The Suffolk garden butterfly survey, 1994

ö

Suffolk Natural History, Vol. 31 T H E S U F F O L K G A R D E N B U T T E R F L Y SURVEY, 1994 RICHARD G. STEWART

The Recording Form This was a double-sided sheet with one side requesting the name, address and telephone number of each recorder, a six figure map reference and details of the garden's size — small, medium (tennis court size) or large. Recorders were asked to place their gardens into a town, suburban, village or countryside category and tick boxes covering other nearby habitats — woodland, heathland arable farmland, park, rough ground or nature reserve. The rest of the first side consisted of a list of Suffolk butterflies, three columns for frequency of visiting butterflies dunng their normal flight period(s) — regulär, irregulär or once only and two columns for recording the earliest and latest sightings.

The second side contained a list of garden nectar sources, and recorders were asked to note the visiting butterflies. Sections were included for records of egg laying and predation, and any additional records and observations.

Distribution Recording forms and an explanatory article were sent to all members of the Suffolk Naturalists' and Ipswich and District Natural History Societies and the Suffolk branch of Butterfly Conservation. Publicity in local newspapers and on BBC Radio Suffolk produced further requests for the form and approximately 1,100 recording forms were eventually distributed.

Returns Information was received from 152 Suffolk gardens, However, some returns lacked Information on the frequency of visiting butterflies or were unsatisfactory in other ways. The grid reference was mssing from 60 forms and the decision was made to group these into the three areas currently used for bird recording. Suffolk Birds 1994 shows these areas on a map inside the front cover There was regional bias with only 34 returns from the North-East and 39 from the South-west, but 79 from the South-East (including 26 from Ipswich) Butterflies recorded Table 1 shows the species recorded, the total number of gardens in which each species was recorded and the number of gardens in which they were regulär or irregulär visitors, or seen only once. On some forms only the presence of the species was indicated and not the frequency of appearance.

Trans. Suffolk Nat. Soc. 31 (1995)

SUFFOLK GARDEN BUTTERFLY SURVEY, 1994

7

Table 1: Butterflies recorded Species

Gardens where recorded

Small tortoiseshell Peacock Red admiral Large white Meadow brown Small white Gatekeeper Orange tip Painted lady Comma Common blue Green veined white Wall brown Small copper Brimstone Small skipper Large skipper Speckled wood Ringlet Holly Blue Grayling Essex skipper Small heath Brown argus Clouded yellow Green hairstreak White letter hairstreak Purple hairstreak White admiral Camberwell beauty Monarch

140 138 137 132 130 127 118 113 106 104 86 72 64 60 54 46 36 36 34 28 21 20 15 9 6 3 2 1 1 1 1

Gardens where the butterfly appeared Seen oncei Irregularly Regularly 4 14 122 2 15 121 3 30 101 0 18 114 5 37 88 1 16 110 7 30 80 17 45 51 16 43 44 13 55 36 10 46 27 9 25 38 15 35 14 20 24 14 13 23 18 5 18 23 7 13 15 10 16 8 8 13 12 13 8 6 6 5 9 3 6 10 3 7 5 5 2 2 6 0 0 0 2 1 2 0 0 0 0 1 1 0 0 1 0 0 1 0 0

No garden records were received for swallowtail or dingy skipper and two claimed sightings of silver studded blues in gardens were not accepted. The garden sightings of Camberwell beauty and Monarch were verified and accepted by Nick Bowles of the Butterfly Conservation Executive Committee.

These garden records can be compared to two other garden surveys, the first being the 1994 National Garden Survey conducted by Butterfly Conservation (Vickery, 1995) and the second being a 1991 Survey which involved a weekly count of butterflies in 500 gardens of Essex Wildlife Trust members (Corke & Davis, 1992). Table 2 lists the ten butterflies recorded in most gardens in the three surveys, in descending order:

Trans. Suffolk Nat. Soc. 31 (1995)

8

Suffolk Natural History, Vol. 31

Table 2: The most abundant butterflies in the 1994 Suffolk and National Survevs and the 1991 Essex Survey.

Suffolk 1994 Butterfly Conservation 1994 Essex 1991 Small tortoiseshell Small tortoiseshell Small tortoiseshell Peacock Red admiral Large white Red admiral Peacock Small white Large white Large white Peacock Meadow brown Small white Gatekeeper Small white Orange tip Holly blue Gatekeeper Meadow brown Meadow brown Orange tip Gatekeeper Red admiral Painted lady *Painted lady Comma Comma *Speckled Wood Orange Tip * = equal ninth.

The same eight butterflies appeared in each list and a comparison of the two 1994 surveys mcreased it to nine. Despite the recent spread of the speckled wood in Suffolk lts frequency still does not match its national status.

Early and Late Garden Sightings Part of this information has already been incorporated in the 1994 report on Suffolk Butterflies (Stewart, 1995). An early small tortoiseshell was recorded in a Woodbridge garden on January 25th and another was seen at Bury St Edmunds on February 8th. Brimstone and peacock were recorded from the same Walberswtck garden on March 2nd and a comma was in an Elmswell garden on March 14th. the same day as a large white was observed at Leiston November s mild weather produced a brimstone at Brent Eleigh on November 15th, a small tortoiseshell at Trimley St. Mary on the 16th, with a red admiral at Knodishall on the 2Ist. The latest record was of a peacock at Pakenham on December 2nd.

Nectar

Sources

Table 3 Covers all plants included on the form, in alphabetical order: Table 3. Nectar sources in the 1994 Suffolk Butterfly Gardens

Species of plant Alyssum Aster Aubretia Bramble Buddleia Candy Tuft Cornflower Dandelion Escallonia Fleabane/Erigeron Forget-me-not

Gardens where recorded 6 5 17 21

110

Total number of butterfly species recorded

18 18

15 13

Trans. Suffolk Nat. Soc. 31 (1995)

13

Survey.

Highest number of butterfly species recorded in one garden 2 1 2 5 13 7 1 2 1 5 2

9

SUFFOLK GARDEN BUTTERFLY SURVEY, 1994

Golden Rod Heather Hebe Heiichrysum Hemp Agrinomy Honesty Ivy Lavender Lobelia Marigold-African Marigold-Corn Marigold-French Marjoram Mich. Daisy Mints Over-ripe Fruit Phlox Polyanthus/Primrose Privet Runner bean (flower) Scabious Sedum Stocks Sweet Rocket Sweet William Thyme Valerian Wallflower

7 7 16 5 7 12 9 38 13 3 2 15 22 29 24 16 9 4 8 13 15 34 3 6 3 10 6 5

6 7 13 9 9 4 9 16 10 6 5 13 17 11 16 5 7 3 10 7 15 14 2 8 4 11 13 7

3 4 7 7 6 3 8 9 7 6 3 5 7 5 7 4 2 2 5 3 6 6 1 3 2 6 10 4

The figures for Buddleia were impressive, bearing in mind that this Information about nectar sources was not forthcoming from every return. Several nectar sources were recorded from ten or fewer gardens, yet their power to attract a ränge of species suggested that more butterfly gardeners should consider planting them. These were: Aster, Candy Tuft, Heather, Heiichrysum, Hemp Agrimony, Ivy, African Marigold, Phlox, Privet, Sweet Rocket, Thyme, Valerian and Wallflower. In addition to the comprehensive list of plants, over 100 were added as nectar sources by recorders. Of these, the following have been included as the most frequent (Table 4).

Table 4: Additional nectar sources in the 1994 Survey

Plant species Garlic Mustard Jasmine (Summer/ winter flowering) Osteospermum Purple Loosestrife Ragwort Rudbeckia Statice

Gardens where recorded

Total number of butterfly species recorded

Highest number of butterfly species recorded in one garden

2 4 4

2

6

2

5 7

6

3

9 12

5 4 5

Trans. Suffolk Nat. Soc. 31 (1995)

10

Suffolk Natural History, Vol. 31

Hyssop was recorded as a nectar source in only three gardens but attracted 11 species, including five in one garden. The most unusual 'food' source was a red admiral attracted to a moth sugar patch.

No information was directly requested about whether the nectar sources were in sunlit positions or if they represented Single plants or more. One relevant comment mentioned five species observed on a patch of 30 Statice plants at Brockley.

Predation There were 11 records of spotted flycatchers taking butterflies. Three of the observers mentioned the presence of young birds. Other birds feeding on butterflies were blackbird, wren, great tit, blue tit, dunnock, house sparrow and song thrush. House sparrows were seen 'dive bombing' Buddleia to catch peacock butterflies at Ufford.

A Southern hawker dragonfly, Aeshna cyanea, was seen taking a peacock and a large white butterfly. Butterflies were also seen taken by a hรถrnet, wasp and a bumble bee. One observer recorded a gatekeeper ensnared by a spider's web and cats were observed as predators in five gardens, catching small tortoiseshell and peacock butterflies.

Egg laying The species laying eggs and their host plants recorded in the Suffolk Garden Survey are shown in Table 5.

Table 5: Butterflies laying eggs in Suffolk gardens, Host plant Brassica (Craciferae) Nasturtium (Cruciferae) Aubretia (Cruciferae) Alharia petiolata (Garlic Mustard) (Cruciferae) Lunaria annua (Honesty) (Cruciferae) Urtica dioica (Common Nettle) (Urticaceae) Humulus lupulsus (Hop) (Cannabaceae) Ribes (Currant) (Grossulariaceae) Allium flowers (Garlic Chives) (Amaryllidaceae)

1994.

Butterflies laying eggs Large White; Small White Large White; Small White Large White; Green Veined White Green Veined White; Orange Tip Orange Tip Peacock Comma Comma Small White; Small Tortoiseshell; Small Copper

The protracted butterfly season in 1994 was underlined by an Ipswich observer who found eggs of the green veined white on Garlic Mustard plants in late August, then caterpillars in September.

Egg laying was noted on brassicas in 17 gardens, with three gardens recording this on Nasturtium. Twenty-two gardens recorded egg laying, which was only 14.5% of the gardens in the survey. This percentage reflected comments in a survey of butterfly activity in gardens and nearby natural habitats: 'Although a wide variety of other species may visit gardens to feed, few remain to breed and most rely on nearby non-garden habitats . . . recent research has shown that butterflies are extremely choosy about where they breed; they need the right food plants with the right physical condiction, growing in the right position with regard to aspect, micro-climate and nature of surrounding Vegetation ' (Stephens & Warren, 1985)

Trans. Suffolk Nat. Soc. 31 (1995)

SUFFOLK GARDEN BUTTERFLY SURVEY. 1994

11

Additional comments: Observers were asked to include additional comments and many of these reflected the individual observer's opinion of 1994 as it affected their recording, compared to previous years in the same garden. Gardens have their own unique micro-climates and comments included: 'you could not have chosen a worse year' (Felixstowe) and 'the worst year since we came here in 1984' (Great Bealings). In an Ipswich garden seven species were missing, having previously been recorded every year since 1987. To balance these comments, two Bramfield observers remarked that 1994 was 'the best year since we moved here two years ago. We have left more Bramble and edge areas uncut than the previous owners'. In a Walsham-le-Willows garden more species were recorded after the end of July than in any previous years and, although the form did not request numbers of butterflies present, 'scores' of ringlets and 'hundreds' of gatekeepers were recorded in a Brockley garden and up to 20 painted lady butterflies at one time on Buddleia at St. Olaves near Yarmouth.

Most observers did agree on reduced numbers and species until the end of June, and the most frequent comment was of the absence of the holly blue, recorded in just over 18% of the gardens in the survey, A separate analysis of small gardens in the countryside or close to the habitats mentioned on the form produced an average of 10.3 species, compared to 8.8 for town and suburban locations. Comparative figures for medium-sized gardens were exactly the same at 12.2 species while in large gardens the figures were 15.1 and 11.7 respectively. This last figure was lower than that in the medium size gardens but it represented a low sample of just 11 gardens, compared to the 53 gardens in the comparative large section. These 53, representing more than a third of the total of gardens in the survey, unduly influenced the overall average of 13.4 species per garden.

Individual gardens More information was requested from the gardens which recorded the most species. Geoff and Pat Heyes observed 16 in their small garden at Beyton. They have been there for six years and planted the garden from Scratch. Most faces East with morning sunshine and in summer much of the garden receives sunshine until late afternoon. Eight plants were listed as nectar sources with 11 species on their Buddleia and 10 on Aster frikatii. Sue Down and Robin Davey live near Tunstall Common and have morning and afternoon sunshine. They have lived there for 10 years and recorded 19 species, including brown argus.

They listed 11 separate nectar plants. Another medium sized garden at Tuddenham Road, Ipswich, had 17 recorded species in 1994, being close to a belt of woodland, rough ground and the Ipswich Cemetery, Anne Beaufoy tends the garden, which since 1937 has been the home of Sam Beaufoy, East Anglia's most eminent lepidopterist.

According to the Essex Survey (Corke & Davis, 1992) a large garden is an important element in attracting a wide ränge of species and the four gardens recording the widest ränge of Suffolk butterflies were all in the large category.

The survey conducted by Stephens and Warren (1985) summarised the garden features that appeared to be particularly attractive to butterflies: "The most

Trans. Suffolk Nat. Soc. 31 (1995)

12

Suffolk Natural History, Vol. 31

important attribute in a garden that was consistently linked with high density and species richness is a rural position: comparable urban gardens recorded in this study all contained far fewer butterflies. There were also several aspects of garden design which appeared to be linked to high butterfly density (although it should be stressed that this association may not necessarily be causative); a lack or limitation of hard surface; a large total area of nettles in fĂźll sunshine; tall grassland (not rye grass) in sunshine: almost all of the garden in sunshine; the presence of internal hedges or shrub borders; the presence of Buddleia; complexity (i.e. the breaking up of garden space with small scale features); large size (over 0.2 ha); shelter around the periphery of the garden (not necessarily on South side) and the presence of a vegetable garden. Other features which may have some positive effect are a relatively large area of herbaceous garden and the presence of Ice-plants, Michaelmas Daisies or Lavender'.

John and Sheila Dolman, recorded 21 species in their one-third of an acre plot at Monk's Eleigh, including the brown argus. They have lived there for four years with a mainly South-facing garden which meets almost all of the criteria above. Shelter is provided by what was formerly a farm hedge and grassland is present along the banks of nearby fields. They recorded 14 nectar sources, with six species attracted to clumps of Marjoram.

Mervyn and Sheila Crawford also recorded 21 species in their garden of just under a quarter of an acre at Great Whelnetham. They have lived there for eight years and many of their butterfly-attracting plants are deliberately arranged in clumps and drifts, including a row of Buddleias along one edge. The West side of the garden, which contains most of the flowers, gets morning sunshine.

Again this garden met almost all of the above criteria, with 14 nectar sources noted and ten butterfly species recorded on Buddleia, with six on Scabious.

Pamela Bull's one-third of an acre garden at Palgrave, on the County border, benefits from rough ground at the rear; this area currently supports colonies of Essex and small skipper, meadow brown, gatekeeper, common blue and small copper. Twenty-one species were recorded and she has lived there since 1988.

The garden direction runs from South West to North East and there is little hard area. Again the above criteria applied, with 16 nectar sources and 13 species recorded on Buddleias.

At Walberswick Mrs. Pawluk's garden is near the sea but there is shelter from hedges and the size, one acre, gives abundant sunshine. She has lived there for 13 years and her garden, originally a barren field, was planted out specifically for butterflies, with plenty of uncut grass areas to encourage the skippers and common blue. She has a great love of butterflies, fostered in her childhood, and comments in her accompanying letter are relevant to its richness as a butterfly habitat: 'The result of my effort has been rewarding and I can judge the difference compared with the well-kept gardens in the area. I am also lucky in having no agricultural spraying touching my plot.' Eighteen different nectar sources were listed and this garden attracted 22 species of butterflies.

I thank the Suffolk Naturalists' Society for granting me a Chipperfield Bursary to undertake this study. Howard Mendel and Martin Sanford at Ipswich Museum provided helpful comments about the layout of the recording form and help is also acknowledge from Dr. Margaret Vickery whose national Butterfly Conservation recording form was the model for the Suffolk Version. Dr.

Trans. Suffolk Nat. Soc. 31 (1995)

SUFFOLK GARDEN BUTTERFLY SURVEY. 1994

13

Vickery also provided pre-publication information about the 1994 Butterfly Conservation national garden survey and Dr. David Corke provided a summary of the Essex 1991 Garden Survey.

References: Corke, D. & Davis S. (1992) Essex Garden Butterflies 1991. Essex Wildlife, 27, 9.

Keble Martin, W. (1965). The Concise British Flora in Colour. London, Ebury Press and Michael Joseph.

Mendel, H. & Piotrowski, S. H. (1986). The Butterflies of Suffolk. Ipswich, Suffolk Naturalists' Society.

Newman, L. H. (1967). Create a Butterfly Garden. London, John Baker.

Payne, M. (1987). Gardeningfor Butterflies. Dedham, Butterfly Conservation.

Sedenko, J. (1991). The Butterfly Garden. New York, Villard Books.

Stephens, D. E. A. & Warren, M. S. (1985). The Importance of Garden Habitats to Butterfly Populations. Dedham, Butterfly Conservation.

Stewart, R. G. (1995). Observations in one butterfly garden: 1994. White Admiral, 30, 8.

Stewart, R. G. (1995). Suffolk Butterflies in 1994. The Suffolk Argus, 5, 24.

Vickery, M. (1995). Garden Butterfly Survey 1994. Butterfly Conservation News, 59, 26.

Richard Stewart, 63 Belstead Road, Ipswich IP2 8BD.

Holly blue

butterflies

Despite 1994 being a poor year for holly blue butterflies I saw them in four Suffolk locations, the final one being in unusual circumstances. On August 28th my wife and I were closely examing the area adjacent to the far end of the croquet lawn in Christchurch Park, Ipswich. This has in the past been productive for this butterfly, having several tall, mature specimens of holly, one of its food plants. We failed to locate any earlier in the year and were on the point of leaving when my wife noticed something small and light coloured, flapping beneath one holly. Closer examination revealed a holly blue, caught by just one foot on a rhododendron growing under the holly. Rhododendron buds have never appeared particularly sticky to us but the butterfly was clearly trapped. By flattening the bud, then gently using my fingernail, I was able to free it and we watched with satisfaction as it flew strongly over the lawned area and landed high up in another tall holly.

Richard Stewart

Trans. Suffolk Nat. Soc. 31 (1995)