Dunscombe

Nestled near Sidmouth on the stunning East Devon coast, you will find what locals call "the head of a secret wooded combe." Here, in the valley of Dunscombe, "Peace and tranquillity" are the first gifts the landscape offers. This beautiful vale, descending gently towards the sea, feels like a world apart—a place to quiet the mind and listen to the whisper of wind in the ash trees. But there is a deeper story here, one of geology, constant change, and extraordinary life.

This seemingly quiet combe is the key to unlocking a National Trust area of outstanding natural beauty, a landscape rich in both flora and fauna. As part of the Jurassic Coast World Heritage Site, Dunscombe is more than a picturesque valley; it is a gateway to understanding one of the most remarkable areas for wildlife in the United Kingdom. This is a journey into the deep natural history hidden within its crumbling cliffs and sheltered slopes, a place where the slow-motion crumble of the earth itself is the architect of a unique and fragile world.

To understand Dunscombe is to first understand the rock beneath your feet. The landscape is a direct expression of its geology, dominated by the Upper Greensand Formation laid down in the shallow seas of the Cretaceous period, approximately 100 million years ago. These coastal cliffs are not a single, solid wall but a complex sequence of sandstones and calcarenites, in places capped by a younger layer of pure white Chalk. Geologists have identified distinct layers here, including the Foxmould Member, the Whitecliff Chert Member, and the Bindon Sandstone Member.

This is a dynamic, living coastline. The cliffs are highly active and unstable, constantly being reshaped by the sea and the rain. With every slow-motion crumble of the cliff face, this process of slumping creates the area's characteristic "undercliffs"—wild, jumbled slopes of land that have slipped towards the sea, suffused with the scent of damp earth and salt spray. This natural instability is driven by a process geologists call "large-scale pervasive dissolution," where rainwater, slightly acidic, has slowly dissolved the carbonate cements in the sandstone over millennia, honeycombing the rock and contributing to its weakness. It is this very decay that is the engine of Dunscombe's unique ecology.

Human history is also written in this stone. The valley is dotted with old quarries where a coarse sandstone known as "Salcombe Stone" was extracted for centuries. This durable local material was used to build some of Devon's most treasured buildings, including parts of the magnificent Exeter Cathedral.

This perpetual geological motion is the engine of Dunscombe's biodiversity. It prevents any single ecosystem from dominating, instead creating a finely grained patchwork of opportunities for life. Within just a few hundred metres, one can move through a half-dozen distinct worlds, each providing a refuge for an incredible diversity of specialised species. It is a masterclass in how constant disturbance can foster life.

• Crumbling Undercliffs: These unstable slopes ensure a constant supply of bare ground. To the casual observer, it is a crumbling cliff; to a specialist solitary bee, it is a city of nesting tunnels carved into the sun-warmed clay.

• Coastal Seepages: All along the cliffs, wet areas form where water emerges from the rock. These calcareous springs, streams, seepages, and small patches of fen are vital habitats, particularly for rare and threatened flies that are found nowhere else in Britain.

• Flower-Rich Grasslands: The cliff tops and the surfaces of slumped landslips are home to grasslands rich in wildflowers. These provide essential food sources for a huge range of insects, from butterflies to bees.

• Wooded Combes: Dunscombe itself is a "beautiful wooded valley," providing shelter and a different set of ecological niches away from the exposed cliff face.

• Shingle Beaches: At the base of the cliffs, shingle beaches offer another distinct habitat, home to unique creatures like the rare Scaly Cricket, which depends on driftwood washed ashore for its nursery.

Historic "Plats": Carved out of the south-facing cliff slopes are small, terraced fields known as "plats." Here, farmers once grew early potatoes, taking advantage of the frost-free microclimate and fertilising them with seaweed from the beach. Though now largely overgrown, these sheltered, sunny spots still harbour chalk-loving plants.

The unique combination of geology and habitat has made this stretch of coast an "invertebrate hotspot" of national importance. What this geological instability means for wildlife is a constant renewal, creating a haven where many of Britain's rarest creatures thrive not in spite of the chaos, but because of it.

A Haven for Moths and Butterflies

While the winds dance across the grasslands above, an important and vulnerable group of moths and butterflies plays out its life cycle. Notable examples include:

• The Morris’s Wainscot moth, a creature that thrives on precarity. In the entire UK, it is found only on this short stretch of coast, where its caterpillars seek out the weakest, most stressed stems of Tall Fescue grass growing on the most insecure ground of the slipping cliffs.

• The White Spot moth is another specialist. Its caterpillars feed exclusively on the seeds of the Nottingham Catchfly, hiding at the base of the plant by day and emerging to feed under the cover of darkness.

• The Wood White is one of Britain's smallest and most delicate butterflies. Its remaining Devon populations are found here, where its caterpillars feed on vetches growing in the sheltered, scrubby grasslands of the undercliffs.

Flies, Bees, and Beetles of the Cliffs

While the moths and butterflies dance in the air, the cliff faces themselves are a vertical stage for other specialists. Here, in the fine cracks of sun-baked clay, some of Britain's rarest insects make their home.

• The Spanish Snout Cranefly is a southern-European species whose only known British home is in a few tiny, spring-fed streams that run down the soft coastal cliffs near Axmouth. Its existence here is incredibly precarious, vulnerable to threats of cliff stabilisation, water abstraction, drainage, and pollution.

• The cliffs are also vital for specialist bees like the Broad-faced Furrow Bee. This species nests in the fine cracks that appear in south-facing clay cliffs as they dry in the summer sun, turning the sheer rock face into a vertical nursery.

• The Cliff Tiger Beetle, known as the "cheetah of the insect world," is a fearsome predator that hunts other insects across the warm, bare ground of the south-facing cliffs, a miniature savanna teeming with life.

Creatures of the Coast and Ponds

From the shingle at the water's edge to the man-made ponds on the clifftops, life has adapted to every available niche.

• The Scaly Cricket is a rare, nocturnal insect found on Branscombe's shingle beach. It is incredibly vulnerable, laying its eggs in pieces of driftwood, a poignant reminder of the importance of leaving natural debris on our shorelines.

• The Fairy Shrimp, a rare and protected crustacean, has been found in the old, man-made dew ponds on the grasslands. These simple, clay-lined ponds, once used for watering stock, are now a critical habitat for this ethereal creature.

Other Notable Residents

Beyond the invertebrates, the cliffs are a wild and dramatic stage for other wildlife. Peregrine Falcons can be seen hunting along the coastline, making use of the high vantage points. The sunny paths and slopes are home to reptiles like the Adder, as well as an array of chalk-loving wildflowers. On a warm day, look closely at the ground and you may see the tell-tale signs of their presence in the common rockrose leaves, sweet violet flowers and salad burnet leaves that line the sunniest spots.

Dunscombe is far more than a tranquil wooded valley. It is a living laboratory where active geology is the driving force behind a world of specialized and rare life. Here, the constant, slow-motion crumbling of the coast creates a dynamic refuge that supports creatures found nowhere else. The story of this secret combe is a powerful reminder that stability is not always a prerequisite for a thriving ecosystem; sometimes, it is the disturbance and change that foster the greatest diversity.

The secret of Dunscombe, then, is not one of stillness, but of constant, creative decay. It is a story written on a crumbling page, revealing that our planet’s most intricate masterpieces are often found not in spite of change, but because of it. It urges us to look past the manicured and the stable, and to find the profound beauty that flourishes at the wild, shifting edges of our world.