 | Corn bunting singing from hawthorn hedge
Photo: Mark Hamblin (RSPB Images) |
The Corn Bunting is one of Scotland's fastest declining birds. From being one of our most common and widespread species in the nineteenth century, breeding wherever arable cultivation took place, there are probably now little over 800 breeding pairs. These birds are concentrated along the east coast from Nairn, Moray and the Buchan Plain to the East Neuk of Fife, with an isolated population on the machairs of the Uists and associated islands. Management to reverse the species' decline is best initially focused on the remaining breeding range of the species and areas on the margins of this. RSS prescriptions to benefit Corn Buntings are likely to be most effective if offered in combination on a single undertaking, rather than in isolation. Important habitats on the farm for Corn Bunting Corn Buntings are birds of arable farmland, relying on grain and associated large-seeded grasses and other broad-leaved weeds outside the breeding season. The presence of cereal-based arable agriculture is therefore critical to Corn Buntings. Corn Buntings nest much later than most other farmland songbirds. Most females do not lay eggs until June, but nesting attempts may then continue until as late as September. Corn Buntings usually nest on or close to the ground in dense vegetation. Cereal crops are favoured but birds will also nest in hay or silage fields, brassicas or set-aside. The habit of late nesting in cereal crops makes Corn Buntings uniquely vulnerable to loss of nests during cereal harvesting, and farms with mixes of autumn-sown and spring-sown cereals may therefore provide optimum conditions for Corn Buntings to begin nesting early and then to have opportunities for replacement or second nesting attempts. Corn Buntings specialise to a greater extent on feeding on the grain of cultivated cereals (oats, barley and wheat). Stubble fields, cattle feeding stands, newly-drilled cereals and grain-rich habitat provided under agri-environment schemes (e.g. unharvested crops) are therefore all important feeding habitats. Grain and weed seed are the main food sources for adult birds throughout the year, and partially-ripe (milky) cereal grain is also taken by adults and fed to nestlings. The combination of a late breeding season, a preference for nesting in growing crops and a seed diet centred on grains is likely to have made Corn Bunting populations especially vulnerable to modern agricultural practices. Agri-environment management for Corn Buntings needs to provide i a supply of grain and other large grass and weed seeds (especially late in the winter and through the spring), ii both early-sown and late-harvested cereal and grass crops on the farm in order to maximise the opportunity for both early and late nesting attempts. iii rough grass cereal field margins/beetle banks, low-input cereal management and maintenance of areas of unimproved/semi-natural grassland as sources of invertebrate food for nestlings. What measures can I carry out under the RSS that will benefit the Corn Bunting? Extensive Management of Mown Grassland for Birds (Prescription 1) This prescription has the potential to provide nesting habitat for Corn Bunting particularly on farms in and on the edge of the current Corn Bunting breeding range in Scotland. Management of species-rich grassland (Prescription 6) Use of this prescription in areas within or on the edge of the current Corn Bunting breeding range may improve the quality of unimproved grassland patches as foraging habitat for Corn Buntings feeding nestlings. Management of grass margin or beetlebank in arable fields (Prescription 20) Management of conservation headlands (Prescription 21) Use of these prescriptions on farms within or on the edge of the current Corn Bunting breeding range can help to provide invertebrate-rich foraging habitat during the breeding season. The prescriptions are likely to be most effective when adjacent to cereal fields. Introduction or retention of extensive cropping (Prescription 24) This is one of the most important prescriptions for Corn Buntings. The encouragement of low-input spring cropping with retention of unsprayed over-winter stubbles has the potential to offer nesting habitat (especially late-season on farms that also have autumn-sown cereals), invertebrate-rich foraging habitat during the breeding season and an over-winter grain and weed seed source on the crop stubble. Management of cropped machair (Prescription 25) Although most of the remaining Corn Bunting population of the Outer Hebrides nests in dune grassland, the retention of cereal cropping on the machair is critical to the retention of Corn Bunting populations because of the species reliance on an over-winter grain and weed seed supply. Unharvested crops (Prescription 26) This is a critical prescription for Corn Buntings since it is the only one specifically designed to guarantee an over-winter seed and grain supply. It helps provide cover and offers a seed supply right through to the date of ploughing-in. Combining and locating prescriptions to maximise benefits for Corn Buntings Prescriptions 24 and 26 with 1, 20 and/or 21. On the Outer Hebrides, where suitable nesting habitat and invertebrate food supplies are less likely to be limiting, the combination of prescriptions 24, 25 and 26 within crofting townships may be particularly beneficial |