• Sim Elliott

Dark Green Fritillaries at the Devil's Dyke. 18.06.22

Updated: 3 days ago

After seeing a couple of Dark Green Fritillary on Friday 17.06.22 on the path that leads into the bottom of the Devil's Dyke, I decided to go back to the Dyke on Saturday to see if I could find any more. I took the 77 bus to the Dyke 77 - Devil's Dyke-Brighton Pier | Brighton & Hove Buses. I walked into the top of the Dyke from the car park, and rather than walk down into the Dyke I turned left (east) along the path (with the fence to the right (south)) that passes through longer meadow grass, full of Bird's-Foot Trefoil and Greater Knapweed. What I discovered is that Dark Green Fritillaries love to nectar of Great Knapweed. To re-frame an oft misquoted line from the film Field of Dreams, "if you find it, they will come"! In the meadows there were many Meadow Brows and quite a few Marbled Whites. I then walked down into the Dyke, looking at the Butterflies on the south-facing north slope (south-facing slopes are the favoured location for many downland butterfly species) and the floor of the Dyke (where I saw some Common Blues and a Brown Argus). I then walked past the woodland at the bottom of the Dyke (and saw a few Speckled Woods) and then onto to Saddlescombe Farm (where I saw a Holly Blue, just before crossing the road), to have a drink and a cake at the excellent café there. I then walked back up the Dyke floor, to the bus stop. On the path to the style to the road I saw a Red Admiral and Hummingbird Hawk-Moth.


There is a National Trust self-guided Butterfly Walk at Devil's Dyke, whilst I walk the paths on the route, I walk them fairly randomly and walk other paths not on the National Trust


All sections of text in this blog in italics are quotations, sources cited.


Map of the National Trust suggested walk:

I walked mostly this walk, but not the 2-3 part, but I added in walking to Saddelsecomb Farm (just to the east of 121 on the above map) for tea and cake at the excellent care (not National Trust)


There are lots of butterflies of note on this walk, including large populations of Adonis blue, chalkhill blue and green hairstreak and smaller populations of brown argus, dark-green fritillary and silver-spotted skipper. Also, large populations of six-spot burnet moths (day-flying) and all three species of day-flying forester moth. There are a variety of chalk grassland flowers too, including drifts of common rockrose and horseshoe vetch and frequent carline thistle, dropwort and downland orchids. Devil's Dyke butterfly walk | National Trust


If you want to see these Butterflies it is useful to know their flight times. The flight times for these butterflies I have quoted from the excellent Blencowe, M. & Hulme, N. (2017) The Butterflies of Sussex: A Twenty-First Century Atlas, published by Pisces Publications in collaboration wit Butterfly Conservation and Butterfly Conservation in Sussex


Adonis Blue: average first sighting 7 May; average last sighting 30 September.; but their are two distinct broods, and often from the end of June to the beginning of August there is a gap in Adonis Blues


Chalkhill Blue: average first sighting 3 July; average last sighting 25 September


Green Hairstreak: average first sighting 13 April; average last sighting 10 July


Brown Argus: average first sighting 5 May; average last sighting 6 October


Dark Green Fritillary: average first sighting 9 June; average last sighting 1 September


Silver-Spotted Skipper: average first sighting 16 July, average last sighting 8 September


The entry in the Butterflies of Sussex for the Devil's Dyke (p. 310) also mentions that it is a good spot for all Sussex skippers.


Essex Skipper: average first sighting 23 June, average last sighting 19 August

Small Skippers: average first sighting 8 June, average last sighting 8 September

Large Skipper: average first sighting 23 May, average last sighting 1 September

Dingy Skipper: average first sighting 14 April, average last sighting 16 August

Grizzled Skipper: average first sighting 5 April, average last sighting 28 June

Butterflies seen on 18.06.22: Dark Green Fritillaries (lots), Meadow Browns (lots), Marbled Whites (some), Large Skippers (some), Common Blues (some), Small Heaths (lots), a Brown Argus, a Red Admirals, Speckled Woods (some) and a Holly Blue (near Saddlescombe Farm)


When I last visited the Devil's Dyke, 04.06.22, see Birds, Butterflies and Wild Flowers. The Devil's Dyke. 04.06.22 (simelliott.net), I saw Common Blues, an Adonis Blue, Small Blues, Speckled Woods, Small Heaths, a Small Tortoiseshells and a Painted Lady


In this post the photographs are organised into groups - butterfly and moth species, wild plants and views - rather than being presented chronologically which is my usual practice.


Dark Green Fritillaries


Greater Knapweed - these are the clumps of Greater Knapweed where I took most of the following photographs of Dark Green Fritillaries


(a * * * * * line separates groups of photos of the same individual butterfly)

This large and powerful butterfly is one of our most widespread fritillaries and can be seen flying rapidly in a range of open sunny habitats. The males look similar to the High Brown Fritillary, which is far rarer but sometimes flies with them on bracken-covered hillsides. The two can be distinguished from the underwing markings, visible when they are feeding on flowers such as thistles.


The Dark Green Fritillary has declined in parts of central and eastern England but remains locally abundant in western England, around the coast of Wales and in Scotland


Size and Family

  • Family: Fritillaries

  • Size: Large

  • Wing Span Range (male to female): 63-69mm

Conservation Status

  • Butterfly Conservation priority: Medium (but a regional priority in several England regions)

  • European status: Not threatened

Caterpillar Foodplants

Common Dog-violet (Viola riviniana) is used in many habitats, but Hairy Violet (V. hirta) is also used on calcareous grasslands, and Marsh Violet (V. palustris) on moorland and wetter habitats in the north and west. Other violets may be used occasionally.


Distribution Trend Since 1970’s = Britain: -33% Dark Green Fritillary | Butterfly Conservation (butterfly-conservation.org)


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A Dark Green Fritillary with a Meadow Brown



Marbled White


The Marbled White is a distinctive and attractive black and white butterfly, unlikely to be mistaken for any other species. In July it flies in areas of unimproved grassland and can occur in large numbers on southern downland. It shows a marked preference for purple flowers such as Wild Marjoram, Field Scabious, thistles, and knapweeds. Adults may be found roosting halfway down tall grass stems.


Found in flowery grassland but may stray into gardens. This species is widespread in southern Britain and has expanded northwards and eastwards over the last twenty years, despite some losses within its range, with outlying populations in Yorkshire and SW Wales.


Size and Family

  • Family: Browns

  • Size: Medium

  • Wing Span Range (male to female): 53-58mm

Conservation Status

  • Butterfly Conservation priority: Low

  • European status: Not threatened

Caterpillar Foodplants


Red Fescue (Festuca rubra) is thought to be essential in the diet of larvae but Sheep's-fescue (F. ovina), Yorkshire-fog (Holcus lanatus), and Tor-grass (Brachypodium pinnatum) are also eaten. It is thought that several other grasses may be used, but the full range is not known.


Distribution Trend Since 1970’s = +29%. Marbled White | Butterfly Conservation (butterfly-conservation.org)


Red Admiral


Small Heath


Meadow Browns


Large Skippers



Common Blue (on Yellow Rattle)


Dingy Skipper


Holly Blue


Moths


Cinnabar Moth


Six-Sport Burnet Moth




Hummingbird Hawk-Moth


Burnett Companion Moth


Fledgling Robin at Saddlescombe Farm


There is an excellent tea shop (not National Trust) at the National Trist's Saddlescombe Farm Saddlescombe Farm and Newtimber Hill | National Trust


A nesting House Sparrow at the barn at Saddlescombe Farm


Wild Flowers


Red Campion


Common Spotted Orchids


A species of St John's Wort genus


Rosebay Willow Herb


Pyramid Orchid


Dropwort


Kidney Vetch


I don't know what this is - a mystery to solved, but is was sandwiched between to red flags for some reason



Views of the Devils's Dyke


The geology of the Devil's Dyke


The artist John Constable declared this spot [the view north from the Devil's Dyke] ‘the grandest view in the world’. Vast views over the Sussex Weald ensure Devil’s Dyke is a popular place to walk, rest and play. Nearby, three information boards and a talking telescope illustrate local landmarks. Outside the Devil’s Dyke Hotel, the car park is full and the balcony teems with alfresco drinkers. Many have travelled inland from Brighton to see this view. But we are about to leave. Millar [Discovering Britain project manager] explains: ‘Most people who come here never actually visit Devil’s Dyke itself. It’s a shame because going into the actual dyke uncovers the story behind this beautiful scenery.’


Devil’s Dyke is Britain’s deepest, widest, and longest dry valley. Its perfect V-shape unfurls below for just over half a mile. The dyke’s size has encouraged many myths. One story goes that it formed when the devil tried to flood the Weald’s many churches. While digging a trench towards the sea, he awoke an old woman. When she lit a candle to investigate, the devil abandoned his trench and fled.


To explore the true story of Devil’s Dyke, we descend the grassy slope towards the valley floor. Patches of bare chalk appear underfoot. ... Standing on the valley floor feels like being in a drained reservoir. The grassy banks on either side loom like parted ocean waves. The dyke is 100 metres deep, twenty times more than the average swimming pool. Ripples continue as Millar explains the dyke’s aquatic geology.


The South Downs, including the dyke, are made of chalk. Chalk is permeable, so water passes through it, but when chalk freezes, it becomes impermeable. During the Ice Ages around 2.5 million years ago, the chalk froze solid with layers of soil and ice on top. When the weather briefly warmed during Ice Age summers, these top layers thawed. ‘Gravity did the rest,’ says Millar. ‘A sludgy mass of water, rocks and soil flowed across the frozen ground. It carved steep valleys into the soft chalk. In effect, we’re walking along the course of an ancient river.’ As we continue, the dyke bends to the left, demonstrating where the water met least resistance. Rory Walsh 27 May 2020 Devil’s Dyke: the longest, deepest and widest dry valley in Britain - Geographical

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