Lewes Downs

Site of Special Scientific Interest · 50.8664, 0.0466

Condition (Natural England)

Favourable (8) Unfavourable Declining (4) Unfavourable Recovering (2)
UnitFeatureConditionArea (ha)Assessed
TQ428107 Favourable 36.13 2015-07-27
TQ428112 Favourable 17.43 2009-11-19
TQ438096 Favourable 38.84 2019-09-24
TQ440092 Favourable 11.3 2020-11-02
TQ441093 Favourable 7.54 2020-11-02
TQ443088 Unfavourable Declining 1.32 2023-02-07
TQ444089 Favourable 3.09 2009-05-29
TQ444100 Unfavourable Recovering 4.43 2015-10-30
TQ445086 Unfavourable Declining 15.86 2023-02-07
TQ445089 Unfavourable Declining 2.91 2023-02-09
TQ446090 Unfavourable Declining 6.75 2023-02-09
TQ448087 Favourable 5.62 2015-10-02
TQ448098 Favourable 13.82 2020-11-02
TQ448102 Unfavourable Recovering 4.43 2015-10-30

Geology & landscape

Rock Type: Chalk

Birds & fish recorded

Birds

SpeciesSeason
grasshopper warbler Breeding
kestrel Breeding
kestrel Wintering
meadow pipit Breeding
meadow pipit Wintering

Description

Area, 149.8 ha. 370.2 ac. Description Lewes Downs is an isolated block of downland which forms part of the South Downs. It is important for the extremely rich chalk grassland and scrub vegetation, which contains a number of southern and oceanic southern species as well as a nationally rare orchid. The site also supports a rich invertebrate fauna including a rare moth, and an important breeding community of downland birds. This block of downland has a south facing scarp slope which is an unusual feature within the South Downs. The majority of the site comprises unimproved species rich chalk grassland, developed on steep slopes over thin rendzina soils. Other habitats which add to the diversity and interest of the site include areas of mixed scrub and semi natural woodland. The richest parts of Lewes Downs are the Old Chalk Pit, Bible Bottom, Malling Combe and parts of Mount Caburn. Here the sward is dominated by sheep's fescue Festuca ovina and upright brome Bromus erectus grasses which form a springy turf with an abundance of characteristic herbs of chalk grassland. Salad burnet Poterium sanguisorba, horseshoe vetch Hippocrepis comosa, yellow wort Blackstonia perfoliata and sqinancywort Asperula cynanchica are widespread and in Caburn Bottom an exceptional quantity of marjoram Origanum vulgare occurs and is important as a food plant for the chalkhill blue butterfly. A number of plants occupying a strictly southern distribution within the British Isles are found on the warm south facing slopes of Malling Combe and Mount Caburn including chalk milkwort Polygala calcarea and round headed rampion Phyteuma orbiculare. One of the largest British colonies of the burnt tip orchid Neotinea ustulata occurs on the upper slope of Mount Caburn, intermittently appearing with the nationally rare early spider orchid Ophrys sphegodes. The orchid flora here, in Caburn Bottom and on the steeper slopes of the chalk pits in the far north of the site is exceptional for its variety and for the number of individual plants. Bee Ophrys apifera, fly Ophrys insectifera, frog Dactylorhiza viridis and musk orchids Herminium monorchis are all present. Scrub which has invaded in several areas, is composed mainly of hawthorn Crataegus monogyna, wayfaring tree Viburnum lantana, blackthorn Prunus spinosa, dogwood Cornus sanguinea and wild privet Ligustrum vulgare. Areas of ash Fraxinus excelsior woodland occur on the eastern edge of the site and south of Malling Combe, where sycamore Acer pseudoplatanus becomes locally dominant. Beneath this canopy hawthorn and elder Sambucus nigra form a shrub layer with a ground flora of dog's mercury Mercurialis perennis and ground ivy Glechoma hederacea. Mezereon Daphne mezereum, an unusual shrub with a restricted distribution also occurs in these woods. The rich habitat mosaic at this site fosters an exceptional Lepidopteran fauna butterflies and moths, including the Adonis blue Polyommatus bellargus and the chalkhill blue L. coridon butterflies. All three British forester moths Adscita species have been recorded here along with the locally rare annulet moth Gnophos annubilata. A number of typical downland birds breed on the site including kestrel, corn bunting, grasshopper warbler and meadow pipit. This is also an important over wintering area for thrushes and finches.

Species mentioned

English name
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Latin name
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IUCN / Red List Type Family
Gnophos annubilata Not listed in GB list Charissa obscurata geometridae
corn bunting Emberiza calandra CR (Breeding) bird-bunting emberizidae
kestrel Falco tinnunculus VU (Breeding) bird-hawk falconidae
meadow pipit Anthus pratensis LC (Breeding) bird-pipit motacillidae
grasshopper warbler Locustella naevia LC (Breeding) bird-warbler locustellidae
Adonis blue Polyommatus bellargus VU butterfly lycaenidae
upright brome Bromus erectus Not listed in GB list grass poaceae
sheep's fescue Festuca ovina LC grass poaceae
squinancywort Asperula cynanchica VU herb rubiaceae
yellowwort Blackstonia perfoliata LC herb gentianaceae
frog orchid Dactylorhiza viridis VU herb orchidaceae
ground ivy Glechoma hederacea LC herb lamiaceae
musk orchid Herminium monorchis EN herb orchidaceae
horseshoe vetch Hippocrepis comosa VU herb fabaceae
dog's mercury Mercurialis perennis LC herb euphorbiaceae
burnt orchid Neotinea ustulata EN herb orchidaceae
bee orchid Ophrys apifera LC herb orchidaceae
fly orchid Ophrys insectifera VU herb orchidaceae
early spider orchid Ophrys sphegodes LC herb orchidaceae
wild marjoram Origanum vulgare LC herb lamiaceae
round headed rampion Phyteuma orbiculare LC herb campanulaceae
chalk milkwort Polygala calcarea VU herb polygalaceae
salad burnet Poterium sanguisorba VU herb rosaceae
dogwood Cornus sanguinea LC shrub cornaceae
hawthorn Crataegus monogyna LC shrub rosaceae
metzereon Daphne mezereum VU shrub thymelaeaceae
wild privet Ligustrum vulgare LC shrub oleaceae
blackthorn Prunus spinosa LC shrub rosaceae
elder Sambucus nigra LC shrub caprifoliaceae
wayfaring tree Viburnum lantana LC shrub caprifoliaceae
sycamore Acer pseudoplatanus Not listed in GB list tree aceraceae
ash Fraxinus excelsior LC tree oleaceae

Insects to look out for

These moths, butterflies and beetles are known to feed on plants recorded at this site, and carry a notable UK conservation status — but a host-plant being present doesn't mean the insect has actually been recorded here. Treat this as "worth watching for," not a confirmed sighting.

SpeciesStatusVia host-plant
Black-veined moth
Siona lineata
Critically Endangered Origanum vulgare
Figure of eight
Diloba caeruleocephala
Endangered Crataegus spp., Prunus spinosa, Prunus spp.
The lappet
Gastropacha quercifolia
Endangered Crataegus monogyna, Prunus spinosa, Prunus spp.
Scarce vapourer
Orgyia recens
Endangered Crataegus spp., Prunus spinosa
Black hairstreak
Satyrium pruni
Endangered Prunus spinosa
Mouse moth
Amphipyra tragopoginis
Vulnerable Crataegus spp., Poterium sanguisorba
The sprawler
Asteroscopus sphinx
Vulnerable Crataegus spp., Fraxinus excelsior, Prunus spinosa, Prunus spp., Viburnum lantana
Mottled umber
Erannis defoliaria
Vulnerable Acer pseudoplatanus, Crataegus spp., Prunus spinosa
Dingy skipper
Erynnis tages
Vulnerable Hippocrepis comosa
Grayling
Hipparchia semele
Vulnerable Festuca ovina
The lackey
Malacosoma neustria
Vulnerable Crataegus monogyna, Prunus spinosa, Prunus spp.
Pale brindled
Phigalia pilosaria
Vulnerable Cornus sanguinea, Crataegus monogyna, Fraxinus excelsior, Prunus spinosa
Silver studded blue
Plebejus argus
Vulnerable Hippocrepis comosa
Grizzled skipper
Pyrgus malvae
Vulnerable Poterium sanguisorba
Brown hairstreak
Thecla betulae
Vulnerable Prunus spinosa
Early moth
Theria primaria
Vulnerable Crataegus monogyna, Prunus spinosa
Pale eggar
Trichiura crataegi
Vulnerable Crataegus monogyna, Prunus spinosa
Flounced chestnut
Agrochola helvola
Near Threatened Crataegus monogyna
Beaded chestnut
Agrochola lychnidis
Near Threatened Crataegus monogyna
Grey chi
Antitype chi
Near Threatened Crataegus monogyna
Garden tiger
Arctia caja
Near Threatened Prunus spinosa
Small heath
Coenonympha pamphilus
Near Threatened Festuca spp.
Large thorn
Ennomos autumnaria
Near Threatened Acer pseudoplatanus, Crataegus spp., Prunus spinosa, Prunus spp.
Dusky thorn
Ennomos fuscantaria
Near Threatened Fraxinus excelsior
Autumnal rustic
Eugnorisma glareosa
Near Threatened Festuca ovina
Grey pug
Eupithecia subfuscata
Near Threatened Crataegus monogyna, Prunus spinosa
White-spotted pug
Eupithecia tripunctaria
Near Threatened Sambucus nigra
Double dart
Graphiphora augur
Near Threatened Crataegus spp., Prunus spinosa
Silver-spotted skipper
Hesperia comma
Near Threatened Festuca ovina
Rosy minor
Litoligia literosa
Near Threatened Festuca ovina
Dark-barred twin-spot carpet
Xanthorhoe ferrugata
Near Threatened Glechoma hederacea

Host-plant data: Cook et al. (2025), Traits data for the butterflies and macro-moths of Great Britain and Ireland, 2024, UK Centre for Ecology & Hydrology / Butterfly Conservation; and Padovani et al. (2020), Database of Insects and their Food Plants (DBIF), UK Centre for Ecology & Hydrology (both Open Government Licence). Contains data supplied by UK Centre for Ecology & Hydrology.

Plant communities

W21 — Hedgerow scrub, Mixed scrub

Crataegus monogyna-Hedera helix scrub

Matches 12 species from the description above: Acer pseudoplatanus, Cornus sanguinea, Crataegus monogyna, Fraxinus excelsior, Glechoma hederacea, Ligustrum vulgare, Mercurialis perennis, Origanum vulgare, Poterium sanguisorba, Prunus spinosa, Sambucus nigra, Viburnum lantana

Hedera helix, Salix cinerea, Acer pseudoplatanus, Ilex aquifolium, Betula pendula, Corylus avellana, Fagus sylvatica, Quercus robur, Fraxinus excelsior, Malus sylvestris, Sorbus aria, Taxus baccata, Ulmus glabra, Ulmus procera, Sambucus nigra, Viburnum lantana, Euonymus europaeus, Cornus sanguinea, Juniperus communis, Ligustrum vulgare, Clematis vitalba, Rhamnus cathartica, Crataegus laevigata, Crataegus monogyna, Prunus spinosa, Juncus effusus, Plagiomnium undulatum, Brachythecium rutabulum, Kindbergia praelonga, Rhynchostegium confertum, Tamus communis, Heracleum sphondylium, Torilis japonica, Arum maculatum, Arctium minus, Cirsium arvense, Lonicera periclymenum, Moehringia trinervia, Silene dioica, Stellaria graminea, Stellaria holostea, Stellaria media agg., Calystegia sepium, Mercurialis perennis, Geranium robertianum, Iris foetidissima, Glechoma hederacea, Lamium purpureum, Origanum vulgare, Stachys sylvatica, Teucrium scorodonia, Allium ursinum, Hyacinthoides non-scripta, Circaea lutetiana, Rumex sanguineus, Anemone nemorosa, Ranunculus repens, Fragaria vesca, Geum urbanum, Potentilla sterilis, Poterium sanguisorba, Rosa arvensis, Rosa canina, Rubia peregrina, Rubus fruticosus agg., Galium aparine, Urtica dioica, Viola riviniana, Anisantha sterilis, Arrhenatherum elatius, Brachypodium pinnatum, Brachypodium sylvaticum, Bromopsis erecta, Dactylis glomerata, Elytrigia repens, Holcus lanatus, Holcus mollis, Poa trivialis, Asplenium scolopendrium, Pteridium aquilinum, Dryopteris filix-mas

W20 — Montane scrub

Salix lapponum-Luzula sylvatica scrub

Matches 2 species from the description above: Dactylorhiza viridis, Festuca ovina

Salix arbuscula, Salix cinerea, Salix lapponum, Salix myrsinites, Salix phylicifolia, Salix reticulata, Empetrum nigrum, Calluna vulgaris, Salix lanata, Vaccinium myrtillus, Vaccinium uliginosum, Carex atrata, Carex bigelowii, Carex binervis, Carex flacca, Luzula multiflora, Luzula sylvatica, Huperzia selago, Selaginella selaginoides, Aulacomnium palustre, Mnium hornum, Philonotis fontana, Plagiomnium undulatum, Rhizomnium punctatum, Dicranum bonjeanii, Dicranum majus, Dicranum scoparium, Fissidens adianthoides, Racomitrium lanuginosum, Calliergonell cuspidatum, Ctenidium molluscum, Hylocomium splendens, Hypnum callichroum, Hypnum cupressiforme, Palustriella commutatum, Plagiothecium denticulatum, Plagiothecium undulatum, Pleurozium schreberi, Ptilium crista-castrensis, Rhytidiadelphus loreus, Rhytidiadelphus squarrosus, Rhytidiadelphus triquetrus, Sanionia uncinata, Scorpidium revolvens, Thuidium tamariscinum, Atrichum undulatum, Polytrichastrum alpinum, Sphagnum capillifolium, Sphagnum fallax, Sphagnum girgensohnii, Sphagnum palustre, Sphagnum russowii, Sphagnum squarrosum, Sphagnum subnitens, Sphagnum teres, Barbilophozia barbata, Chiloscyphus polyanthos, Diplophyllum albicans, Lophocolea bidentata, Plagiochila porelloides, Ptilidium ciliare, Scapania undulata, Cladonia squamosa, Peltigera canina, Angelica sylvestris, Caltha palustris, Hieraclium spp., Saussurea alpina, Solidago virgaurea, Campanula rotundifolia, Succisa pratensis, Valeriana officinalis, Rhodiola rosea, Vaccinium vitis-idaea, Thymus praecox, Epilobium anagallidifolium, Dactylorhiza viridis, Euphrasia officinalis, Rhinanthus minor, Oxalis acetosella, Oxyria digyna, Polygonum viviparum, Rumex acetosa, Anemone nemorosa, Ranunculus acris, Thalictrum alpinum, Alchemilla alpina, Alchemilla glabra, Filipendula ulmaria, Geum rivale, Galium boreale, Galium saxatile, Saxifraga aizoides, Saxifraga hypnoides, Saxifraga oppositifolia, Saxifraga stellaris, Viola riviniana, Agrostis canina, Agrostis capillaris, Anthoxanthum odoratum, Deschampsia cespitosa, Deschampsia flexuosa, Festuca ovina, Festuca rubra, Nardus stricta, Dryopteris dilatata, Phegopteris connectilis

W22 — Hedgerow scrub, Mixed scrub

Prunus spinosa-Rubus fruticosus scrub

Matches 2 species from the description above: Mercurialis perennis, Prunus spinosa

Hedera helix, Acer campestre, Corylus avellana, Ulex europaeus, Prunus spinosa, Plagiomnium undulatum, Brachythecium rutabulum, Eurhynchium striatum, Kindbergia praelonga, Thuidium tamariscinum, Atrichum undulatum, Lophocolea bidentata, Achillea millefolium, Cardamine flexuosa, Lonicera periclymenum, Moehringia trinervia, Silene dioica, Silene uniflora, Stellaria media agg., Mercurialis perennis, Geranium robertianum, Stachys sylvatica, Teucrium scorodonia, Hyacinthoides non-scripta, Oxalis acetosella, Digitalis purpurea, Plantago lanceolata, Veronica chamaedrys, Armeria maritima, Rumex acetosa, Filipendula ulmaria, Geum urbanum, Rosa canina, Rubus fruticosus agg., Rubus idaeus, Galium aparine, Urtica dioica, Viola riviniana, Agrostis capillaris, Brachypodium sylvaticum, Dactylis glomerata, Festuca rubra, Holcus lanatus, Holcus mollis, Poa trivialis, Asplenium scolopendrium, Pteridium aquilinum, Dryopteris borreri, Dryopteris filix-mas