Issue 82 ~ Summer 2012 - Suffolk Naturalists` Society

WHITE
ADMIRAL
Newsletter 82
Summer 2012
SUFFOLK NATURALISTS’ SOCIETY
CONTENTS
EDITORIAL
SNIPPETS
THE SUCCESSFUL RETURN OF A SUMMER
HOLIDAYMAKER
NEW DRAGONFLY RECORD FOR SUFFOLK Leucorrhinia pectoralis
CHANTRY PARK BIO-BLITZ 2012
BATS IN WOMEN’S HAIR
POEM The Bat and the Blonde
SAWFLIES
WIND TURBINES, BATS AND BIRDS
DIGITAL PHOTOGRAPHY WITH THE
MICROSCOPE - Choice of digital camera
REPORT ON THE 2012 AGM
OLIVE CRESCENT - POTENTIAL COLONY IN
SUFFOLK
A WHITE MINK AT LACKFORD
A CELEBRATION OF SUFFOLK GEOLOGY
ABSTRACT OF PAPER BY PRESENTED BY
COLIN HAWES AT EUROPEAN WORKSHOP ON
CONSERVATION OF SAPROXYLIC BEETLES
LETTERS NOTES AND QUERIES
Invasive species - Green Alkanet
Halesworth Millennium Green invitation
David Walker
Ben Heather
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SBRC
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Adrian Knowles
Martin Sanford
G.M. GathorneHardy
Martin Sanford
Tom Langton
Philip M. Greaves
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7
David Walker
Tony Prichard
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21
Jeff Martin
Roger Dixon
Colin Hawes
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27
Nick Miller
Nicky Rowbottom
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Cover photograph of Nightingale at RSPB Minsmere taken by Peter Heather
ISSN 0959-8537
Published by the Suffolk Naturalists’ Society
c/o Ipswich Museum, High Street, Ipswich, Suffolk IP1 3QH
Registered Charity No. 206084
© Suffolk Naturalists’ Society
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SUFFOLK NATURALISTS’ SOCIETY
David Walker
30 Reade Road
Holbrook
Suffolk IP9 2QL
[email protected]
SUMMER 2012
Two unusually dry winters; double the normal rainfall in April and June, the highest
since records began; the jet stream shifting south yet again; severe flooding in
Russia; record heat waves in North America – surely evidence of climate change?
Why aren’t the climate scientists screaming ‘We told you so’? But science doesn’t
work like that, it’s based on statistically reliable evidence. True, says Peter Stott,
head of climate monitoring and attribution at the Met Office, the globally warmer
atmosphere now carries 4% more moisture over the oceans than in the 1970s and this
could be leading to increased rainfall. But the only aspect of climate change’s impact
on the weather that most academics agree on is the need for more research. Unlike
the climate change deniers who have something to protect (like investment in the oil
industry) scientists are just seeking the facts. Dr David Schultz, at the centre for
atmospheric science at the University of Manchester says: “It’s hard to extrapolate
the past few summers to global warming as a whole. That’s the message I would
give if you want to be fair about what the data is showing and our state of the
science”.
***
Springwatch – sneered at by some serious naturalists for being too populist – gets
good viewing figures. But in the mix there is some useful education. As well as
following the fate of individual fluffy fledglings and cuddly fox cubs, the resident
geek in the person of Chris Packham is always there to point out the harsh reality of
competition and survival in the wild or analyse a lump of smelly droppings or make
a controversial statement such as castigating cat owners for letting their pets out at
night. It’s a matter of balance. Packham may not be to everyone’s taste, but he is
outnumbered by the ever-smiling Michaela Strachan and the slightly bumbling
Martin Hughes-Games. The popularity of the programme shows they have got
something right.
Can the SNS learn from this? The success of the recent ‘Taster Day’ at the
Flatford Field Studies Centre points to a demand for hands-on events that offer
learning opportunities. After all, we have plenty in our midst who could contribute to
owl pellet or droppings workshops or Q & A forums, with bar charts if necessary!
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SNIPPETS
•
“Plant Galls” by Margaret Redfern, the latest volume in the New Naturalist
Library, is an excellent book. Encyclopaedic in its coverage (more than you’ll
ever need to know), beautifully illustrated with line drawings (technically
superb life cycle diagrams) and photos, it is a reminder of what a complex and
thrilling subject biology is.
SWT’s plan to reintroduce the Fen Raft spider to Castle Marshes, near Beccles,
seems to be working. Four nursery webs, each containing about 200 spiderlings
have been found on Water Soldier plants in the marshes. Project leader Helen
Smith bred 3,000 spiders in test tubes in her kitchen prior to releasing them.
Studies in the USA have shown that glyphosphate (Roundup) at sublethal,
environmentally likely concentrations caused morphological alterations in two
species of frog tadpoles.
Beekeepers are being asked to kill and report all instances of the non-native
Asian Hornet Vespa velutina. This aggressive invader, which is now established
in France, can destroy a bee colony in two hours. Sightings should be reported
to [email protected]
A study of Lyme Disease in dogs has shown that the disease is more widespread
than previously thought. Remember to cover the skin on your feet and legs
when walking in areas of bracken.
By twitching their whiskers upwards, outwards and straight ahead dormice use
them to navigate when climbing trees. Dr Robyn Grant at Sheffield University’s
‘Active Touch’ lab says that similar processes occur in other rodents but not in
the non-rodent water shrew and that this shows that dormice share a common
ancestor with other rodents.
The mosquito Culex modestus, not seen in the UK since 1945, has been
recorded in marshes in north Kent and south Essex. It is thought to be a vector
of West Nile Virus.
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VACANCY – EDITOR OF WHITE ADMIRAL
Owing to David Walker’s retirement an immediate vacancy has arisen for the
position of editor of the White Admiral newsletter.
White Admiral is published three times a year. It aims to inform SNS members of
activities and developments within the Society and in Suffolk’s natural history
generally, in a fresh and lively manner.
The role is unpaid but approved expenses can be claimed.
If you are interested and would like more information please contact
The Hon. Sec., Suffolk Naturalists’ Society, c/o Ipswich Museum, High Street,
Ipswich, IP1 3QH, telephone 01473213479 or [email protected]
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THE SUCCESSFUL RETURN OF A SUMMER HOLIDAYMAKER
The nightingale (Luscinia megarhynchos) is one of our most notable and distinctive
summer visitors. Seldom seen but when heard, its powerful and impressive song is
enough to attract the interest of any nearby birdwatcher to try and catch a glimpse.
This is exactly what led to my uncle, a keen naturalist and birdwatcher from
Cumbria, to track down and photograph a singing nightingale in the scrub around the
wardens’ office at RSPB Minsmere. My uncle (Peter Heather) is a regular visitor to
Suffolk and its ‘birding’ hotspots and follows the various forums citing bird
occurrences as well as taking many excellent photos.
Together on the 19th May we visited Westleton and Dunwich Heath and were
treated to many brilliant photo opportunities of Dartford warbler, but it was stopping
by at Minsmere on our route home that provided the highlight of the day. Peter
suggested searching for nightingales in a spot east of the wardens’ office, where he
had photographed them the week before. We listened and observed a singing
nightingale and Peter was, for the second time, able to get good close pictures (see
cover photo).
The most interesting part of this and his previous sighting only came to light
once Peter had returned home and was editing his pictures. From the photos, the
nightingale was clearly ringed but the resolution of one photo was so great, that even
the ringing number was clear.
Photo by Peter Heather
Peter informed Minsmere staff who were able to confirm that this very bird was
ringed almost exactly a year earlier during a ringing demonstration by the Waveney
Bird Club. The secretary of the club, Chris McIntyre was able to detail further that
“this nightingale was an adult when ringed on the 6th May last year, so it’s already
defied the odds by completing at least two journeys to Africa and back.”
The successful re-identification of this specific bird confirms how faithful
individual nightingales are to their particular breeding territory and highlights the
importance and value of their often overlooked scrub habitat.
Ben Heather
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NEW DRAGONFLY RECORD FOR SUFFOLK – LEUCORRHINIA PECTORALIS
A male specimen of the Large White-faced Darter or Yellow-spotted White-faced
Darter Leucorrhinia pectoralis was recorded by Edwina and Alan Beaumont on 16th
June 2012 at Dunwich. Their record, confirmed by Adrian Parr, reads as follows:
“It was sunny and very windy at about two fifteen. We were walking
along Docwra’s Ditch at Dunwich, TM475678, which separates the heath
from Minsmere. The dragon fly was in the third pool west from the beach. The
dragonfly was fairly active and frequently attacked by a four spot chaser. It landed a
number of times on reeds and also on the timber rail on the little bridge which is
where we were able to photograph it. The water is probably slightly acidic judging
from the vegetation which includes a lot of Marsh St Johns Wort.”
This is the first UK record of the species in 150 years.
Immature male Leucorrhinia pectoralis photographed at Dunwich by Alan Beaumont
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CHANTRY PARK BIO‐BLITZ 2012
“Bio-blitzes” are a recent phenomenon: a range of experts and the general public are
invited to “do” a site, recording as many plants and animals there on a single day.
On 16th June Ipswich Borough Council organised just such an event at Chantry Park
on the southern outskirts of Ipswich. I attended in my capacity as SNS Recorder for
bees, ants and wasps; several other recorders were also present.
Despite slightly blustery conditions, the previously forecast rain held off and so
the more sheltered parts of the park were explored. One of my first finds was one of
the rarest bees in the country! The presence of the mining bee Lasioglossum
sexnotatum in south Ipswich has previously been reported in White Admiral and the
Society’s Transactions, so its presence at Chantry Park is perhaps not totally
surprising. However, given its Red Data Book 1 “Endangered” status, it is always a
nice find. It was taken from planted Geraniums in a formal garden within the park,
thus showing the value of such habitat to invertebrates.
Having caught this so early, I strongly expected that I’d had my highlight of the
day already. However, one of the last finds possibly eclipsed even this, at least in a
local context. The specimen was a fairly drab, medium sized mining bee that was
clearly from the large genus Andrena. This was retained for later examination.
Back home it was shown to be a male Andrena fulvago – the first Suffolk record
since June 1799! This ancient observation was made by the Reverend Kirby (one of
the forefathers of Hymenoptera study in the UK) in Barham, near Ipswich.
Although present in scattered localities across southern England (including
Essex) and the south Midlands, this Barham record stood as the only ever record of
this species to have been found in East Anglia (Cambridgeshire, Suffolk and
Norfolk). The Chantry record came from the flower-rich County Wildlife Site
meadow within the park, which is likely to be ancient grassland and it is quite
possible that this bee has been living here waiting to be discovered for many, many
years.
Seek and ye shall find!
Adrian Knowles
Hymenoptera Recorder
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White Admiral 82
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BATS IN WOMEN’S HAIR
A little over 50 years ago, Jock Cranbrook (4th earl and father of our current
President) conducted some experiments and published the results in a series of notes
in Transactions (see below). These make quite amusing reading in themselves.
Whilst sorting through a batch of papers that Cranbrook Jnr had deposited here I
came across the attached poem which I thought members might enjoy reading in
the Admiral. I have written to Lord Cranbrook who replied as below.
“I overlooked that poem, in the papers I passed to you.
Geoffrey Malcolm Gathorne-Hardy was my father's cousin, a distinguished
veteran of the Boer War and WW I. He was a good artist, and we have
several pictures that he drew of the devastation of the countryside in the
war, and a nice picture of a Glis glis that he found in the trenches, and
sketched because it was an animal he did not recognise.
He was also a scholar of the Norse and Norway. He translated Norse
legends, and also translated the Norwegian national anthem into English. I
think he was one of the first to recognise that the Norsemen probably
reached the N. American continent.
This poem must have been a joking communication between cousins.
If you publish it, this is the vein in which you give it a wider readership.”
Martin Sanford, SBRC
TSNS 11: 193. Notes and Observations. 1958.
BATS IN WOMEN’S HAIR. It is often said that bats are in some way attracted by
women’s hair and that once in contact they become inextricably entangled, the two
victims having to be separated by scissors wielded by a man. Reports of such
occurrences are much like those of the Indian Rope Trick; one’s informant knows
somebody, who knows somebody else, who had a friend – etc. etc., but the story of
bats in the hair is so widespread that the gift of a Noctule (Nyctalus noctula) by Mr.
D. Jones of Higham and of three smaller bats, Long-eared (Plecotus auritus)
Natterer’s (Myotis natteri) and Daubenton’s (M. daubentoni) by Mr. R. Stebbings of
Bury St Edmunds seemed to offer sufficient material for experiment. Of women only
two young 18 year old blondes were available, one with relatively short curly hair,
the other with longer wavy hair done up behind in a bun: it does not seem likely that
there would have been any different result with older women or with brunettes. In
the case of the smaller bats each was placed in turn upon the volunteer’s head, each
walked about without becoming entangled in any way and finally took flight without
any difficulty. The experiment was repeated several times with the same results.
None of the small bats had been long in captivity, all were still a little nervous when
handled and apt to bite and therefore likely to “panic” – if bats do panic – when
placed upon a hairy and unaccustomed substratum. The noctule on the other hand
had been in captivity for several months and was very tame, hurrying towards a hand
placed in its cage and crying like a puppy for food. It had been found lying injured
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on a road in mid-winter and had never attempted to fly when in captivity and seemed
to have arthritic swellings in one knee joint and one wrist. A freshly caught Noctule
does seem liable to panic in a house and the experiment should obviously be
repeated with such an animal. In the case under review the tame noctule walked
about on the volunteer’s heads with no apparent difficulty. I should like to be able to
record the names of these two martyrs to science but they prefer to remain
anonymous. CRANBROOK
TSNS 11: 271. Notes and Observations. 1959.
BATS IN WOMEN’S HAIR. A newly caught Pipistrelle, (P. pipistrellus) struggling,
squeaking and biting, was pushed into the fairly long curly hair at the back of the
head of a brunette in the middle 30’s. The bat climbed with care up onto the crown
of the victim’s head and took flight without getting entangled in any way. Suffolk
Naturalists can take a vicarious pride in the fact that three Suffolk women have been
found (see TSNS 11: 193) ready to test the truth of a hoary superstition. It is to be
hoped that some brave West Country women will try with the Horseshoe bats
(Rhinolophus, sp.), which are not available in Suffolk.
CRANBROOK
TSNS 11: 325. Notes and Observations. 1960.
BATS IN WOMEN’S HAIR. Since the experiments reported in Trans. S.N.S. XI, pp.
193, 271, it has been suggested to me that none of the human subjects concerned had
hair of the length of their grandmothers, around which the stories of disastrous
entanglements must have arisen. I was indeed told by a near contemporary that in the
early 1890’s a Norfolk peeress, now deceased, combing her long fair hair before two
candles and a mirror had just reached the extreme end of the comb-stroke, the point
at which many of the shorter hairs float in the air like a golden spray, when a bat
flying into it became inextricably entangled. I was able to repeat this romantic
situation, though by electric and not candle light, with a Whiskered Bat (Myotis
mystacinus) and a nineteen year old blonde with long fair hair. The bat entered the
hair with wings half-spread, closed them instantly and fell through the golden mist
onto the floor with a most unromantic thud.
CRANBROOK
The Bat and the Blonde
Since bats and humans shared at nights
A common cave, as troglodytes,
Women have held as gospel truth
This warning taught them in their youth:“A FLOATING TENDRIL OF YOUR HAIR
A FLYING BAT WILL OFTEN SNARE,
WHOSE FRUITLESS STRUGGLES ONLY MAKE
HIS BONDS MORE DIFFICULT TO BREAK,
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TILL WRAPPED IN HAIR, THE CREATURE SOON
DIES, STIFLED IN A CLOSE COCOON,
WHERE ITS REPULSIVE CORPSE MUST STAY
TILL EVERY TRESS IS SHORN AWAY”.
A peer of scientific bent,
Who lived at Glemham, was intent
Upon two questions; - Was it true
That this was what a bat might do?
And – So time-honoured a tradition –
Can it be merely superstition?
He was a specialist in mammals, Not whales or elephants or camels –
But smaller types with humbler roles,
Like shrews and mice and bats and moles.
He wished to thrash the matter out,
And solve the problem past a doubt.
“Poor bats, I can’t untried condemn ‘em”,
Muttered this kindly earl from Glemham.
So, for this scientific end,
He sought a sympathetic friend,
Explained the case, and how he meant
To test it by experiment;
Adding, “I should esteem it highly
If you could find a corpus vile,
Since ladies with appropriate hair
Have grown exceptionally rare”.
“A corpus vile?” cried his friend,
“Nay, something better I can lend;
“I have a secretary here
“Whom I can trust to volunteer;
“A blonde, superlatively fair,
And graced with rich abundant hair, Long, flowing tresses like Godiva’s,
Or some Victorian survivor’s.
She’s game for any kind of task
That I or anyone may ask.
Were there a million bats about,
She’d stand her ground and face it out,
Intrepid at the call of duty;
And, what is more, she is a beauty;
No movie-star could match her glamour
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- Though she’s a virtuous maiden, damn her! –
But though myself I’ve never kissed her
No bat is likely to resist her”.
So said, so done; the maid’s consent
Obtained for this experiment,
The noble earl, with great delight,
Proposed a test that very night,
And led the lady to his flat,
Armed with the necessary bat.
(Culled from the famous Glemham ‘tip’,
Where luscious crickets creep and skip,
The specimen was fine and fat –
A really first-class ‘cricket-bat’).
Arriving at his flat, the earl
Got down to business with the girl.
He placed his victim in a chair,
And told her to let down her hair,
And comb it out, until it spread
A golden web about her head;
Then flung the bat, with careful aim,
Into that aureole of flame.
He scored a negative result:
Propelled as from a catapult,
The bat, bewildered but unbound,
Slithered directly to the ground.
It only roused the maiden’s merriment
When he repeated the experiment;
Her hair unscathed, the bat once more
Subsided gently to the floor.
“The case is proved”, declared the earl,
“Bats are no danger to a girl;
“Our twice-repeated test has shown
“They always leave the hair alone”.
“Good gracious!” commented the bat,
“The fellow’s talking through his hat.
“Would he attempt a close embrace
“If chucked into a lady’s face?
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“Forced landing, when you’re on the wing,
“Of course, is quite another thing.
“Next, though a gentleman responds,
“I’m told, most readily to blondes,
“Noctules – allow me to remark,
“Decidedly prefer the dark.
“This lady’s hair is far too bright,
“It sheds a most conspicuous light;
“The threads from which her web is spun
“Shine out as clearly as the sun;
“But next time your trap is set,
“Just bait it with a nice brunette!”
G. M. Gathorne-Hardy
Cranbrook’s experiments caught the imagination of the
popular press. This photograph was published in Reveille.
Photo kindly supplied by Lord Cranbrook.
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SAWFLIES
Sawfly Cimbex connatus found at Lackford
Photo: Emma Kerridge
This impressive insect found during the SWT’s May Festival at Lackford Lakes on
May 20th is the large sawfly Cimbex connatus. The insect is over 2 cm long with a
wingspan of about 5 cm. It superficially resembles a hornet, but the clubbed
antennae are distinctive and it lacks the narrow waist and fearsome sting of the
hornet.
This appears to be the first confirmed Suffolk sighting of the species since
Morley found a larva on Alder at Freston Wood in August 1904 (VCH Vol. 1 p. 16).
After Morley’s 1904 record, the species was not seen again in Britain until 1997
when it turned up near Salisbury in Wiltshire. Since then, it has been recorded with
steadily increasing frequency throughout southern and eastern England, as far north
as Yorkshire. It has now been found in about 20 vice counties, including several
records in Oxfordshire and Buckinghamshire, as well as Wiltshire. The larvae feed
on alders, using native Alnus glutinosa and the introduced Grey Alder A. incana and
Italian Alder A. cordata. When fully grown, they are about 5 cm long and have a
dark dorsal stripe all the way along the body. They generally feed between July and
September, but may still be found as late as October. Many of the recent records of
Cimbex connatus seem to be associated with amenity-planted Italian Alder in such
exotic places as supermarket car parks. It is likely that at least some of the modern
records are the result of accidental re-introductions.
Thanks to Tony Irwin at the Castle Museum, Norwich for his advice and help
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with identification. Tony informs me that this species has also been seen recently in
Norfolk, chiefly in the Yarmouth area.
The sawflies are an interesting group to record. Many species are host-specific
with easily recognised larvae, but we have few records, even for common garden
species like the Solomon’s Seal Sawfly Phymatocera aterrima which regularly
defoliates my Polygonatums or the equally voracious Aquilegia sawfly Pristophora
aquilegiae.
The Royal Horticultural Society have been collecting records of the Berberis
Sawfly Arge berberidis, an invasive garden pest of Berberis and Mahonia, which
probably became established in the UK in 2000 and is now widespread in England.
The caterpillar-like larvae are up to 18 mm long, creamy white with black spots and
yellow blotches. The adult sawflies are 7-9 mm long, bluish black with dark grey
wings and upswept antennae. It has several generations a year and can be found
throughout the summer months. See http://www.rhs.org.uk/Science/Plant-pests/
Berberis-sawfly for a profile of this species and maps of its spread. It was seen at
Bury St Edmunds and Chevington in 2007, at Newmarket in 2009, at Debenham and
Bramford in 2010 and near Ipswich and Woodbridge in 2011.
John Grearson of Wiltshire and Swindon BRC has produced a handy
introduction to Sawflies on the WSBRC Website at:
http://www.wsbrc.org.uk/YourRecords/CountyRecorder/sawflies/recording/
PageTemplate.aspx
Martin Sanford
Above: Larva of Cimbex connatus
Right: Berberis Sawfly
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WIND TURBINES, BATS AND BIRDS
Following the article on this subject in the last SNS Transactions (Vol. 47), barn owl
expert Jeff Martin has written to me on the potential impacts of wind turbines on
birds saying how pleased he was that the issues have been raised. In particular he
considered that in addition to the potential for barn owls to be killed by turning
blades he has heard of an incidence where wind turbines have had a secondary
negative effect on them. In this case a pair of barn owls disappeared following
disturbance from the start of the installation and subsequent operation of the turbine.
Jeff suggested that if wind turbines are placed on open ground which barn owls use
for hunting, then the general disturbance, and any consequential damage or loss of
the surrounding habitats, may well cause barn owls to desert their territory. He
believes the detrimental effect on the barn owl could be from the noise and
distracting movement of the turbines. He writes “Barn owls rely mainly upon their
hearing for hunting, and any intrusive background noise is likely to have a negative
effect upon their ability to hear their prey as it rustles about in the under-growth. It is
well known that due to the detrimental effect that wind has upon their hearing, barn
owls, and other owls, do not generally hunt in windy weather. At such times it is
possible, with care, to get very close to a roosting barn owl, and to watch it with
normal torch light from a distance of no more than 3-4m.”
In addition to Jeff’s letter, The Barn Owl Trust has released a statement on the
subject: “Monitoring at existing wind turbine/anemometer sites for Barn Owl
injuries/fatalities is undoubtedly inadequate at the present time and mortality may be
under-recorded. Given the anticipated proliferation of wind turbines, a strong
argument exists for long-term (ideally independent) monitoring systems to be
implemented in the vicinity of wind turbine sites.”
Suffolk barn owls are reported to be at low levels; the number of pairs has
fluctuated following a decline since the 1930s, with an estimated 150 pairs
remaining in the county in 1985. There were an estimated 125 pairs in 2005 and 192
pairs in 2011 (SWT 2012). Lack of foraging habitat caused by the general
deterioration of the quality of grasslands and declines in barn owl roosts in large old
trees and open barns, may explain this, but could wind turbines add a new significant
negative force on barn owl survival? Planning applications for smaller turbines,
(generally about 5-30 metres high and generating 5-15 kW) are being applied for
most numerously in East Anglia, at a rate of hundreds per year. The suggestion is
that this will continue for the foreseeable future.
On the issue of the impact of noise, it is notable that wind turbines vary greatly in
their noisiness. Smaller turbines seem noisy close up – within 50 metres or so, but
are much quieter 100 metres away. Medium (up to 100 metres high) and bigger ones
(125 metres) can be detected by the human ear at 2000 metres and are noticeable at
1000 metres, especially when they are pointing directly towards or away from you.
Noise also varies greatly with wind speed. Cowlings on the turbines are presumably
thin to help prevent over-heating . Noise reduction has been achieved to varying
degrees by different manufacturers. Noise limits set by local authorities generally
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mean that medium and large turbines must be 500 metres away from dwelling
houses. This is not enough for humans let alone the noise perception of animals with
far more sensitive hearing.
It must be a concern in terms of quiet enjoyment of the countryside by humans
that turbines are heading for the more remote and the tranquil places, where absolute
silence at night can still be experienced, despite the noticeable increase in aeroplanes
over the last 20 years. While the hum of turbines and chopping blade noise of
turbines could or should make us pleased to hear renewable energy being generated,
noise is a significant factor in moves to shut down night time generation of two
turbines in Kessingland in Suffolk; it is reported that the hum can be heard indoors
by residents 600 metres away at night, an intrusion into previously quiet homes, and
is a potential cause of ill health. Medium sized turbines can also be heard indoors at
that distance.
Further communications from others have drawn my attention to Red Kites
killed and injured by turbines in Wales (Welsh Kite Trust – two incidents), although
unless the collision is witnessed some might claim that those found under turbines
are not proven to be killed by them.
This brings us to a number of further related issues raised with me or that have
come to my attention in the first half of 2012 that may be of interest to members.
Firstly, reports that some companies set up to promote and sell wind turbines are
approaching farmers and other land owners en masse, asking for permission to
apply for turbines at locations suitable for passing generated electricity into the grid.
Some seem to be doing this with minimal consideration their impact on bird and bat
populations. Typically this involves doing a check on biological records and then, if
no records exist saying that there is no impact, or that it is insignificant, even if bat
habitat is nearby and easily locatable with a bit of fieldwork and investigation. Some
have been caught out not doing checks properly. However, the matter has not been
aided by current advice sheets from Natural England and the Suffolk Biodiversity
web site that were revised in March and April 2012. The problem is that some
ecological consultants are promoting a de minimis interpretation of these guidelines
and the Habitats Directive and UK law and their own view on what is known as
favourable conservation status to say that such a minimalistic approach is
acceptable. Goodness knows how many turbine sites have been handled already with
this approach, particularly in Norfolk where there seem to have been most
applications, but if the damage done to bats can be shown, then retrospective partial
or total shut down of some of these turbines is a distinct possibility.
In April, following exchanges with planning departments in a Suffolk District
Council, I managed to get a turbine application that was steaming towards approval
pulled from the decision process at the last minute. Calls to provide more detailed
advice to District Councils on Wildlife matters have been heeded by the Suffolk
Wildlife Trust and emergency action is warranted. Mid Suffolk District Council has
required night shut-down of a turbine during the bat active season at one site
showing that some planning advice is working. The 50 metre rule, pushing turbines
away from hedgerows and other features at least helps to minimise potential damage
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to bats that occasionally or regularly cross fields rather than following linear features
such as hedges. At this time of uncertainty and doubt over the sufficiency of national
bat surveillance – a strict requirement of the Directive – failure at the regional and
detailed site level is a triple whammy against bats and surely not lawful.
On the subject of uncertainty of impact in respect to bird mortality and wind
turbines, more information is coming to light. In one study, turbines were reported to
kill up to two non-raptor birds and up to around 50 bats per year (Jana and Pogacnik
2008). In another study, and of great concern, is in a review of 12 wind farms
(groups of turbines), where a breeding bird density decrease of 15-52% within 500
metres of turbines was noted (Pearce- Higgins et al 2009). This seems to be mainly
an upland study and aimed at groups of, rather than individual turbines. The study
sites mostly have well established breeding bird densities around them. In this sense,
conditions may not be the same as in our more fragmented lowland landscape where
bird densities are often already much lower. We are starting to see small turbines set
close or even right next to hedgerows in Suffolk (e.g. a recent one near Halesworth –
see picture) where it is hard to think that birds and bats will not be killed or injured.
Presumably any bird nesting depletion zones here in East Anglia (due to noise or
disturbance factors) will be lower than the upland examples, but we just don’t know,
and Suffolk’s generally good bat numbers may be more at risk than birds. This is all
guesswork however, in the absence of proper advance investigations. Certainly
people should be wary of the medium sized (generally under 300 kW) turbines that
are both noisy and have a wide blade ‘foot-print’.
Wind turbine positioned next to hedge in Halesworth
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The lack of research into bat and bird impacts is as worrying offshore as it is
onshore. The wintering Red throated Divers mentioned previously appear to be
shifting from turbines in the London Array and have moved north off Sizewell to an
area used by ship to ship oil transfer. Like barn owl they are generally low fliers but
the noise and sight of them may be off-putting. The Habitats Directive requires
governments to control where the best alternative zones and sites are for turbines and
not to leave it to industry forces and under-supported local authorities to police.
Further care is needed, not least by our major national bird charity who recently
announced they are spending funds on planning for a medium sized wind turbine up
at the Cambridgeshire HQ. The announcement came between two prominent media
stories, one in the Times and one in the Guardian. The first in the Times by Richard
Black: Wind farms ‘not major bird mincers’ pointed to the BTO/RSPB (Pearce
Higgins et al. 2009, 2012) studies concluding local bird nesting depletions and
uncertainty, while the Guardian ‘Windfarms do not cause long-term damage to bird
populations’ on the same evidence found what appears to be a very different
conclusion. Was this apparent PR sandwich a co-incidence? The fact is that no-one
can say how small and medium turbines will impact on birds and bats in Suffolk or
the UK, either onshore in different landscapes or offshore until the surveys and
monitoring are in place. The data from the quoted studies might equally have been
headlined ‘research casts concern over wind turbine impacts’. No doubt thinking on
this will be thorough, as a dead red kite, dead bats or depleted nesting birds at a bird
charity HQ might dent membership support. This should perhaps cause a rethink
towards alternatives such as photovoltaic perhaps at a different, well selected site for
the most important reason - to set a good example to others.
References
Jana, S. and Pogacnik, M (2008) The impacts of wind farms on animal species. Acta
veterinaria
Volume: 58, Issue: 5-6, Pages: 615-632
Pearce-Higgins, J.W. , Stephen, L., Langston, R.H.W., Bainbridge, I.P. and Bullman,
R. 2009. The distribution of breeding birds around upland wind farms.
Journal of Applied Ecology 46: 1323-1331.
Pearce-Higgins, J. W., Stephen, L., Douse, A. & Langston, R. H. W. (2012) Greater
impacts of wind farms on bird populations during construction than
subsequent operation: results of a multi-site and multi-species analysis.
Journal of Applied Ecology, 49, 386-394.
Suffolk Wildlife Trust (2012) A countywide call to action. Suffolk Wildlife. May
2012
Tom Langton
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DIGITAL PHOTOGRAPHY WITH THE MICROSCOPE
Choice of Digital Camera
Often digital photomicrography is attempted with a pre-existing camera and
almost any digital camera can be utilised to record images from the microscope;
several ingenious arrangements to couple less-suitable cameras to microscopes have
been published. However, if selecting a new camera there are several important
considerations.
The most fundamental decisions relate to how the camera is to be used, and how
the images are to be used. If the camera is to be used for general photography as
well as photomicrography, a conventional consumer level compact camera or digital
single lens reflex (DSLR) is necessary to provide a lens function. Alternatively if
the camera can be wholly dedicated to the microscope, a specialised microscope
camera system may be appropriate. However, it is the balance between sensor
resolution (number of pixels) and cost that is probably most important. Digital
cameras have evolved rapidly in their short existence; a ten-fold increase in sensor
resolution of consumer level cameras has been achieved in as many years whilst
prices have dropped in real-terms. Almost any modern digital camera will now
provide more than adequate resolution for all but magazine quality publishing.
The next question relates to overall sensor size. The physical dimensions of the
sensor will have an impact on how much of the field of view of the microscope can
be projected onto the sensor and therefore recorded. Larger sensors will record more
of the visual field of view, assuming no change in projection optics. The situation is
however, complicated by compact cameras that have a built-in zoom lens and
several images with smaller fields of view can now be ‘stitched’ together by
software to make a larger overall image. Both sensor resolution and sensor size have
a major impact on cost of the camera; the third (and often over-riding question) in
selecting a camera is ‘how much do I want to spend?’
The cheapest starting-point for digital photomicrography is a dedicated webcam.
These are supplied with optics to replace the microscope eyepiece and simply drop
into place in the microscope tube. Connection to a computer via a USB link
provides power to the camera and software included with the camera provides the
control. Both still and video images can be recorded to the computer. The great
advantage of webcams is their low cost and ease of use. Against this, sensor
resolution is very low and the camera can only be used in combination with a
computer. A typical webcam of 1.3 MP will produce prints of tolerable quality up to
6” x 4”.
When conventional film cameras were used for photomicrography, the camera
would always be used with no lens attached; it was unheard of to use a fixed lens
(e.g. rangefinder) camera with the microscope. However, compact digital cameras
(with a fixed zoom lens) have been very successfully used for photomicrography.
For some years, the Nikon 950 (and subsequently 995 / 9500 models) has been the
most popular compact camera because of the ease of coupling to the microscope
using an eyepiece with male screw thread corresponding to the female filter screw
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thread at the front of the camera lens and because of the tilting view screen which
makes focusing easy. However, these models have now been out of production for
several years and are now only available second-hand. Older models are now prone
to terminal failure without warning.
A wide range of compact digital cameras is now available and some are more
suitable for photomicrography than others. In looking for a model suitable for use
with a microscope, the following features are important:
• A female screw thread to the front of the lens designed to allow filters or
lens adapters to be fitted. This thread can be used via an adapter, to connect
the camera to the microscope.
•
Zooming of the lens is achieved through internal movement and the front
lens element does not protrude in front of the lens barrel beyond the filter
screw thread.
•
Availability of a remote control to trigger the shutter without physical
contact with the shutter-button (which would cause vibration to occur) or
•
Remote control of the camera functions directly from a computer via a USB
link.
For photomicrography, compact digital cameras have many advantages; low cost,
high sensor resolution (especially in ‘top end’ cameras that match the resolution of
digital SLRs), and relative ease of use. The main disadvantage comes from the fixed
camera lens which is less flexible than a removable-lens DSLR and can introduce
optical artefacts (such as ‘hot spots’ or ghosting) in the recorded image. These can
often be eliminated in many instances by trial and error if a range of projection
optics are available; there seems to be no way of determining if a particular camera
and projection lens is compatible other than trying it. Undoubtedly the best
approach is to follow a recommendation on model of compact digital camera from
an existing microscope user, either through personal contact or via an internet forum.
Arguably the best ‘all-round’ camera for photomicrography is the DSLR. The
removable lens allows for easy coupling using a T-mount adapter and
photomicrographic systems designed for use with 35mm film cameras (and now
available at very low cost second-hand) can be used, providing advantages such as a
focussing telescopes (still more accurate than using the camera or computer screen)
and vibration-free shutter mechanisms.
Most currently available DSLRs have
CMOS sensors with resolution of at least 12 MP; sensor size is usually smaller than
35mm film and is often based on the APS-C film format of approximately 22 x 15
mm (the exact dimensions vary between manufacturers). The main disadvantage of
DSLRs is the vibration that can occur from movement of the camera mirror when the
shutter is released. For low magnifications, or with long (> 3 seconds) exposures
this has little practical impact but for shorter exposures or higher magnifications, the
vibration can cause blurring of the recorded image.
In selecting a DSLR for use with the microscope, the following features are
desirable:
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Live View. This function is available on a growing number of DSLRs available
on the market and allows a real-time image to be displayed on the camera screen
or, if coupled to a computer with appropriate software, on the computer screen.
Live View makes focussing much more reliable than viewing through the camera
eyepiece; most DSLRs do not have interchangeable focus screens designed for
finding accurate focus at high magnifications. The ‘refresh’ rate of Live View is
much lower than for video and therefore it is less useful for tracking and
focussing rapidly-moving objects under the microscope; in these instances
coupling the camera to a relay lens system with focussing telescope is to be
preferred.
Remote control of the camera from a computer via a USB link. Some
manufacturers include this software free with the camera but others do not and
the software can be an expensive addition. There are also excellent ‘third party’
remote control software programmes (see ‘Image Capture’ below) but it is wise
to check compatibility before buying a camera.
‘Silent’ Live View option, which some cameras (e.g. Canon) have (usually
buried in the ‘Special Settings’ menus). In conventional Live View mode, the
camera mirror flips into the ‘up’ position and the mechanical shutter opens
allowing the image to be ‘seen’ by the digital sensor and displayed. When the
shutter button is triggered, mechanical shutter closes and then re-opens to
provide the correct exposure; in some systems the mirror also flips down to allow
exposure sensors located in the reflex housing pentaprism to determine the
correct exposure. These actions induce some vibration which can cause slight
blurring of high magnification images. Designed to prevent camera shutter noise
from scaring wildlife, silent Live View mode utilises an electronic shutter that
does not require the mechanical shutter to first close (or the mirror to flip down)
to make an exposure. For the microscopist, silent Live View mode is desirable
for higher magnification photomicrography. More information and results of
trials on Silent Live View can be found on Charles Krebs’ website, listed under
Resources).
The ability to record video. Several DSLRs released in the last year now have
the ability to digitally record high quality video. This can be of great use to the
microscopist working with live specimens or dynamic processes such as
crystallisation.
A potentially interesting and very recent development is the availability of digital
cameras with removable (interchangeable) lenses that have eliminated the DSLR
mirror. Whilst the author has no practical experience of these systems, the absence
of a mirror would appear to significantly reduce shutter vibration. Both Olympus
and Panasonic have released a number of models; whilst there is as yet no accepted
terminology for this design of camera, both manufacturers’ cameras are marketed as
‘Micro Four Thirds’ system, which relates to a sensor size of 18.0 x 13.5 mm; field
of view will therefore be smaller than with an APS-C DSLR of similar cost.
Dedicated digital cameras are made by the major microscope manufacturers (as
well as dedicated specialist imaging companies). These systems tend to be of lower
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resolution and higher prices than consumer level cameras but are of very high
sensitivity to cope with the low levels of fluorescence and confocal microscopy.
Such systems (by virtue of their price) are generally not used outside of specialist
laboratories but are slowly becoming available on the second-hand market. Potential
buyers should be very cautious of the risks involved with these electronic systems,
sold outside of the manufacturer’s support or warranty. Lower cost dedicated
microscope cameras are available via internet auction websites but reports of image
quality from some systems have been disappointing.
Philip M. Greaves
This article is adapted with permission from a fuller version first published in the
Quekett Journal of Microscopy 2010, Vol. 41 part 4.
REPORT ON THE 2012 ANNUAL GENERAL MEETING
On a wet and windy April night thirty-four members braved the weather to attend the
AGM and Spring members’ evening at ‘The Flying Fortress’ public house just
outside Bury St Edmunds, a comfortable enough venue. It was good to see faces in
the audience different from the usual stalwarts who turn up at the Holiday Inn,
presumably members from the north-west of the county, if so vindicating the
grumbles that events are too often Ipswich-centric.
Chairman, Joan Hardingham, reported a busy year for Council in which a lot has
been achieved. In the Hon. Sec.’s report, Gen Broad outlined the bursaries awarded
in 2011-12, a growth area. Treasurer, Graham Simister assured us that despite
making a small loss the society is in good financial shape and attempted to explain
the ongoing on-off confusion surrounding the sale of Rose Hill.
Dr Roger Dixon was elected onto Council.
After the break there were five short presentations with Powerpoint illustrations.
Juliet Hawkins talked enthusiastically about Suffolk Wildlife Trust’s Grove Farm
farmland nature reserve, outlining her project there, which is supported by an SNS
bursary. Arthur Rivett described how the use of new technology in conducting bat
surveys is revealing more species than previously recorded in several locations. An
update on the Buckthorn-Brimstone initiative was given by Rob Parker. The Orford
Ness Bio-blitz recording day planned for August 4th was detailed by Dave Fincham.
The tell-tale holes on honeysuckle leaves made by larvae of the Broad-bordered
Hawk-moth, yet another fascinating example of naturalist’s detective skills, were
neatly described by Tony Prichard, ending the talks.
The evening was rounded off nicely by a slide presentation showing the state of
the Rose Hill ‘reserve’. It was still raining heavily on the drive home.
David Walker
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OLIVE CRESCENT ‐ POTENTIAL COLONY DISCOVERED IN SUFFOLK
The Suffolk Moth Group visited the privately-owned Old Hall Wood just south of
Ipswich on the 29th June as one of the events on its field programme. With the erratic
weather this year there was a bit of uncertainty about whether the event would go
ahead given a rather brisk breeze blowing and an outside risk of rain. Eight members
of the group turned up for the event including some from Hertfordshire and in the
end we managed to put out nine lights in the more deciduous parts of the wood,
including an area with some older oak trees.
By the end of the night we had recorded just over 120 species, which I'd
consider a bit on the low side for this time of year in such a good woodland site.
However, there were some moths of particular interest to make up for the lower
number of species seen with Assara terebrella, Red-necked Footman, Shaded Fanfoot, Spatalistis bifasciana and Festoon but the most notable species of the night was
Olive Crescent, with twelve adults recorded in a couple of areas of the wood. This is
a BAP species that is rather scarce throughout the whole of the UK, occurring in just
a few woods, the nearest being Stour Wood just across the water in Essex. Last year
the moth group had a joint meeting with the Essex Moth Group at Stour Wood when
good numbers of Olive Crescent were seen, so it would appear to be doing well
there.
In Suffolk the moth has been recorded only once previously, at Ipswich Golf
Course by Neil Sherman in 2005, and in recent years the moth group has visited a
few of the woods south of Ipswich with one of the aims being to look for Olive
Crescent but at the time we were unsuccessful. Two of these visits were to Old Hall
Wood in mid-June rather than late June but still within the flight period of the moth
so I would have thought that we would have a fair chance to have seen the moth
previously if it had been in the wood. The numbers of moths attracted to the lights
suggests a local population in the wood and given the absence of the moth at
previous visits it seems likely that the colony could be of recent origin.
The Olive Crescent larva feeds on the withered leaves of oak, beech and sweet
chestnut in the autumn and it can be found by searching or ‘beating’ for the larva. To
determine if the moth is breeding in Suffolk we plan to carry out some autumn visits
to Old Hall Wood and other neighbouring woods to look for larvae.
Tony Prichard
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A WHITE MINK AT LACKFORD
On Wednesday 20th June 2012, I was shown the picture of a white mustelid by local
naturalist and wildlife photographer David Hosking. The photograph was taken at
the Suffolk Wildlife Trust reserve at Lackford Lakes, on the previous day.
Both David and I were unsure of the species. Was it a feral ferret (Mustela furo),
or was it an American mink (Mustela vison)? Due partly to the colouring, but also to
the facial features, I was inclined to opt for ferret. With David’s permission I sent the
photograph to mammal expert John Dobson, in Essex, who was also unsure what
species it was, but who also leant slightly towards ferret. John then forwarded the
photograph to mammal expert Dr Johnny Birks, who has a particular interest in
mustelids. Some members will recall his visit to Ipswich some years back, when he
gave a very interesting talk at the highly successful Mammal Mania conference.
His initial reaction was ‘Wow – fascinating photo!’ He then stated that it was “a
really interesting beast. My gut instinct says it is an unusually coloured mink (not
true albino as the eyes are clearly not pink but blackish), but it would be useful to
hear from the photographer how confident the animal was as a swimmer. I feel mink
rather than ferret as, although ferrets can swim, I am not sure they would be so
confident as to swim carrying prey like this; also, the fur is quite a bright white,
whereas most albino ferrets, especially the adults, actually have obviously yellowish
fur rather than white”.
Following some correspondence, it was finally agreed that the species concerned
was in fact a white-coloured mink, although it is interesting to read the additional
comments from Dr Birks. He said that “Mink are highly polymorphic in terms of
coat colour (this is one reason why they were so useful as fur animals, because it was
easy for breeders to produce a wide range of colours by selecting for the recessive
coat colours in their breeding programmes), so my guess is that this may be a
throwback to one of those recessive coat colours. There was a pure white mink (not
albino) bred in captivity that created all sort of challenges for breeders because that
fur colour was genetically linked to deafness, so the mother mink never reacted
when their babies were squeaking in distress!”
In the wild, the offspring of most mink tend to be dark brown, with a general
appearance of black overall. Many of these have been trapped and disposed of at
Lackford in the past, but this colouring appears to be unusual for Suffolk. Bullion
(2009) reported that although Suffolk mink are usually chocolate brown, with a
white chin spot, pale chestnut or grey variants sometimes turn up.
Dunstone and Macdonald (2008) point out that on fur farms there have been a
number of experiments from mutated individuals to produce a wide variety of
colours for the commercial fur trade, including white, or Aleutian. However, in feral
populations Silver Blue, a pale silvery blue coloured variety is the second most
common to be trapped in the UK. For example, in Devon 3% of those trapped were
Silver Blue, while in southern Scotland as much as 9% of the population was of that
colour.
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White Admiral 82
In Suffolk the distribution of mink has been shown to track the river system
(Bullion, 2009). They rarely turn up in lakes, although admittedly the River Lark
flows into Lackford Lakes. This suggests that overland dispersal to inland lakes or
ponds does not take place. The first documented occurrence of a mink in Essex,
however, was at Abberton Reservoir, when one was killed on 25th September 1962.
The movements of mink appear to be poorly understood (Dunstone & Macdonald,
2008) although the information available at present suggests that the distances
covered by dispersing juveniles from late summer onwards may be lengthy, whilst
those of rutting males during the winter may be extensive.
The matter of mink is an emotive subject, especially when one is seen carrying a
water vole (Arvicola terrestris) or a duckling. Such emotions are not so heightened,
however, when ‘more natural’ predators, such as pike (Esox lucius), are involved,
whilst the impact that they might have in helping to control rabbit (Oryctolagus
cuniculus) populations (Dunstone, 1993) is often over-looked. Mink have a very
wide range of prey in their diet, and water voles are just one.
The demise of the water vole has been laid squarely at the foot of the mink, but
as Dunstone and Macdonald (2008) have illustrated, the arrival of mink occurred at a
time when many water vole populations were already low, due to loss of habitat. In
Essex Dobson (1999) was concerned that mink have been made a scapegoat for the
decline of water voles, and that attention has been deflected away from the changes
that have taken place along our waterways. He was of the opinion that poor riparian
habitat management, human disturbance and pollution might be having far more
reaching consequences on wildlife than mink. Given the undoubted catholic diet
upon which mink survive (Dunstone & Macdonald, 2008) there is, perhaps, some
considerable substance in that view.
The manner in which many of our river and lakeside banks are managed, should
concern not only water vole conservationists, but other supporters of riparian
wildlife, such as ornithologists, botanists, lepidopterists, dragonfly enthusiasts etc.
Perhaps this is a subject that is worthy of discussion?
References
Bullion, S. 2009. The Mammals of Suffolk. Suffolk Naturalists’ Society & Suffolk
Wildlife Trust, Ipswich.
Dobson, J. 1999. The Mammals of Essex. Lopinga Books, Wimbish.
Dunstone, N. 1993. The Mink. T & A.D. Poyser, London.
Dunstone, N. and Macdonald, D.W. 2008. in Mammals of the British Isles.
Handbook 4th ed.Harris, S. & Yalden, D.W. (eds.), The Mammal Society,
Southampton.
Jeff R. Martin
17 Moss Way, West Bergholt, Colchester, CO6 3LJ
A photograph accompanying this article is on p. 26
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A CELEBRATION OF SUFFOLK GEOLOGY
Saturday May 12th saw the launch of GeoSuffolk’s new book, “A Celebration of
Suffolk Geology” to mark the 10th Anniversary of the earth science group. Held at
the Reg Driver Centre in Christchurch Park, 53 people attended, with most of the
authors and sponsors present. Joan Hardingham represented the Suffolk Naturalists’
Society, which became a partner at an early stage in the two-year project. The event
started with introductory speeches by Bob Markham and myself, the project editor,
followed by the official ‘unveiling’ by Lord Cranbrook, Society Patron. A glass of
bubbly and lunch followed.
In the afternoon Bob led a geological walk around the Park. To commemorate
the event, Prof. Rory Mortimore, President of the Geologists’ Association, planted a
fine specimen of Fitzroya cupressoides, named after Vice Admiral Robert FitzRoy,
who was the Captain of the Beagle and a Suffolk man! The tour ended at
Christchurch Mansion, where guests dispersed to enjoy the exhibits.
On the following day 24 of the participants met for a field excursion to examine
the geology of GeoSuffolk’s flagship site, Sutton Knoll. The weather was beautiful
(for a change), and the two-day event ended with an excellent ‘roast’ lunch at The
Sutton Plough.
The Volume itself is believed to be unique of its type in Great Britain. It does
not purport to be ‘a geology of Suffolk’, rather, it aims to provide a flavour of what
Suffolk geology and geomorphology have to offer, to appeal to the serious academic,
as well as the well-informed amateur and to the non-specialist. It has been
recognised that there is a need to attract the non-scientist and non-geologist in an
attempt to broaden the appeal of earth science. The papers are therefore something
of an eclectic mix with a variety of articles, ranging from academic and new research
to historical and educational to personal commentaries and reminiscences –
something, it is hoped, for everyone. Details of the contents can be found on the SNS
web-site.
The book, with 42 contributors and 38 articles, runs to nearly 500 pages, with
over 350 figures, and is in full colour throughout. It is the product of two years
planning, development and writing.
Generous sponsorship played a major rôle, with nearly £10,000 raised towards
production costs, and included a grant from SNS. At least a quarter of the 600 copy
print-run will be distributed free to schools, universities, libraries and museums as
part of GeoSuffolk’s continuing outreach programme.
Copies of the volume cost £20 and can be obtained through SNS by calling in
person at Ipswich Museum (ask for Gen Broad, Martin Sanford or Ann Ainsworth)
or the Reg Driver Centre. Postal copies can be obtained by contacting
[email protected] (£8 should be added to cover p&p). All cheques should be
made payable to “GeoSuffolk”.
Roger Dixon
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White Admiral 82
Contributions to White Admiral
Deadlines for copy are 1st February (spring edition), 1st June (summer edition)
and 1st October (autumn edition).
The opinions expressed in White Admiral are not necessarily those of the Editor
or of the Suffolk Naturalists’ Society.
White Admiral 82
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© David Hosking
Above: Photo of white Mink at Lackford Lakes taken on 19th June 2012
Right: Male Stag Beetle
tethered to the flight mill
26
© Colin Hawes
White Admiral 82
Abstract of paper presented by Colin Hawes at the VII European symposium and
workshop on conservation of saproxylic beetles, 12‐14 May 2012, Granada, Spain
Flight capacity and dispersal of the stag beetle Lucanus cervus (LINNAEUS,
1758), (Coleoptera: Lucanidae) in south-east England
The ability to disperse from natal sites is crucial for the maintenance of gene flow
between neighbouring populations and the colonisation or re-colonisation of suitable
unoccupied habitat. Dispersal distance data are also essential for providing reliable
information on which to base habitat conservation strategies. Such data is vital too
for estimating the likely effect of climate change on this species.
Dispersal of the stag beetle Lucanus cervus has previously been measured by the
author using mark- release- recapture (2006) and radio-tetemetry (2007-2009) at two
sites in the county of Suffolk (England). Results suggest that L.cervus has a low
dispersal rate and range, especially in the case of female beetles when there is a
plentiful supply of suitable decaying broad-leaved wood available at their natal site,
or close to the site of their emergence.
A laboratory-based study, described here, examined the flight capacity of L.
cervus using a flight mill. Tethered-flight experiments were conducted on 50 stag
beetles (25 males and 25 females) under controlled conditions. Non-stop flight was
timed up to a maximum of one hour. Eight sets of data were recorded: (i) body mass,
(ii) elytrum length, (iii) maximum flight speed, (iv) mean flight speed, (v) maximum
distance travelled, (vi) mean distance travelled, (vii) weight loss per km flown, (viii)
mean weight loss per km flown. Non-stop flight for one hour was achieved by both
sexes. Males showed a greater propensity for flight than females, which confirmed
observations made in the field. Flight distances achieved were considerably greater
than dispersal distances shown by radio-telemetry, and greater than telemetrically
measured dispersal distances for beetles in Germany and Switzerland.
Continuous non-stop flight for one hour has not been previously demonstrated
for L. cervus, as far as is known. Results suggest that long-distance dispersal of
several km may be possible for some individuals of both sexes in this species. If this
is confirmed, we may need to reconsider our conservation strategy for this beetle.
Colin J. Hawes
School of Biological Sciences, Royal Holloway, University of London. Egham,
Surrey, United Kingdom
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LETTERS, NOTES AND QUERIES
Invasive species – Green Alkanet
I have been astonished by the sudden rampant spread of this species, Pentaglottis
sempervirens, which forms smothering carpets of large plants. I decided to spray this
year, using SBK brushwood killer, and can report that the initial effects seem
promising.
I have often observed the plant growing in small numbers in gardens or where
thrown out. There have been two plants near my garden for many years, and five
years ago it started spreading in the garden and a neighbour’s, outrivalling its
nuisance relative Omphalodes verna. This year it unexpectedly appeared in quantity
throughout my neighbouring wood, which prompted me to spray immediately.
Another wood in the area has an acre or more already dominated.
The plant has very deep roots which are resistant to pulling. It grows here in
oak leaf mould on light soil, particularly along paths, competing well against nettles.
Pretty in small quantity, en masse the floppy foliage and stalks look unsightly.
I wonder if other people also feel this extreme rate of spread seems likely to
continue, and whether anyone else is contemplating emergency action.
Nick Miller
Tiger Hill Cottage, Bures, Suffolk CO8 5BW
The biggest Millennium Green in Britain seeks expert help ‐ can you add to our
list?
Halesworth Millennium Green is a large area (c.50 acres) made up of riverside
meadows (some grazed, some mown), rivers, and drainage ditches, ponds, hedges, a
bit of heathland and secondary woodland (some 80+ years old). Brown Argus and
Green Hairstreak have been seen this year, and a marsh orchid is one regular
excitement. There are nesting barn owls and kingfisher, also harvest mice and water
voles, slow worms and grass snakes. Otters use the river which runs through the
middle and a colony of the ant Formica fusca was found last year. The site is
managed for conservation and for public access by volunteers (led by Richard
Woolnough) and we really want to gather more details about what lives here, with an
eye to managing it in an even more targetted, scientific way. We've been awarded a
BES grant to do some popularising of ecology and conservation next year and would
very much welcome Suffolk Naturalists’ help. So - if you'd like a day out in a
beautiful place finding new (for us!) species please contact Nicky Rowbottom 01502
578470.
See more on www.halesworth.ws/millenniumgreen/index.php
Nicky Rowbottom
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White Admiral 82
SUFFOLK NATURALISTS’ SOCIETY BURSARIES
The Suffolk Naturalists’ Society offers five bursaries, of up to £500 each, annually.
Morley Bursary - usually awarded for studies involving insects (or other
invertebrates) other than butterflies and moths.
Chipperfield Bursary - usually awarded for studies involving butterflies or moths.
Cranbrook Bursary - usually awarded for studies involving mammals or birds.
Rivis Bursary - usually awarded for studies into the County’s flora.
Simpson Bursary - in memory of Francis Simpson; this will be for a botanical
study where possible.
Any member wishing to apply for a bursary should write, with details of their
proposed project, to the Honorary Secretary. As applications are normally
considered at the Council meeting in May of each year, proposals should be with the
Hon. Sec. by 30th April.
Applications made at other times will be considered but, even if considered
worthy of an award, may not be successful if all the bursaries for the current year
have already been taken.
The following two conditions apply to the awards:
1.
2.
Projects should include a large element of original work and applications must
include a breakdown of how the bursary will be spent.
A written account of the project is required within 12 months of receipt of a
bursary. This should be in a form suitable for publication in one of the Society’s
journals: Suffolk Natural History, Suffolk Birds or White Admiral.
THE SUFFOLK NATURALISTS’ SOCIETY
FOUNDED IN 1929 by Claude Morley (1874 -1951), The Suffolk Naturalists’
Society pioneered the study and recording of the County’s flora, fauna and geology,
to promote a wider interest in natural history.
Recording the natural history of Suffolk is still one of the Society’s primary
objects, and members’ observations are fed to a network of specialist recorders for
possible publication before being deposited in the Suffolk Biological Records
Centre, which is based in Ipswich Museum.
Suffolk Natural History, a review of the County’s wildlife, and Suffolk Birds, the
County bird report, are two high quality annual publications issued free to members.
The Society also publishes a newsletter, White Admiral, and organises two members’
evenings a year plus a conference every two years .
Subscriptions: Individual members £15.00; Family membership £17.00;
Corporate membership £17.00. Joint membership with the Suffolk Ornithologists’
Group: Individual members £28.00; Family membership £32.00.
As defined by the Constitution of this Society its objects shall be:
2.1 To study and record the fauna, flora and geology of the County
2.2 To publish a Transactions and Proceedings and a Bird Report. These
shall be free to members except those whose annual subscriptions are in
arrears
2.3 To liaise with other natural history societies and conservation bodies in
the County
2.4 To promote interest in natural history and the activities of the Society.
For more details about the Suffolk Naturalists’ Society contact:
Hon. Secretary, Suffolk Naturalists’ Society, c/o Ipswich Museum,
High Street, IPSWICH, IP1 3QH. Telephone 01473 213479
The Society’s website is at www.sns.org.uk