Thursday, March 18, 2010

Ride-Side Sallows

Please stand in silence for the lovely sallows that lined the main ride
of Straits Inclosure, Alice Holt Forest. I counted and graded them last
June, when there were 210 individual sallow bushes, including 127 large
broad-leaved bushes. Last July these bushes hosted a spectacular flight
of iris.

There are now only 61 bushes.

The Forestry Commission needs to resurface this ride to enable it to
support heavy vehicles necessary for extracting timber from the far end
of the wood. The job had been on the cards for several years. The ride
was cut out in 1987 and the new bare edges formed an excellent seed bed
for sallow germination. Many sallows established themselves in the
ditch, which in theory needed cleaning out.

I had discussions with the FC Head Forester about this issue a few years
ago, and felt we had agreed a reasonable compromise, but that
(excellent) forester moved on and no further communication took place,
despite my offers and the fact that the FC office at Alice Holt was
fully aware of the significance of these bushes, the number of Purple
Emperor enthusiasts visiting the wood, and my work. To be fully honest,
though, iris functions within a dynamic matrix that encompasses at least
the whole of Alice Holt, so it is hard for us to be too precious about
one particular part of the matrix at any particular point in time.

The really sad thing is that few of the retained bushes are suitable for
iris, most are on the sunny north side (south-facing) and nearly all
have been over-exposed, whereas the butterfly clearly favours shaded
bushes. Also, most of the 61 have been high pruned and / or are very
spindly. Some people may feel that their retention smacks of tokenism.


Several other tall sallows were removed last autumn, during
sensitively-conducted thinning works in the far end of the wood. We can
assume that other bushes will be removed or damaged during the current
thinning works. Lying on heavy Gault Clay, this is not an easy wood for
timber extraction.

In effect, please do not expect to see iris in any numbers in Straits
Inclosure for at least another ten years. This year they will be very
scarce there.

I've been dealing with the FC at Alice Holt over the issue of ride-side
sallow management since the autumn of 1976 and have made precisely no
progress with them on this matter whatsoever, and neither has any other
body.

From the FC's point of view, the ride-side shrub zone hinders access to
the crop and overhanging bushes present health & safety issues (to
contractors, staff and visitors, especially cyclists and horse riders).
But the real issue is that sallows colonise bare ground, and the only
bare ground that appears in many modern woods is along the ditches. The
challenge is really to re-set this ride edge shrub zone, crucial to
iris, camilla, betulae, etc, back off the ride. To this end three small
bays were cut out along the Straits main ride in the autumn of 2007, and
a few sallow seedlings are appearing there.

Meanwhile, anyone wanting some iris larvae - for whatever purpose -
should search the buds and forks of the lying cut sallows along the
Straits main ride, especially along the shady southern side. Help
yourself.

We need to produce some clear succinct guidance on the management of
sallows for Purple Emperors (and much other - I hate the word but I'll
use it here - biodiversity). Indeed, this is something we can develop
through this website - whether anyone will listen is a different matter,
but at least we can aim to provide accurate information.

In despair,
Matthew

Mid-March Survival

We now have 17 wild hibernating larvae left, one of which is shrunken
and probably dead. During the first half of March six were lost -
presumably all to bird predation. Five of those were on buds and one in
a fork. It was disappointing to lose one from a fork, a nice grey larva
well tucked in. Some of the surviving larvae have greened up a little
more.
Methinks a change in the weather cannot come soon enough, to give the
birds something else to do, though the predation rate might actually
worsen as April approaches. Also the buds need to swell. Two of my
larva-bearing sallows are silvering up, and one or two others are
thinking about it, but there is basically no sign of spring in the wood
at all. It takes me ages to check them now, after having to remove all
my markers.

Thursday, March 4, 2010

Theft 3

In response to Piers' comments. I am 100% certain that the larvae were removed by deliberate cutting of the individual twiglets supporting them, or in the case of one larva hibernating on a scar on a 1cm thick branch, the branch itself. This is already clear in my account, and I emphasise that I would not have written what I did had I not been absolutely sure, as my natural inclination would be towards giving the benefit of the doubt. Note my sentence expressing the hope that the perpetrator will want to rear them and release them back on site. That is my genuine hope. But yes, those larvae were important to what is not a 'survey' but a scientific study which will add to our understanding of the insect.

Incidentally, the majority of iris sites are not SSSI (Alice Holt isn't for a start) - I looked into that a while back and think I came up with a figure of less than 40% SSSI. But like Piers - and this is the really important bit - I naturally want to see the best in all people who are captivated by this most enigmatic insect and am tired of the divisions that exist within our passion, although they emanate largely from untoward incidents like this.
Meanwhile, I saw my first butterfly of the year on Mon March 1st, a small tortoiseshell trying to escape from the bowels of Swindon. In Greek mythology the soul, psyche, was often portrayed as a butterfly. Maybe it wasn't a small tortoiseshell but my soul? This is the first time that my season has been opened by a tortoiseshell since 2003, and ends a sequence of four year's launched by the red admiral.
Matthew

Wednesday, March 3, 2010

Theft Part 2

Butterfly collecting, like most activities, has always had it's fair share of both gentlemen and rogues. And for those of us who take an interest in historic specimens, the knavish tricks of the roguish element from days long past continue to confound us even to this day. It would be a mistake to romanticise the past in this respect; some of the most crooked elements of the hobby were at their most active in the mid nineteenth century; busy selling continental specimens for princely sums at auction after carefully applying false data in order to convince those collectors blinded by enthusiasm (and with more cash than cognisance) that the insects were genuine immigrants captured on British soil, or from tiny colonies in remote areas of the countryside. Anyone who follows the lucrative sale of specimens on Ebay will see that little has changed today; fraudulent specimens do still appear on the market, and there seems to be no end of people all too willing to spend (on occasions) hundreds of pounds for them!
As for the removal of livestock from a SSSI, yes this is indeed illegal, and yes the law is indeed an ass; primarily for existing at all when it could never be enforced. I broke the law in the outside lane of the motorway yesterday on my way to work; and the landlord who served me my first pint of draught ale certainly did. The law is particularly ass-ish when it fails so miserably to protect the very thing that it exists to serve. Certainly in theory an individual could be prosecuted for removing five iris larvae from an SSSI, but it wouldn't prevent a major supermarket building a super-store on the site should they feel so inclined. But I digress. Anyone currently rearing iris in captivity is likely to be fostering stock that originates from an SSSI in this day and age; and the fact that iris larvae can command eye watering prices at the AES show etc. only fuels a situation that could serve to encourage unscrupulous individuals to procure stock from the wild. Iris is also notoriously difficult to pair in captivity, often requiring the use of a hand pairing technique which is difficult to master. George Hyde mastered this technique and bred several fine series of iris (I believe these are in Doncaster Museum but I could be very wrong). Heslop never managed to, and Hyde's reluctance to reveal the secrets of his success eventually led to a minor falling out between the pair; Heslop being deeply jealous of Hyde's successes in this area.
As for the larvae Matthew has been observing (I hesitate to refer to them as 'Matthew''s larvae), given that the losses are reported at what MO describes as the 'subsidiary' rather than the 'main' site (and only apparently a maximum of five larvae) is it a certainty that this is a deliberate act of collecting the larvae? Could it not be that the larvae were inadvertently removed as an indirect consequence of someone innocently lopping branches from the sallow (for whatever reason that may be...)? I harvest hazel for 'pea sticks' and 'bean poles' from long abandoned hazel coppices local to me each Winter; I hope that no one was judiciously monitoring anything on those particular hazel stools..!
Perhaps the perpetrator isn't necessarily as wicked as Matthew has suggests, rather just misguided, and spurred to rear iris in captivity as other contributors to this site do after having read the fascinating articles published on this very web site. It is to be hoped that if the larvae have been taken, that the individual concerned means no harm and is experienced enough in the dark arts of iris rearing to ensure that the resulting imagines shall grace a 'Wiltshire wood' this coming summer.
Don't get me wrong, I am not condoning the disruption of a potentially valuable survey (this aspect of the affair is deplorable); I am merely attempting to see the best in people who are captivated by this most enigmatic insect.

Piers Vigus

Tuesday, March 2, 2010

Theft

I must also report that a maximum of five larvae have been removed from my subsidiary study site – the secateurs cut marks are all too obvious. I was following only a few larvae here, though the survival rate was higher, providing a useful comparison with the main study locality.

Whoever did this must have spent a lot of time searching, as a planned operation rather than a piece of opportunism. Many of the markers were far from obvious, and most were on branches from where larvae had long been lost. Several marked feeding locations of 2nd generation Poplar Hawk Moth larvae which I followed in order to see whether they made it through to pupation (some did). For what it is worth, this removal of larvae is illegal, as the site is an SSSI, and the activity is also against the owning organisation’s bylaws. But the law is often an ass, and is even more regularly made into an ass.

Obviously, it is bitterly disappointing that some people interested in Purple Emperors are prepared to take advantage of work that will assist our understanding of this butterfly, especially when the work is being carried out in an open, giving manner, with regular reporting via this website. They must consider personal possession far more important than effort aimed at assisting the insect’s conservation, and people’s understanding of the butterfly. The ruthlessness here is astounding, as is the utter selfishness. But some people seem to live outside of shame and without conscience or integrity.

It might not be right to assume that the collected larvae will end up as set specimens – assuming they produce imagines. They might have been collected for sale as pupae, or to provide photographs of pristine specimens (the females hang around for photo calls but the males tend to ascend instantly). It would be marvellous if they had been collected by someone incensed at Oates’ apparent intransigence in not protecting these larvae from predators! In which case, rest assured that I wanted to place little pieces of netting round every one, and have lost sleep through not having done so in the interests of science.

The truth is that this butterfly does attract some odd – and at times downright nasty - people, and generates some most bizarre behaviour (as this website wondrously illustrates). Also, more than anyone else I know how addictive Apatura iris can be - but such is humanity’s relationship with the heady combination of elusiveness and beauty. Furthermore, I understand the appeal of butterfly collecting better than a great many butterfly enthusiasts do, and am decidedly neutral over the collecting of aberrations, partly because I rather miss meeting old boys out on the downs in search of syngrapha or whatever. It is, though, sad that what integrity there was has all but gone out of butterfly collecting, leaving only rottenness. But of course, the collecting of specimens can now be done in a benign way, through photography. It has moved on wondrously.

I have of course removed, albeit belatedly, markers from all locations that have held or still support Purple Emperor larvae at both my study localities. The study will continue, and I look forward to reporting on it further, to the benefit of everyone who loves this butterfly, irrespective. One of the aspirations behind the setting up of the Purple Empire Website was the, perhaps naïve or vain, hope of bringing all people interested in this butterfly closer together, whatever their perspective. The incident described above rather makes that aspiration unrealistic, which saddens me deeply. We can do better.

Matthew Oates

February Losses


February started with 32 larvae in hibernation at my main study site. None had been lost during the first 17 days of January but then four went missing during the last 14 days of that month (to assumed predation) and another desiccated and perished.

I can report that eight were lost to assumed bird predation during February and one more to ‘desiccation’. 24 are now extant.

So far this winter, 16 larvae have been lost to apparent predation. It is highly unlikely that any of these have moved position, given the cold weather.

Since mid January the (apparent) predation rate has been running at circa two per week, and may well be increasing. There is a distinct predation hot spot in a central area of the site, from where nine out of 12 hibernating larvae have vanished to assumed predation. This area is alive with flocks of tits, more so than the rest of the wood.

So far this winter 16 larvae have succumbed to apparent bird predation, of which 14 were on buds and two on scars on stems. We have no idea how normal this is as there is no base line data – this is the base line. I need to do comparable studies over several winters. Two have died due to ‘desiccation’, a phenomenon well known to those of us who breed iris.

Matthew