Neil Hulme

[lee3764]

Hi Neil,
Nice speaking with you when you visited Cornwall recently.........I am grateful that you have given other folk an opportunity to see the Long-tailed Blues at kingsdown Leas. On the strength of our telephone conversation and this posting I am considering undertaking the 350 odd mile journey from Cornwall in a week or twos time. I will keep a daily watch on this site and your postings and others to sort out my plans bearing in mind I have 2 young children (8 & 10) to take with me.........and a wife! My 10 year old is on 49 different species (as I am) this year alone in England and a L.Tailed Blue would hit the magical 50 in one year! He is already on 52 different British species in Britain in his lifetime too!!
Keep up the great reporting folks & Neil too!
All the best & hoping too for plenty of L.T. Blues this Autumn,
Lee Slaughter (Cornwall).
Joint founder member of Butterfly Conservation (Cornwall Branch) in 1993 and butterfly fieldtrip organiser for 20 years.

[Neil Hulme]

"There'll Be Tailed Blues Over
The White Cliffs Of Dover"

The events leading up to the much anticipated emergence of Long-tailed Blues on British soil started in the first week of August, when weather conditions combined with a good butterfly season to trigger a northwards movement of both common migrants and exotics. On 3rd and 4th August hundreds of Large and Small Whites appeared in almost every downland coombe I visited, along with increased numbers (but modest by 2009 standards) of Painted Lady and Clouded Yellow. 140 Clouded Yellows were reported in a lucerne field at Thorney Island on 7th August.

Causing great excitement was the quick-fire appearance of Long-tailed Blues at Dover (5th/6th August), Arundel (8th August), Pett (near Rye) and South Wilts (9th August). The species was first noticed at Kingsdown Leas (east of Dover) by the ‘Bockhill Birders’ on 11th August, and it is they who should take credit for setting the ball rolling, for without focused searching this butterfly will often go undetected. It is here that most people will ultimately gain great pleasure from seeing this rarity; many have already visited to see the initial wave of LTBs. The species later appeared elsewhere, including sites at Newhaven, Hayling Island and North Kent coast.

Alongside the LTBs came European (gorganus) Swallowtails at Friston Forest (3rd August), Reculver (4th August), Dungeness (6th August), Steyning (8th August) and elsewhere through August. Other exotics included Queen of Spain at Titchfield Haven (15th August) and Monarch at Shoreham (19th August).

Long-tailed Blue is really a Mediterranean species, with strong migratory instincts taking it up through mainland Europe each summer, although it rarely makes it across The Channel. On the ‘birdforum’ website, stevefrance64, located in Soule Pays Basque, posted his observations of an “explosion” on his home patch, with counts of 20+ per hour from about 3rd August onwards. This burgeoning population may have triggered a movement northwards through France and over the water.

Many of the LTBs spotted have been ovipositing females and Matthew Oates and others found numerous eggs on the broad-leaved everlasting pea (Lathyrus latifolius) spread over nearly 1 km along the cliff tops at Kingsdown Leas. An autumn emergence of British LTB appeared inevitable.

Having seen a total of 6 LTB (5m, 1f) on 18th and 19th August, all of which I interpreted as primary migrants (rather than the progeny of earlier arrivals), I returned to Kingsdown Leas on 18th September. This was earlier than originally intended, having learned from the literature, and from those who have bred the species in captivity, that the life-cycle in this species is very rapid (5 – 6.5 weeks). In captivity it can apparently be even quicker than this!

Soon after 11.30 am I had a perfect female LTB sitting in front of me, perched on its food-plant. I watched her for about 20 minutes before she disappeared for good, which was just long enough for my hands to become steady enough for a few pleasing shots. Despite a long, fruitless wait for another sighting, I went home on Cloud Nine.

On 20th September I had a longer than predicted wait for some sunshine and warmth, during which I found a spectacular Great Green Bush-cricket. As 2 pm approached male Adonis Blues started to open their wings, including a few surprisingly good specimens. As the sun finally broke through I located another fresh female LTB, this time spending about 10 minutes with her before she disappeared.

Perhaps most surprising was the second sighting; a LTB which was almost unrecognisable it was so worn. I only saw it briefly before it retired to the upper reaches of a pine to roost, so could not determine its sex. Given the likely individual lifespan of an adult, this probably crossed The Channel during the last days of August, inferring additional movements beyond the original influx. This is supported by the report on ‘birdforum’ by tittletattler, who observed one coming in off the sea on 25th August.

These butterflies are providing a once-in-a-lifetime spectacle at the end of one of the best seasons I can remember in over 40 years of butterfly-watching. Hopefully they will put on a good show for others through the remainder of September, and well into October if the weather is kind.

Great Green Bush-cricket

Adonis Blue male

Long-tailed Blue female

Long-tailed Blue female

Long-tailed Blue habitat

Long-tailed Blue female

View towards St Margaret's

[Jack Harrison]

I once saw many on an (unidntified pea-like bush) just before Christmas somewhere in north Arabia area (Dubai?) So not just a Med species.



That picture is stunning. I'm jealous.

Jack

[Neil Hulme]

Thanks Jack.

"So not just a Med species" - Correct, I'm really referring to its European distribution here. It's actually pretty global.

BWs, Neil

[David M]

That is a magnificent (not to mention highly helpful) report, Neil.

I may even be tempted to pay a visit myself if things continue to progress positively. It looks as though the weather is going to be both mild AND benign next week, which is unusual around the equinox. Once in a generation opportunity, perhaps?

[selbypaul]

Fantastic update Neil - The full story of how they came to be in Kent, with sound evidence, makes for excellent reading.

Like you say, its potentially a once in a lifetime event, especially given the rarity of long periods of Azures High Pressure this past ten years.

What a year 2013 has been. It will live long in the memory!

[Butterflysaurus rex]

In a word wonderful

[millerd]

That photo of a fresh female LTB would challenge the best taken anywhere in the world - and it was in Kent. Absolutely beautiful.

Dave

[Paul Harfield]

Hi Neil

Congratulations on tracking down the first of these British Long Tailed Blues and thanks for sharing it with us Great report and photos I am hoping to pay a visit myself, so as not to miss this 'once in a lifetime' event. I appreciate that this is a bit of an unknown quantity, but do you have any thoughts as to the duration of this emergence Weather permitting, do you think the likelihood of seeing a British Long Tailed Blue will have increased or decreased in 2 weeks time

Oh, and by the way, how long is a piece of string

[David M]

Oh, and by the way, how long is a piece of string

Less than the 400 miles round trip I'll need to make, probably.

[Neil Hulme]

Thanks all - much appreciated. I received a text from Matthew Oates this evening, informing me that another had been seen on the Leas today, but I have no further details yet. The emergence of wild, British specimens has only just begun, and I suspect that they will continue to appear well into October. If travelling any distance I'd give it a week, and chances of connecting with them will be greater in two weeks time than now.
BWs, Neil

[Susie]

Sounds well worth a visit

[Neil Hulme]

LTB Life Cycle And Timings

I've been asked by several people about the life-cycle timing in Long-tailed Blue, as this has a bearing on the period over which the butterfly is likely to emerge. This species can go from egg to adult very swiftly, which is typical of the more successful, migratory species. This might vary between 5 and 6.5 weeks, depending largely upon environmental conditions. In this case early stage development would have been very rapid before the weather collapse on 6th September, and somewhat retarded thereafter. It is therefore likely that the emergence of wild, British specimens will now be strung out over several weeks.

In captivity the life-cycle can be even quicker. Mark Colvin recently bred through some eggs laid during the early August influx at Newhaven. His first adults emerged on 11th and 12th September, about a week earlier than they would have done in the wild. 'Forcing' is the result of keeping the early stages under cover, in more advantageous conditions. Mark has meticulously recorded the development of the early stages and there should be an excellent article in the next issue of the BC Sussex Butterfly Report. There can be no better reason to buy a copy when it's published!

[Jack Harrison]

...without focused searching this {LT Blue] butterfly will often go undetected...

This is certainly true in my limited experience of the butterfly abroad. It’s not a butterfly that “hits you in the face”.

With circa 10 primary immigrants being reported let me speculate that this was less than 1% of the total immigrants to Britain. That would imply a minimum of 1,000 arrivals. I would hazard a guess that the number seen is much less than 1%, perhaps a mere 1/100th of 1%, So – and I would be the first to accept that my logic might be faulty – that would mean some 10,000 LT Blues reached these shores.

Incidentally, the archive weather charts show that winds were favourable with a light southerly drift on 4th and 5th August. There were also reports of a good showing of Aurora Borealis on that date but that of course can’t have anything to do with the immigration. Unless........magnetic disturbance, etc. After all, some birds are alleged to use magnetic lines of force to assist navigation.

Jack

[Neil Hulme]

Hi Jack,

This is a very interesting subject, and one not easy to decipher with confidence. I think your first set of figures is probably about right, and the study of Von Roer (1970) casts some light on the issue. Only 1-2% of his marked, captive-bred Camberwell Beauty butterflies were observed and reported in the Ruhr district of Germany. Long-tailed Blues in the wider, UK countryside and so late in the season would be less obvious, but these figures at least give us a starting point. I suspect that when all the records are in we will have a count of c.20 primary immigrants along the South Coast. A total influx of several thousand LTB is probably a reasonable guestimate.

BWs, Neil

[Neil Hulme]

LTB Update

Having seen an image of the butterfly, Matthew Oates has confirmed that the single Long-tailed Blue seen on Saturday 21st September at Kingsdown Leas was a male in perfect condition. I can't wait to get back there!

[Neil Freeman]

Hi Neil, just caught up with your LTB post..... WOW

A fascinating report accompanied by great images, those LTB image are beautiful. And not forgetting the Adonis Blue and Great Green Bush Cricket, in any other post they would have attracted comment in themselves.

Excellent stuff,

Edit; Just a thought but given that this is a migratory species is there any likelihood that some of this home grown generation will disperse further inland? Obviously a lot will depend on the weather at this time of year.

Neil F.

[essexbuzzard]

Congrats,Neil! Fantastic stuff!

Given reasonable weather(!) perhaps we can realisticly hope LTB will continue to be seen there for another month,lets hope!

Clearly this species can complete it's breeding cycle in a remarkably short period,even during September's low temperatures and,hopefully,this will give many of us a perhaps unique opportunity to witness this remarkable event.

Pleeeease keep us updated on progress!

I'm getting itchy feet already!

[Neil Hulme]

Thanks Neil and Mark.

Neil: It is unlikely they would move northwards from the site, given the relatively small size of the population and weather conditions. Certain triggers are required to encourage migratory behaviour.

Mark: Latest update from Matthew Oates this evening - he saw at least 5 different males and a female on the Leas today.

BWs, Neil

[essexbuzzard]

Thanks Neil.


I will be heading that way tomorrow of Thursday,weather forecast permitting.


Just need to find the nearest car park...