A Late Summer’s Day at Cogden Beach

I’ve driven along the coast road eastwards from Burton Bradstock many times but the view as the road levels out at the top of the first hill never fails to lift my spirits. That first glimpse of the sea. Those coastal hills spread out ahead as they slope gently down to the water. That vast shingle beach with its fringe of foam, stretching into the distance. This time I was on my way to Cogden Beach, part of the larger Chesil Beach and one of my favourite west Dorset places where I can be outside in the air, close to the sea and surrounded by nature.
The road dipped down and I reached the car park above Cogden but I had never seen it this full. Many people were taking advantage of the warm, sunny, late July day and I was lucky to find one of the last parking spaces. The view from the car park across Chesil Beach was as familiar and fascinating as always. The strip of pale brown shingle swept eastwards across my field of vision in a broad arc turning sharply towards Portland, its distinctive wedge shape held in a blue haze as if suspended above the water. The sea was a uniform azure, a colour so intense in that day’s strong sun that I couldn’t stop looking. Towards Portland, though, the sun intervened, casting its light downwards across the sea, silvering the surface which shimmered in the breeze like crumpled aluminium foil.
I left the car park and headed down hill towards the sea across the short grass that appeared to have been grazed recently, a pity as this had eliminated most of the flowers, and the insects. Dark sloes and ripening blackberries showed in the path-side scrub, sure signs that the year was moving on. Families passed me, some laden with colourful beach kit, others dressed for coastal walking. Stands of intensely pink, great willowherb and sun-yellow fleabane grew in a damp area as the path approached the shingle. A small flock of about 50 birds, probably starlings, surprised me by flying up from the scrub in a mini-murmuration. They banked and wheeled, flying back and forth for a short time before settling back on the bushes where they chatted noisily to one another.
I walked on to the shingle beach where, ahead of me, a small windbreak village had grown up. Some of the inhabitants were simply soaking up the sun, others were swimming or enjoying stand up paddleboards while some concentrated on their fishing. Heat shimmered from the pea-sized pebbles but a light breeze kept the temperature pleasant. Desultory waves made their way up the beach disturbing the shingle which retreated in a rush leaving some white water.
Towards the back of the shingle was the wild garden of beach plants that emerges afresh from the pebbles each spring and summer making this place so special. I stopped to look at the sea kale that grows so profusely here. Its thick, cabbage-like leaves were a glaucous green tinged with varying amounts of purple that seemed to come and go according to the angle of vision rather like the colours on a soap bubble. Flowering season was long past but the memory lingered and each clump was adorned with a large fan of hundreds of spherical greenish-yellow seeds Among the clumps of sea kale were the roughly crimped leaves of yellow horned-poppy, displaying its distinctive papery yellow flowers alongside some of the very long, scimitar-like seeds pods. The almost primaeval vision created by these rare and unusual plants growing from the shingle was completed by clumps of burdock with its prickly green and purple hedgehog-like flowers.
The coast path heads westwards along the back edge of this wild garden of beach plants and for the most part it is rough and stony. In places, however, shallow holes have appeared exposing the sandy soil beneath. Large black and yellow striped insects were moving about in some of these exposed holes. Sometimes these insects would dig, rather like a dog with sand shooting out behind them. Sometimes they encountered a small stone and lifted it away, secured between two legs. These are beewolves (Philanthus triangulum), spectacular solitary wasps up to 17mm long that were once very rare in the UK but, since the 1980s, have expanded their range.
I watched them for a short time before heading west on to the shingle. I soon reached the area where there are low cliffs at the back of the beach composed of thickly packed firm sand, topped by rough grass and clumps of desiccated thrift. These cliffs were punctuated by small holes, sometimes with a spill of sand emerging and here I found the same beewolves with their distinctive yellow and black markings. They were coming and going from the holes regularly and sometimes they would rest in a hole and look outwards.
Beewolves have an interesting lifecycle. The insects emerge from hibernation in the summer and the females begin to dig nest burrows up to a metre long in friable soil or sand with as many as 30 side burrows that act as brood chambers. At about the same time the females choose males for mating. Each female then hunts honeybees, paralysing them with her sting and bringing them back to place in each brood chamber where she also lays a single egg. This matures into a larva that feeds from the honeybees, hibernates over winter and emerges the following summer as a new beewolf. Although this may seem slightly gruesome, the number of beewolves in the UK is still low and does not impact significantly on the honeybee community. Also, adult beewolves are herbivores feeding only on pollen and nectar collected from flowers so acting as important pollinators.
I was able to witness some of this activity including a female returning with prey held beneath her to be mobbed by other beewolves and common wasps trying to steal her cargo. For most of the time, however, these insects get on with their lives quietly, unseen by visitors. I did notice one couple who chose a pleasant spot on the top of the low cliffs to sit and admire the view, only to find they were surrounded by beewolves. The couple moved but in fact these beautiful insects are not predatory and pose no threat to humans.
By mid-afternoon, it was time for me to leave. I took in one last view along the coast and headed back up the hill knowing that I would return in another season.
Cogden Beach is at the western end of Chesil Beach and can be accessed either via the South West Coast Path or from the National Trust Car Park on the coast road (B3157) between Burton Bradstock and Abbotsbury. OS grid reference SY 50401 88083, GPS coordinates 50.690271, -2.7035263.

Philip Strange is Emeritus Professor of Pharmacology at the University of Reading. He writes about science and about nature with a particular focus on how science fits in to society. His work may be read at http://philipstrange.wordpress.com/