Wednesday 21 August 2013

Brown Hairstreak Central 21st August 2013

Elated by my unprecedented success at seeing so many Brown Hairstreaks last Sunday I returned today to Otmoor to try and repeat the experience. Heaven knows when such an opportunity will present itself again so it seemed wise to make the most of it. Let's face it the last few years have been pretty dire as far as butterflies are concerned and this year is surely exceptional.

I arrived in the mid morning with a gentle wind swaying the umbellifers, the grass was still damp underfoot from either dew or overnight rain but the sun was rapidly climbing into a blue sky and drying off the moisture. There were lots of cars in the reserve car park but no-one came down the Roman Road as presumably everyone headed for the main part of the reserve. I wandered back and fore along the track in my silent and solitary quest and initially there was no sign of any Brown Hairstreaks although there were plenty of other butterflies. I stood by my favourite spot, the cul-de-sac of brambles, willowherb and angelica, half way down the track and just waited which really was no hardship in the gentle breeze, warming sun and soothing quiet of the Roman Road. 

The Roman Road

Cul-de-sac of brambles and angelica a favoured spot of Brown Hairstreaks
Two Commas were feeding on the bramble flowers as were a few Meadow Browns and Large Whites and a dissolute Large Skipper was sunning itself on a purple Great Willowherb flower but there was no sign of any Brown Hairstreak and the Wild Angelica flower heads, unlike on Sunday, were devoid of the tiny dark triangle perched on the froth of white flowers which signified the presence of a hairstreak. 

A wandering party of tits and warblers, the latter mainly ChiffChaffs and Willow Warblers moved through the hedgerow, excited and calling, the warblers zipping in and around the angelica stalks catching insects. A larger bird hung upside down from one of the angelica stalks. It was a Nuthatch and acrobatically it snatched insects from the stalks. I have never seen this behaviour before but that is the charm of relaxed observation, there is always something to see and learn. The party moved on, now invisible in the hedgerow but still audible with an errant Common Whitethroat the last to leave.

A Southern Hawker dragonfly patrolled the upper air space then came to rest on a willow, hanging in sinister beauty from the shaded trunk to which it clung. It moved it's eyes like some mechanical toy and cleaned them jerkily with one of it's black legs. 

I strolled back along the track and on some brambles straggling through the sheltering hawthorns a small brown butterfly fluttered hesitantly over the blackberry flowers, about to settle then not, constantly dithering. Finally it settled and there was a somewhat frayed and ragged specimen of a male Brown Hairstreak. I watched as it flew from flower to flower. I found another male, nearby on the other side of the track, this one less worn but still looking somewhat faded and with chunks out of the lower wings

Male Brown Hairstreak.
Compare the colour of its underwings to those of the female pictured below
Enthused by this initial success I went in quest of more. My search centred on my favourite blackberry cul-de-sac and sure enough as I stood there I noticed a tiny orange triangle on a delicate white blackberry flower amongst the green foliage. It could have been dismissed as just a small dead leaf but a look through the binoculars confirmed it was a pristine Brown Hairstreak feeding on the delicate pink blushed blackberry flowers. I watched it diligently feeding, moving with almost mincing steps as it worked it's way around the flower and then I tickled it's body with a grass stem to make it open it's wings and sure enough it did exactly as desired and flashing two large orange patches on it's forewings confirmed it was a female. 

Female Brown Hairstreak
I fell to contemplating this experience and that of the previous Sunday. All the females I have seen on both days have been a really bright orange brown on their undersides.They really do stand out. All the males I have observed have been much darker on the undersides of their wings. Almost drab compared to the female. Is this a diagnostic way of telling male from female without waiting  for them to open their wings, which can take an awfully long time if indeed it does occur at all whilst watching them? The Brown Hairstreak unconcerned with my deliberations flew down to my feet and then perched on some nettles right by the track. I took it's picture with the camera and then with my I-phone, holding it literally millimetres from it's delicate wings and body. Untroubled it carried on it's own private existence. It transferred it's attentions to a thistle head and after some time flew up onto some Greater Bindweed leaves and opened it's wings to the sun. Unsettled it soon rose and ascended into the tops of the blackthorn bushes standing sentinel along the track. 

The sun was now high in the sky and the increasing warmth resulted in squadrons of Common and Ruddy Darters, previously invisible, appearing and accompanying me like planes in formation, flying low before me along the track. Without exaggeration there were hundreds. I stopped to look at another Comma flashing marmalade orange wings on the blackberry leaves and as I watched a Hornet tried to mug it but the Comma was too quick and with a flick of it's wings evaded the lumbering Hornet. Thwarted the Hornet careered around the blackberry flowers attempting to capture any insect that was not on full alert to it's presence. The attacks were not subtle and the last I saw it had, unsurprisingly, not been successful. Two hours had passed and my wanderings up and down the track produced no less than nine Brown Hairstreaks, four females, three males and two which had to be left as just a sighting. The gentle wind sighed as did I. Autumn is on the way. These last days of warm breezes and summer sun will soon be gone as will the hairstreaks

No comments:

Post a Comment