Introduction
Wren’s Nest National Nature Reserve is a world-renowned geological site of exceptional importance located in Dudley, in the West Midlands. Established in 1956, it holds the historic distinction of being the first NNR chosen purely for its exceptional geology.
This urban reserve, managed by Dudley Council, also has a range of habitats that have developed on the lime rich soils following past mining activity.
Geology
Wrens Nest sits on an ancient Silurian coral reef that is over 400 million years old. It is globally famous for its highly diverse fossil records and significant industrial mining heritage.
Silurian geology
Wrens Nest is of worldwide renown for its exceptional range and abundance of Silurian fossils. These creatures lived in a shallow warm sea and included corals, bivalves, sea lilies and a specific trilobite which is the signature species of this reserve. Abundantly found during 19th-century mining, it became so famous it was nicknamed the “Dudley Bug” and features on the town’s official coat of arms.
Habitats
The reserve features a mosaic of different habitats, which have developed on the lime rich soils. These habitats have often developed following the abandonment of the old limestone mining works.
Limestone grassland
The thin, calcium-rich soils across the quarry floors and step trenches support vibrant limestone grasslands.
Ash and elm woodlands
Woodland covers significant parts of the reserve, particularly around Mons Hill in the northern section and Wren’s Nest Hill in the south. The canopy is dominated by ancient and planted Ash, Beech, and Sycamore trees. Because ash trees let plenty of light filter through to the woodland floor, a dense ground layer of shrubs, mosses, and ferns thrives beneath them.
Subterranean Caverns & Abandoned Mines
The legacy of Victorian limestone mining created a vast underground cave and canal network that is now a subterranean ecosystem.
Key species
Lime loving plants
The thin, lime rich quarry floors provide the ideal conditions for a range of lime loving plants. These include: bee orchid, pyramidal orchid, autumn gentian, small scabious, quaking grass, small scabious, common gromwell and milkwort.
Bats
Because they maintain a cool, stable temperature, the deep fissures and blocked-off caverns are classified as a nationally important hibernation site for bats. Seven protected species use this safe habitat, including Daubenton’s, Natterer’s, and Whiskered bats.
© Natural England/Alice Maramao
White letter hairstreak
In summer, the grasslands act as a haven for up to ten different species of butterflies, including the locally uncommon white-letter hairstreak. This butterfly depends upon the growth of elm and has managed to survive despite the ravages of Dutch elm disease.
The sunny limestone banks also support populations of Common Blue, Small Copper, Dingy Skipper, and Small Tortoiseshell butterflies.
Further info
Natural England’s West Midland NNRs: https://www.gov.uk/government/publications/west-midlands-national-nature-reserves/west-midlands-national-nature-reserves#wrens-nest
Dudley Borough Council:
Black Country Geopark
https://blackcountrygeopark.dudley.gov.uk/sites-to-see/wrens-nest-national-nature-reserve
You must be logged in to post a comment.