The limestone rock at Wren's Nest provides an environment where a distinct range of habitats and species of plants and animals are found.
When quarrying ceased, the bare rock surfaces left behind were exposed to weathering by wind, rain and frost. As the process of weathering continued, mosses and lichens colonised the bare rocks, forming pockets of soil in cracks and hollows. Soon enough soil accumulated for seeds, blown in by the wind or dropped by birds to germinate and slowly the bare rock became colonised by plants.
Limestone grasslands are usually rich in different species of wild flowers, and early summer at Wren’s Nest is marked by fine displays of yellow, pink and white, with a great variety of plant forms and leaf shapes.
Many of these plants are locally rare and Wren’s Nest is one of the few places in the West Midlands where attractive plants like Small Scabious, Milkwort, Quaking Grass and Hoary Plantain can be seen.
The limestone grassland at Wren's Nest also supports good numbers of common Spotted Orchid, Bee Orchid and Pyramidal Orchid, shown right
On Wren's Nest hill in the sourthern part of the Reserve most of the oldest Ash, Beech and Sycamore are survivors of trees planted over the last 200 years. Ash woodlands has a good range of shrubs and a wide assortment of mosses, ferns and other plants growing on the woodland floor.
Grasslands on the Reserve are cut once a year towards the end of summer, a style of management which favours an attractive variety of wild flowers and grasses including Sweet Vernal Grass, Crested Dog's-tail and Hay Rattle. Where deeper and richer soils have developed, coarser grasses like Cocksfoot will be found, with swathes of Willowherb, Thistle and Bramble.
At the height of summer on a warm sunny day, a walk across Wren's Nest should allow you to see as many as ten different kinds of butterfly.
Clumps of thistles and knapweed are a good place to see Red Admirals, Skippers and Small Tortoiseshells which visit them to feed on nectar. Many other insects also take advantage of the rich sources of nectar at Wren's Nest, such as Bumble Bees, Hoverflies and a great variety of beatles. Brown Hawker and Common Darter dragonflies may be found hunting along hedgerows or in quarries.