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The southern cliffs of Gower continue the Carboniferous Limestone and its delights.
William Condry, The Natural History of Wales
CLIFFS ARE ONE of the most natural habitats on earth and contribute more to the variety of wildlife in an area than their surface coverage would indicate. Despite some areas being heavily quarried in the past, the south Gower coast is one of the classic British botanical localities, having many species that are nationally rare – and these are sometimes abundant. As with other areas of high plant diversity this richness results from a combination of geology, climate and history. Limestone cliffs typically support large numbers of scarce plants and, as described earlier, the Gower climate is characterised by mild winters, cool summers and a prolonged growing season. It is also one of the strengths of the southern coast that so much of it consists of a broad belt of semi-natural vegetation, unlike a great deal of Britain where coastal habitats have been ploughed and reseeded right up to the cliff edge. The south-facing cliffs, which at their highest are some 70 metres above sea level, rather than being vertical for the whole of their length, contain many areas that slope gently from the cliff top to the sea (Fig. 39). The slope is often quite gradual, with the cliff tops being cut by the slades and lying some way inland, but there are some remarkable features along the coastline such as the Knave, a conical rock that dominates the inlet to the west of Paviland (Fig. 40).
At the base of the main cliffs, which are for the most relict features, lie the present-day undercliffs. As described in Chapter 3, many of these are made of soft rock, formed by wave action on concreted material that has accumulated from the weathering Carboniferous Limestone above and blown sand from the sea. These areas of soft rock are rich in invertebrates, and their insect communities, like the botany, are of national importance.
FIG 39. Looking east along the south Gower cliffs from Tears Point. (Harold Grenfell)
Royal Commission on the Ancient and Historical Monuments of Wales for Figures
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FIG 40. An aerial view of the remarkable conical rock known as the Knave. (Peter R. Douglas-Jones)
Royal Commission on the Ancient and Historical Monuments of Wales for Figures
The coastline is particularly noted for the range of habitats that occur, from intertidal rocks and the exposed maritime grasslands in the west, to blackthorn Prunus spinosa and hazel scrub within the more sheltered valleys in the east. In addition there is an interesting mosaic of habitats on the cliffs, the gentler slopes being covered by acidic soils while the limestone outcrops, containing crevice, ledge and scree communities, are surrounded by dry grassland which grades into neutral grassland and then into acid heath vegetation, often within a few metres of the outcrop. In comparison to other areas of coastal limestone, however, the maritime influence on the cliff vegetation is quite limited, due to the very high relict cliffs and the presence of extensive rocky beaches at the base of the cliffs that act as wave breaks. The large tidal range also reduces the amount of thrown spray reaching the cliffs, as the waves obviously break well away from the cliffs when the tide is out. The least maritime communities are the gorse and limestone heaths, acid grasslands, bracken and bramble, and the blackthorn scrub of the inland part of the cliffs.
Salt-tolerant plants on the lower part of the cliffs typically include spring squill Scillia verna, golden samphire Inula crithmoides (Fig. 41), rock sea lavender Limonium procerum, buck’s horn plantain Plantago coronopus, thrift Armeria maritima, sea campion, scurvygrass Cochlearia officinalis, sea beet Beta vulgaris ssp. maritima and the only maritime fern, sea spleenwort Asplenum marinum. Sea spleenwort rarely grows far beyond the immediate spray zone and the most luxuriant plants only occur on the lower parts of the most exposed cliffs. In Gower it occurs in small numbers in crevices, overhangs and caves and is rather sparsely scattered along the coast. The saltwater spray it receives is important since it allows the fern to benefit from the winter warmth brought by wave-splash, the sea acting as a giant radiator that warms and cools very slowly, minimising the occurrence of frost to which sea spleenwort is extremely susceptible.
There have been few descriptions of the lichen flora of Carboniferous Limestone in Britain, so it is worth describing the situation on the Gower cliffs in some detail. The communities appear to be rather species-poor, with many western species absent. Well-illuminated limestone on the vertical faces of the cliffs is typically dominated by small crustose lichens that form small-scale mosaics, including Xanthoria aureola, Ramalina siliquosa and the orange crustose lichens of the genus Caloplaca (Fig. 42). One species, C. granulosa, although frequently found in Gower, is extremely rare in the rest of Britain. On damp surfaces, with a slight to moderate degree of shading, these lichens are largely replaced by species such as Acrocordia conoidea, Dermatocarpon miniatum and in some areas the rarely recorded Leptogium diffractum. Despite the standard outcrops of rock having a relatively limited species diversity, a wider range of species exists in microhabitats, such as underhangs. Underhangs not receiving direct rain, for instance, are well colonised by a thick white form of Direina massiliensis f. sorediata, the thalus of which contains copious amounts of calcium oxalate. Associated species include Caloplaca ochracea, Diploicia canescens and the small dispersed thalli of Placynthium garovaglii.
FIG 41. Golden samphire, a plant of the spray zone. (David Painter)
Peter R. Douglas-Jones for Figures
Where soil has formed and filled the crevices in the rock, grasses and mosses such as tuberous pocket-moss Fissidens taxifolius and rock pocket-moss F. dubius are able to exist and begin to dominate the flora, together with a wide range of liverworts, such as Riccia sorocarpa. One species of lichen, however, Squamarina cartilaginea, is able to compete with these plants and grows out of the crevices and onto the adjacent surface, but in general this ‘terricolous’ lichen flora is poorly developed compared to sites elsewhere in Britain. The most diverse and interesting assemblages are associated with north-facing habitats.
On apparently bare areas of the rock are pinhole-sized pits, thin light-grey crusts and small black or yellow fruiting bodies which belong to a large number of endolithic (within stone) lichens that grow just beneath the rock surface. Not much is known about these specialised organisms and few of the current books on lichens even mention them. Studies into the process of rock penetration, however, involving isolation and growth of the organisms involved and the microscopic examination of rock surfaces, are slowly producing a better understanding of these fascinating communities. A proper survey of all the lichens on the cliffs is in fact long overdue, given that elsewhere many coastal lichen communities have been shown to be nationally important.
Although sea cliffs are a harsh environment for plants it seems that the species found on them, while not growing under ideal conditions, are able to tolerate a situation that is too severe for plants capable of growing on similar cliffs inland. Woody plants growing on the sloping sections of cliffs, such as juniper Juniperus communis, are often stunted and deformed, have slow growth rates and may be very old. Juniper is one of the most striking late-glacial relict species in Gower and is found mainly in sites that are protected from cliff fires, as it cannot regenerate after being burnt In contrast the competing gorse can regenerate and therefore tends to replace it, as happened at Seven Slades after a fire in 1965.
FIG 42. The lichens Xanthoria aureola and Ramalina siliquosa on the cliff face. (Margaret Hodge)
David Painter for Figures
Other important plants to be found on the cliffs include nit-grass Gastridium ventricosum, purple gromwell Lithospermum purpureocaeruleum, white horehound Marrubium vulgare and wild asparagus Asparagus prostratus. Wild asparagus is confined to the coasts of western Europe and it is a rare and decreasing species with many colonies being of only one sex. There are probably less than 50 plants in Gower, although it can also be a very difficult species to see amongst other vegetation. The two best times to survey are in May–June before other vegetation grows up, and in autumn when the berries ripen and senescent plants appear yellow. Given its rarity, plants should not be collected. Since the population is so small it is thought that the species may be susceptible to genetic deterioration, through genetic drift and inbreeding. It has been suggested that the gene pool should be supplemented by introducing individual plants from other sites to counteract this. It is difficult to know, however, exactly how many individuals there are in a population as some clumps may be composed of more than one individual (as shown by some patches with plants of different sexes). Isolated fronds may be distinct plants or belong to an adjacent clump. The rhizomes of some large plants may also fragment, giving the appearance of more than one plant.
The first Gower record of wild asparagus was from Culver Hole in 1821 and this appears subsequently to have been the best-known site. It is likely that the population has been significantly reduced historically by collecting, and in 2001 only four plants remained. In 1904 H. J. Riddelsdell found a second group on cliffs in Oxwich Bay, but the exact location is unknown. There were no further records for Oxwich until plants were rediscovered in 1989. Two discrete populations are now recognised, the first on windblown sand on low cliffs and the second, found during a National Trust survey in 1996, on limestone cliffs. This second population may be Riddelsdell’s original group. Dillwyn (1840) also reported wild asparagus ‘on the Wormshead, and several other cliffs in Gower’, and there was a record for ‘sands of Broughton Bay near Whiteford Burrows’ by H. J. Riddelsdell, but it no longer exists at these sites.
The absence of a number of the common species of limestone grassland is remarkable, with tor-grass Brachypodium pinnatum, dwarf thistle Cirsium acaule, upright brome Bromopsis erecta and meadow oat-grass Helictotrichon pratense all absent from the peninsula. Another common species thought to be absent, dropwort Filipendula vulgaris, has recently been discovered at an isolated location on Oxwich Point. Downy oat-grass Helictotrichon pubescens is abundant, while tree-mallow Lavatera arborea grows on the cliffs between Mewslade and Fall Bay. This is a robust biennial up to a metre in height, with purplish flowers.
Several uncommon limestone species are relatively abundant in Gower, including hoary rock-rose, bloody crane’s-bill Geranium sanguineum and spring cinquefoil Potentilla neumanniana. A number of species, such as basil thyme Clinopodium acinos and horseshoe vetch Hippocrepis comosa, approach the western limits of their range in the peninsula. The horseshoe vetch in Gower is the scarce late-glacial relic diploid, found only in scattered refuge sites in the west (like goldilocks aster and hoary rock-rose), not the later-arriving tetraploid of English chalkland. Other rare plant species in Gower that occur at a number of widely separated sites on the limestones of western Britain include the small restharrow, which also grows at one site on the Pembrokeshire limestone, in Devon on the Torbay limestone, and in the Channel Islands on Guernsey and Alderney. The hoary rock-rose (Fig. 43) is recorded from Gower, Pembrokeshire, North Wales, the west of Ireland and at two localities in northern England. Many of the species of open habitats which have distributions of this type, and which are in many cases limited to a few favourable naturally open refuge sites on basic soil, were more widely spread in the late and early postglacial periods when the climate was relatively warm and open base-rich habitats were common after the retreat of the glaciers and before the spread of the forests. Progressive acidification of the soil, the spread of woodland and the increasingly maritime climate in Britain after the formation of the English Channel have all contributed to the reduction in the range of the species to their present refuge sites, of which the Gower cliffs are an excellent example.
FIG 43. Hoary rock-rose, a rare plant with a discontinuous distribution on the limestone of western Britain. (David Painter)
the Estate of Evan Evans for Figure
Areas of limestone heath are dominated by gorse, sometimes with bell heather Erica cinerea or bracken, and contain a large number of associated calcicole and calcifuge species in an intimate mixture. Gorse (Fig. 44) is one of the most highly structured plants, the tight cluster of rigid stems forming an ideal framework for web-spinning spiders such as Theridion sisphium. While gorse bushes usually occur as a more or less complete cover, the more open forms of heath in which it occurs as a mosaic with patches of grassland are probably a response to grazing. Anthills are common and support a different flora in which wild thyme Thymus polytrichus and common rock-rose Helianthemum nummularium are abundant. The most frequent species associated with gorse are ribwort plantain Plantago lanceolata, common dog-violet Viola riviniana, glaucous sedge Carex flacca, salad burnet Sanguisorba officinalis ssp. minor, cat’s-ear Hypochoeris radicata and red fescue.
Away from the typical thin limestone soils, in places where glacial drift deposits have accumulated and there are thicker, more acid soils, the flora is dominated by bracken or purple moor-grass Molinea caerulea, with bramble and sometimes common and western gorse Ulex gallii. Some of the most frequent associates are Yorkshire-fog Holcus lanatus, sweet vernal-grass Anthoxanthum odoratum, tormentil Potentilla erecta and wood sage Teucrium scorodonia. This community is often subject to fire.
FIG 44. Gorse and fox cub in Mewslade Valley. (Harold Grenfell)
the author for Figures
FIG 45. Wall cotoneaster on Mumbles Hill Local Nature Reserve, a serious threat to flowers of the limestone. (Harold Grenfell)
Various species of non-native cotoneaster have become naturalised along the coast. It is likely to become an increasing problem in Gower as there are now some 80 species being cultivated for their ornamental fruits, all of which are very attractive to birds, which eat the fruits and then excrete the seeds, often some distance away from the original plant. Cotoneaster is also planted extensively as part of landscaping schemes in urban Swansea. On Pennard cliffs, a particularly species-rich area of cliffs where many rare native plants grow, entire-leaved cotoneaster Cotoneaster integrifolius, Diels’ cotoneaster C. dielsianus, Himalayan cotoneaster C. simonsii and wall cotoneaster C. horizontalis have all established themselves and are spreading, having invaded the cliffs either from nearby gardens or from already-established populations elsewhere. The same species also occur on Mumbles Hill, a Local Nature Reserve, and at one time the reserve was covered with a deep cotoneaster scrub (Fig. 45). This was scraped off with a bulldozer and burnt in order to allow the limestone grassland to recover, but it will be a continuing task to keep it clear as it will grow back from the smallest remnant. The plants are also well established on the steep slopes of the hill, where management is impossible. As elsewhere in Gower, on Mumbles Hill there is an interesting distinction between the limestone grassland on the summit with autumn gentian Gentianella amarella and autumn ladies tresses Spiranthes spiralis and the maritime heathland growing on the lower slopes on pockets of windblown soil. Autumn ladies tresses also frequently occur on the short grassland that is cut regularly for amenity purposes on the more urban areas of the coast around Mumbles and Langland. Unfortunately this grass is often mown just as the plants are coming into flower.
The cliffs between Thurba and Deborah’s Hole are a stronghold for yellow whitlowgrass, an attractive alpine flower which occurs nowhere else in Britain and which is now the ‘county flower’ of Glamorgan (Fig. 46). In 2002 Plantlife, the plant conservation charity, launched a campaign which it hoped would lead to each county in the United Kingdom adopting its own wildflower emblem. For Glamorgan the original voting list in 2002 included fen orchid Liparis loeselii, dandelion Taraxacum sect., yellow whitlowgrass, dune gentian Gentianella uliginosa, sea stock Matthiola sinuata and monk’s-hood Aconitum napellus. The top two flowers from this round were yellow whitlowgrass and dandelion and the final vote, announced on 5 May 2004, confirmed whitlowgrass as the chosen species. The whitlowgrass family gets its name because the plants in question were alleged to cure ‘whitlows’, a painful inflammation of the finger or toe, especially near the nail.
Yellow whitlowgrass is locally common in narrow crevices on the upper cliffs between Pwlldu Head and Rhossili. The plant is, however, widely distributed in continental Europe, where it extends from the Pyrenees through the Alps to the Carpathians. It has been claimed that the Gower populations are very different from those in continental Europe and that it is therefore native to Britain. Molecular studies indeed show that the Gower population is genetically distant from any single European population and it seems most likely that it is again a late-glacial remnant, which passed through a bottleneck of small population size before subsequent diversification within the isolated relict area. Yellow whitlowgrass is a variable species, however, and most of the varieties appear to grade into one another geographically and morphologically.
FIG 46. Yellow whitlowgrass, the ‘county flower’ of Glamorgan, near Overton. (Harold Grenfell)
The plant was not discovered in Gower until the late eighteenth century. Its comparatively late discovery is probably due to its extremely early flowering season, inaccessible habitat and restriction to one small area in a little-visited part of the country. It was first reported by William Turton in 1803 ‘growing wild abundantly on walls and rocks around Pennard Castle’, but was actually discovered by John Lucas in 1795 ‘near Worm’s Head’. Dillwyn’s Contributions Towards a History of Swansea, published in 1840, includes the following account of yellow whitlowgrass in ‘An alphabetical account of the rarer flowering plants and ferns which have been found within twenty miles of Swansea’:
Draba aizoides was first noticed on the walls of Pennard Castle, by the late Mr. Lucas, of Stouthall, who communicated his discovery to Dr. Coyte, of Ipswich, and it was the Doctor’s fault, as he admitted to me, that the merit of this interesting discovery was withheld from Mr. Lucas. The plant was afterwards shown by Mr. Lucas to Dr. Turton, and the latter sent the specimen to Sowerby which has been figured in English Botany. It grows also on most of the higher cliffs, and in many inaccessible places along the coast from Pennard to Wormshead.
While correct details of the distribution of yellow whitlowgrass in Gower were given by Dillwyn and to a lesser extent by John Gutch the following year, later botanists often knew only of the Pennard Castle locality (Fig. 47). Although the castle is constructed of Old Red Sandstone the whitlowgrass grows in crevices in the lime-rich mortar. For many years this was seen as the classic location and the early floras, following the descriptions of Turton and Gutch, gave its locality as ‘Pennard Castle and rocks near’ as though this was its sole location, which is simply not true. Such misinformation did protect the plant, however, as it resulted in collectors missing some of the best sites. Edwin Lees, for example, an astute amateur botanist from Worcester, wrote in The Botanical Looker-Out in 1842:
The yellow Draba aizoides is now (March) in flower on its only known habitat in Britain, the deserted walls of the secluded fortalice of Pennard castle. Its singular aspect there will be noticed more in detail under the month of September at which time in 1839 I visited the spot. As it is an early flowerer it is an acquisition to any rockwork.
FIG 47. Pennard Castle, the classic site for yellow whitlowgrass. (Harold Grenfell)
Yellow whitlowgrass belongs to the Cruciferae and the bright yellow flowers, which in some years may appear as early as the first week of March, have four free petals in the shape of a cross. It flowers freely in Gower, with about 90 per cent of plants flowering in any one year, and the potential for the population to expand is high. The fruits, however, which are set by the end of April, are often grazed heavily by snails, particularly brown-lipped snail Cepaea nemoralis and common snail Helix aspersa. In the more sheltered sites the snails can destroy the majority of the developing fruits before the seeds have matured, along with many flowers. When not damaged by snails the flowers can produce copious quantities of nectar and are open at a time of year when the only competing species for insect pollinators is gorse. Insects collected from whitlowgrass flowers near Overton in 1969 included the blowfly Calliphora erythrocephala, the hoverfly Eristalis aeneus, white-tailed bumblebee Bombus lucorum, red-shanked bumblebee B. ruderarius and early mining bee Andrena haemorrhoa.
Most of the plants grow in deep crevices in the limestone cliffs, forming cushions of compact leaf rosettes, although young specimens are often found in turf on thin soil around and below the primary cliff habitat. Their density is largely determined by the availability of suitable crevice sites and is commonly 1 to 5 plants per square metre. The species cannot regenerate from detached rosettes, because it cannot form adventitious roots and has no dormant buds. It also appears to be difficult for a seedling to survive for more than a few months near a well-established plant, but when an older plant dies it may be replaced by the growth of nearby seedlings surviving from the previous autumn. The light seeds are only spread a few metres from the parent plant and wider dispersal appears difficult. Yellow whitlowgrass is, for example, usually absent from apparently suitable habitats in former limestone quarries which have not been worked since the late nineteenth century, and the only walls it grows on are those of Pennard Castle.
Since 1987 whitlowgrass on the coast between Rhossili and Mewslade has been monitored on a regular basis. Its overall distribution has remained stable, but the counts have shown that there has been a slight decline, mainly of plants within easy reach of sheep, or of enthusiastic gardeners and collectors. On Pennard Castle there has been a 25 per cent decline since the early 1980s, with plants disappearing from the lower section of the walls. But there is no problem in growing it from seed, as it produces copious amounts and is self-fertile. Indeed it is better to grow native whitlowgrass than the imported continental material available from suppliers of alpine plants.
Yellow whitlowgrass is usually associated with a restricted plant community that includes three grasses, red fescue, sheep’s-fescue Festuca ovina and cock’s-foot Dactylis glomerata, together with greater knapweed Centaurea scabiosa, salad burnet, Portland spurge Euphorbia portlandica, wild carrot Daucus carota, small scabious Scabiosa columbaria and wild thyme. This restriction to a narrow habitat and plant community is striking in view of the wide range of habitats that occur adjacent to the current populations.
Despite the rich list of plants the first sight of the cliffs can be extremely disappointing. Grazing pressure from sheep along most of the south coast, especially the western end, is very high and as a consequence in places the turf is extremely short and many of the flowers eaten before they set seed (Fig. 48). In fact at the western end of the coast there is almost a total lack of flowers, despite the very high number of plant species present in the close-cropped grassland. The absence of flowers means that there are no pollen or nectar sources for the invertebrates. A reduction in grazing pressure would, in theory, help the conservation of the fauna enormously. Allowing higher vegetation to develop and more plants to flower would connect currently isolated sites, as more mobile species, such as bees and wasps, would forage more widely and have the opportunity to colonise new nesting areas. There is a clear gradient along the coast, ranging from cliffs dominated by long ungrazed scrub and bracken at the eastern end to severely overgrazed cliffs at the western end. Current sheep numbers are about three times higher than in 1866 if the data from parish returns are to be believed. Information drawn from the Rhossili Agricultural Returns suggests that sheep stocking levels dropped during the Second World War, but then increased rapidly to almost five times the number of grazing livestock units by 1984. This change reflects the improvement of grassland due to application of inorganic fertiliser.
In some areas the species composition resembles semi-improved grassland due to recreational pressure and proximity to improved pastures. This is particularly noticeable along the coast near Worms Head, where the effect is intensified by sheep lying up at night, which leads to localised heavy dunging in sheltered places. This issue of ‘agricultural eutrophication’ on the south Gower coast was the subject of a detailed study (Etherington and Clark, 1987) which focused on the stretch of cliff from Worms Head to Port-Eynon, part of which is common land. The conclusion was that since 1935 there had been a reduction in cover and abundance of prostrate species such as wild thyme, common bird’s-foot-trefoil Lotus corniculatus, squinancywort Asperula cynanchica, common rock-rose and the rare hoary rock-rose, and an increase in agricultural weeds and perennial rye-grass. The increase in rye-grass is particularly dramatic as it was not present in 1935, but it is now a common component of the grassland. The deterioration of the botanical interest is due to an increase in the number of sheep grazing on the clifftop commons, coupled with the application of fertilisers to adjacent fields and certain areas of the grassland. These practices have led to an unparalleled increase in plant nutrients, both from inorganic fertilisers and from sheep urine and dung. The species that have declined cannot tolerate competition from tall, fast-growing species, which are favoured by the high nutrient levels.
FIG 48. Sheep grazing on the Gower cliffs. Overgrazing of these slopes is a serious conservation issue. (David Painter)
Agricultural intensification east of Mewslade has long been of concern to conservation organisations, and several recent studies have been directed towards obtaining a clearer understanding of processes (Etherington and Clark, 1987; Dawson, 1989). Reseeding of clifftop grasslands and subsequent fertiliser applications have caused noticeable changes in semi-natural communities in many areas and there have been many negotiations with the graziers directed towards reducing these impacts. Such eutrophication is far less obvious within the National Nature Reserve and the places where it does occur are usually close to the areas used for stock feeding. Elsewhere, grazing continues to exert an impact by modifying the flora of the limestone grassland (bloody crane’s-bill and greater knapweed are particularly sensitive to grazing) and by preventing a succession to gorse scrub in the more sheltered areas. In contrast Horton Cliffs and Slade Cliffs have valuable patches of limestone grassland, but parts of these are becoming scrubbed over, or are heavily grazed by horses and cattle, while at Slade Cliffs part of the common is regularly spread with manure. Cattle grazing is, however, a traditional form of management on the cliffs at Horton.
It is clear therefore that the cliffs are an unstable mixture of grassland, heathland and scrub that is maintained by a combination of grazing, burning and a harsh maritime climate. Relaxation of grazing is unlikely to lead to the succession proceeding beyond coastal scrub, but this would result in the loss of most of the grasslands except where these are located in an exposed position. It is likely that some communities of the lower cliff, such as the steeply sloping limestone grasslands, could be wholly maintained by existing physical and chemical factors due to their open and exposed character. Scrub communities on parts of the coast around Oxwich Point, for example, may have already reached a climax due to the effects of strong winds and salt spray, but there is likely to be scope for considerably more scrub development especially in areas such as Mewslade.
A recent survey of the area recommended that a comprehensive grazing plan should be developed in order to conserve the plants and insects of this very rich coastline. It has been difficult for the three conservation organisations that jointly own and manage the area, the National Trust, the Wildlife Trust and the Countryside Council for Wales, to tackle the issue because the situation is complicated by the land ownership. The most degraded areas are registered common land and are grazed by sheep owned by local commoners. There was an attempt in the early 1990s to address this issue through a trial reduction in grazing levels and it was hoped that lower overall stocking rates would provide sufficient herbage for the sheep, so that they would be less likely to graze the vegetation on the cliffs, but sadly the initiative did not get very far. In 1996, however, the Wildlife Trust bought back the agricultural rights associated with their property at Overton. Elsewhere in Gower the common rights must be strenuously protected, but given the seemingly insuperable problems here the removal of rights would, at least, restore the cliffs to their rightful glory. A reduction in overall livestock numbers, as a result of the reform of the Common Agricultural Policy since farmers are no longer being paid subsidies on the basis of the number of animals that they own, might, however, render this approach unnecessary.
Historically areas of gorse were burnt by the farmers who grazed sheep on the cliffs, as a means of promoting fresh, palatable growth and controlling scrub invasion. This burning still takes place during the winter months, but burns also occur in the dry summer months. Such events control the advance of scrub, and well-developed scrub communities are found only in situations that are well protected from fire such as old quarries or areas of scree. A severe burn can destroy the humus-rich topsoil together with all the microorganisms within it, leaving a sterile subsoil. The bare soil is susceptible to wind erosion, leading to the exposure of bulb and root systems and ultimately to the exposure of the limestone bedrock beneath.
Where areas of cliff vegetation burn the open exposed ground is colonised by a temporary but typical community of plants, scarlet pimpernel Anagallis arvensis, which often shows variable flower colours, cut-leaved crane’s-bill Geranium dissectum, Yorkshire-fog, ox-eye daisy Leucanthemum vulgare and spring cinquefoil. The fire also activates the seeds of the gorse and these species then disappear as the gorse reinvades the area. A survey of nit-grass carried out in 1985 noted a positive association between the density of the species and previously burnt gorse stands (John, 1992). Effects on invertebrates are unknown, but such information as is currently available suggests that the size of the burn is an important factor regarding speed of recolonisation.
The mild climate and the wide variety of habitats combine to produce ideal conditions for invertebrates, and the peninsula’s soft coastal cliffs have been known as a key location for bees, wasps and ants for many years. More than any other group of invertebrates they are under threat nationally due to the precise habitat requirements of many of the species, which make them very sensitive to environmental changes, and to the low population levels at which they normally occur. The ecological and economic importance of these insect communities cannot be overemphasised. The decline of bees, wasps and ants in the countryside is a reliable indicator of profound environmental poverty as they are a ‘key piece in the environmental jigsaw and as they decline or become extinct at local or national levels so does a myriad of other organisms’ (Fowles, 1996). It is therefore extremely important to conserve areas, such as Gower, that hold rich invertebrate faunas. Many nationally rare species occur in the peninsula, as well as many others that are extremely scarce in Wales. At the time of writing the Countryside Council for Wales and Liverpool Museum are about to complete a three-year study of the invertebrates of soft cliffs throughout Wales, ending with selected sites in Gower. More information may therefore be forthcoming in the near future.
The low cliffs of ‘head’ deposits from the last ice age are a noticeable feature of the coastline between Rhossili and Oxwich and occur less frequently from Pennard Burrows to Mumbles Head, where they tend to support more scrubby vegetation. The importance of the cliffs for insects relates to their capacity to provide a continuous supply of microhabitats rarely found elsewhere. The regular erosion of the crumbly soils creates areas of bare ground and maintains pioneer plant communities which can include large numbers of plants such as bird’s-foot-trefoil, horseshoe vetch, kidney vetch Anthyllis vulneraria and hogweed Heracleum sphondylium. All these provide rich food sources for bees and wasps during the flight period and support large communities of plant-eating insects such as weevils. The bare areas supply nesting areas for bees and wasps and suitable hunting areas for ground beetles and spiders while seepages and pools provide the wet mud required by some species for nest building and refuges for insects with an aquatic stage in their life cycle such as craneflies. For instance the cranefly Dicranomyia goritiensis is known from coastal cliff seepages at Longhole Cliff. It has been agricultural policy in the past to bring as much land as possible into use and as a result the natural vegetation has in places been squashed into a narrow coastal belt. A small number of clifftop fields have therefore been included within a Tir Cymen agri-environment agreement and are managed as fallow or spring cereal and stubbles as an experiment to see if it is possible to increase the abundance and diversity of nectar sources in the vicinity of the soft cliffs.
Elsewhere in Gower there are few similar habitats, except for the west-facing solifluction terrace, 2 kilometres long, at the base of Rhossili Down. Despite its length it may be of less interest for insects, certainly in the southern part where the soft cliffs are mostly vegetated and stable and extremely heavily grazed by sheep. North of the Old Rectory, however, there is a rich leguminous sward, which is likely to support a varied invertebrate fauna, but this may be more similar to that of Llangennith Burrows than the typical Gower soft cliffs. The seepages and streams here provide a sharp contrast to the conditions on the south coast.
Some of the earliest invertebrate records are from Horton and concern the mining bees Andrena rosae and Andrena marginata noted in 1914 by Hallett, together with a nationally scarce ‘nomad’ cuckoo bee Nomada flavopicta. Andrena rosae nests in bare ground on light soils, including well-used paths, and possibly shares a communal nest entrance to its burrow with other females, as closely related species do. Its life history has not been studied in Britain and it is still unclear, for instance, which plant species are visited for pollen. The summer brood probably collects umbellifer pollen, but the spring brood might use a variety of early flowering plants. First-brood adults are on the wing between late March and the end of May, whilst the summer brood appears between mid-July and early September. The bee was found again at Horton Cliff in March 2002, by P. M. Pavett from Cardiff Museum, but to date there have been no other records. Nomad bees, such as Nomada flavopicta, are wasp-like bees that are parasites of various mining bees; they do not actually feed on their hosts, but merely take the food that was intended for the host larvae. Like other cuckoo bees they have no pollen-collecting equipment.
More intensive surveys at Horton over recent years have shown that it continues to support a nationally important community of bees, including a nomad cuckoo bee Nomada fucata at one of its few locations in Glamorgan and long-horned eucera Eucera longicornis. There are also large colonies of long-horned eucera at the Sands and Fall Bay, with smaller populations scattered elsewhere. The south Gower coast may therefore be one of the most important British localities for this declining bee. The speciality of the Horton area, however, is a solitary mining bee, Andrena hattorfiana. Both males and females are the same size as worker honeybees, but are much darker. It was first reported in 1854 from Clyne Wood and there was evidently a colony established here as the associated cleptoparasite Nomada armata was also collected at the same time. It seems unlikely that the latter still occurs in Wales, but as the mining bee has recently been rediscovered here it would be worth surveying suitable localities along the coast. There were no further records of Andrena hattorfiana after 1854 until Hallett caught several females at Llangennith in 1921. After another long period without records P. M. Pavett collected two males on limestone grassland at Horton in 1993 and the species was also present there in 1995. The bee is dependent on the pollen of small scabious as the sole source of food for its overwintering larvae in their underground nests. Unfortunately the plant is extremely palatable to grazing animals and they often eat all the flowers.
The dotted bee-fly Bombylius discolor (Fig. 49) is mostly restricted in Wales to the short stretch of coast between Port-Eynon and Penmaen Burrows, with records from Horton Cliff, Overton Cliff and Overton Mere. This large species is easily distinguished by the spots on its wings and is on the wing from late March to mid-June, with numbers peaking in April. The bee-fly declined substantially in Britain during the 1960s and 1970s, mainly as a result of changing agricultural practices that destroyed its nesting sites and suitable flowers, although there was a limited revival in 1996 and 1997 in response to a sequence of hot summers. One of the best places to find the insect is on the cliff slopes a short distance to the east of Horton village. Little is currently known about this species, although it appears to be a parasite of some of the larger mining bees, probably Andrena flavipes, which are active in the spring. What is clear is that the bee-fly can only flourish in areas, such as the Gower coast, where large congregations of nesting bees are present.
FIG 49. Dotted bee-fly, a large species easily distinguished by the spots on its wings. (David Painter)
Other rare species found on the Horton cliffs include a mason cuckoo bee Stelis punctulatissima, which occurs only at only one other site in Wales (at Powys Castle Park) and a number of wasps including the spider-hunting or digger wasp Priocnemis schioedtei, a large red and black species that currently occurs nowhere else in Wales and whose prey includes sac or foliage spiders. In contrast solitary wasps such as Cerceris arenaria prey almost exclusively on weevils and the ground around their nesting holes is often littered with the bodies of the black vine weevil Otiorhynchus sulcatus and other related species. The weevil Cathormiocerus maritimus was found for the first time in Glamorgan in 2002 at Overton Cliff and Overton Mere.
Information on bees, wasps and ants from other parts of the south Gower coast is limited, but the low cliffs at Overton Cliff and Overton Mere support a number of bees including a brassy miner bee Lasioglossum puncticolle and Hylaeus pictipes, which, like the spider-hunting wasp, are found nowhere else in Wales, together with Andrena hattorfiana and Nomada fucata. The latter is a kleptoparasite of Andrena flavipes, which was incredibly abundant along the coast in June 2004 (Fig. 50). The ichneumon Methocha ichneumoides has been recorded from Common Cliff, Overton Mere and Overton Cliff, while the warmth-loving ant Formica cunicularia is often found along the coastal paths, with records from eight sites in 2002. Coastal footpaths can be important for burrowing insects as they provide patches of bare soil in sunny situations. The relief and aspect of the ground is also particularly important for ant species and the occurrence of the four common red ants of the genus Myrmica found on the Gower coast is related to this. M. rubra and M. ruginodis live in more thickly vegetated areas than M. scabrinodis and M. sabuleti, while M. rubra and M. sabuleti need warmer sites so they have more restricted distributions. If the cliff top is well vegetated M. scabrinodis may be absent.
The rare picture-winged fly Myopites eximia is associated with the splash-zone vegetation at the base of the cliff, developing in galls that it creates on the golden samphire. The gall is distinctive and the enlarged, hardened capitula, remaining above the basal leaves, are readily detected amongst the dead growth of the previous year. Galled capitula bear outgrowths that are the lignified walls of the attacked achenes standing out above the receptacle. Other insects characteristic of the area include the micro-moths Epischnia banksiella, whose larvae also feed on golden samphire, and Coleophora ochrea, the larvae of which feed on rock-rose.
Another moth whose larvae feed on rock-rose, in this case the withered and decaying leaves, is the silky wave Idaea dilutaria (Fig. 51). It is probably one of the most notable insects in the peninsula, being the only macro-moth present that is listed in the Red Data Book and therefore recognised as critically endangered. The adult is quite plain in appearance, although as the common name suggests the wing surface has a silky sheen. Only three populations of this moth are known in Britain, one on the Great Orme in North Wales, another near Bristol and the one in Gower, which is by far the largest and most thriving. The silky wave occurs at six sites on the coast: the Knave, Overton Cliff, Overton Mere, Port-Eynon, the Sands and Oxwich Point. All of the sites are steep, south-facing areas of open calcareous grassland, and populations are confined to areas where grazing is light or absent. It used to be reported more widely in England and Wales, but some of the old records are misidentifications or the result of confusing changes of name in the past, so it may have always been a scarce species. Further research is needed on its ecology before there can be any confidence about its survival in this country, but the correct grassland management is obviously a key factor.
FIG 50. The mining bee Andrena flavipes that occurs in large, if compact, colonies and which was common on the south Gower coast in 2004, particularly on Horton Cliffs. (Jonathan Mullard)
Barry Stewart for Figures
FIG 51. The critically endangered silky wave moth, one of the most outstanding insects on the peninsula. (David Painter)
the author for Figures
Additional species associated with rock-rose are the flea beetle Aphthona herbigrada, the seedbug Macroplax preyssleri, which is only known in Wales from Overton and Horton cliffs, and the nationally scare pollen beetle Meligethes solidus, recorded from Mumbles Head and Overton Mere.
The coastal juniper colonies support a characteristic fauna that includes juniper aphid Cinara juniperi, juniper shieldbug Elasmostethus tristriatus and two moths, juniper carpet Thera juniperata and juniper pug Eupithecia pusillata. In addition there are several species of micro-lepidoptera and flies that are known to be specific to juniper and which are internal feeders on the shoots, leaves, fruits and buds, but there have been no studies of these in the area so far.
Gower is also one of the twenty outstanding British localities for crickets and grasshoppers and related insects, with sixteen species having been recorded including grey bush cricket Platycleis albopunctata, Lesne’s earwig Forficula lesnei, and tawny cockroach Ectobius pallidus. Species such as these, which are only found in the vicinity of the coast, still have a restricted distribution thought to result from the forest cover that was present when they arrived in Britain during the early postglacial period. For some reason they been unable to spread inland since the forest was cleared. Interestingly, on the continent they show no preference for coastal areas.
The grey bush cricket is a nationally scarce insect, but it can easily be found in Gower when active and calling in warm weather; it is harder to find when conditions are cooler. The colonies are at their peak between late July and September and in comparatively warm areas, such as the peninsula, a few individuals may persist into November. Lesne’s earwig is also a rare and nationally scarce species that can be found in reasonable numbers in the area. It is particularly associated with old hedgerows or areas of scrub, especially where there is traveller’s-joy or wild clematis Clematis vitalba, but this is by no means the only habitat and areas of tall herbage along the coast are also worth checking. Unlike the common earwigs it has much-reduced hind wings and so cannot fly. Areas of limestone scree along the coast support the mottled grasshopper Myrmeleotettix maculatus. This insect, whose song is said to resemble an old-fashioned watch being wound up, has a distinctive marbled appearance.
Cockroaches are a mainly tropical group of insects allied to the grasshoppers and crickets. While the most familiar species are those associated with human habitation, the three species of small native cockroaches are less well known. On the whole, these are secretive insects and much smaller than their larger, notorious cousins. Even the dusky cockroach Ectobius lapponicus, which is the largest, is only 11 millimetres in length. It is very difficult to distinguish adult females of this species from those of the tawny cockroach. The latter is found in a wide band across southern England, but only two colonies, the one in Gower and another recently discovered in Suffolk, are north of the Thames. Of the native species it is the least specific in its choice of habitat and can be found in woodland rides and clearings, in calcareous grassland, heathland and coastal dunes. More research is needed to determine the extent of the tawny cockroach in the peninsula and whether other species are also present.
Few butterflies are true species of coastal cliffs, but like the other insects they occupy a range of habitiats that provide an abundance of food and nectar plants and where the structural features of the vegetation provide suitable microclimates for larval growth, mating, egg laying and roosting. Species recorded from the coast include small blue Cupido minimus, there being a number of colonies where the larval foodplant kidney vetch is found, brown argus Aricia agestis, wall brown Lasiommata megera, grayling Hipparchia semele, small pearl-bordered fritillary Boloria selene and dark green fritillary Argynnis aglaja. Whereas the strongest populations of the small pearl-bordered fritillary are associated with the larger areas of common land the dark green fritillary is more of a coastal butterfly, although populations do occur inland in situations similar to those used by the former species. The adult dark green fritillaries have a preference for purple flowers as sources of nectar, such as knapweeds and thistles.
Notable beetles on the cliffs include three species in which the larvae feed and develop in the nests of bees and wasps, the rare Metoecus paradoxus, Meloe prescarabaeus and the oil beetle Meloe violaceous, which has been recorded from Slade. The oil beetle is so named because it can give off a strong-smelling liquid from a gland behind the head. In contrast to the other two species M. prescarabaeus is widespread on the Gower coast and larvae were abundant during 2003 and 2004. The Meloidae family are soft-bodied beetles with a narrow neck and often have short wing cases, which makes them relatively easy to identify in the field. They are of particular interest because of their complex life cycles, the early stages of the British species being parasites of solitary bees. In spring the female beetles lay several thousand eggs in the soil, in a number of different batches. The eggs soon hatch into tiny louse-like larvae, with strong claws, that crawl up onto dandelion heads and other spring flowers and await the arrival of the host insects. Only a small proportion find the right host and the unsuccessful larvae die. The successful ones are carried to the bee’s nest, where they detach themselves and find an egg to eat. After this the larva feeds on the bee’s food reserves of pollen and nectar, undergoing a series of moults before emerging as a mature adult. Other beetles found in the area include the bloody-nosed beetle Timarcha tenebricosa, which like the oil beetle also produces a fluid, the burying beetle Necrophorus humator, which buries carrion for its larvae to feed on, and the minotaur beetle Typhaeus typhoeus, which uses rabbit and sheep dung for its larvae.
Perhaps the most prominent beetle of the cliff grasslands, certainly during the late evening in June and July, is the glow-worm Lampyris noctiluca. Female glow-worms often appear a few days before the first male. The female usually begins to glow soon after dusk, which during the season is usually between 2200 and 2300 hrs. The display continues for two or three hours and if after that time the female has not been successful in attracting a mate she will stop glowing, retreat into the grass and return for another attempt the following night. The larvae feed almost exclusively on slugs and snails. Recent research has revealed that during the day the female tries to escape the light by using the abandoned burrow of a solitary bee, so it is important to conserve such bees if glow-worms are to survive in the peninsula. Dillwyn recorded in 1829 that glow-worms were ‘not uncommon on dry hedgebanks; but the light is not so brilliant as it is on chalky soils, nor have I observed the small light in the males which is always sufficiently obvious about Dover [where he started his interest in natural history]. I placed some of these insects in oxygen, and could not detect any increase in their brilliancy.’ There are only isolated reports of glow-worms on the Gower cliffs and elsewhere, and more work is needed to establish the size and location of populations. Indeed there is scope for further survey work on all the coastal invertebrates present in Gower, and in many cases more information on the life histories of species is also needed, in order that effective management strategies can be developed. Even now naturalists are only beginning to glimpse the intricate web that binds together invertebrates such as oil beetles, solitary mining bees, cuckoo bees and glow-worms, and there are undoubtedly more connections that need to be understood before the survival of these species can be assured.
The warm south-facing cliff slopes are also ideal for reptiles, and common lizard Lacerta vivipara, grass snake Natrix natrix, slow-worm Anguis fragilis and adder Vipera berus can all be found along the coast. Adders feed mostly on rodents and lizards, striking their prey to inject venom and then following the scent trail of the dying animal. They are most easily seen on dry cloudy days, when they need to bask to raise their body temperature. On a very hot and sunny day they might bask in the morning or evening sun, but they remain in the shade during the middle of the day. Elsewhere adders have declined in abundance since the 1960s, mainly because of habitat losses, but the populations in Gower have remained relatively strong. To date there have been no detailed studies of reptiles on coastal cliffs, but as they require dense ground cover, which in turn supports rich populations of insects and small mammals, the Gower cliffs are an ideal habitat. The Herpetological Conservation Trust is, however, coordinating a national adder census and if the project is a success it will become an annual count.
The Gower coast is an important area for scrub-nesting birds and these include linnet Acanthis cannabina, whitethroat Sylvia communis, stonechat Saxicola rubetra and yellowhammer Emberiza citrinella. The area is particularly noted for the extremely high density of breeding yellowhammers. The stonechat, which has its largest and most consistent populations in the maritime scrub land of the southwest of Britain, was listed in the Swansea Guide of 1802 and over 200 years later it is still a common sight on the cliffs, especially where there are gorse bushes. Feeding mainly on insects, worms and spiders, they are easy birds to see as they perch at the tops of bushes, where they give their distinctive call (Fig. 52). They breed densely on the coast and in some years there can be two or three pairs per kilometre. The cliffs near Worms Head and Common Cliff used to be of local importance for a small kittiwake Rissa tridactyla colony; this is no longer the main colony, however, as for some reason most of the birds disappeared from this location and took up residence on Mumbles Pier. Guillemots Uria aalge and razorbills Alca torda are also present. Other notable birds nesting on the cliffs are ravens Corvus corax, peregrine falcons Falco peregrinus and choughs Pyrrhocorax pyrrhocorax.
FIG 52. Stonechat, near Middleton, a common sight on the cliffs. (Harold Grenfell)
The chough was once a common breeding bird in Britain, but has declined steadily since the beginning of the eighteenth century and until recently was confined to Ireland, the west of Scotland, the Isle of Man and Wales. A few birds have, however, lately returned to their ancestral haunts in Cornwall. Up until the 1840s it bred regularly in Gower and Dillwyn considered it a fairly common bird. By the end of the nineteenth century, however, it had disappeared. The Reverend Davies noted in 1885 that ‘The rocks which form part of this sandy cove [Three Chimneys in Broughton Bay] used to be frequented by a small colony of red-legged crows, the heraldic bird known as the chough but of late years they seem to have abandoned the place, as none have been seen here for some time.’ One school of thought is that a succession of cold winters started the decline. The birds also suffered from indiscriminate shooting and trapping. Their feeding habits were unfortunate and as they searched in the clifftop grassland for invertebrates many were caught in rabbit traps, particularly after the introduction of the now illegal gin trap. A few of the trapped birds were kept as pets and Dillwyn records that ‘My late friend, Mr Bowdler, of the Rhyddings, kept a tame one, which displayed the most extraordinary sagacity in pilfering and hiding whatever came in the way.’ This is the man who ‘bowdlerised’ Shakespeare, by taking out all the ‘rude’ words and who stated, ‘My object is to offer these plays to the public in such a state that they may be read with pleasure in all companies, and placed without danger in the hands of every person who is capable of understanding them.’ Although criticised for tampering with Shakespeare’s text, Bowdler deserves a certain amount of credit for making the plays well known to a wide audience. It is interesting to think that while he was editing the text he had to contend with an unruly chough. Many more choughs were sold for food. Sir John Llewelyn, Lord Swansea, recalled in 1900 that they had been sold in Swansea Market as ‘Billy Cocks’ and were ‘much prized by French sailors as an article of diet’.
Following this decimation, from being a relatively common bird choughs became rare visitors to Gower. A family of four was seen in Caswell Bay in August 1944, and individuals were sighted in 1943, 1972 and 1974. It was not until 1990, however, that the first pair of choughs reappeared, and there was great excitement among local naturalists when the birds were seen prospecting for a nest site near Mewslade, but no nest was built. They usually begin breeding in late April, building a large cup-shaped nest of sticks, bound with grass stems and lined with wool or hair, in a cliff crevice or cave. Neither bird was ringed so their origin was unknown. Breeding was finally confirmed in 1991 (Fig. 53) when a pair produced three young, one of which was unfortunately taken by a peregrine immediately after leaving the nest hole. Following that date a pair, presumably the same birds, bred each year until 1994 and again in 1999. Unfortunately in 1995 a local farmer shot two birds near their breeding area, after which a number of conservation bodies set up the Gower Chough Group, to carry out annual surveys of the number of birds and their locations, in order to monitor the population.
FIG 53. Adult chough feeding the two surviving young in 1991, the first successful Gower brood since the late nineteenth century. (Harold Grenfell)
Between 2000 and 2001 two pairs of choughs bred at Mewslade and Pennard and in 2002 a third pair nested at Pennard. Two different birds have attempted to breed at Bacon Hole, but although feeding at the nest site has been recorded no fledglings have been seen to leave the nest. The result of all this activity was seven birds fledged. At the last count there were fourteen choughs in Gower. They continue to nest in holes in the cliff and are therefore well protected from normal disturbance and predators. The Gower cliffs are a popular climbing area, however, and this activity could disturb the birds (Fig. 54). Climbing around Yellow Wall, and more recently the area around Bacon Hole, is therefore restricted. The restriction on Yellow Wall runs from 1 March to 15 August, and this long exclusion period is to allow time for a pair of birds to have a second attempt at breeding if the first fails. In the years when a successful brood is produced early the birds have usually left the nest by mid-June and climbing would not disturb them. The National Trust, who own the majority of the climbable Gower coastline, the Countryside Council for Wales and the British Mountaineering Council meet twice a year to discuss areas where climbing might disturb nesting birds or damage rare plants.
FIG 54. Climber on the cliffs at Mewslade. (Harold Grenfell)
Only one set of fledglings has been ringed so not much is known about dispersal or survival, although one Gower-bred bird was reported at Stackpole on the Pembrokeshire coast. In addition a female ringed at Stackpole first bred in 2002 close to Bacon Hole and raised one chick. The female of the 1998 pair had been colour-ringed as a nestling at Castle Martin. There is obviously now some interchange of birds between Gower and Pembrokeshire, only a few miles apart across Carmarthen Bay. In fact there is generally a definite expansion of the chough’s range in South Wales as birds are now also present at Dunraven Bay on the Glamorgan Heritage Coast to the east of the peninsula.
Food availability is one of the main factors influencing the breeding success of choughs in the peninsula and the maintenance of large areas of high-quality feeding habitat, rich in soil invertebrates, is extremely important for their survival. Choughs eat worms, caterpillars, ants and other insects such as beetles, particularly dung beetles. The birds like mainly short turf, less than 2 centimetres in height, together with open patches of bare ground. Microhabitats with large numbers of prey such as the yellow meadow ant Lasius flavus can be significant at certain times of the year. Populations of the ants occur at very high densities along much of the cliff line, being associated with undisturbed semi-natural grassland communities.
The peregrine falcon (Fig. 55) has continued to breed successfully on the cliffs since it returned to Gower in 1987, after a gap of 31 years, having been seriously affected at a national level by organochlorine pesticides eaten by its prey, usually pigeons. Prior to this populations in Gower had also been weakened by the Destruction of Peregrines Order of 1943. The peninsula was one of the areas identified where any person authorised by the Secretary of State for Air could take or destroy peregrines or their eggs. This was because ‘it has been found that these birds are causing considerable losses among homing pigeons employed by the Royal Air Force and Army Pigeon Services.’ In Gower, where there might have been two to four pairs before the decline, the bird returned later than elsewhere, but it is now once again securely established. Between 1987 and 1991 a pair bred annually, producing 13 young over the five years, including a brood of four in 1989. Recently there have been new sightings at Great Tor, with the possibility of a nest on the south face. Despite their extent, however, the cliffs have few potential nesting sites because most of them have a gentle slope; while on those that are vertical most of the ledges are too narrow. There is therefore limited scope for the creation of new territories and most of the young birds have left the peninsula. In north Gower the tors on the west coast supported breeding peregrines in the past, and offer the best prospects for the future, but to date the potential nest sites have not been occupied.
FIG 55. Peregrine falcon at Mewslade, one of the classic areas for this species. (Harold Grenfell)
Peregrines generally choose the highest cliffs for nesting – that is those with the most commanding outlook and the best protection for eggs and young. Persecution of peregrine falcon chicks and eggs goes back at least 750 years and it has been suggested that the selection of nest sites has evolved as a response to human predation. Writing in his history of west Gower, published in 1894, the Reverend Davies says ‘I should mention that Worms Head, and the Paviland Cliffs nearby, used to be a very noted place, as the haunt of the Peregrine Falcon; and some 20 or 30 years ago, a gentleman living in Gloucestershire, who followed the ancient sport of hawking, used to employ old Jeremiah Cox, one of Mr Talbot’s Keepers, to procure him annually a pair of these young birds or their eggs.’
Ravens (Fig. 56) were once common throughout Britain, but like the peregrine a long history of persecution has restricted its range to the more remote and coastal regions. At one stage virtually all the gamekeepers and farmers in Glamorgan shot them as a matter of course. Thankfully a more enlightened approach developed and in 1907 the pioneer naturalist–photographer Richard Kearton took a picture of an adult raven on Pennard cliffs. The bird gradually re-established itself during the early years of the twentieth century and in the 1950s about twelve pairs of ravens were breeding regularly in the Pennard area, mostly on the cliffs, but also on occasions in trees. They now breed at very high densities on the cliffs and occupy traditional territories, based on particular cliffs, or trees, that provide nest sites. Ravens have a varied diet; they will kill their own prey, usually small birds such as meadow pipits Anthus pratensis, but they also eat carrion and forage for eggs, reptiles, insects and seeds.
FIG 56. Raven calling and grasping turf with its bill. There are large young in the nest on the ‘Patella beach’ below, near Overton. (Harold Grenfell)
Green woodpeckers Picus viridis, the largest and most colourful of British woodpeckers, are a common sight on the Gower cliffs. They can often be seen feeding on the closely grazed turf, where they feed on ants and their larvae. The highest breeding numbers in Britain are in South Wales, as green woodpeckers are vulnerable to severe winter weather, which occurs relatively infrequently in this area, and they need high levels of sheep grazing to create the short turf they require for feeding.
A recent and exciting addition to the breeding birds on the coastal cliff slopes is the Dartford warbler Sylvia undata. The Dartford warbler is a relatively sedentary bird and is unusual among British warblers in not migrating for the winter. It is usually associated with dry heathland with mature heather and plenty of gorse, a habitat that is plentiful in the peninsula. In colder areas than Gower it runs the risk of starving to death in a severe frost when it cannot locate the insects on which it relies for food. The warbler is particularly associated with young gorse bushes as these have an abundant invertebrate fauna. In contrast mature bushes, which are hollow below the canopy and therefore contain fewer invertebrates, are not utilised by the birds. Gorse that is cut or burnt over a fifteen-year cycle, though, has been shown to provide an ideal habitat for Dartford warblers, and this is another factor that makes the Gower cliffs attractive to this species.
Dartford warblers were once found throughout southern England, but following a severe reduction in the bird’s habitat it was rarely recorded outside Hampshire and Dorset until the mid-1990s. There is an interesting record, however, of an individual bird in Gower, at Langland in December 1969, and another individual was recorded in Singleton Park, Swansea, in April 1980. Two Dartford warblers were also seen during a survey of Llangennith Moors in 1991, but it was not until ten years later, in 2001, that the species was discovered breeding in the peninsula near Port-Eynon Point. More recently in 2003 there were sightings of birds at Rhossili. There has therefore been a clear westward expansion of its range in Wales. Growing numbers of native birds like the Dartford warbler, which used to stay close to the south coast, have now ventured northwards – and this is almost certainly due to global warming.
