The restoration of the Red-billed Chough in Cornwall

The Red-billed Chough Pyrrhocorax pyrrhocorax has a restricted range in Britain and has been in long-term decline since at least the early 1800s. Southwest England was a former stronghold and Cornwall was the last county in England from which it was lost as a breeding species, the last successful breeding attempt being in 1947.The reduction of suitable foraging habitat owing to changes in the management of clifftop pastures, and the direct impact of human activities are thought to be the main factors responsible for the loss of Red-billed Choughs from the southwest. Recently, there has been much interest in restoring the Red-billed Chough to Cornwall, and this has increased following a small influx of birds to the county in spring 2001 and successful breeding in 2002.The Cornwall Chough Project has been launched to monitor the birds currently present, and to encourage natural recolonisation through appropriate management of coastal habitats.There is now more potentially suitable habitat in Cornwall, and adjacent parts of Devon, than at any time since the species was last present, and such habitat is likely to increase further during the next few years. A brief history of the Red-billed Chough in England The Red-billed Chough was once widespread along the south and southwestern coasts of England, and also occurred on both the west and east coasts of northern England. A longterm decline was already apparent during the early 1800s, and by 1860 the species had ceased to breed in Northumberland, Kent, Sussex, Hampshire and the Isle of Wight (Brown & Grice in prep.). The species was lost from Cumbria by about 1865 and from Devon by 1910, and then remained only in its stronghold of Cornwall (Holloway 1996). Even here, it had become scarce by the early part of the twentieth century. After 1930, the majority of the known nest sites were between Watergate Bay and Tintagel on the north coast and, although only 3-4 sites were occupied in any one year, young continued to fledge almost annually until the last successful breeding in 1947. Two birds were present here between about 1960 and 1967 with just a single bird remaining until 1973 (Penhallurick 1978). The extinction of the Red-billed Chough in England has generally been attributed to a loss of suitable foraging habitats (e.g. Batten et al. 1990). The species favours heavily grazed, closecropped coastal pastures enriched with animal dung, and with patches of bare ground where invertebrates are easily accessible. Such habitats have been lost either because they have been ploughed and converted to arable farmland, or because the abandoning of grazing has led to establishment of rank vegetation or scrub where foraging becomes more difficult for Red-billed Choughs. Meyer (2000) highlighted the crash in the Cornish tin-mining industry in the late 1800s as a possible factor in the Red-billed Chough’s decline. Once pit ponies and other livestock kept by miners around their crofts were no longer required, the extent of heavily grazed pasture was reduced. In the 24 British Birds 96 • January 2003 • 23-29 The Red-billed Chough in Cornwall meantime, other pastures were improved through the addition of inorganic fertilisers, thus reducing the variety of plants and invertebrates that they supported. As the English Red-billed Chough population fell, so it became an ever more attractive target for specimen collectors, particularly during the Victorian era when trophy hunting for eggs and adult birds was at its peak (Penhallurick 1978). The fact that the Red-billed Chough is a corvid, albeit one which poses no threat to gamebirds or livestock, probably also made it a target for persecution, along with the almost universally disliked Magpie Pica pica and Carrion Crow Corvus corone (Batten et al. 1990). The direct impact of humans in this way may well have been the final straw for a population already depleted by habitat loss. The Red-billed Chough in Cornwall The Red-billed Chough has a particularly strong association with Cornwall and this is reflected in its alternative local name of ‘Cornish Chough’. Despite its absence for the majority of the last 50 years, it remains a popular bird with many people in the county and is even featured in the county’s coat of arms (fig. 1). The species also features strongly in Cornish legend. King Arthur was reputedly transformed into a Red-billed Chough when he died (Penhallurick 1978), the red feet and beak presumably representing the violent and bloody end to which he came! For many years, a group of conservation organisations, involving both governmentfunded bodies and voluntary organisations, have been exploring means of restoring the Red-billed Chough to England. ‘Operation Chough’ was launched in 1987 and a great deal of research was carried out into the habitat requirements of the Red-billed Chough in order to assess the species’ future prospects in Cornwall. The focus in recent years has been on trying to restore as Fig. 1. The cultural importance of the Red-billed Chough Pyrrhocorax pyrrhocorax in Cornwall is apparent from the county’s coat of arms.The tinmining industry is also recognised, and this may have played a role in providing suitable foraging habitat for choughs through the grazing of pit ponies and other livestock around miners’ cottages. much semi-natural habitat as possible into suitable condition for the species, concentrating on the coast of north Cornwall and adjacent areas in Devon. Much has already been achieved through land being entered into management agreements, either based on the voluntary cooperation of landowning bodies such as the National Trust and their tenant farmers, or through the Government’s Countryside Stewardship scheme, sponsored by the Department for Environment, Food and Rural Affairs (Defra). It is particularly important that Defra has been willing to amend its national Countryside Stewardship guidelines in order to maximise the potential for restoring good Red-billed Chough habitat in the region. This has enabled details such as livestock densities and the time of year when grazing animals are present to be adjusted so that the best possible foraging habitats can be created. In 2000, Richard Meyer suggested that there was sufficient apparently suitable habitat along the Cornish coast to sustain a population of Red-billed Choughs (Meyer 2000). It was then widely believed that the species was unlikely to return without human assistance, since Redbilled Choughs are generally sedentary and southwest England is a considerable distance from the nearest established populations. Adults are extremely site-faithful and although juveniles disperse more widely, they typically show strong natal philopatry, returning to breed close to their own place of birth (Batten et al. 1990; Cross & Stratford unpublished). The nearest populations are in southwest Wales, southern Ireland and Brittany, northwest France, all being separated from Cornwall by large stretches of water. Between 1980 and 2000, there were just three apparently genuine records of Red-billed Chough in Cornwall, with several further records thought to relate to birds which had either escaped from captivity or been deliberately released (Brown et al. 2002). Perhaps unsurprisingly, there have been regular calls for the Red-billed Chough to be reintroduced into Cornwall. This would not be an easy option as a suitable donor population would need to be identified and techniques established for releasing birds. In particular, the fact that the Red-billed Chough lives in social groups, in which the young learn to forage from more experienced adults, would need to be taken into account. Simply releasing young birds into an area, as has been the case with other re-establishment projects in Britian, such as those involving Red Kites Milvus milvus and Ospreys Pandion haliaetus, would not necessarily result in the successful establishment of a viable population. Some wildlife centres have attempted to breed Red-billed Chough, in captivity to provide birds for release into the wild. Although there are estimated to be 60-70 captive individuals in Britain, however, efforts to produce viable young have so far met with very little success (Brown et al. 2002). The historic events of 2001 and 2002 have, in any case, stalled any thoughts of reintroduction, at least in the short term, and have led to a significant change in emphasis for Red-billed Chough restoration efforts in Cornwall. Range expansion and the 2001 influx The first encouraging development involved a significant expansion in the breeding range of Red-billed Chough in south Wales. Between the two breeding atlases for Britain and Ireland (Sharrock 1976; Gibbons et al. 1993), and despite some loss of ground in the stronghold of Pembrokeshire in the far southwest, birds had managed to reach the Gower Peninsular, over 40 km to the east and separated from the Pembrokeshire populations by the wide expanse of Carmarthen Bay. Breeding has been regular here during the 1990s. In the late 1990s, another site, approximately 40 km farther east than Gower, was colonised (Welsh Birds 2000, 2001). These relatively large extensions of the breeding range showed that recolonisation of suitable habitat some distance from established populations was possible, and gave hope to those keen to see the bird back in southwest England. The north Devon coast is less than 40 km from Gower, from which it is easily visible on a clear day. This may account for a recent increase in records from north Devon, and may provide a potential route for the ultimate recolonisation of suitable coastline throughout the southwest. If the expansion of the breeding range in south Wales had been somewhat surprising, then the events of 2001 in southwest England were totally unexpected. A small influx of Redbilled Choughs took place between late January and May, involving sightings of birds along the south coast from the Isles of Scilly to Portland in Dorset. Establishing the true picture was hampered by access restrictions imposed as a result of the outbreak of foot-and-mouth disease, but at least four different individuals 25 British Birds 96 • January 2003 • 23-29 The Red-billed Chough in Cornwall