A week ago, I went down to the south Devon coast below the village of East Prawle to find the rare long-horned bees that live there. Their main nest site is located in the low cliffs near Horseley Cove and I scrambled down the steep path to the foot of the cliffs to have a look. It was a beautiful sunny day and the area was bathed in sunshine while the sea, a deep blue in that day’s light, fussed on the jumble of large boulders that lie just off shore. The sea was calm when I visited but in the winter these boulders will defend the cliffs from the worst of the storms creating a protected microenvironment.
Tracts of reddish soft rock peppered with pencil-sized holes were evident across the cliffs and several bees, roughly honeybee-sized, were patrolling the area showing a particular interest in these cavities. They swung in and moved quickly just above the surface sashaying back and forth and from side to side like hyped-up ballroom dancers. They looked very fresh and were rather lively and It was difficult to discern details but when I focussed my attention on a single insect I could see a pale yellow face, a bright russet thorax and two extra-long antennae, for these were the male long-horned bees (Eucera longicornis) I had come to see. One landed briefly and I marvelled at his magnificent antennae, each as long as the rest of his body.
Numbers varied but there were always a few about and sometimes up to six at one time, weaving around one another, creating a loud buzz. My presence didn’t seem to bother them, some flew around me and another collided with me but they carried on regardless. They are driven by procreative urges and having emerged from their nest holes in the soft rock within the last week or so, they were now waiting to catch a virgin female as she appeared. Mating had, though, already begun. On two or three occasions, a bee flew directly into a hole and didn’t reappear. Photos confirmed that these slightly chunkier bees with golden pollen brushes on their back legs were female Eucera longicornis, already mated and preparing their nests.
Eucera longicornis is rare and much declined and one of many special insect species found along this stretch of coast, designated a Site of Special Scientific Interest. The cliff top meadow above the nests was a mosaic of wildflowers and earlier I had found a few male Eucera feeding on bird’s foot trefoil. The coast path either side of the meadow had, however, been treated with herbicide and strimmed, virtually eliminating wildflowers, seriously degrading this important site.
One of my favourite parts of the coast path in south Devon is the section between Prawle Point and Start Point. Between these two imposing coastal landmarks the path follows the meandering line of the low cliffs and, unusually for this part of Devon, there are few hills and walking is easy. The area inland of the coast path is notable for the line of steep rocky cliffs that, many years ago, formed the coastline when sea levels were higher. Between these inland cliffs and the present coastline is a flattish area, about a field’s width across, mostly used for pasture and arable farming. One section, a long curving coastal meadow (above Horseley Cove), is left uncultivated and many wild flowers grow here and, to a lesser extent, along the edges of other parts of the coast path. With the rocky coastline and rugged inland cliffs, the area retains a wildness and I come here to be close to the sea and to immerse myself in nature in all its fullness.
The stretch of coastline between Start Point and Prawle Point is a nationally important site for rare invertebrates and was designated as a Site of Special Scientific Interest (SSSI) in 1986. For some years now, I have been coming here in early summer to watch the rare long-horned bees (Eucera longicornis) (see here as well) that use the soft rock cliffs for nest sites and forage from the wild peas and vetches that flourish in this environment. The area is also a stronghold for the cirl bunting and I often see and hear these rare birds when I visit. If I am lucky, I may also see seals swimming nearby or basking on the rocks at Peartree Point .
Earlier this year, in April, I walked along this section of the coast path and was alarmed at what I found. The long curving coastal meadow, filled with wildflowers later in the year, was intact but outside of this area there was considerable evidence of herbicide use. Some fields to the east of the meadow and the paths around them had been drenched with herbicide prior to planting new crops. The chemicals had reached the hedges that line the sides of the coast path and the area looked barren and dried out (picture below). To the west, where the coast path runs between the cliff edge and arable fields, there had been spot spraying of “weeds”. It looked as though attempts were being made to eliminate wildflowers alongside areas where crops are grown.
Wildflowers are very important for supporting the insects and, indirectly, the birds that flourish here and I was concerned by this apparent degradation of the site. I decided to make several visits across the summer to see how the site recovered and how the insects fared.
My first visit was in late May and I found good numbers of male long-horned bees in the coastal meadow, foraging mainly on bush vetch. This flower scrambles through the bracken that lines the cliff edge of the meadow. With its slightly untidy looking flowers that start a deep purple but open to pale lilac petals, bush vetch provides excellent early forage (picture below). The long-horned males looked very fresh with their yellow face, bright russet thorax, shiny black abdomen, legs coated with fine hairs and their trademark very long, shiny, black antennae. They are such iconic, beautiful creatures and it was a pleasure to see them moving swiftly about the site between flowers. I also went to look at the nest area in the soft rock cliffs below the meadow where the vertical, reddish surface is peppered with pencil-sized holes. Males appeared here regularly looking about the site for females. They arrived and performed a meandering flight across the nest area, sometimes repeating this before flying off. There was some play-fighting and a few overexcited males got tired of waiting and tried to mate with their male cousins.
The coastal meadow looked glorious. A dense coating of knee-high grasses grew across the site lending it a sheen of pale browns, greens and muted reds. Many flowers grew among the grasses in addition to the bush vetch, including buttercup, catsear, common vetch, speedwell, hop trefoil, wild carrot and along the cliff edge to the western end, bird’s foot trefoil, thrift and bloody cranesbill, a rich kaleidoscope of colours . For the most part, herbicide-treated areas outside the meadow had grown back although some flowers had been eliminated.
Female Eucera longicornis appeared in June and by the third week of the month they outnumbered males. One hot spot for females was a hedge along the sea side of the coast path where it skirted a field just to the east of the flowery meadow. Narrow-leaved everlasting pea grew here in moderate amounts, its bright pink flowers proving very attractive to the females. I watched them feeding from the flowers; they looked rather different from the males, their antennae were a more conventional length and they appeared chunkier with striking golden plumes of pollen-collecting hair on their back legs. When they arrived, they landed on the lip of the flower pushing the large sail-like upper petal backwards to access nectar. Narrow-leaved everlasting pea also grew through the cliff edge bracken in the coastal meadow and female long-horned bees were foraging there too. Although many other flowers were growing here including several large patches of the yellow scrambling meadow vetchling, the females showed an absolute preference for the wild pea. I also spent some time by the nest area watching a regular stream of females returning to their nest, some carrying large lumps of sticky pollen on their back legs. A few males hung about the nest site and others foraged from bush vetch in the meadow but they paid little attention to the females, all mated by now.
Although the coastal meadow was still looking outstanding with its rich fabric of grasses embroidered by so many wildflowers, the situation elsewhere on the site was not as encouraging. Wilting plants in several locations indicated more herbicide usage and the path along the coastal hedge mentioned earlier had been strimmed on the sea side and treated with herbicide again on the field side (more wilting plants, pictures below). To cap all of this, when I visited in the second week of July, cattle had been allowed into this area trashing the hedge and eating all the narrow leaved everlasting pea growing there. In previous years, this hedge and the wild pea that grows here have been critical for the survival of the female long-horned bees so this could have been catastrophic. Fortunately, this year large amounts of the wild pea with its bright pink flowers had grown up in the coastal meadow and many females were foraging there instead.
So, based simply on this year’s observations and the numbers I saw, the long-horned bees seem to be doing well at this south Devon site. The colony is moderate in size and numbers seem to be holding compared with observations made in previous years.
There has, though, been significant degradation of the local environment this year with loss of wildflowers following herbicide use and cattle damage to an extent I had not seen before. In order to support these rare bees and perhaps to increase the size and extent of the colony of long-horned bees, the numbers of wild flowers should be increasing along the length of the coast path rather than being restricted to the coastal meadow as currently seems to be happening. This degradation of the site surely runs counter to the legal protections associated with an SSSI?
Another concern at this site is the fate of the six banded nomad bee (Nomada sexfasciata), the UK’s rarest bee. This bee is a parasite of Eucera longicornis and in the UK is only known at this south Devon site. I last saw it in 2017 when I made several sightings. Since then, it has been seen by others on only one occasion each subsequent year so it is very rare. This year, I saw several Nomada species by the nest area in late June. One stayed for a short time but was definitely not Nomada sexfasciata and the others disappeared too quickly for verification. I believe there have been no other sightings this year.
The south Devon site needs support to protect the unique flora and fauna present there, especially the rare bees and other insects that live in this special habitat. Buglife and the South Devon Area of Outstanding Natural Beauty are developing a project termed Life on the Edge which aims to protect the site and increase the number of wildflowers. It is currently seeking funding so we have to hope it gets that support.
The state of the site across spring and summer
The featured image at the head of this post shows a male Eucera longicornis on bird’s foot trefoil in late May.
The Lockdown may be easing but with coronavirus still circulating and with little sensible guidance coming from central government, life is far from normal. So, I am continuing my Lockdown Exercise Walks and avoiding large gatherings where possible. In this eighth Walk, I want to take you to one of my favourite parts of the south Devon coast near Prawle Point, Devon’s southernmost headland.
The forecast for the coast was good so, towards the end of the third week of June, we headed off across the rolling hills of the South Hams towards Kingsbridge. The weather, though, seemed to be unaware of the forecast. Great slabs of grey cloud loomed ahead and there were clear signs of recent rain. I began to wonder if this trip were such a good idea but we pressed on, knowing how quixotic the Devon weather can be. At Kingsbridge we picked up the coast road turning right at the village of Frogmore across a watery inlet to follow four miles of narrow, winding lanes.
Not only are the lanes narrow here, they are enclosed by Devon hedges, creating a narrow corridor with steep banks. At this time of year, the banks are smothered with lush vegetation, mostly green but enlivened by splashes of white cow parsley, yellowing Alexanders and bright pink foxglove remnants. In just one spot, a large patch of rosebay willowherb coloured the bank coral pink as if paint had been spilt and when we stopped to let an oncoming car pass, a few spikes of purple tufted vetch cried out to be seen.
As we approached the village of East Prawle we passed the duckpond with its large clumps of chrome yellow monkey flower and parked by the village green. Hazel wanted a longer walk, whereas I wanted to spend time looking at flowers, so we agreed to meet later. I began by heading towards the coast down a steep road edged by rough stone walls. Fulsome clumps of red valerian clung to the stone, rain-remnant drops of water hanging from the flowers like tiny glass globes. The sun began to break through the cloud that had brought the rain, the water droplets sparkled like fairy lights and butterflies flickered among the flowers. Now and then, I glimpsed the coast spread out below and the sea, a uniform misty blue.
Near a row of coastguard cottages, I entered a narrow lane lined by green hedges coloured by more valerian, also honeysuckle and bramble. The lane turned sharp left to descend more steeply across slippery exposed bedrock and through scrub and woodland. A chiff chaff called and I stopped to gaze at the flowers and insects on a bank of bramble caught in the morning sunshine. Suddenly a woman appeared down a nearby path that joined the lane looking surprised to find me standing there.
“Are you alright?” she asked
“I’m just looking at the flowers” I replied, trying to reassure her.
“Yes, there are lots of flowers about. Have you seen the pink sweet peas on the coast, they don’t smell like the garden variety?” she continued.
“That’s narrow- leaved everlasting pea, a perennial wild form of the garden variety and coincidentally its pink flowers are part of the reason I’m here today, some rare bees feed from them” I replied.
“It’s so difficult to identify wild flowers from books” she worried.
“Yes, I sometimes leaf through the entire book to identify something I have seen.”
I told her I could wait if she wanted to go ahead down the lane so that we maintained physical distancing but she said there was no need as she was taking another path to the right and promptly disappeared.
Leaving the woodland, I passed between arable fields along another enclosed path with the sea now ahead of me. These fields occupy a gently sloping coastal plain stretching between steep inland cliffs with rocky outcrops and the present low cliffs above the sea. The steep inland cliffs give the area an enclosed, almost claustrophobic feeling whilst creating a gentle microclimate. Barley grows in these fields, spring sown so that its seed and stubble can be left after autumn harvest to provide winter food for the rare cirl buntings that now flourish here. As I walked, the distinctive rattle of one of the birds echoed around the inland cliffs. The barley was a soft, uniformly yellowish-green carpet so I assumed it had been well sprayed with herbicide.
When I reached the coast, I headed westwards along the coast path between the cliff edge and the barley field. The cliff edge was fringed with bracken and blackthorn, the latter providing good nest areas for the cirl buntings. Tall stems of hemp agrimony grew here along with a profusion of narrow-leaved everlasting pea scrambling through the bracken and the scrub, grabbing on with fine tendrils. Large, mostly pink, pea-type flowers (see picture at the head of this post) were scattered about the plants, not in large numbers but frequently enough to make an impact. The large upper petals, like bright pink sails decorated with fine green striations, stand out above the smaller lower petals that resemble miniature boxing gloves, with an unusual bluish-pink hue.
Silvery bees patrolled the area around the flowers weaving their way deftly and quickly among the vegetation and I wondered how they were able to navigate so easily. Sometimes they stopped to take nectar and from their very long black bootlace antennae I recognised these as male long-horned bees (Eucera longicornis). This part of the south Devon coast contains the largest UK colony of these very rare and very distinctive bees. The sun had now come out making it feel quite warm and I stayed by the flowers for a while. A few female long-horned bees soon appeared carrying large chunks of pollen so I presume they were coming to collect nectar. They share only a passing resemblance to their male counterparts: they have short antennae and are covered in thick pale hairs. They hang below the pink flowers holding their body in a tightly curved crescent as they feed and the flowers of narrow-leaved everlasting pea seem to be a very important pollen source for the insects.
I moved on through two latch gates to enter a narrow but long coastal meadow stretching between cliff tops fringed with bracken and scrub and the inland cliffs that tower above. The meadow hadn’t been cultivated or grazed and was thick with knee-length grasses and wild flowers. Grasshoppers rose as I walked and small brownish butterflies danced around me. This is a floral paradise, a mosaic of colour and form.
The predominant flowers at the beginning of the meadow were the white hemispheres of sea carrot rising like so many large mushrooms through the thick grass to dominate the landscape. There were also some of the nodding yellow heads of cat’s ear, popular with red-tailed bumblebees, and the pinkish-purple flowers of common vetch. Partially buried in the grass I noticed the small, bright pink flowers of centaury with their prominent yellow stamens. Narrow-leaved everlasting pea climbed through the cliff-edge bracken attracting more long-horned bees to its pink flowers, so I stopped to watch.
I dragged myself away and further on, a rough path took me down the low cliff to an area of soft rock riddled with small pencil-sized holes, thought to be the principal nest site of the long-horned bees. As I waited to see the insects returning to their nests, I was conscious of the sea grumbling around the rocks behind me and the patchwork of colours it held. The water was mostly a shimmering deep blue but with darker areas hiding submerged rocks and tinged green where it washed over shallow sand. My reverie was interrupted when the woman I met earlier appeared on the rocks around the cliff corner. She seemed keen to talk and I learnt that she lived in London but had come down to stay in her cottage when the lockdown was imposed.
I scrambled back up to the coast path and as I walked westwards in the direction of Prawle Point, the floral mix in the meadow changed. Cat’s ear now dominated lending the meadow a yellow cast. Along the cliff edge, the bracken had been replaced by tracts of yellow bird’s foot trefoil and purple tufted vetch. I also noticed lady’s bedstraw and hedge bedstraw and the bright reddish-purple flowers of bloody cranesbill. This kaleidoscope of colour brought more bumblebees and solitary bees although I thought the vetches looked past their best, perhaps a result of the dry spring.
Hazel appeared, having finished her walk and we made our way back up to East Prawle starting along a field-edge wall where brambles and other wildflowers grew. Cirl buntings sang and, in the sunshine, a male long-horned bee fed from one of the flowers, butterflies danced together and a fine mason wasp collected nectar.
It’s been a good summer. We’ve had some fine weather and I’ve been able to spend time on a beautiful part of the south Devon coast looking for the long-horned bee (Eucera longicornis). It’s one of my favourite insects and one of our rarest bees and there is a strong colony on the coast between Prawle Point and Start Point where low, soft-rock cliffs meander around headlands, in and out of rocky coves and along seaweed-covered beaches. I visited this area several times between May and July but my most interesting day was on June 23rd, just after the summer solstice.
It was breezy and warm but partly cloudy when I arrived at the coast. The sea was a uniform grey-blue although now and then the sun broke through the cloud, creating shimmering areas of white water. I started by following the coast path eastwards along the cliff top from Prawle Point. The sea-side of the path was fringed with scrub and rough grass along the cliff edge whereas the landward side was fenced and mostly used for arable farming. Many kinds of wild flower grew along both sides of the path including a few generous clumps of purple tufted vetch scrambling through the scrub. After about a mile of easy walking, the enclosed path reached a gate giving on to a broad, open area, not farmed for some years, as far as I know.
I was completely unprepared for the view that greeted me after I closed the gate. Here was a meadow where thousands of the small, dandelion-like flowers of cat’s ear moved with the breezes to create a mobile yellow canopy above the grass. Lower down were many tiny yellow globes of hop trefoil and bright pink semi-circles of common vetch. This is a paradise for insects and I saw many red-tailed bumblebee workers moving purposefully about the chrome-yellow flower heads.
But that wasn’t all: the area along the cliff edge was a kaleidoscope of purples, yellows and pinks, mostly flowering legumes such as bush, kidney and tufted vetches, bird’s foot trefoil and meadow vetchling, restharrow and narrow-leaved everlasting pea. The number and variety of flowers was greater than I can remember from previous years, perhaps the warm spring had suited the legumes.
The range of flowers, especially the legumes is ideal for the long-horned bee. I had seen one or two males back along the enclosed path and now I saw several more, also nectaring on the curving, purple, tubular florets of tufted vetch. There is something other-worldly, almost primeval about these insects with their yellow mask-like face, orange-chestnut hair (in fresh insects) and their impressively long antennae, resembling stiff black bootlaces and about the same length as rest of their bodies. They are particularly striking in flight, antennae held so that the bee can negotiate whatever obstacle it meets; controlling those antennae must involve some impressive micro-engineering. There were also females about feeding on lemon yellow pea-like flowers of meadow vetchling. Chunkier than the males, they have shorter antennae and, on their back legs, generous pollen brushes resembling golden harem pants.
I scrambled down a rough track to the main Eucera nest area, a section of reddish, soft-rock cliff, pock-marked with hundreds of pencil-sized holes. Behind me the sea soughed rhythmically on nearby rocks and an oystercatcher sang its plangent song. Female Eucera arrived at the nest site bringing pollen and nectar to provision their nests but they were not alone and I saw several other bee species that seemed to be using the nest area.
One species I had hoped to see was the very rare Nomada, and I had nearly given up hope when the bee suddenly appeared; I was so surprised, I nearly fell backwards off the rocks. Like others of its kind, it is wasp-like, with a yellow and black-banded abdomen and orange legs and antennae. It was the pattern of the bands, six yellow bands on a black body that told me that this was Nomada sexfasciata, the six-banded nomad bee, one of Britain’s rarest bees. This site on the south Devon coast is the only place where it is found in the UK; it is nationally endangered so it was very exciting to see it.
It moved about the nest area furtively as if trying not to be noticed and after looking in to a few of the holes it moved on. Later that day I had more sightings of the Nomada; whether it was the same bee or several I cannot say. As a nomad, the bee has no nest of its own but lays its eggs in the nest of another bee, in this case the long-horned bee. The Nomada eggs develop into larvae and take over the nest, killing the host larvae and eating their pollen store. It depends for its survival on a strong Eucera colony and this one in south Devon is one of the largest in the UK.
Long-horned bees and their Nomada used to be found widely across the southern part of Britain in the early 20th century. They favour a range of habitats such as coastal soft rock cliffs, hay meadows and woodland rides for nest sites and require unimproved flowery grassland for feeding, being especially dependent on flowering legumes for their pollen sources. With agricultural intensification leading to a loss of habitat, especially flowers, these bees have been squeezed out and are now confined to a very few sites.
It’s not difficult to see how they could be supported. At the south Devon site, all that is required is to ensure a consistent source of flowering legumes along the coast, the soft rock cliffs already provide the nest sites. I recently met Catherine Mitson who is working with Buglife on a project to support the south Devon colony of Eucera longicornis and Nomada sexfasciata by increasing the number of flowers. Catherine is very enthusiastic and I have great hopes now for the survival of both the long-horned bee and its nomad.
The featured image at the top of this post is a male long-horned bee on bird’s foot trefoil (May 23rd 2017)