Butterflies at Sutton Hoo.

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Butterflies at Sutton Hoo In 2017, I surveyed the butterflies at Sutton Hoo (TM24Z) with a total of nine visits between 5 April and 23 September. These had a minimum of seventeen and a maximum of twenty-eight days between visits, the variation caused mainly by the vagaries of the weather. The exception was on 25 July when a later than normal visit, from mid-afternoon to early evening, was made to target Purple Hairstreaks. The route taken was from the driveway close to Wilford Bridge, Melton, following it as far as the track up to the Sutton Hoo restaurant, surveying this on both sides then back to the driveway as far as the second entrance to Dairy Farm. Here a footpath turns right, bordering gardens and hedgerows then passing through meadows and along Ferry Cliff, close to the river Deben, with superb views across to Woodbridge. I then doubled back to the driveway, which passed Little Sutton Hoo and up to the burial ground, with Top Hat wood surveyed en route. I entered the burial ground at the far gate, followed the main path through then back to the Exhibition Hall and finally passed along Chestnut Walk woodland. I had to retrace my steps along three parts of the route so did not survey it as for a transect walk though I was careful not to count any butterflies more than once. Habitats included deep marginal vegetation along the driveway, meadows, woodland, grassland, saltings, plus fields used for grazing and crop cultivation (Plates 13-16).

Nectar and Egg-Laying Sources: The following were observed, roughly in seasonal order: Common Nettle, Blackthorn, Ground Ivy, Dandelion, Red Dead-nettle, Pussy Willow, Celandine, Garlic Mustard, Hedge Mustard, Lady’s Smock, Gorse, Broom, Dock, Sorrel, Germander Speedwell, Bluebell, Hawthorn, Bird’s-foot Trefoil, Bramble (flowers and fermenting blackberries), Creeping Cinquefoil, Plantain, Oak (honeydew), Hop, Hawkweed, Ragwort, Honeysuckle, Knapweed, Red Campion, Viper’s Bugloss, Clover, Sowthistle, Spear, Creeping and Marsh Thistle, Burdock, Yarrow, Rape (field escape), Fiddleneck (Phacelia-cultivated crop), Ox-eye Daisy and Ivy. Four garden plants bordered the route - Laurel, Phlox, Mexican Orange Blossom and Buddleia, all being good nectar sources. Of these sources, the one attracting most species, especially Gatekeepers, Ringlets and meadow browns, was Bramble and a profusion of Viper’s Bugloss along the path up to the restaurant attracted many Small Skippers.

Butterfly Species Recorded: Twenty-two were observed in 2017, the best total being 187 of 16 species on 6 July.

The order below follows that of the official Suffolk butterfly recording sheets: Small Skipper: total of 84, recorded on just two visits with 64 on 19 June.

Essex Skipper:2, both on 6 July.

Large Skipper:3, on two visits.

Brimstone: 2 on 29 April but no summer sightings.

Large White: 17 on seven visits.

Small White: 9 on four visits.

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Both of these were disappointing because there was passage of both species from the continent and the site is close to the river Deben, rivers often being used as routes inland from the coast.

Green-veined White: 14 on seven visits.

Orange Tip: 10 on two visits.

Purple Hairstreak: 4 on two visits. The 25 July survey was particularly frustrating, with wind, cloud and infrequent short bursts of sunlight. I repeatedly walked along a short stretch of the driveway especially where Oak and Ash were close to each other. It took about an hour and a half to locate one which, in flying, disturbed a second specimen.

Small Copper: 16 on four visits, including two var. caeruleopunctata, with a series of blue spots along the bottom edge of the hind wings, both on 10 July. A pair battling for territory at the burial ground end of Top Hat wood was pointed out to an excited young girl and her parents.

Brown Argus: 1 on 26 August, close to the path near Top Hat wood.

Holly Blue: 1 on 6 May. Holly is relatively rare on site though Ivy is abundant.

Red Admiral: 17 on six visits but only two nectaring on Ivy, which grows in abundance near Dairy Farm and Little Sutton Hoo. Small Tortoiseshell: 1 on 19 June. My own 2017 records from elsewhere indicate a poor year with just one double figure count.

Peacock: 12 on four visits.

Comma: 16 on six visits.

Speckled Wood: 5 on five visits, a very poor return given the abundance of dappled shade, its preferred habitat.

Grayling: 5 on three visits, mainly around Top Hat wood.

Gatekeeper: 43 on three visits, a species usually abundant but over a relatively short flight period.

Meadow Brown: 136 on five visits.

Ringlet: 67 on three visits with 43 on 6 July. It was recorded in the highest numbers towards the top of the path leading to the restaurant, on the right-hand side.

Small Heath: 43 on three visits. Those near the restaurant path were nectaring on Creeping Cinquefoil and on 26 August sixteen were along or close to the main path through the burial ground.

Two particular species, Common Blue and Painted Lady, I recorded a Common blue on site 16 August 2005 and Martin Sanford at the Suffolk Biodiversity Information Service has kindly provided on sire records between 2003 and 2015. These included Common Blues from Stella Wolfe and A.C. Edwards in 2010 and from Peter Maddison in 2015.

The normal larval foodplant, Bird’s-foot Trefoil, is not abundant on site. Painted Lady records prior to 2017 were also surprisingly few, given the site’s proximity to the river Deben. I recorded two in 2016 and others were from Stella Wolfe in 2003 and 2007, Derek Longe in 2003, Mike Easterbrook in 2007 and Giovanni Grieco in 2009. A Clouded Yellow was recorded by Victor Short in 2014 and a Wall by John Mills in 2013.

I recorded a Silver-washed Fritillary, nectaring on Bramble, in 2015.

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This brings the 2003-2017 total of butterfly species to twenty-seven, a high total for an inland Suffolk site. One species, the Green Hairstreak, was diligently searched for in 2017, given the presence of its two larval foodplants, Broom and Gorse. The latter is abundant along the driveway and within the burial ground. There were also no sightings between 2003 and 2015 but Martin Sanford found two earlier site records, two from me in 1998 and 2001 and from JDM (initials only) with a total of six in 1998. Hopefully future recorders may be able to discover if this species still exists at Sutton Hoo. Richard Stewart, ‘Valezina’, 112, Westerfield Road, Ipswich, IP4 2 XW. Errata: Suffolk Natural History 2016: ‘Butterflies on Rushmere Common - A 2016 Survey’-page 40, line 9. ‘Horseshoe Vetch’ should be Kidney Vetch. Stella Wolfe is thanked for pointing this out.

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Plate 13: Sutton Hoo: Looking down from the restaurant area towards the river Deben – a good site for Ringlets, Small Heath and Small Skippers (p. 96).

Plate 14: The footpath from Dairy Farm towards Ferry Cliffs with bramble bushes on either side (p. 96).

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Plate 15: View along a stretch of the Ferry Cliff path with the Deben on the left (p. 96).

Plate 16: Ferry Cliff path – dappled shade attracts Speckled Wood butterflies (p. 96).

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