The branch drafts species action plans for
those moths and butterflies of conservation concern that can be found
in Suffolk. These plans are used to direct moth and butterfly
conservation work in the county.
There are no Butterfly Conservation
reserves in Suffolk but the branch views the whole of the county as its
reserve and acts to promote conservation of butterflies wherever it may
be needed. Recent work parties have helped improve the habitat at
various sites for the Silver-studded Blue butterfly, one of Suffolk's
more localised butterflies. Advice is provided on maintaining suitable
habitats for butterflies and moths to landowners and agencies within
Silver-studded Blue Translocation to Blaxhall Common
- 2012 Update
In 2007, the Suffolk Branch undertook an exciting project to
benefit one of
rarest butterflies, the Silver-studded blue.
The purpose of the project was to create a new colony of
Silver-studded Blues on Blaxhall Common by relocating adult
butterflies from sites elsewhere on the Sandlings heaths.
Donor sites at Lower Hollesley
Common and Minsmere’s Sawmills colony each provided 30 adult
butterflies, and these were translocated to Blaxhall Common in June &
July of 2007. The
butterflies laid eggs and have now survived their first five winters.
A transect walk was undertaken by volunteers, and in the
summer of 2008, a dozen or so Silver-studded Blues were to be seen
enjoying their new habitat. Both
sexes remained on the wing for a month or so.
The 2009 monitoring proved that
wild pairings had occurred and the new colony was present in slightly
increased numbers. Numbers
increased in 2010, and in 2011 the transect walk achieved a record
index of 155, finding up to 45 adults on the wing over a 9 week period
from 2 Jun to 28 July.
The 2012 season has been another success at Blaxhall - in
the face of a generally awful year of disruptive weather.
This marks five seasons of
progressively rising numbers, flying for a longer flight period each
year, which is most encouraging. The
area of the common over which they are flying has also expanded
Silver-studded Blues are only found on heathland and have
very specialised needs. They
prefer low-growing bell heather and their life-cycle depends on the
presence of a species of black ant that looks after the butterfly
during the early stages of its life. Blaxhall
Common does have healthy populations of the ants,
Lasius psammophilus, and
excellent heathland habitat which (to the human eye) appears ideal.
The passage of time suggests
that the butterflies are content with their new home.
The scheme is a
joint project between the Suffolk Branch of Butterfly Conservation and
Suffolk Wildlife Trust, who manage the site at Blaxhall.
It was made possible thanks to a grant from the
and Heaths Connect fund, using money raised by Suffolk Secrets, a
local tourism business. A keen
team of local volunteers are playing a continuing part in the
maintenance of the heath and monitoring the new colony.
The Silver-studded Blue is one of the
rarest butterflies. It has
suffered a significant long-term decline in numbers, although in
recent years, this has been stabilised, largely due to improvements in
heathland management such as that carried out by members of the
has a small but nationally important population of Silver-studded
Blue, a butterfly that features in the UK Biodiversity Action Plan and
may only be legally introduced with proper authorisation and
appropriate ecological safeguards.
An Update on the Population of Silver-studded
Blue over the 6 years since its Translocation to Blaxhall Common.
The translocation in 2007 of 60 adult
Silver-studded Blues to Blaxhall Common in 2 batches from 2 different
donor sites was notified to the Joint Committee for the Conservation
of British Insects, and followed up with a detailed account of the
re-establishment attempt in a special edition of the Suffolk Argus
(2008). The consents
required us to accept the obligation to maintain the habitat and to
monitor the health of the colony over a minimum period of 5 years.
What follows is a progress report on what appears to have been
a successful establishment.
A longer version has been submitted to Invertebrate Link and to
Butterfly Conservation’s head office.
The code of conservation practice for the
translocation of invertebrates (JCCBI, 2010) and the International
guidelines for reintroductions and translocations (IUCN, 2013) both
stress the need for responsible post-release monitoring, outcome
assessment and continuing management of the release site.
The importance of disseminating information on establishment
attempts is also stressed.
The Common is owned by Blaxhall Parish Council
and the Suffolk Wildlife Trust is responsible for the management of
the site, both professionally and with the assistance of a team of
local volunteers led by Terry Peake.
Over the period since the translocation, the common has been
forage harvested in such a way as to create patches of pioneer
heather, extending the area of suitable habitat for the Silver-studded
Blue. The volunteer work
parties have kept the silver birch encroachment under control and have
cleared areas of gorse and other scrub.
A single-species transect was established in time for the
emergence of the 2008 generation, and has just completed its 6th year
of monitoring. This too
has been organized by the volunteer team, with the results fed back to
the County Butterfly Recorder and to UKBMS.
Transect results have been the prime means of monitoring the
health of the colony. The
table below provides 4 different elements of results, 3 of them
entirely transect derived:
A progressively rising single day peak count for each year.
2. The total count for the whole transect season. This
also rose progressively, apart from a slight dip in 2012 (a poor
season for most species).
3. The number of
consecutive transect weeks in which P. argus was recorded.
4. within the 8 sections of the transect, and latterly beyond
the boundaries of the transect. The observations were made
mostly by the local volunteers, and some by casual recorders on
occasional expansion has been to a triangle of pioneer heather to the
south west of Section 1. On two occasions, singletons have been
seen to the south of the B1069.
One additional element became available in
2013, through the co-operation of Dr Neil Ravenscroft, a professional
ecologist living in Blaxhall.
He conducted an independent assessment of the flight areas,
walked 3 mini transects and extrapolated the likely population of the
entire site to something in the order of 900.
(Ravenscroft, N., 2013,) .
This is materially higher than the sum of the peak one-day
transect count and the highest off-transect count (160 + 51 = 211),
and may be optimistic. It
caters for the incomplete detectability of butterflies in the heather
habitat not visited by the transect route.
It is clear from the table that the establishment
attempt got off to a very satisfactory start and this was featured in
the journal of the Royal Entomological Society “Antenna” (Parker,
2012). The two donor sites
have also been monitored, and show no evidence of damage following the
donation. The receiving
site passed the fragile three to five-year danger zone and the results
for 2013 look re-assuring by every measure .
However, there is no cause for complacency; regular habitat
management remains a key requirement if this colony is to continue to
thrive . Fortunately the
motivation of everyone involved remains strong.
Monitoring Silver-studded Blue Population at Blaxhall
Highest single-day Count
60 released 
Transect Annual Total
Flight period In transect weeks 
Fllght Area 
2008 close to 3 original
2009 some off-transect sightings
2012 first single sighting south of road
2013 plus 51on
pioneer heather in SW close to road
Independent Agreement of Total Population for entire
site  900
 The 2013 season started late and was
compressed to 6 transect weeks, with mass emergence pushing peak
single day count to 160.
 Simplified to transect
weeks; when earlier or later sightings arose these
extended the flight period, but are ignored here for consistency
 Off-transect sightings varied from year to year.
In 2013, the 51 counted off
transect were present a week before the peak count of 160.
 See Ravenscroft, N., 2013 for method used for population
assessment on14"‘ July 2013.
IUCN, 2013, Guidelines for
Reintroductions and other Conservation Translocations.
JCCBI, 2010, Invertebrate Translocation – a code of conservation
Parker, R., 2008 .
Report on Translocation of Silver-studded Blue,
Plebejus argus to Blaxhall
. In Suffolk Argus Special Edition, Summer 2008
Parker, R., 2012 .
Monitoring a translocation of Silver-studded Blue in
. In Antenna 36 (1).
Ravenscroft, N., 2013 (unpublished email) Silver-studded Blue Counts
Ecological Survey of
Not all of our Silver-studded Blue sites are flourishing, and concerns
about dwindling populations and deteriorating habitat at several of the
Sandlings Heaths prompted a detailed ecological survey in 2009. Similar
work was done in 1994 & 2003, and an ecological consultant was
commissioned to undertake a fresh study embracing four sites considered
to be at risk (Purdis Heath, Martlesham Heath, Blackheath and Westleton
Common, all of which had different problems). The opportunity to check
the health of one of the donor sites for the Blaxhall translocation
(Lower Hollesley) was taken, and the suitability of Snape Warren for a
future re-establishment was also investigated.
The full 34 page report is available in PDF
format. There are two versions, one a low-resolution document the other
a higher resolution document. You will need an appropriate PDF viewer
or plugin to be able to read the documents.
resolution Silver-studded Blue 2009 Report (875KB)
resolution Silver-studded Blue 2009 Report (2250KB)
Ipswich Heaths Project
A landscape-level project, aimed at restoring
lowland heathland habitat of 300 hectares on 14 sites in Ipswich, has
been awarded a WREN Biodiversity Action Fund grant of over £100,000.
The project was born from a desire to conserve and enhance the
remaining patches of heathland in and around Ipswich, part of what was
once a continuous band of mainly coastal lowland heathland called the
Sandlings, which stretched between Felixstowe and Lowestoft
In 2009 the Suffolk Branch of Butterfly Conservation commissioned
a condition study of several significant county heathlands that held
Silver-studded Blue colonies. From that the Branch instigated a
series of practical emergency measures to rescue an ailing colony from
probable extinction at one of the sites, Purdis Heath, where in less
than 20 years the count had dropped from 2,000 to less than 10.
The biggest factor contributing to their decline was insufficient
management, leading to scrub succession and loss of optimum breeding
habitat for the Silver-studded Blue and other heathland species of
conservation concern. Volunteers have since stepped in to help
manage the site and reverse the decline, undertaking operations such
as tree removal, creation of bare ground habitat and heather cutting.
This year the count has risen, too early to declare the population as
recovering, but an encouraging sign nonetheless.
The Ipswich Heaths Project, delivered by Sharon Hearle (Project
Officer), will now enable the scale of restoration to be dramatically
accelerated, extending the work to include all 14 sites. Funding
will also pay for contractors to carry out some of the larger scale
works needed. However, community groups and volunteers will
continue to be integral in making the project a success, supporting
the project officer with practical conservation work and site
Heaths — Progress at Purdis
The Ipswich Heaths
project, funded by a WREN Landfill Communities Fund grant, is a
landscape-scale lowland heath restoration on 11 sites on the eastern
fringes of Ipswich. The
heathland habitat close to Ipswich is now much reduced and fragmented
by new housing, industrial and recreational pressures, combined with a
lack of conservation management, this has had a devastating impact on
the number of butterflies and moths found.
As recently as the 1980s the
project’s main site, Purdis Heath, had over 2000 Silver-studded Blue
regularly counted, tragically the peak count in 2010 was just four.
Since then, Butterfly Conservation and other groups and
individuals have stepped up the level of habitat management work,
focusing largely on reducing scrub from the heather areas, cutting the
heather to promote a diverse age structure and creating bare ground to
promote fresh pioneer heather and encourage ants.
All these things are needed to
improve the site for the Silver- studded Blues chances of survival.
In addition to the practical
work the site has been well studied, not least by Darren Flint, whose
MSc research project involved a study of the population changes of
Silver- studded Blue (Plebejus
argus) on Suffolk’s lowland heathland in 2013, focusing on Purdis
Heath. Darren observed male
SSBs actively protecting nectar sources (Bell Heather), a fact he
couldn’t find noted in the literature and certainly an interesting
behaviour that warrants further exploration.
A transect has also been set up
and so monitoring the butterflies has become much more organised.
In 2013 the peak count of SSBs was 40, a tenfold increase from the
precarious situation in 2010. But
we are not in a position to sit back and relax yet!
This is still a very low number
and much more work is needed. However,
we can take encouragement that at least things are moving in an upward
trend. Other good news, as
reported by Darren in his MSc research project, correlating with the
increase in butterflies is that the flight area has increased.
In 2009 was just 0.1 ha of
heathland in the north-west corner, which has now grown to cover
1.03ha spread over three sizeable patches spread across the heath. A
930% increase and not that far off the 1985 peaks of 1.3ha.
Thanks to the grant from WREN there is scope to do a lot more habitat
management at Purdis Heath. Throughout
the winter scrub was cut and cleared from more areas of heather, most
significantly between the heath and the adjoining golf course.
This is to try and create a
link between the sites and increase the SSBs availability of habitat
to spread in to. The population
of SSBs will again be monitored between the flight period of June-July
and it is hoped that we will be reporting another increase in the
Autumn of 2014.
Areas that were previously beneath tree canopy and with
ground deep in leaf and gorse litter have been converted to bare
ground habitat. In time (with a helping hand of heather cuttings
loaded with seed) the area will blossom into pioneer heather heathland
again. And hopefully along with the flora will come the fauna we
all want - the ants and their grateful friends the Silver-studded
you would like to get involved with volunteering at Purdis Heath
please feel free to email our warden, Julian Dowding from our
2014 Work continues at Purdis Heath
Work parties take place at Purdis Heath on the 1st
Saturday of the month over Autumn and Winter. We meet at 10.00am on
Bucklesham Road side of the site. Please email Helen Saunders at for details if you are interested.
You will then receive an email nearer the time, with information about
the work to be carried out
We've finally been getting on with the last stage of this season's
work at the heath. This involves mainly scraping with JCB down
to the sand /or soil mineral layer and some weed treatment on the