Barmouth Hillside
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Geology & landscape
Geological Period: Cambrian
Birds & fish recorded
Birds
| Species | Season |
|---|---|
| cuckoo | Breeding |
Description
Description A nationally important geological site which exposes an almost continuous rock section from the upper part of the Rhinog Grits, through the Hafotty Formation (Manganese Group), Barmouth Grit and into the Gamlan Formation, all belonging to the Harlech Grits Group of probably upper Comley Series -lower St. David's Series (Lower-Middle Cambrian) age. The locality is of interest for its clear demonstration of the thick clastic sequence, but which also includes the chemically precipitated manganese beds, which appear to allow a general correlation with the St. Tudwal's area and Newfoundland. Many horizons are rich in sedimentary structures (convoluted bedding, grading, flow-marks, groove casts, load casts), and trace fossils also occur. About one third of the site is occupied by woodland. On an exposed, west-facing slope this sessile oak Quercus petraea dominated wood is severely wind-stunted, much of the canopy being only 3-7 m high. In the acidic and well drained parts of the wood, oak is accompanied by downy birch Betula pubescens and hazel Corylus avellana with species such as wood sage Teucrium scorodonia and bluebell Hyacinthoides non-scripta in the ground flora. Localised nutrient enrichment due to the presence of manganese shales results in a more lush flora including ramsons Allium ursinum and cuckoo-pint Arum maculatum with ash Fraxinus excelsior often abundant. The woodland has a varied breeding mammal and bird population; lesser spotted woodpecker is recorded. Wood ants also occur. Remarks: Within the Snowdonia National Park.
Species mentioned
Show the 9 species mentioned in the description, with red-list status| English name search for this in other sites |
Latin name search with Google |
IUCN / Red List | Type | Family |
|---|---|---|---|---|
| lesser spotted woodpecker | Dryobates minor | EN (Breeding) | bird-woodpecker | picidae |
| ramson | Allium ursinum | LC | herb | liliaceae |
| lords and ladies | Arum maculatum | LC | herb | araceae |
| bluebell | Hyacinthoides non-scripta | LC | herb | liliaceae |
| wood sage | Teucrium scorodonia | LC | herb | lamiaceae |
| downy birch | Betula pubescens | LC | tree | betulaceae |
| hazel | Corylus avellana | LC | tree | corylaceae |
| ash | Fraxinus excelsior | LC | tree | oleaceae |
| sessile or durmast oak | Quercus petraea | LC | tree | fagaceae |
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.
| Species | Status | Via host-plant |
|---|---|---|
| Oak lutestring Cymatophorina diluta |
Endangered | Quercus petraea |
| Heath fritillary Melitaea athalia |
Endangered | Teucrium scorodonia |
| Scarce vapourer Orgyia recens |
Endangered | Betula spp., Corylus avellana, Quercus spp. |
| The sprawler Asteroscopus sphinx |
Vulnerable | Betula spp., Corylus avellana, Fraxinus excelsior, Quercus spp. |
| Broom moth Ceramica pisi |
Vulnerable | Betula spp. |
| Mottled umber Erannis defoliaria |
Vulnerable | Betula spp., Corylus avellana, Quercus spp. |
| The lackey Malacosoma neustria |
Vulnerable | Corylus avellana, Quercus spp. |
| Pale brindled Phigalia pilosaria |
Vulnerable | Betula pubescens, Corylus avellana, Fraxinus excelsior, Quercus spp. |
| Early moth Theria primaria |
Vulnerable | Quercus spp. |
| Pale eggar Trichiura crataegi |
Vulnerable | Betula spp., Corylus avellana, Quercus spp. |
| Oak hook-tip Watsonalla binaria |
Vulnerable | Quercus petraea |
| Flounced chestnut Agrochola helvola |
Near Threatened | Betula spp., Quercus spp. |
| Kentish glory Endromis versicolora |
Near Threatened | Betula pubescens |
| Large thorn Ennomos autumnaria |
Near Threatened | Betula spp., Corylus avellana, Quercus spp. |
| September thorn Ennomos erosaria |
Near Threatened | Betula spp., Quercus spp. |
| Dusky thorn Ennomos fuscantaria |
Near Threatened | Fraxinus excelsior |
| Autumnal rustic Eugnorisma glareosa |
Near Threatened | Betula spp., Hyacinthoides non-scripta |
| Double dart Graphiphora augur |
Near Threatened | Betula spp., Quercus spp. |
| Clay fan-foot Paracolax tristalis |
Near Threatened | Quercus spp. |
| Frosted green Polyploca ridens |
Near Threatened | Quercus petraea |
| White prominent Leucodonta bicoloria |
Regionally Extinct | Betula spp. |
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.