Wednesday 13 June 2018

Black Hairstreak





Black Hairstreak colony found in Sussex. It sounds ridiculous, an early April Fools joke perhaps, but it appears to be true.





The butterflies are certainly there, on Ditchling Common, but how did they get there? The size and spread of the population suggests that the colony must have been established a long time ago. The best suggestion at the moment is that they were introduced in the 60s or 70s and have sat there, unnoticed for the past fifty years, slowly expanding their territory.






Fifty years without being noticed, it sounds unlikely but then these butterflies have a very short flight period, they stay mostly in the tops of trees, and this is probably not a well watched site for butterflies. With reports of 90+ Black Hairstreaks counted on one day this could well be one of the most numerous sites in the country.






There were a lot of people there today trying to photograph the butterflies and the area is getting a bit trampled. I expect it will be even worse by the end of the weekend. It's a pity that we do so much damage in our pursuit of a good picture.

For me the best aspect of the visit was that the butterflies were coming down onto the bracken and  also nectaring on the brambles making them easier to see. On other sites I had only ever found them in the tops of trees or down nectaring at heights of around six to ten feet.






I understand further investigation of various records is being carried out in an attempt to identify the source of the introduction. However their presence in Ditchling Common raises a number of questions. This is a species that although considered scarce and very localised, does exist over a huge range through Europe, Asia, and as far as Japan. We assume that in the UK they can only exist in the belt of land through Oxfordshire, Northamptonshire and into Cambridgeshire but why should this be. Habitat requirements do not seem to be particularly onerous and could exist almost anywhere in the south of the country.

There have been many records for the Black Hairstreak from the South of England. A number of colonies were identified in the Surrey area in the 70s and the assumption was made that these had spread from an introduction near Cranleigh in 1952 *. Possible but this is a highly sedentary butterfly. These colonies were all viable and only appear to have been lost through habitat destruction.

There are also historical records for elsewhere in the south of England but these are now all considered to have been misidentifications of the White-letter Hairstreak.

Perhaps the ramblings of a half informed amateur, but could there be more colonies out there in the South of England waiting to be found.






I have no qualms about adding it as number 47 on my Sussex list. People will argue the merits of introducing a species into an area where it has not existed before but these have now survived for about fifty generations and they still look to be prospering. That's good enough for me.




*(PDF) Black Hairstreak. Available from: https://www.researchgate.net/publication/275958378_Black_Hairstreak [accessed Jun 14 2018].




Tuesday 12 June 2018

More Green Stuff





It has all been very quiet on the birding front and even the butterflies have been slow as we wait for the summer species to appear. The solution, spend some more time looking for Orchids. Sussex can sometimes seem like a Bermuda Triangle for interesting birds, particularly at this time of year, but I can't complain about the variety of Orchids. You just need a lot of time to search for them.

Hollingsbury Hill and Wellcombe Bottom with twelve species of orchid recorded, looked like a good starting point. We didn't manage to the find the scarce Man Orchids but Fly, Greater Butterfly, Chalk Fragrant and especially Common Twayblades were found in good numbers.



Fly Orchid  -  Ophrys insectifera



Fly Orchid  -  Ophrys insectifera



Greater Butterfly Orchid  -  Platanthera chlorantha



Greater Butterfly Orchid  -  Platanthera chlorantha



Chalk Fragrant Orchid  -  Gymnadenia conopsea



Chalk Fragrant Orchid  -  Gymnadenia conopsea



Common Twayblade  -  Neottia ovata



Common Twayblade  -  Neottia ovata



Common Twayblade  -  Neottia ovata


As with the Twayblade above, not every orchid gives you a colourful flower to photograph and to help you locate them. Some are just dull greens and tend to blend into the background. The Twayblade being taller is easier to see. The Frog Orchid below, at another site, took a lot more searching and it looks as though this is as good as it gets flower wise.



Frog Orchid  -  Coeloglossum viride


The Birds Nest Orchid goes one step further. A dull brown colour, it survives by digesting fungi in the ground rather than by the process of photosynthesis. It only appears above ground as a flower spike. Fortunately in its favoured environment of deep leaf litter in shaded Beech woods there is little else growing to conceal it. This specimen just a bit past its best!



Birds Nest Orchid  -  Neottia nidus-avis



Back to more colourful varieties, Pyramidal Orchids are now starting to appear in good numbers all across the downs.



Pyramidal Orchid  -  Anacamptis pyramidalis



Pyramidal Orchid  -  Anacamptis pyramidalis


and below a very pale Chalk Fragrant



Chalk Fragrant Orchid  -  Gymnadenia conopsea v albiflora


At least I assume all the Fragrants were variety Chalk Fragrant. I am not sure that I have the skills yet to differentiate between Chalk, Heath and Marsh.







Thursday 7 June 2018

Orchids





On Tuesday I may have made a fatal mistake. Poor returns on the Sussex Commons, with very few birds found and with a cold easterly wind keeping the butterflies in cover, left us with an afternoon and nowhere to go. Dave suggested having a look for a particular orchid that he wanted to photograph and I was happy to go along with the idea.

I have spent many a session standing by whilst Dave crawled around on his hands and knees gardening and photographing wild flowers, but I have never really understood the fascination with orchids. This would have probably just been another one of those sessions except that we didn't find the the target species.

Nothing brings the "train spotting" genes to the fore like missing a target and Wednesday morning having regrouped and clarified our search data we set off for another go. It wasn't exactly easy to find but after a bit of searching we were successful, the Bee Orchid v flavescens.



Bee Orchid v flavescens  -  Ophrys apifera v flavescens



Bee Orchid v flavescens  -  Ophrys apifera v flavescens



Floret of the Bee Orchid v flavescens  -  Ophrys apifera v flavescens


Also in the same area, the Common Spotted Orchid, more Bee Orchid and also a few Frog Orchids.



Common Spotted Orchid  -  Dactylorhiza fuchsii



Common Spotted Orchid  -  Dactylorhiza fuchsii



Common Spotted Orchid  -  Dactylorhiza fuchsii



Common Spotted Orchid  -  Dactylorhiza fuchsii



Bee Orchid  -  Ophrys apifera



Bee Orchid  -  Ophrys apifera



Bee Orchid  -  Ophrys apifera



Frog Orchid  -  Coeloglossum viride



Frog Orchid  -  Coeloglossum viride



Then on to Ferring Rife where Southern Marsh Orchids seem to grow in profusion. I say seem to, as there are references on the web, to some experts believing most of them to be hybrids of the Common Spot and Early Marsh Orchids, both of which are present on the site in smaller numbers.

With my knowledge of Orchids that level of identification is beyond me. It looks like a Southern Marsh Orchid so that is what I will call it.



Southern Marsh Orchid  -  Dactylorhiza praetermissa



Southern Marsh Orchid  -  Dactylorhiza praetermissation



Southern Marsh Orchid  -  Dactylorhiza praetermissa



Floret of the Southern Marsh Orchid  -  Dactylorhiza praetermissa


And the Early Marsh Orchid



Early Marsh Orchid  -  Dactylorhiza incarnata



Early Marsh Orchid  -  Dactylorhiza incarnata



Early Marsh Orchid  -  Dactylorhiza incarnata



Floret of the Early Marsh Orchid  -  Dactylorhiza incarnata


Then I managed to find a picture of a Dark-red Helleborine that we photographed on Gait Barrow a few years ago. It was a bit past its best but I am glad I took the time to record it.



Dark-red Helleborine  -  Epipactis atrorubens



I thought this would be easy. Just take a few pictures of Orchids and identify them from pictures on the web. I can't believe how complex the identification can be. Hybrids, sub-species, variants and colour morphs, all have left me with little confidence in anything I am putting a name to. Two days lost just reading up on Orchids.

It has been suggested that I have picked up a dose of  "Orchidelirium" a highly contagious disease. I really didn't need this. Life is too short.