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BUTTERFLY RECORDING IN THE FYNN VALLEY R. G. STEWART The Butterfly Monitoring system (BMS) has collected, analysed and published transect data since 1976. Devised by Dr. E. Pollard, the transect details were published as a 14 page booklet of ‘instructions for independent recorders’ (Hail, 1981). A transect is a walk along a fixed route to count butterflies and ideally it should cover a wide variety of habitats, avoid covering the same ground more than once and be divided into a maximum of fifteen sections. This should be walked once a week, at a steady pace, from the beginning of April to the end of September, a total of 26 weeks. The transect walker should count only butterflies within an imaginary ‘box’ stretching 2·5 metres on either side and 5·5 metres ahead. Other conditions apply: doing the transect ideally between 10·45 am and 3·45 pm, with consideration of wind speed, amount of sunshine and temperature. All data is recorded on weekly transect sheets, summarised at the end of the recording year and sent to the transect coordinator, Rob Parker the County Butterfly Recorder. This data is then sent to the United Kingdom Butterfly Monitoring Scheme, based at Butterfly Conservation headquarters in Dorset. An annual report is issued to all transect recorders.

The river Fynn is a tributary of the river Deben and the transect of 15 sections starts at Tuddenham St. Martin, following along or close to the river as far as Playford, then turning back to return to Tuddenham St. Martin. It has been walked since 2000, though foot and mouth restrictions prevented recording in 2001. The transect covers a variety of habitats, including cultivated fields, grazing meadows and wet meadows adjacent to the river, woodland, alder carr and small areas of reedbed. The walk normally takes about an hour and three quarters but extends over two hours when numbers of butterflies increase in summer. Despite the length the walk passes just three houses and two Anglia Water buildings, one a sewage treatment station. The East Suffolk railway line from Ipswich to Lowestoft runs alongside two of the sections. The land is owned mainly by two local farmers and their stewardship is benign, creating a rich biodiversity. Some of this wildlife has been included in section descriptions. The central grid reference given for the transect is TM205472. The squares covered are TM1947, TM1948, TM2047 and TM2147. TM2048 has also been recorded but is not included in the actual transect walk.

Section Analysis Please refer to the map for further details. At the end of each section a list of butterfly species is included. These are prefaced by ‘ 8+’, indicating that eight species, Small White, Green-veined White, Red Admiral, Peacock, Comma, Gatekeeper, Meadow Brown and Ringlet, have been recorded in all fifteen sections. For the purposes of transects Small and Essex Skippers can be counted under ‘Small/Essex’ because of the difficulty in identifying them as separate species except at very close quarters. ‘Small/Essex’ is only included if neither Essex nor Small Skipper has been recorded in that section.

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River Fynn Transect, Sections 1–15. Running alongside the Fynn between Tuddenham and Playford.

Section One – approx. 600 metres From the top of the hill leading into Tuddenham St. Martin a bridleway lane faces south then bends westward. It initially passes between two gardens, where Holly Blue is often recorded, then opens out to fields with an abundance of nectar sources. A tall hedge on the right has extensive clumps of Ivy, attracting Hornets, Red Admiral and Comma butterflies in the last few weeks of the walk. Here there are extensive views to the left across the Fynn Valley and this is a good section for seeing and hearing Chiffchaff, Whitethroat, Yellowhammer, Lark, Cuckoo, Turtle Dove and Green Woodpecker, the last mentioned having been recorded in every section.

Butterflies recorded: 8+ Small/Essex Skipper, Large Skipper, Large White, Orange Tip, Holly Blue, Painted Lady, Small Tortoiseshell, Speckled Wood, Wall, Grayling = 18.

Section Two – approx. 300 metres A straight section of the same lane faces south with shorter hedges on both sides and cultivated fields. This is also a good section to hear and see the birds listed in Section One and Nightingale has been recorded from a scrub area at the start of the section. Bramble is abundant and Hop, one of the larval food plants of the Comma.

Butterflies recorded: 8+ Small Skipper, Essex Skipper, Large Skipper, Large White, Holly Blue, Painted Lady, Small Tortoiseshell, Speckled Wood, Grayling = 17.

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Section Three – approx. 400 metres The same lane heads west then bends to the south, with taller hedges and large mature oaks reducing the amount of sunlight compared to the previous two sections. Common (Stinging) Nettle and Ivy are abundant.

Butterflies recorded: 8+ Small Skipper, Large Skipper, Large White, Grange Tip, Holly Blue, Painted Lady, Small Tortoiseshell, Speckled Wood, Wall = 17.

Section Four – approx. 500 metres A footpath off the lane to the east enters a damp meadow with reedbeds.

Nightingales have been recorded at both ends of this section, with Fox and Muntjac seen on the path. Southern Marsh orchid grows in abundance and other flora includes Great Willow Herb, Reedmace, Water Mint, Lady’s Smock, Hemp Agrimony and Fleabane. This is usually the first section where the Banded Demoiselle damselfly is recorded. In 2004 a drainage ditch was dug either side of part of the central path to deal with excess water. After passing the Anglia Water station the path becomes drier with a meadow on the right and ends by the River Fynn at Rosemary Bridge, where Kingfisher and Grey Wagtail have been recorded.

Butterflies recorded: 8+ Small Skipper, Essex Skipper, Large Skipper, Clouded Yellow, Large White, Orange Tip, Small Copper, Brown Argus, Common Blue, Painted Lady, Small Tortoiseshell, Speckled Wood, Wall, Small Heath = 22.

Section Five – approx. 800 metres A permissive path follows the river and from 2007 sheep fencing has created two separate fields. Tall willows are a feature along the river, and are used by nesting Green Woodpeckers. Kingfisher and Banded Demoiselle are present and Water Vole has also been recorded. Comfrey, Burdock, Hemp Agrimony and Thistles are the main nectar sources (see Plate 4).

Butterflies recorded: 8+ Essex Skipper, Large Skipper, Clouded Yellow, Large White, Orange Tip, Small Copper, Brown Argus, Common Blue, Holly Blue, Painted Lady, Small Tortoiseshell, Speckled Wood, Wall, Grayling, Small Heath = 23.

This is one of the best sections for number of species.

Section Six – approx. 200 metres From a second river bridge the transect path turns south along a track with meadows on either side, one usually grazed by sheep. Water voles have been recorded in adjacent dykes and Dandelion is a good early nectar source. This is the only section in which Large White has not been recorded. The low number of species reflects the short length.

Butterflies recorded: 8+ Essex Skipper, Common Blue, Painted Lady, Small Tortoiseshell, Wall, Small Heath = 14.

Section Seven – approx. 500 metres A footpath heads east, passing through a damp meadow and with beds of Common Nettle at the foot of the hill, close to which is an imposing Ash tree where Little Owls have nested. From the top of the hill there are extensive views to west and north. The drier meadow here has good numbers of

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Meadow Brown and Skippers and the section is one of the best for recording Small Copper and Brown Argus. The East Suffolk railway line from Ipswich to Lowestoft runs parallel to this section (see Plate 5).

Butterflies recorded: 8+ Small Skipper, Essex Skipper, Large Skipper, Large White, Small Copper, Brown Argus, Common Blue, Holly Blue, Painted Lady, Small Tortoiseshell, Speckled Wood, Wall, Grayling, Small Heath = 22.

Section Eight – approx. 900 metres After higher woodland with Bluebells followed by thick beds of Bracken the path goes downhill to alder carr woodland with reedbeds, a pond and a pedestrian bridge spanning a stream feeding into the Fynn. Before the canopy closer over there are Marsh Marigolds, Celandines, Wood Anemone and Bugle flowering. Muntjac tracks are often noted on the muddy path, Great Spotted woodpeckers nest in the wood and Nightingales have been recorded at both ends. This is the stronghold of the Speckled Wood, which prefers dappled shade, and it will be interesting to note the effect of railway maintenance work on the south side, the line running parallel to this section. With the cutting down of several trees more light will enter the woodland. Most species except for Speckled Wood have been recorded in more open areas at the start and end of this section but in the dappled shade Green-veined White has often been recorded nectaring on Herb Robert. This is the only section where the Small Tortoise-shell has not been recorded and has one of the lowest sunlight percentages, second only to section 10.

Butterflies recorded: 8+ Large Skipper, Large White, Orange Tip, Holly Blue, Speckled Wood, Grayling = 14.

Section Nine – approx. 400 metres A damp meadow, grazed by horses and cattle, with the river Fynn on the left.

Bird observations have included Grey Heron, Kingfisher, Shelduck and from 2004 onwards the Little Egret. This is one of the best sections for Banded Demoiselle and Bramble bushes in the hedge attract many butterflies, particularly Meadow Brown. Numbers of Meadow Brown and Ringlet make this one of the two sections with the highest numbers of butterflies.

Butterflies recorded: 8+ Small Skipper, Essex Skipper, Large White, Orange Tip, Brown Argus, Common Blue, Holly Blue, Painted Lady, Small Tortoiseshell = 17.

Section Ten: approx. 100 metres This marks the furthest point in the walk and the remaining sections head back from Playford to Tuddenham St. Martin. At either end of this shaded lane is more open habitat where most species have been recorded, except for Speckled Wood. Its very short length and lack of sunlight have produced the lowest species count.

Butterflies recorded: 8+ Large White, Orange Tip, Holly Blue, Small Tortoise-shell, Speckled Wood = 13.

Section Eleven – approx. 600 metres Several return sections, including this one, form part of the official Fynn Valley Path: this is the same damp meadow as in Section Nine but on the other

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side of the river. It also has large numbers of Ringlet and Meadow Brown and Gatekeepers nectar on the many Bramble bushes. Small Tortoiseshells are often recorded close to Common Nettle beds and Purple Hairstreak has been recorded off the transect in Oaks, where it feeds on honeydew.

Butterflies recorded: 8+ Small Skipper, Essex Skipper, Large Skipper, Large White, Orange Tip, Small Copper, Brown Argus, Holly Blue, Painted Lady, Small Tortoiseshell, Speckled Wood, Wall, Small Heath = 21.

Section Twelve – approx. 600 metres This has the most varied set of habitats, including veteran Oaks, shaded woodland, reedbeds with nesting Sedge Warblers, many Bramble bushes, more open sunlit stretches, a self-seeded Buddleia unfortunately off transect, a Willow plantation and scrub areas where up to three Nightingales have been recorded in one day. One area has decreased in species, especially Large Skipper, Small Copper and Brown Argus, as a consequence of Bracken encroachment on both sides of the path but conversely harvesting in the Willow plantation has increased the areas of sunlight, producing an extensive bed of Lady’s Smock in spring and tall Thistles in summer. It is important to keep to the same route but in high summer this has involved clearing tall vegetation and trailing Brambles from a narrow path which is no longer part of the official route. Persistence was rewarded in 2006 when the only Green Hairstreak recorded on the transect was seen here, on a Bramble leaf. Gorse, one of its larval food plants, is present but off transect.

Butterflies recorded: 8+ Small Skipper, Essex Skipper, Large Skipper, Large White, Orange Tip, Green Hairstreak, Small Copper, Brown Argus, Common Blue, Holly Blue, Painted Lady, Small Tortoiseshell, Speckled Wood, Wall, Grayling = 23.

This section has one of the highest totals of species.

Section Thirteen – approx. 200 metres This short lane heading west has a tall hedge but an open field on the south side gives an abundance of sunlight. Great Spotted Woodpeckers have nested in the large Oak and Little Owls have been observed on fence posts. Early nectar is provided by Blackthorn and Red Deadnettle and in summer Burdock is abundant and is particularly used for nectaring by Peacock and Painted Lady.

Butterflies recorded: 8+ Small Skipper, Essex Skipper, Large Skipper, Large White, Orange Tip, Small Copper, Brown Argus, Common Blue, Painted Lady, Small Tortoiseshell, Speckled Wood, Wall = 20.

Section Fourteen – approx. 600 metres Two fields head further away from the river, the second maintained as grassland and with a continuous tall hedge to the south. Elm is present in the hedgerow in both section thirteen and fourteen but White-letter Hairstreak has not been seen. At its highest point this section has panoramic views over the river to the south. The second field is the most productive for numbers and species and is the transect stronghold of the Small Heath, which benefits from nearby nectar sources and a variety of grass heights. Often counts reach

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Yearly totals Year

Butterflies

Species

2002 2003 2004 2005 2006

1761 2769 2123 2544 2002

23 23 23 21 22

double figures. Purple Hairstreak has also been recorded here, off transect.

Butterflies recorded: 8+ Small Skipper, Essex Skipper, Large Skipper, Clouded Yellow, Large White, Orange Tip, Small Copper, Brown Argus, Common Blue, Holly Blue, Painted Lady, Small Tortoiseshell, Speckled Wood, Wall, Grayling, Small Heath = 24.

This is the best section for number of species and the total on transect has now risen to 25 with the first Brimstone, nectaring on Red Deadnettle during the first walk in 2007.

Section Fifteen – approx. 800 metres Known as Donkey Lane, this section has a concreted path from Fynn Lane to the Anglia Water Sewage Works. The filter beds and attendant insects sometimes attract many feeding Swallows, House Martins and Swifts.

Towards the end there are extensive views back to the village and across the river to Section One. Speckled Wood frequents short areas of dappled shade, Bramble bushes attract many Gatekeepers and Green-veined Whites nectar on Hemp Nettle.

Butterflies recorded: 8+ Essex Skipper, Small Skipper, Large Skipper, Large White, Orange Tip, Common Blue, Holly Blue, Painted Lady, Small Tortoiseshell, Speckled Wood, Wall, Grayling, Small Heath = 21.

With the addition of Purple Hairstreak and Brimstone the total of species recorded is 28, making this part of the Fynn Valley one of the best inland sites for butterflies in Suffolk (Stewart,2001).

The highest one walk total of species was 19 on 22 and 25 July 2006 and the highest number of butterflies recorded was 515 on 16 July 2003.

Comments on Species The first six numbers represent the annual index from 2000 to 2006, excluding 2001.

Small Skipper: 8, 4, 7, 13, 1, 0.

Recorded in 10 sections.

Essex Skipper: 13, 2, 2, 4, 3, 5.

Recorded in 11 sections.

Small/Essex Skipper: 19, 21, 50, 59, 58, 26.

Recorded in all sections except Eight and Ten. The lower numbers for Small and Essex Skipper reflect the fact that most Skippers are registered under Small/Essex as permitted by the transect instructions.

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Large Skipper: 22, 12, 15, 18, 13, 12.

Recorded in all sections except Six, Nine and Ten. As already indicated, numbers have dropped in one of its most productive areas in Section Twelve as a result of Bracken replacing some nectar sources.

Clouded Yellow: just three records of this migrant, one each in Sections four, Five and Fourteen, all in 2000.

Large White: 41, 34, 67, 31, 50, 17.

Recorded in every section except Six. Numbers can be increased by migrants.

Small White: 29, 14, 45, 76, 34, 22.

Recorded in every section. Numbers can be increased by migrants.

Green-veined White: 99, 60, 76, 155, 153, 50.

2006 was the lowest annual index, after two good years, but the species has been recorded in all sections and often nectars on Hemp Nettle, which has been recorded in nine sections.

Orange Tip: 30, 18, 14, 9, 8, 5.

Although this species has been recorded in 12 sections the decline from 2000 has been continuous. The two main larval food plants, Lady’s Smock and Hedge Mustard, have only been recorded in three and five sections respectively.

Green Hairstreak: just one recorded from Section Twelve in 2006.

Small Copper: 19, 8, 8, 8, 8, 8.

Recorded in seven sections, with ab. caeruleopunctata Ruhl, described by Emmet & Heath (1990) as ‘one in which there is a postdiscal series of blue spots on the upperside of the hindwing’, being seen in Section Five, 25 July 2005. This species has also suffered from Bracken encroachment in Section Twelve.

Brown Argus: 7, 10, 8, 4, 6, 3.

Recorded in eight sections but easily overlooked on a steady walk and this may explain the low annual index for 2006. There has been no noted loss of habitat except as mentioned above in Section Twelve.

Common Blue: 46, 18, 34, 9, 8, 11.

Despite 14 being recorded in section Fourteen on 16 July 2003 there has been a steady decline since that year. The meadow colonies may have suffered from wetter conditions and the main larval food plant, Bird’s-foot Trefoil, has only been recorded in three sections.

Holly Blue: 6, 13, 4, 20, 16, 5.

This species has a well documented series of good and bad years, probably closely linked to a small wasp, Listrodomus nycthemerus, which specifically parasitizes the Holly Blue larvae and can result in high mortality levels: ‘The variations in abundance of this butterfly from year to year appear clearly in the Butterfly Monitoring Scheme data, which show that in recent decades the periodicity of cycles has been around 6–7 years’. (Asher, Warren et al. 2001).

The same authors comment on the parasite: ‘When the butterfly is abundant

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the wasp increases, but the build up of parasitoids causes such mortality of Holly Blue pupae that numbers of butterflies decline. A decline of the wasp follows and the reproductive success of the Holly Blue increases, so starting the cycle again’.

Of its two larval food plants, Holly is scarce on transect but Ivy grows in abundance.

Red Admiral: 71, 28, 114, 27, 27, 99.

The balance of three poor and three good years reflects how numbers of this migrant vary each year. It is often recorded on opening Ivy umbels in September and its larval food plant, Common Nettle, is abundant. This species has been recorded in every section.

Painted Lady: 7, 5, 105, 9, 0, 44.

The same comments apply as for Red Admiral and this migrant was not recorded on transect in 2005. As a contrast in 2003 it was recorded in 12 sections with a total of 47 on 31 July 2003. It is particularly attracted to Burdock and Thistles, the main larval food plant.

Small Tortoiseshell: 91, 14, 141, 129, 115, 22.

In 2006 this species was not recorded after 18 July. As the annual indices suggest it can quickly recover, aided in some years by migrants. Common Nettle, its larval food plant, is abundant, and the butterfly has been recorded in every section except Eight.

Peacock: 113, 17, 40, 19, 32, 44.

Except for the high annual index in 2000 the numbers have been low and for no obvious reason. The larval food plant, Common Nettle, is plentiful. This butterfly has been recorded in every section.

Comma: 60, 50, 71, 52, 82, 53.

This species also uses Common Nettle as one of its larval food plant and the other, Hop, is in several sections, being particularly abundant in Section Two. The Comma has also been recorded in every section.

Speckled Wood: 59, 85, 193, 120, 145, 140.

Section Eight usually has the highest numbers with 12 as a maximum on one day. Higher numbers since 2003 reflect a spread into every section except Six and Nine.

Wall: 42, 17, 17, 3, 0, 0.

Despite being recorded in 11 sections it has not been seen on transect since three were recorded in Section Eleven on 25 July 2004. The habitat does not appear to have changed. Fox, Asher et al. (2006) state that ‘The decline of inland populations of the Wall since the 1970’s has been dramatic and severe’, adding that ‘research is underway to improve our understanding of this butterfly’s ecology’.

Grayling: 2, 2, 4, 5, 7, 6.

This was recorded from just two sections in 2000 but has now spread to a further six. Never a common transect species it often basks on the path then lands on the recorder; twenty times in two minutes in Section One on 27 August 2006.

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Gatekeeper: 178, 84, 258, 321, 405, 141.

Recorded in all sections especially nectaring on Bramble and with highest numbers in Sections Five, Nine, eleven and Fifteen.

Meadow Brown: 2144, 1079, 1220, 718, 1054, 1037.

The very high annual index in 2000 was largely the result of high weekly totals in six consecutive summer weeks: 396, 442, 472, 361, 366, 298 respectively. Such totals have not been repeated over such a span of weeks but high numbers of this species, especially in Sections Five, Seven, Nine and Eleven, have had a strong influence on yearly totals. In 2000 Meadows Browns represented 61·1% of the year’s total and percentages in subsequent years have been: 2002: 61·2%; 2003: 44·0%; 2004: 33·8%; 2005: 41·4%; 2006: 51·7%. The Meadow Brown has been recorded in every section.

Small Heath: 29,46,77,87,71,80.

For a species in national decline the Small Heath has strengthened its numbers on the transect, expanding from just Section Fourteen in 2000 and 2002 to a further six sections, all in small numbers. The strongest colony is still in Section Fourteen.

Ringlet: 208, 121, 199, 225, 248, 171.

This species has a relatively short flight period and faded Ringlets can easily be confused with Meadow Browns. Numbers are highest in the damp meadows in Sections Seven, Nine and Eleven; recorded in every section.

Proposed plans for extensive housing developments in the north of Ipswich could impact on parts of the transect, if the plan for a northern by-pass was resurrected. Consequently all transect records of butterflies, birds and mammals have been sent to the relevant County Recorders.

References Asher, J. Warren, M., Fox, R., Harding, P., Jeffcoate, G., & Jeffcoate, S. (2001). The Millennium Atlas of Butterflies in Britain and Ireland. Oxford University Press, Oxford.

Emmet, M., & Heath, J., (1990). The Butterflies of Great Britain and Ireland , Vol.7:I. Harley books, Colchester, Essex.

Fox, R., Asher, J., Brereton, T., Roy, D., & Warren, M. (2006). The State of Butterflies in Britain and Ireland. Pisces Publications, Newbury, Berkshire.

Hall, M. L., (1981). Butterfly monitoring Scheme – instructions for independent recorders. ITE, Abbots Ripton, Huntingdon.

Stewart, R. G., (2001). The Millennium Atlas of Suffolk Butterflies. Suffolk Naturalists’ Society, Ipswich, Suffolk.

Mr R. G. Stewart Valezina 112WesterfieldRoad Ipswich Suffolk IP4 2XW Tel: 01473–216518

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R. Stewart R. Stewart

Plate 4: Fynn transect. Section 5 follows a permissive path through fields and close to the River Fynn. Comfrey, Burdock, Hemp Agrimony and Thistles are the main nectar sources; 23 butterfly species have been recorded. (p. 65).

Plate 5: Fynn transect. Section 7 looking back from the lane in section 13 to the end of section 12 . The latter has the most varied habitats on the transect and 23 species have been recorded (p. 66).