Notes for Butterfly Recorders

There are now 36 species on our recording sheet (residents and regular migrants).  I have added Purple Emperor, Marbled White and Chalkhill Blue to reflect recent spread of these species.  In addition, if the weather is kind again and the winds catch migratory European and North African species then we could expect to see Camberwell Beauty, Queen of Spain Fritillary and Long-tailed Blue too.  Please note that the sheet now reflects the adoption by Butterfly Conservation of the new Checklist of the Lepidoptera of the British Isles.  This has led to some significant changes to the order that our butterfly species are now listed in.

For those not used to submitting records, the basic details needed are the “four Ws”, i.e.:
“What” – i.e. species.
“Where” – preferably an Ordnance Survey grid reference*, though an accurate location name or a post code etc., will do. 
“When” – self evident!
“by Whom” – name and contact details of recorder.

In addition, a count of minimum numbers seen is useful, with any evidence for breeding (e.g. mating observed, ovipositing females seen or larvae found). A simple numbers code is useful if you have not been able to keep a precise count:
A        One
B        2-9
C        10-29
D        30-100
E        100+

Records come in from over two hundred regular recorders (BC members and non-members alike) and from a variety of schemes:

Transects. A new transect at Knettishall Heath brought our total to 19 full transects along with a new single-species transect at Purdis Heath, Ipswich. This is the highest standard of input, as a weekly count has been conducted for more than 10 years at some sites, using an established scientific methodology. Single-species transects are also used to monitor Silver-studded Blue and Purple Hairstreak.

Garden Records. Homeowners who send their records annually provide a valuable foundation for most of our common species. Some are sent to the national BC scheme, others come direct to me.

BTO Garden Birdwatch. Birdwatchers engaged in the British Trust for Ornithology Garden Birdwatch have the option of recording easily-identified butterfly species within their on-line recording scheme. These are recovered and entered to the Suffolk database at least once in each 5-year period.

Casual Sightings or Roving Records. Enthusiastic naturalists and butterfly watchers visit sites of high wildlife value and send in a variety of records – from a single Large White to a detailed specific site survey. Voluntary wardens of SWT reserves often send dependable records for their sites year after year. Many BC members and recorders make the effort to visit the tetrads known to be under-recorded, progressively filling the "black holes" in the county distribution maps. Often visits to the great unknown can be an unexpected delight, sometimes turning up hairstreaks and other valuable records.

Wider Countryside Butterfly Survey. The WCBS is organised and analysed at BC Head Office level, and uses volunteers from BC and BTO membership.  It is targeted at the same set of randomly selected squares annually, but as these are visited just in July and again in August, some early species get missed (e.g. Orange-tip and Green Hairstreak).  The scheme is now entering its 6^th season, and results are passed back to County Recorders.  Essentially transect-like rules are applied, but the walk is done only twice a year instead of 26 times (optional extra visits are not discouraged though with many squares being monitored from May through to September).  Recorders are given a square and they are responsible for recording butterflies and submitting results.  We are trying to find recorders for the remaining Suffolk squares so if you would like to join WCBS for 2015; there is still time to enrol with Suffolk Co-ordinator Twm Wade at: twm.wade@yahoo.com

Big Butterfly Count. BC Head Office has put a lot of effort into organizing the Big Butterfly Count as a piece of nationwide citizen science. Lots of novice recorders have taken part, identifying butterflies for 15 minutes in a site of their own choosing. Suffolk harvested over 4000 records of mainly common species flying during July and August 2013. Although the places visited were mostly within our well recorded areas a few new tetrads were included and therefore, were a positive contribution to reducing the amount of Suffolk black holes.

Transects - Methodology

The methodology and development of transect monitoring for butterflies has been reviewed in detail elsewhere (Pollard and Yates, 1993).  In brief, a fixed-route walk (transect) is established at a site and butterflies are recorded along the route on a regular (weekly) basis under reasonable weather conditions for a number of years.  Transect routes are chosen to sample evenly the habitat types and management activity on sites.  Care is taken in choosing a transect route as it must then remain fixed to enable butterfly sightings to be compared from year to year. 

Transects are typically about 2-4km long, taking between 45 minutes and two hours to walk, and are divided into sections corresponding to different habitat or management units.  Butterflies are recorded in a fixed width band (typically 5m wide) along the transect each week from the beginning of April until the end of September yielding, ideally, 26 counts per year.  Transect walks are undertaken between 10.45am and 3.45pm and only when weather conditions are suitable for butterfly activity: dry conditions, wind speed less than Beaufort scale 5, and temperature 13°C or greater if there is at least 60% sunshine, or more than 17°C if overcast. 

Due to the vagaries of the British and Irish weather, it is rare in practice to achieve a full set of 26 weekly counts. However, a small number of missing values can be estimated using other counts during the season. 

Single species (as opposed to normal 'all species') transects have been increasingly established in recent years.  Whilst such transects must follow the standard methodology and must record populations at least once a week throughout the flight period, the focus on a single (or small number of) species reduces both the time required to walk each transect and, more significantly, the number of weekly counts.  With many demands on the time of site management staff and volunteer recorders, this reduced method has enabled population monitoring of particular threatened butterflies to be undertaken when otherwise it would not have been possible.  By regularly recording a fixed route in standardised conditions, the number of butterflies seen on a transect can be compared from year to year.

Non-Native Species

Background
There have been several incidences of non-native species being recorded in the UK in recent years which has posed questions to BC Branches and volunteers.

Legal situation
The introduction of non-native species into the UK is illegal under the Wildlife and Countryside Act (1981) and Butterfly Conservation does not support any such activity.  If BC Branches or members hear of people deliberately releasing non-native species, they should strongly discourage such activity because it is against the law and also because it runs the risk of damaging the ecology of native species, for example by introducing non-native pathogens and parasites. 

Accidental releases of non-European species
In many cases, it is clear that sightings of non-native species originate from releases of bred stock, for example non-European species which may have escaped from Butterfly Houses.  Such sightings are of little relevance to the work of Butterfly Conservation. 

Sightings of non-native European species
Where European species are recorded near the coast, or even inland, it is often not easy to separate releases from natural migration.  Sightings should be reported to our county recorder Bill Stone or to .  Advice should also be sought from them before giving the sightings any publicity.  There are pros and cons of publishing such records that must be judged on a case by case basis.  If it is possible that a migration is occurring, then it would be worth publicising sightings so that other observers can keep a look out (e.g. Long-tailed Blue).  However, if a very rare migrant appears to have established a colony it may be best to keep details secret until any breeding can be assessed.  There is a huge interest in photographing rare migrants which could damage a small breeding colony, and there is a risk that some people may want to collect the adults, or take eggs or larvae for rearing.  If the latter is felt to be likely, it is best to keep the locality secret until the situation can be properly assessed in discussion with the county recorder and Richard Fox (or Nigel Bourn or Martin Warren in his absence) of Butterfly Conservation. 

Established colonies of non-native species
We know that many species are spreading rapidly northwards in Europe due to climate change and some will inevitably arrive and establish colonies.  For example, nearly 30 moth species have become established in the UK this century, some due to natural colonisation others as a result of accidental importation (e.g. in the horticultural trade).  If a non-native species succeeds in establishing a breeding colony (e.g. evidence of successful breeding over two or more seasons), by whatever means, our strategy should be to monitor the results so that it can add to our understanding of the impacts of climate change.  The rearing and further release of the species should be discouraged so that we can learn the natural behaviour of the species in our climatic conditions.  Again, such colonies should be reported to the County recorder and advice sought about any publicity.

Assisted colonisation of non-native species
Some naturalists are advocating that we help species adapt to climate change by “assisting” their colonisation of new countries.  Aside from the legal issues, Butterfly Conservation believes that such measures should not be attempted at the current time as it would confuse scientific understanding of natural responses to climate change, undermine local conservation efforts in the natural range and might have unexpected adverse effects here, but will be reviewing this advice in coming years.  There may be situations in the future where sedentary species in other parts of Europe are at high risk of extinction because their original habitats are becoming unsuitable due to climate change and there is no possibility of natural spread.  Assisted colonisation may thus be the only option to ensure their survival.  If such cases do arise, we will consult widely with Lepidopterists across Europe to agree a continent-wide conservation strategy. 

Butterfly releases at ceremonies
There is an increasing and disturbing trend of live butterflies being released at weddings, funerals and other ceremonies.  In some cases such releases may be illegal. Butterfly Conservation strongly disagrees with this practice for four main reasons:
1) It disrupts natural distributions and the study of them;
2) Bred individuals may have different genetic traits compared to wild ones and releases may disrupt the genetics of natural populations;
3) There is a risk of spreading diseases into wild populations, especially from high density breeding and releasing programmes;
4) Such releases send the wrong message about human attitudes to nature and other living creatures and distracts from the real problems facing butterflies.

Brown Hairstreak (Thecla betulae) in Suffolk ?

We have been receiving sightings of the Brown Hairsteak in Suffolk.  According to the literature, including The Butterflies of Suffolk by Mendel and Piotrowski (1986), this butterfly was recorded in Suffolk in the early 1900s but then a gap of nearly 50 years until two sightings in the 1940s at Stanton and Bently Woods.  They wrote 'there is a slim chance that it may again be discovered in some forgotten corner'.  It would seem that 70 years later this may have happened.

Bill Stone (Suffolk Butterfly Recorder) writes
As a County Butterfly Recorder one of the privileges attached to the role is to be able to reveal the sighting of a rare butterfly or, the occurrence of a new species or, perhaps the most important, the reoccurrence of a species thought lost to the county.  The Brown Hairstreak is a species that falls in the latter category.  Recently, information was passed to me which strongly suggested that Brown Hairstreak was flying in the county.  But, and of particular note, that this species had been present in Suffolk for a number of years.  Disappointingly, those with knowledge of these Suffolk Brown Hairstreaks had not felt that they could share this either with me as current County Recorder or with Rob Parker my predecessor.

That aside, the butterfly's presence has now been reliably confirmed again in Suffolk and we should now welcome and celebrate that this species is flying, albeit in small numbers in our county.  In the last few weeks the species has been recorded by way of photographed adults and of the presence of laid eggs on mature and established Blackthorn (Prunus spinosa) stands within the Orwell Country Park, Ipswich and along Belstead Meadows.  In addition, a number of references to the Brown Hairstreak being found in the Ipswich area have been published online via social media along with site details.  The butterfly is also believed to be present at a number of locations, in suitable Blackthorn habitat in the Copdock, Capel and Bentley areas.  However, these sightings still need to be substantiated and evidenced.

It is unclear at present if these Brown Hairstreaks are the result of a deliberate introduction, by way of their presence on planted Blackthorn or the natural remnants of a population thought lost.  So, in respect of accurately recording Suffolk's Brown Hairstreak then I would ask the following:  

Firstly, to those who have been aware of Brown Hairstreak before now then I would ask you to send me your records with as many details as possible.  This will help me to add records relating to previous years and establish the butterfly in our county data set.

Secondly, I would encourage recorders to now look for the butterfly in the areas identified above and report any sightings or evidence of the butterfly's presence. But, please respect these locations, keep to footpaths and keep your disturbance to an absolute minimum.

However, given that we are now at the end of the Brown Hairstreaks flight season the best way of recording is to search in the winter months for eggs laid on Blackthorn.   A female Brown Hairstreak will lay her tiny sea-urchin type white eggs singly on the twigs of blackthorn, normally no higher than about six feet.  Normally, the eggs are laid close to new growth (1-2 years), near a bud or developing spine. (See the photo).  The eggs then pass the winter in this state, with the larva hatching the following spring by way of it cutting a hole in the top of the egg.  Please let me know of any eggs located and counted.

See the sightings page for Sep 9th and 11th (click here)

If you see or have seen a Brown Hairstreak at any stage of the lifecycle please email sightings@suffolkbutterflies.org.uk

Silver-washed Fritillary

The return of the Silver-washed Fritillary, Argynnis paphia

The Silver-washed Fritillary was present in Suffolk in the 1940s, but became scarce by 1959, and had not been seen until recently.  In 2006 it had a very good year in the southern counties of UK, and dispersed widely.  We had 3 sightings in Suffolk, one of which was at Theberton Wood, and it was believed that these may have spread from the re-introduction site near Coggeshall in Essex.  Perhaps some of them may since have bred in Suffolk.  In 2009, it was a surprise to discover 3 in a private wood near Stowmarket.

On 20th July2010, Rob Parker re-visited that wood.  To his delight, he found no less than eleven and plenty of violet, in what had been considered a rather small and unpromising site for breeding.  Assuming no-one is releasing them (the owner says not) this is very encouraging for a spread of the species.  The wood in question is small, but has plenty of violet.  The same afternoon, he went on to Pakenham wood (TL9367) to check on the White Admiral (just one very tatty one).  In the same glade, he was amazed to find one male A. paphia on the thistle.  Ten minutes later, another appeared, and some impressive sky climbing courting flights went on

Since then, singles have been reported from sites spread widely around the county and the 2010 totals reached a minimum of 24 SWT seen in 10 Suffolk sites by more than 13 dependable observers.  Most of these were singletons and most were photographed. Six of the localities are woods with violets, where there is every  chance of natural colonization


In the same timeframe, it was found in 15 locations in Norfolk, some close to Suffolk.  Meanwhile, the re-introduced colony in Essex is flourishing, and appears to have spread, having reached RSPB's Stour Wood on the Suffolk border

Probably the very hot days in July triggered dispersal, a natural spread, in some ways similar to the  dispersal of White Admiral, also in July.  These sightings from Essex, across Suffolk and well into Norfolk, were identified early because they were so unusual.  Later in the season, most counties where Silver-washed Fritillary is more commonplace noted that 2010 had been another good season for the species, with strong numbers at known sites and dispersal to new locations too.

Keeping tabs on the presence or otherwise of SWF became a priority for 2011 and 2012, and enthusiastic observers visited suitable woods in July - particularly those where they were seen in 2010.  They are powerful, majestic fliers and may be spotted from a distance, but they are also fond of thistles, so getting close enough for a photograph is not too difficult.  Take a look at your reference books now, to make sure you can separate A. paphia from other fritillaries, and the males from the females - look for the scent scales along the veins on the males - if you are lucky enough to see the upper surface of the forewings.

In 2012, it was clear that the Silver-washed Fritillary had returned in strength; it was breeding in 6 of the 2010 woods, and observers were delighted to see it flying in greater numbers (not just 24 sightings in Suffolk in one year, but now over 20 in one wood on one day).  One chap was lucky enough to see 3 mating pairs in one afternoon at Pakenham Wood, and produced the fine photograph [below]. Dispersal continues, and at the time of writing they had been seen in a further 5 woods in 2012.  That does not mean they will all become breeding woods however, and several of the 2010 woods seem not to have held their visitors.

Here is a list of the best of the woods for observing Silver-washed Fritillary.  All of these have at least some public access (please respect the private parts to preserve the landowners' goodwill)
Bradfield Woods (SWT)
Wolves Wood (RSPB)
Theberton Wood (FC)
Northfield Wood (WT)
Norton Wood (private with footpaths)
Dunwich Forest (FC/ SWT – look in the glades with oak and bramble)
Reydon Great Wood (private, crossed by Hadleigh railway walk)
Pakenham Wood (private with public footpath crossing through the wood)


   

A mating pair of Silver-washed fritillaries in Pakenham Wood with a flyby. Photo by Bill Stone, July 2012 and A male Silver-washed Fritillary in a Suffolk wood – Photo Rob Parker, July 2010

Purple Emperor

The Purple Emperor has been historically present in Sufolk but disappeared in the 1950s.  The last sighting was probably around Raydon.

Since John Quinn made his freelance introductions at Theberton Wood circa 2001-2004, and the population became public knowledge in 2005, iris has continued to fly in that small wood.  John agreed not to make any further releases thereafter so that we could be confident that it really was self-sustaining.  Happily, they went from strength to strength, and observers watched them 2005-2011, whilst forestry work thinned the conifers, retained most of the sallows and opened rides and canopy somewhat.  A number of sightings were also made at RSPB Minsmere (just 3 miles away to the northeast) suggesting that the population was doing very nicely, and in 2011, one male turned up at North Warren, 6 miles to the south east.

Enthusiasm continued after John's death, and Theberton Wood is tended by Sam, a forester who is generally to be found amongst the July enthusiasts.  A sallow cutting operation late in 2011 left fallen branches which were painstakingly searched for iris larvae, and 17 were found on twigs and taken into captivity to overwinter.  They survived very well, and Sam was able to release 16 during the first week of July 2012, progressively as they emerged, and before the wild population had taken to the wing in a year of extraordinary fluctuations of weather that would probably have delayed emergence of the wild population.  By early August, fresh wild adults were flying in company with the worn released specimens.

It is unfortunate that this release has masked the performance of the truly wild population, but it can be argued that they were Theberton stock that would otherwise have perished.  The Emperor was certainly observed at Theberton in 2012, but as usual, valid counts are difficult to obtain, and the County Butterfly Recorder has not received many sighting reports or subjective judgments of population strength.  The best, on 26th July, identified 4 separate females (3 with distinctive damage, and one fresh-looking perfect specimen) and one male - a minimum of 5 still flying at that date, and the females engaged in apparent egg-laying behaviour.  Encouragingly, iris was found to have spread more widely in the wood, and was seen basking in the recently-widened main ride

The Purple Project

In this Summer issue of the Suffolk Argus you will have read the report by Liz Goodyear and Andrew Middleton on their efforts to locate suitable woodlands for Purple Emperor in Suffolk.  Ignoring introduced populations, I am a great believer that the Purple Emperor could exist, albeit in small numbers, much more widely in Suffolk than our records suggest.  However, in order to find and accurately record this magnificent butterfly there is going to be a need for a significant amount of focussed surveying effort over a number of years.  To try to provide some structure and coordination to this recording effort I would like to introduce the “Purple Project”.

This recording scheme will initially focus on a number of woodlands which have been identified by Liz and Andrew in their report as having a Purple Emperor suitability rating as either “Red” (very good habitat- abundant sallow, sallow thickets (100+, 100s) or “Orange” (good habitat-good numbers of sallow, maybe a sallow thicket, 50-100).  Other Suffolk woodlands can be added if the woodland is identified as being suitable and when records for Purple Emperor are received from new woodlands

In short, the Purple Project will require recorders to visit identified woodlands as often as possible during the flight period and undertake observations both within the wood but perhaps more importantly from external view points.

The following woodlands are those rated by Liz and Andrew as “Red” and “Orange” and with reasonable public access

Red
Mellfield Wood (TL9259/9260/9160)
SWT Bradfield Woods (TL9358/ 9258)
SWT Bonny Wood (TM0651/0751/0752)
Woodland Trust Northfield Wood (TM0259/0260)

Orange
Raydon Great Wood (TM0540/0440)
RSPB Wolves Wood (TM0543/0544)
Old Hall Wood (TM1139/ 1240/1239)

Habitat and adult behaviou

In order to look for the Purple Emperor it is perhaps important to have an understanding of habitat preferences and behaviour of the adult butterfly.  In Suffolk, the Purple Emperor’s main flight period is between mid-July and mid-August.  It is often seen flying at the same time as both White Admiral and Silver-washed Fritillary and the three species share a love of mature deciduous woodland.  However, for Purple Emperor it is important that the woodland should ideally contain or, have close by, a good quantity of the primary larval food plant, Goat Willow (Salix caprea).  Purple Emperors also prefer Oak rich woodland but they are known to fly between woodlands and suitable habitat.

In suitable woodlands male Purple Emperors can occasionally be seen feeding on the ground mid-morning (and again late afternoon) where they seek out sources of salt, moisture and other nutrients. It is believed that salt is essential for both the male and the female to assist in egg development and the male will pass some of his own salt reserves through his sperm during mating. Many sources for both salt and essential nutrients are utilised but especially from animal faeces.

After morning feeding, male Purple Emperors will slowly accumulate height and move up to a congregation area within or very close to the wood.  These areas tend to feature the highest point of their habitat or particularly prominent trees, also referred to as master trees.  These areas can also feature along the edge of the woodland.  One favoured feature of a congregation area is where there is natural depression in the canopy in the shape of a half bowl and which attracts full sun.  Favourite trees for congregation tend to be broad leafed trees such as Oak, Beech and Ash as the leaves allow the butterfly to perch on. Ideally, the leaf selected will allow the butterfly clear views of its territory and to orientate itself so that it can remain in full sun.  Males will then use these particular leaves to watch from, leaving frequently to patrol their own territories and await the entry of an unmated female.  They will also continue to feed, favouring aphid honey dew and in particular sap runs from Oak. Purple Emperors rarely use flowers for nectar although in some woods they have been observed favouring Sweet Chestnut, blossoms and buddleja

Female Purple Emperors normally become active towards midday and will head to the male territories.  If a fertile male is in residence then he will challenge the female and the female will lead him away to a high point to copulate.  This could be a long distance away from the male territory and the female often utilises an Oak or Ash tree as her resting place.  However, if a female who has already been mated enters a male territory then she will avoid his attentions by flying down to the ground.  The male will eventually lose interest and return to his territorial perch.  Egg laying will normally take place midday through to early afternoon and the female will look for sallow leaves that are shaded from full sun.  This is to avoid the eggs and young larvae becoming exposed to extreme temperatures and suffering from desiccation.  The egg is laid on the upper surface of the leaf and often near the edge.

Survey methods

The following points will, hopefully, assist in maximising recording opportunities for woodland visits for adult Purple Emperors:

Because  a male Purple Emperor could settle on suitable ground anywhere in woodland it is best to look for their congregation areas and attempt to identify males on territory. As discussed above, the congregation areas tend to feature the highest point of the wood so it’s best to look for this during an initial visit or utilise an Ordnance Survey map. You may need to stand at a distance away from the wood to achieve this.

Where no clear or accessible high point exists, explore the wood and look out for a woodland edge or ride which features an indentation in the canopy and importantly, offers exposure to sun.

Find a suitable point to watch from and start to look up for butterflies flying from their perches, scan regularly. Remember that most afternoon flights will be above the canopy.

Try and match your visit with good weather. The Purple Emperors will be at their most active from midday through to late afternoon, they prefer full sun and temperatures above 22 degrees Celsius.

Remember the Purple Emperor is a large butterfly; it can soar and glide powerfully and effortlessly. Purple Emperors will often chase each other or other butterflies and insects so look out for this aggressive behaviour and aerial pursuits.

Keep to footpaths and authorised routes

Importantly, use a good pair of binoculars and prepare yourself for a sore neck

If you are interested in getting involved in the Purple Project then please let me know which of the woodlands listed above you can visit.
Details of all visits made are important, please record when you visited, the weather conditions, times and which parts of the woodland you were able to watch. Negative visits for Purple Emperor will also be very useful
If you see Purple Emperor then please let me know as soon as possible. Ideally, a photograph or video footage would be of great use too.
Finally, if you know of any other suitable woodland then let me know

Good luck!
Bill Stone
Suffolk Butterfly Recorde

Purple Emperor in Ramsey Wood

Having gotten sporadic sightings of all 3 of the great woodland butterflies Silver-washed Fritillary, White Admiral and Purple Emperor at Millennium wood in the last 3 years, I gave Adrian Richards, who was keen to explore an area so close to Ipswich a tour.  He was amazed by the quality of habitat and the continual presence of the larval food plants for all 3 species.  Unfortunately we did not see any of those targets in the 2 hours we were there but that’s the way it goes sometimes. 

Adrian kept mentioning the great numbers of Fritillaries and Admirals he had seen at Ramsey Wood just a 15 minute drive away so suggested we went there.  Despite the declining weather by the time we got there, we managed to see 4 White Admirals and 12 Silver washed Fritillaries, all in very good condition, advising the season was late.  On wandering  through the wood I couldn’t help but notice the sheer volume and quality of Sallows, and on speaking to a couple who had just seen a "large brown butterfly" got my hopes up for a possible Purple emperor.  Adrian commented on how he always keeps an eye out for Purple Emperor and that there was no reason they wouldn't be there. 
 
The habitat looked ideal and located virtually in-between Bonny and Millennium Wood we couldn’t Rule out Purple Emperor.  We spent ages walking up and down the central ride checking Tree tops, manure heaps, dog faeces and oak sap leads but with only Commas and Red Admirals to show for it.  At 14:30  a grey cloud loomed , we lost our enthusiasm and started heading back to the car.
 
To my amazement I spotted a large butterfly gliding around the top of a gigantic Ash tree that had reached above a few large oaks.  I screamed Purple Em peror but by the time Adrian had turned round he missed it.  Excited that it may have been “His majesty” we waited until a break in the clouds.  Thankfully the butterfly was still there.  The Flight pattern was characteristic emperor but it wasn’t until we got views through binoculars we could be certain.  Purple iridescence then confirmed was a Male as expected and it continued to circle the ash for a further half an hour,  Perhaps a master tree!.  We believe this is the first confirmed Purplr Emperor sighting for this wood.  After 10 minutes another Emperor butterfly flew past initiating a dogfight.  My camera wasn’t up to scratch for getting a detailed shot but here are a few poor quality “ID shots”.  It was very fresh and again suggests the emperor season is still young.  We also think Wolves wood across the road must be worth a visit.  

 

David Dowding and Adrian Richards

Peacock Migration

Hi there,  

I am a member of Herts & Middlesex BC, spending my annual 2 weeks holiday here in Aldeburgh, where I’ve been visiting (and lived as a kid) since the late 1960s.  

I mention this to emphasise a point – I have never in my life seen so many Peacock butterflies – dozens and dozens, as reported also on your sightings page by others. I noticed the same at Minsmere. In fact, most butterflies on buddleia are peacocks. I’ve seen very few other nymphalids ...  

Now for the explanation .... on the hottest day last Thursday, I spent about twenty minutes on the beach and noticed a few peacock butterflies coming off the sea, but never paid much attention as I was distracted by my family. The next day, with an hour on my hands, and my brother and niece, we noticed that the Peacocks were all coming at right angles to the beach, from the sea – clearly migrating. We saw all of them from about 50 metres out, and up to 25 metres either side of us.   We estimated one per minute over that one hour, and as I say, on a front across the beach of say 50 metres. This represents a staggering number of butterflies coming ashore: conservatively 1200 specimens per kilometre front.

Given the large numbers at Minsmere, it seem safe to assume that the front extends at least to there, and presumably much further afield, both south and north. Every so often a small wave of 4-5 Large whites would also come in.  We also noted a lot of small flies, and a couple of very large dragonflies. Overhead we spotted large numbers of swifts flying very high, massed over the beach, clearly enjoying the feast.  

To be honest, I was initially sceptical and of the opinion that the butterflies were just  confused Suffolk specimens that had drifted off to sea, but it quickly became obvious that this was not the case. The butterflies were flying in directly from the see, and because of their white colour, the Pieris could be seen much further away, probably up to 200 metres distance. There can be no doubt they were migrating.  

The weather conditions on Friday when we observed this were interesting – it was very hot, and sunny, the sea was calm, and there was a light breeze coming off the Suffolk coast.  At around 5 pm this suddenly changed – a light cold breeze kicked up off the sea, onto the land, the sea became a little choppy, and almost immediately we saw no more butterflies.  I have no idea if the butterflies had timed their departure to avoid the cold breeze, or if the breeze itself was enough to seal their doom at sea ...  

It was fascinating that the only species migrating were Peacock and Large White; and I confess I was not aware of any reports for the migration of either species, so I wanted to make sure I report this to you so that it is “official”(!) although I have no idea if this is “old news” to you or if it is worthy of mention in your sightings or in your newsletter?  

Best wishes,   Andrew Neild (FRES; Scientific Associate of the McGuire Centre, University of Florida)


Andrew,

Thank you for sending your report through. It’s always really useful to get considered comment regarding butterfly migration in Suffolk. 

Your observations reflect what others saw further north (Minsmere/ Kessingland/ Lowestoft) particularly with large numbers of Peacock along the beaches and slightly inland.

Other species reported included Small White and Painted Lady. 

Suffolk does experience localised movement of butterflies where they hug the coast and move north or south. This sometimes explains why oddities turn up from other coastal counties like Kent. However, it’s likely that the butterflies seen by you have moved across from Holland and Belgium making the most of favourable weather. Hopefully, the majority of butterflies involved in this movement will have passed through before the weather conditions changed. 

If you have any other butterfly records from your holiday in Suffolk then please send them through as they will be very useful.

Kind regards,
Bill Stone
Suffolk Butterfly Recorder