WHITE ADMIRAL - SNS: Suffolk Naturalists' · PDF filePOEM The Bat and the Blonde SAWFLIES ......

32
WHITE ADMIRAL Summer 2012 SUFFOLK NATURALISTS’ SOCIETY Newsletter 82

Transcript of WHITE ADMIRAL - SNS: Suffolk Naturalists' · PDF filePOEM The Bat and the Blonde SAWFLIES ......

Page 1: WHITE ADMIRAL - SNS: Suffolk Naturalists' · PDF filePOEM The Bat and the Blonde SAWFLIES ... treated to many brilliant photo opportunities of Dartford warbler, ... nightingale and

WHITE ADMIRAL

Summer 2012

SUFFOLK NATURALISTS’ SOCIETY

Newsletter 82

Page 2: WHITE ADMIRAL - SNS: Suffolk Naturalists' · PDF filePOEM The Bat and the Blonde SAWFLIES ... treated to many brilliant photo opportunities of Dartford warbler, ... nightingale and

CONTENTS

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

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 SBRC Adrian Knowles Martin Sanford G.M. Gathorne-Hardy Martin Sanford Tom Langton Philip M. Greaves David Walker Tony Prichard Jeff Martin Roger Dixon Colin Hawes Nick Miller Nicky Rowbottom

1 2 3 4 5 6 7 11 13 17 20 21 22 24 27 28 28

Page 3: WHITE ADMIRAL - SNS: Suffolk Naturalists' · PDF filePOEM The Bat and the Blonde SAWFLIES ... treated to many brilliant photo opportunities of Dartford warbler, ... nightingale and

White Admiral 82 1

SUFFOLK NATURALISTS’ SOCIETY

SUMMER 2012

David Walker 30 Reade Road

Holbrook Suffolk IP9 2QL

[email protected]

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!

Page 4: WHITE ADMIRAL - SNS: Suffolk Naturalists' · PDF filePOEM The Bat and the Blonde SAWFLIES ... treated to many brilliant photo opportunities of Dartford warbler, ... nightingale and

White Admiral 82 2

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]

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.

Page 5: WHITE ADMIRAL - SNS: Suffolk Naturalists' · PDF filePOEM The Bat and the Blonde SAWFLIES ... treated to many brilliant photo opportunities of Dartford warbler, ... nightingale and

White Admiral 82 3

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.

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

THE SUCCESSFUL RETURN OF A SUMMER HOLIDAYMAKER

Photo by Peter Heather

Page 6: WHITE ADMIRAL - SNS: Suffolk Naturalists' · PDF filePOEM The Bat and the Blonde SAWFLIES ... treated to many brilliant photo opportunities of Dartford warbler, ... nightingale and

White Admiral 82 4

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.

NEW DRAGONFLY RECORD FOR SUFFOLK – LEUCORRHINIA PECTORALIS

Immature male Leucorrhinia pectoralis photographed at Dunwich by Alan Beaumont

Page 7: WHITE ADMIRAL - SNS: Suffolk Naturalists' · PDF filePOEM The Bat and the Blonde SAWFLIES ... treated to many brilliant photo opportunities of Dartford warbler, ... nightingale and

White Admiral 82 5

“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

CHANTRY PARK BIO‐BLITZ 2012

FOR SALE CHEAPLY

Biological Journal of the Linnean Society – A Journal of Evolutionary Biology (1988-2002), Entomologist’s Record and Journal of Variation (1976-2007), Ento-mologist’s Gazette (1981- 2007) and British Journal of Entomology (1988-2007). Further details available. Buyer collects. Offers to: David Nash, 3 Church Lane , Brantham CO11 1PU. [email protected]

Page 8: WHITE ADMIRAL - SNS: Suffolk Naturalists' · PDF filePOEM The Bat and the Blonde SAWFLIES ... treated to many brilliant photo opportunities of Dartford warbler, ... nightingale and

White Admiral 82 6

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

BATS IN WOMEN’S HAIR

Page 9: WHITE ADMIRAL - SNS: Suffolk Naturalists' · PDF filePOEM The Bat and the Blonde SAWFLIES ... treated to many brilliant photo opportunities of Dartford warbler, ... nightingale and

White Admiral 82 7

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,

Page 10: WHITE ADMIRAL - SNS: Suffolk Naturalists' · PDF filePOEM The Bat and the Blonde SAWFLIES ... treated to many brilliant photo opportunities of Dartford warbler, ... nightingale and

White Admiral 82 8

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

Page 11: WHITE ADMIRAL - SNS: Suffolk Naturalists' · PDF filePOEM The Bat and the Blonde SAWFLIES ... treated to many brilliant photo opportunities of Dartford warbler, ... nightingale and

White Admiral 82 9

- 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?

Page 12: WHITE ADMIRAL - SNS: Suffolk Naturalists' · PDF filePOEM The Bat and the Blonde SAWFLIES ... treated to many brilliant photo opportunities of Dartford warbler, ... nightingale and

White Admiral 82 10

“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.

Page 13: WHITE ADMIRAL - SNS: Suffolk Naturalists' · PDF filePOEM The Bat and the Blonde SAWFLIES ... treated to many brilliant photo opportunities of Dartford warbler, ... nightingale and

White Admiral 82 11

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

SAWFLIES

Sawfly Cimbex connatus found at Lackford Photo: Emma Kerridge

Page 14: WHITE ADMIRAL - SNS: Suffolk Naturalists' · PDF filePOEM The Bat and the Blonde SAWFLIES ... treated to many brilliant photo opportunities of Dartford warbler, ... nightingale and

White Admiral 82 12

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

Page 15: WHITE ADMIRAL - SNS: Suffolk Naturalists' · PDF filePOEM The Bat and the Blonde SAWFLIES ... treated to many brilliant photo opportunities of Dartford warbler, ... nightingale and

White Admiral 82 13

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

WIND TURBINES, BATS AND BIRDS

Page 16: WHITE ADMIRAL - SNS: Suffolk Naturalists' · PDF filePOEM The Bat and the Blonde SAWFLIES ... treated to many brilliant photo opportunities of Dartford warbler, ... nightingale and

White Admiral 82 14

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

Page 17: WHITE ADMIRAL - SNS: Suffolk Naturalists' · PDF filePOEM The Bat and the Blonde SAWFLIES ... treated to many brilliant photo opportunities of Dartford warbler, ... nightingale and

White Admiral 82 15

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

Page 18: WHITE ADMIRAL - SNS: Suffolk Naturalists' · PDF filePOEM The Bat and the Blonde SAWFLIES ... treated to many brilliant photo opportunities of Dartford warbler, ... nightingale and

White Admiral 82 16

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

Page 19: WHITE ADMIRAL - SNS: Suffolk Naturalists' · PDF filePOEM The Bat and the Blonde SAWFLIES ... treated to many brilliant photo opportunities of Dartford warbler, ... nightingale and

White Admiral 82 17

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

DIGITAL PHOTOGRAPHY WITH THE MICROSCOPE

Page 20: WHITE ADMIRAL - SNS: Suffolk Naturalists' · PDF filePOEM The Bat and the Blonde SAWFLIES ... treated to many brilliant photo opportunities of Dartford warbler, ... nightingale and

White Admiral 82 18

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:

Page 21: WHITE ADMIRAL - SNS: Suffolk Naturalists' · PDF filePOEM The Bat and the Blonde SAWFLIES ... treated to many brilliant photo opportunities of Dartford warbler, ... nightingale and

White Admiral 82 19

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

Page 22: WHITE ADMIRAL - SNS: Suffolk Naturalists' · PDF filePOEM The Bat and the Blonde SAWFLIES ... treated to many brilliant photo opportunities of Dartford warbler, ... nightingale and

White Admiral 82 20

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.

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

REPORT ON THE 2012 ANNUAL GENERAL MEETING

Page 23: WHITE ADMIRAL - SNS: Suffolk Naturalists' · PDF filePOEM The Bat and the Blonde SAWFLIES ... treated to many brilliant photo opportunities of Dartford warbler, ... nightingale and

White Admiral 82 21

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 Fan-foot, 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

OLIVE CRESCENT ‐ POTENTIAL COLONY DISCOVERED IN SUFFOLK

Page 24: WHITE ADMIRAL - SNS: Suffolk Naturalists' · PDF filePOEM The Bat and the Blonde SAWFLIES ... treated to many brilliant photo opportunities of Dartford warbler, ... nightingale and

White Admiral 82 22

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.

A WHITE MINK AT LACKFORD

Page 25: WHITE ADMIRAL - SNS: Suffolk Naturalists' · PDF filePOEM The Bat and the Blonde SAWFLIES ... treated to many brilliant photo opportunities of Dartford warbler, ... nightingale and

White Admiral 82 23

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

Page 26: WHITE ADMIRAL - SNS: Suffolk Naturalists' · PDF filePOEM The Bat and the Blonde SAWFLIES ... treated to many brilliant photo opportunities of Dartford warbler, ... nightingale and

White Admiral 82 24

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

A CELEBRATION OF SUFFOLK GEOLOGY

Page 27: WHITE ADMIRAL - SNS: Suffolk Naturalists' · PDF filePOEM The Bat and the Blonde SAWFLIES ... treated to many brilliant photo opportunities of Dartford warbler, ... nightingale and

White Admiral 82 25

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.

Page 28: WHITE ADMIRAL - SNS: Suffolk Naturalists' · PDF filePOEM The Bat and the Blonde SAWFLIES ... treated to many brilliant photo opportunities of Dartford warbler, ... nightingale and

White Admiral 82 26

Right: Male Stag Beetle tethered to the flight mill © Colin Hawes

Above: Photo of white Mink at Lackford Lakes taken on 19th June 2012

© David Hosking

Page 29: WHITE ADMIRAL - SNS: Suffolk Naturalists' · PDF filePOEM The Bat and the Blonde SAWFLIES ... treated to many brilliant photo opportunities of Dartford warbler, ... nightingale and

White Admiral 82 27

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

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

Page 30: WHITE ADMIRAL - SNS: Suffolk Naturalists' · PDF filePOEM The Bat and the Blonde SAWFLIES ... treated to many brilliant photo opportunities of Dartford warbler, ... nightingale and

White Admiral 82 28

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

Page 31: WHITE ADMIRAL - SNS: Suffolk Naturalists' · PDF filePOEM The Bat and the Blonde SAWFLIES ... treated to many brilliant photo opportunities of Dartford warbler, ... nightingale and

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. Projects should include a large element of original work and applications must

include a breakdown of how the bursary will be spent. 2. 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.

Page 32: WHITE ADMIRAL - SNS: Suffolk Naturalists' · PDF filePOEM The Bat and the Blonde SAWFLIES ... treated to many brilliant photo opportunities of Dartford warbler, ... nightingale and

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