at this site.

Walking up the slope we finally managed to find a Marbled White that settled on a scabious flower head.

A close up.

It is one of my favourite butterflies and when I see them I can always remember when I first identified them while on holiday in Dorset back in the early nineties.

It was a very hot day and there was a good selection of butterflies, but again lacking the quantity.  Nice to see the Chalk Hill Blues on the wing.