March 2011

[Wildmoreway]

Is anyone else noticing a shortage of lesser celandine in flower?

I've seen plenty in flower around Torbay.

[Piers]

Re the isle of Wight Large Tortoiseshells
Yes,I believe so.
Hopefully,someone more in the know will be able to supply detailed information on the sightings at this location

This is an interesting development that hopefully someone will be able to provide further information on.

Something isn't quite cricket here, specifically the absence of a sudden flush of pristine individuals in the locality during late July/early August; the one sure sign of a breeding population

Several people did make an effort to visit the area of the spring sightings from a couple of years ago (the same area as these recent reports I believe) at the time of year one would expect to observe the offspring of these bold explorers from the near continent, but to no avail.

If there were a resident population (transitory or otherwise ) one would expect the summer emergence to be the most obvious indication of their presence as the butterflies make busy engorging on nectar in preparation for a winter slumber.

To date however, despite sightings in consecutive spring seasons, there has been no indication whatsoever that the butterfly has actually bred in Vice-county 10.

Felix.

[Susie]

Lesser celendines are out around here (Horsham, West Sussex, area) but still not in huge numbers.

I came across my first wild native daffodils today

[David M]

I've seen quite a few Lesser Celandines on the wetlands around where I work. Dandelions are starting to come out too.

[marmari]

Re isle of Wight Large Tortoiseshells.
Sightings from one recorder are 2006,2008,2009,and this year at this location.None seen in 2007 and 2010.
All records are March/April and none were seen at any other time of year.
This year is the earliest record on the 7th March.
The latest record was on the 11th April.

[Gibster]

Regards the Large Tortoiseshells though...I'm intrigued! Felix puts forward a good argument against there being an established population (of admittedly unknown origin) on the Isle of Wight. Marmari lists dates which hint at a rather determined breeder!

Several years ago a Large Tortoiseshell was seen and photographed in midwinter at the bird observatory at Portland Bill, Dorset. The following summer there were at least two reported from further up the island. I managed to see one of them which was pretty darn sweet. The following winter one was photographed resting in a tree in the bird observatory garden. This, to me, would seem to hint at a breeding population? However, I don't think they've been seen since so whether this was a natural transient establishment or failed release scheme we'll probably never know. Smart butterfly though, and speedy too!

It's a pity that breeders don't log all their release attempts onto a national register at the end of each year. Anonymously if need be.

Gibster.

[Padfield]

The observations mentioned here are quite consistent with a resident population of large tortoiseshell, whether or not there are independent reasons to believe in someone releasing them.

Large tortoiseshells hibernate very predictably and are typically found in exactly the same places in March year after year - and by same place, I mean right down to the same corner of a track. They are much less predictable in the summer and are often apparently absent from places where they were relatively common in spring, perhaps because they have gone into hibernation quickly. A certain percentage seem to disperse and these can be found well away from known hibernation spots.

Last year I recorded spring large tortoiseshells on 11 separate occasions but summer insects only on one occasion (two insects), on 27th June. That was at a site I have never visited in spring. In other words, I saw no large tortoiseshells at all last summer at any of their spring sites.

March and April are the large tortoiseshell months, extending up to late May in the mountains here.

Although some have doubted whether LT ever was a true British breeding butterfly the evidence from Suffolk suggests very strongly that it was. The species has been abundant in the past (the beginning of the 20th century, for example) and its Suffolk numbers have not correlated with immigration years of other species. I still have high hopes for it returning!

Guy

[millerd]

Let's say, for the sake of argument, that someone is releasing them. How would this work? Would they be bred and released in the August in the hope that they might hibernate? If so, there would be no guarantee (from the behaviour described) that they would regularly reappear in the same place. Alternatively, assume they are being released in the spring, every year in the same spot. That would require someone to breed the butterflies and keep them in artificial hibernation over the winter, and then release. Their appearance might be suspiciously fresh.

Or are there other ways to achieve this?

Dave

[Wildmoreway]

I do have a suspicion that some of our "native" species may be more dependant upon immigration and less succesfull at hibernation than might be the common perception. It was interesting how quickly the Small Tortoiseshell population recovered its numbers a couple of years back. Also late summer/autumn 2009 I saw few Small Torts. yet last spring in early April they were abundant. I almost wonder whether they were actually individuals that had arrived from the continent, perhaps offspring from an early brood in Southern Europe.

[Neil Hulme]

Hi Felix/all,

Felix stated "there has been no indication whatsoever that the butterfly has actually bred in Vice-county 10." As I'm also a fully paid-up member of Club Pedant, I would certainly agree with your statement had you used the word 'evidence' rather than 'indication' - but I sort of agree anyway.

Gibster wrote "Marmari lists dates which hint at a rather determined breeder". I wouldn't say that was a logical conclusion based on this pattern of sightings, unless someone is actually aware of a local breeder that is regularly chucking stock out. For someone to achieve this lengthy pattern 'artificially' would involve a great deal of futile effort and actually be very difficult. In one of marmari's 'absence' years I recall a LT being seen a few miles away at Parkhurst Forest? In terms of interpreting data such as this, I'm with Ockham and his trusty 'razor'.

I'm pretty sure that Felix is suggesting that these are regularly occurring (in albeit low numbers), over-wintering migrants - and that might well be the case.

As far as a breeding population is concerned, my own 'jury' will remain out until Felix's 'summer LTs' make an appearance. That's what we need to see. However, the fact that we haven't seen them yet doesn't preclude the possibility that they're around. LTs would soon disperse after emerging and are far less 'visible' than post-hibernation, territorial males. They will only be around feeding for a couple of weeks before hibernating, so it would require a bit of luck to spot one. Anyone who knows the terrain here will realise that location might be tricky - and I doubt that there are many keen butterfly-watchers in the immediate area. Rather intriguingly, on 2nd April 2009 I saw two LTs here, including a female that was behaving in a manner that suggested she MIGHT be egg-laying at the top of a tall sallow.

Still no evidence of breeding, but it wouldn't surprise me if that evidence were to appear at some point.

Neil

[Piers]

Although some have doubted whether LT ever was a true British breeding butterfly the evidence from Suffolk suggests very strongly that it was. The species has been abundant in the past (the beginning of the 20th century, for example) and its Suffolk numbers have not correlated with immigration years of other species. I still have high hopes for it returning!

Guy

There is little doubt that the LT was indeed a breeding species in Blighty, with populations heavily bolstered by annual immigration from the continent. It has also been supposed that the populations in this country were transient, relying upon this annual influx for their continued presence, that is if they survived the winters here at all in anything close to viable quantities.

The flush of sightings across the southern coastal counties of Albion in the spring months of the last few years suggest genuine immigrant individuals, possibly in numbers worthy of real note when you consider the possible ratio of those sighted against those actually present.

Some have speculated that these sightings are all the work of determined 'breeders'. This is a suggestion which I find fairly ludicrous considering the concerted and coordinated efforts that a team of such individuals would have to make, working across the south from Kernow to Kent and synchronising their breeding programmes, in order to affect the pattern of sightings that have been witnessed by casual observers.

It would appear that this species has been certainly stretching it's legs somewhat over recent years and I would not be at all surprised (if the trend continues) to hear of evidence of the species finally breeding again in the south of England before too long.

I would certainly agree with your statement had you used the word 'evidence' rather than 'indication'

I gotta stand firm on this one my Sussex chum. The recent sightings in our fair southern shires have not indicated or suggested (well, to me at least) that the species has been breeding in England's green and pleasant land.

Felix.

Post scriptum:
The last recorded (presumed natural) breeding of the species in this country* was an egg mass discovered by well known lepidopterist Margaret Brooks at Rode Bird Gardens near Frome in Somerset. The year was 1978 if memory serves me correctly. Margaret suspected that the cluster of ova that she had discovered were indeed large tortoiseshell and she showed them to Roy Stockley for his opinion. Stockley was less confident, however Brooks retained the ova and sure enough upon emergence it was clear that the larvae were indeed that of the large tortoiseshell. Amazingly, this stock was kept going in captivity for a couple of decades in this country as what amounted to a captive population by the now somewhat diminished community of keen lepidoptera breeders. Even towards the end of this quite incredible run, the imagines produced from the stock were perfectly healthy and of excellent size.

* of which I am aware at least; happy to be informed otherwise...

[Gibster]

Marmari lists dates which hint at a rather determined breeder!

I appear to have been misunderstood. I find it hard to believe that somebody would be releasing the same species in the same general area for the last decade (or maybe more) in the hope that the species would eventually 'set seed and root' and become established. Hence I dubbed this fictitious character as 'a rather determined breeder!'. Sorry if that didn't come across clearly enough. At least I knew what I meant!

Guy comments:

The observations mentioned here are quite consistent with a resident population of large tortoiseshell, whether or not there are independent reasons to believe in someone releasing them.

Large tortoiseshells hibernate very predictably and are typically found in exactly the same places in March year after year - and by same place, I mean right down to the same corner of a track. They are much less predictable in the summer and are often apparently absent from places where they were relatively common in spring, perhaps because they have gone into hibernation quickly. A certain percentage seem to disperse and these can be found well away from known hibernation spots.

Last year I recorded spring large tortoiseshells on 11 separate occasions but summer insects only on one occasion (two insects), on 27th June. That was at a site I have never visited in spring. In other words, I saw no large tortoiseshells at all last summer at any of their spring sites.

Which raises the very real possibility that Large Tortoiseshells could be established on the IOW. Which I find intriguing (stop me if I'm going around in circles here!)

All the best,

Gibster.

[Gibster]

Just wondering, has there been a recent range expansion in European populations of Large Tortoiseshell? Are they turning up in 'new' localities or recolonising old haunts? Any country 'first confirmed breeding records'? Or any other species, for that matter! Geranium Bronze aside...

Gibster.

[David M]

The Large Tortoiseshell seems to be quite a 'quirky' butterfly in the sense that it is more predictable when fresh out of hibernation than it is after a summer brood.

This begs the question: what happens to all the newly emerged adults in high summer? I accept they may go into hibernation rather quickly, but if there are numbers being observed early in the year, then one would anticipate larger numbers (albeit spread over a wider area) to be recorded later in the year.

Another thing I can't get my head round is why a perfectly functioning insect that is designed to be at its best in warm temperatures would decide to hibernate right at this most opportune time yet emerge and fly around when conditions are far, far more austere the following April.

[cjs]

Saw a Comma on Tuesday the 8th a lovely sunny day.
Sparrows have been lining their nests with the fibres off the hanging baskets. They could be laying in a few day's.

[David M]

There are a couple of crows currently bringing nesting material to one of my chimney tops

[Padfield]

Another thing I can't get my head round is why a perfectly functioning insect that is designed to be at its best in warm temperatures would decide to hibernate right at this most opportune time yet emerge and fly around when conditions are far, far more austere the following April.

Each species has different strategies to maintain its tenuous hold on existence! Purple emperors do what you think large tortoiseshells should do, and look what amazing lengths they have gone to to make it work... The new-born larvae have to eat manky, tough sallow leaves, frequently covered in various mildews, and then hibernate on the branches while still tiny little creatures. They have evolved incredible camouflage to make this work and still many are lost. Large tortoiseshell caterpillars, on the other hand, get to eat fresh spring greens and don't have to survive the winter at that vulnerable stage. Instead, nature's creative energy has gone into camouflaging the adults.

To see large tortoiseshells swooping around in early spring, nipping through the still bare trees, dining out on sallow blossom and basking on bare ground is wonderful. I think they've found their niche!

Guy

[Gibster]

by Felix » Wed Mar 09, 2011 9:28 pm

Gibster wrote:
Which raises the very real possibility that Large Tortoiseshells could be established on the IOW.

Oooh Seth, that's a very bold statement to make in the face of such underwhelming evidence..! and around we go...

Whaaaat??? I simply couldn't make a more airy fairy non-statement if I tried!!!

But Kipper, Guy and yourself (doubtless three of the most in-the-know chaps here) well, you all know LTs are breeding don't you? You just won't tell the rest of us!



Your turn again...

[Padfield]

Felix, unlike Kipster, thinks of himself as a dipster, not a lepster, Gibster.

Guy

[Padfield]

Not that kind of dipster. What I meant, of course, is that you prefer Diptera to Lepidoptera...

Back to March 2011?

Guy