I spent last weekend exploring the quarries of Portland for the Silver-studded Blue - Plebejus argus. Listed below are the sites I visited and the number of butterflies that I encountered. On the Saturday, I arrived at 12 am, it was sunny but in the afternoon cloudy with some rain and windy. In the late afternoon it was full sunshine. On the Sunday it was warm with sunny spells. I must admit that I had trouble finding many pristine examples to photograph.
Tout Quarry - 8. 5 males - 3 females.
Kings Barrow Quarry - 1 male.
Broadcroft Quarry - 9. 6 males -3 females.
Nicodemus knob. Coastal site to the east of King's Barrow Quarry - 0 . My visit here on the Friday coincided with windy weather and perhaps I was too early on the Saturday, the bank below the rock feature was in shadow. On the 25th June 10 were recorded here - Dorset butterfly sightings.
On the Saturday in Tout Quarry, I made the aquaintance of Ken a local naturalist and entomologist from Easton. Ken like others, considers the Portland Silver-studded Blue as subspecies cretaceus. A equal number of other lepidopterists state that cretaceus is infact extinct.
I have seen historical cretaceus specimens from quite a few of its localities on its former range of the North and South Downs. The females of cretaceus were a bit of a mixture, some with various amount of blue scaling on the wings, often confined to the inner areas of the forewings . The red sub marginal spots were often much brighter in the females on the chalk downs. Also there is the historic specimen from Dover on the species page showing the brown female. Historical specimens are a very valuable resource for study and I have included a few of the rarely seen extinct chalkland race of cretaceus.
The eastern most locality for cretaceus was the chalk downland near Bishops Waltham in Hampshire and females from this locality were very pretty with various amounts of blue scaling. The extinct chalk downland cretaceus race was thus seperated from the Silver-studded Blue on Portland by a considerable distance and the extensive lowland heathland populations of Plebejus argus.
On Portland the limestone race is quite a scarce butterfly with very small populations quite unlike the extensive colonies of the other limestone race caernensis on the Great Orme. It seems to me that the Silver-studded blues on Portland may be a relic population cut off from the extensive heathland colonies in Dorset. It really does not seem suited to its quarry habitat, which as Broadcroft quarry shows, rapidly becomes overgrown with scrub, with the butterfly there mainly occurring in the conservation scraped areas to the east of the quarry road. un - helmeted local youths on their mini motor bikes seem to like this area and spoil what would be a lovely site.
In Tout Quarry, the Silver-studded blues I found were along one short sheltered enclosed section of the sculpture park and the males liked one particular area of low privet-bramble to bask on where on two occasions they were joined by females.
Other notable butterflies seen were Lulworth Skipper. 2 at Broadcroft quarry.
Chalkhill Blue 1 male - very early for this butterfly. Tout Quarry.
Grayling. 2 at Tout Quarry. Photo.
Dingy Skipper 1 at Tout Quarry. Very late for this butterfly. photo.
May I remind members that if they find any blue females of Silver-studded blues among the lowland heath populations of southern England to show them here. Preen Heath in Shropshire has some and so has the dune population in Cornwall.
Peter.
Tout Quarry.
Broadcroft Quarry.
Historical specimens of subspecies of cretaceus.
Tout Quarry.
The Portland Silver-studded Blue.
The Portland Silver-studded Blue.
Last edited by nomad on Mon Jul 07, 2014 7:10 pm, edited 4 times in total.
- Pete Eeles
- Administrator & Stock Contributor
- Posts: 6815
- Joined: Tue Jan 17, 2006 6:10 pm
- Location: Thatcham, Berkshire
- Contact:
Re: The Portland Silver-studded Blue.
Great report, Peter - thanks for sharing!
Cheers,
- Pete
Cheers,
- Pete
Life Cycles of British & Irish Butterflies: http://www.butterflylifecycles.com
British & Irish Butterflies Rarities: http://www.butterflyrarities.com
British & Irish Butterflies Rarities: http://www.butterflyrarities.com
Re: The Portland Silver-studded Blue.
I am glad you enjoyed the report Peter. I had a wonderful weekend. I stayed in the Bird Observatory.
- Neil Freeman
- Posts: 4471
- Joined: Fri Jul 23, 2010 6:25 pm
- Location: Solihull, West Midlands
Re: The Portland Silver-studded Blue.
Hello Peter,
Very interesting report and great photos too. I was in Weymouth for a family holiday last week and managed to do some butterflying, part of which was a few hours on Portland last Monday(30th June).
I only had time to visit Broadcroft and Tout quarries looking for Silver-studded Blues and my experience was similar to yours, 7 males and 1 female at Broadcroft and 4 males and 2 females at Tout. Most were very worn and faded, especially at Broadcroft, but I did find a nice condition male at Tout Quarry.
I also saw 3 male SSBs on Bindon Hill at Lulworth on 2nd July which I reported in the July sightings thread,
viewtopic.php?f=8&t=7713
I have never seen SSBs reported from here before, although I understand one was seen on transect recently, and an wondering how they got there ? I am not sure where the nearest lowland heath population is but I visited Tadnoll Heath earlier the same day and saw half a dozen SSBS there.
Reports and photos will be in my diary, hopefully later this week when I have caught up a bit.
Cheers,
Neil.
Very interesting report and great photos too. I was in Weymouth for a family holiday last week and managed to do some butterflying, part of which was a few hours on Portland last Monday(30th June).
I only had time to visit Broadcroft and Tout quarries looking for Silver-studded Blues and my experience was similar to yours, 7 males and 1 female at Broadcroft and 4 males and 2 females at Tout. Most were very worn and faded, especially at Broadcroft, but I did find a nice condition male at Tout Quarry.
I also saw 3 male SSBs on Bindon Hill at Lulworth on 2nd July which I reported in the July sightings thread,
viewtopic.php?f=8&t=7713
I have never seen SSBs reported from here before, although I understand one was seen on transect recently, and an wondering how they got there ? I am not sure where the nearest lowland heath population is but I visited Tadnoll Heath earlier the same day and saw half a dozen SSBS there.
Reports and photos will be in my diary, hopefully later this week when I have caught up a bit.
Cheers,
Neil.
Re: The Portland Silver-studded Blue.
Hi Neil
A really surprising find of Silver-studded Blues on the chalk of Bindon Hill. Like you, I have never heard of them from that locality. I wonder how long they have been at this site. It would be very interesting to see if there is a small breeding population, as I expect this lovely little butterfly bred in this area. Your find certainly warrants further investigation. I agree that the Silver-studded Blue on Portland is a scarce butterfly with very small populations. I expect the stone at Portland has been quarried for a very long time creating a open habitat. The original habitat must have been open limestone grassland.
Regards Peter
A really surprising find of Silver-studded Blues on the chalk of Bindon Hill. Like you, I have never heard of them from that locality. I wonder how long they have been at this site. It would be very interesting to see if there is a small breeding population, as I expect this lovely little butterfly bred in this area. Your find certainly warrants further investigation. I agree that the Silver-studded Blue on Portland is a scarce butterfly with very small populations. I expect the stone at Portland has been quarried for a very long time creating a open habitat. The original habitat must have been open limestone grassland.
Regards Peter
Re: The Portland Silver-studded Blue.
Fine report Peter, its little wonder Silver-studded Blue has proved so fascinating for lepidopterists over countless years, the advent of the digital camera has replaced the net and we are able to take countless record shots and peruse for abberants and the unusual on our PC screens at leisure
sharing information with others about such interesting historical records as you present in your post only adds fuel to the fascination. Myself and David M spent an exceptional day with the species in Pembrokeshire on Saturday week and I now share with yourself and many others a special enthusiasm for S-s B
Thank you for sharing!
Bill
"When in doubt...venture out"
![Smile :)](./images/smilies/icon_smile.gif)
![Wink :wink:](./images/smilies/icon_wink.gif)
Thank you for sharing!
Bill
![Very Happy :D](./images/smilies/icon_biggrin.gif)
"When in doubt...venture out"
Why not visit my website at http://www.dragonfly-days.co.uk
Re: The Portland Silver-studded Blue.
Hi Bill
I am pleased that you enjoyed my report. I also enjoyed reading your account of your trip to see the little visited Pembrokeshire populations and seeing your fine images taken on your trip. It is true, this is a really fascinating species to study for geographical variation. Perhaps next year, I will go to see the population occurring on Holyhead mountainin in Anglesey. I believe the females here are very blue and quite similar to caernensis.
Regards Peter.
I am pleased that you enjoyed my report. I also enjoyed reading your account of your trip to see the little visited Pembrokeshire populations and seeing your fine images taken on your trip. It is true, this is a really fascinating species to study for geographical variation. Perhaps next year, I will go to see the population occurring on Holyhead mountainin in Anglesey. I believe the females here are very blue and quite similar to caernensis.
Regards Peter.
- Neil Freeman
- Posts: 4471
- Joined: Fri Jul 23, 2010 6:25 pm
- Location: Solihull, West Midlands
Re: The Portland Silver-studded Blue.
Hi Peter,
Report and photos from Portland now in my PD,
viewtopic.php?f=29&t=5424&p=87662#p87662
Cheers,
Neil.
Report and photos from Portland now in my PD,
viewtopic.php?f=29&t=5424&p=87662#p87662
Cheers,
Neil.
Re: The Portland Silver-studded Blue.
Hello Peter,
Yes indeed, our Pembrokeshire colony is the only Silver-studded Blue population outside North Wales, the Great Orme is reknown for var. caernensis and as you mention the Holyhead Mountain population in Anglesey have interesting female colours to find and study. The other 'stronghold' of the species in North Wales is in the Dulas Valley, I have no personal knowledge of this site though. Morfa Harlech is also worthy of investigation and is not too far from Anglesey (Ynys Mon). You could have quite a Silver-studded holiday in North Wales with a little planning. The Great Orme in particular is a stunning place with much to recommend a visit, but you might have already enjoyed that pleasure
I shall be doing a post in my Personal Diary in a day or two outlining our day spent with the Pembrokeshire colony, do hope you can take a look.
Kind Regards,
Bill
"When in doubt...venture out"
Yes indeed, our Pembrokeshire colony is the only Silver-studded Blue population outside North Wales, the Great Orme is reknown for var. caernensis and as you mention the Holyhead Mountain population in Anglesey have interesting female colours to find and study. The other 'stronghold' of the species in North Wales is in the Dulas Valley, I have no personal knowledge of this site though. Morfa Harlech is also worthy of investigation and is not too far from Anglesey (Ynys Mon). You could have quite a Silver-studded holiday in North Wales with a little planning. The Great Orme in particular is a stunning place with much to recommend a visit, but you might have already enjoyed that pleasure
![Wink :wink:](./images/smilies/icon_wink.gif)
I shall be doing a post in my Personal Diary in a day or two outlining our day spent with the Pembrokeshire colony, do hope you can take a look.
Kind Regards,
Bill
![Very Happy :D](./images/smilies/icon_biggrin.gif)
"When in doubt...venture out"
Why not visit my website at http://www.dragonfly-days.co.uk
Re: The Portland Silver-studded Blue.
Hi Bill
Yes, I went to the see the Silver-studded blue subspecies caernensis on the Great Ormes a few weeks ago. A lovely subspecies and a beautiful site. Please see my post on this forum where you can see my report and images. I believe the populations in the Dulas Valley are also introduced caernensis. The Holyhead populations of this species seem very interesting with the blue females, which are perhaps larger and I have never heard of this population referred to as subspecies caernensis. The Morfa Harlech colony also would be good to visit and study.
Perhaps next year I will combine the two. Anyone here been to see either of these Silver-studded blue colonies. I look forward to your personal diary post.
Kind Regards Peter.
Yes, I went to the see the Silver-studded blue subspecies caernensis on the Great Ormes a few weeks ago. A lovely subspecies and a beautiful site. Please see my post on this forum where you can see my report and images. I believe the populations in the Dulas Valley are also introduced caernensis. The Holyhead populations of this species seem very interesting with the blue females, which are perhaps larger and I have never heard of this population referred to as subspecies caernensis. The Morfa Harlech colony also would be good to visit and study.
![Smile :)](./images/smilies/icon_smile.gif)
Kind Regards Peter.