The British coasts are especially noted for their bird life. Tidal sand and mud flats provide feeding and roosting sites for wildfowl and waders, both resident breeding species and wintering birds which breed in the arctic and sub-arctic. Migrant warblers, thrushes and finches use coastal scrub for feeding and resting. Seabirds such as guillemots, razorbilis, kittiwakes, shags, fulmars and gannets congregate in dense populations on coastal cliffs to nest. Dunes and salt marshes provide undisturbed nesting and feeding areas for many terrestrial species such as meadow pipits and skylarks, stonechats and whinchats. Even shingle beaches are important as nesting areas for terns and ringed plovers. The breeding habitats and nesting seasons of a number of bird species are detailed in Waterways and Wetlands.
Protection of shore nest sites
The major problem for birds which nest on coastal sites is disturbance from humans. Cliff-nesting birds are on the whole protected by inaccessibility, but beach- and dune-nesters are highly vulnerable. Terns, which nest just above the tide-line on sand and shingle beaches, are easily disturbed by people and their dogs, and when adult birds are off the nest the eggs and chicks fall easy prey to gulls, crows and kestrels. They are also preyed upon by foxes. Unseasonable storms and high tides make breeding success even more precarious.
Protection of shore-nesting birds has focused on the little tern (Sterna albifrons), one of the rarest breeding seabirds in Britain. Unlike the other terns, which usually nest in extensive colonies, little terns occur in small scattered groups of from five to twenty-five pairs on beaches very close to the high tide mark. Breeding begins late in April and the young are usually fledged by early August. Voluntary wardening schemes at a number of sites have failed to give adequate protection, particularly against serious egg collectors. In 1975 the RSPB, Nature Conservancy Council, North Wales Naturalists’ Trust and local ornithological societies in Clwyd and Gwynedd banded together to appoint full-time summer wardens at three little tern colonies. The wardens, backed by voluntary assistants, have kept a continuous watch on nests and conducted an intensive education campaign among beach users. These measures, plus fencing and signposting around the perimeter of colonies, have significantly cut down human disturbance. Electric fences about 250mm (10″) high, inside the perimeter fences, have proved a deterrent to foxes (Thomas and Richards, 1977, pp60-1).
Little terns which choose to nest in compact groups have more success than those in scattered groupings, since they are able to mob potential predators more effectively. Once the young chicks are out of the nest, about mid-June, they ‘are more likely to survive where they can scatter into nearby sand dunes when predators threaten or the tide is high. However, disturbance from the dunetops is more disruptive than that from the beach because the tops form the skyline from which the terns expect predators to appear (Mason, 1974). Where terns nest below the spring tide mark, or where tide tables and long-range weather forecasts predict exceptionally high tides, wardens can protect nests from flooding by moving them up the beach a few inches a day. This is done by making a new scrape adjacent to the old one, transferring the eggs and obliterating the old nest. Nest moving should only be considered as a last resort since it increases disturbance of the breeding sites.
On some RSPB reserves, control of breeding gulls has been necessary to reduce competition with terns and other rare breeders and predation on young birds. Thomas (1971) gives results of trials and management suggestions. Often it is not enough just to provide other birds with more nest sites, since an expanding gull population may appropriate these when their own preferred sites are full. At Havergate, Suffolk, gulls have been harassed and their breeding success reduced by the removal of nests and eggs. This forces the gulls to recommence breeding activities, often at a distance from the original nest site. At several reserves, including Dungeness in Kent, the control method is to kill and preserve eggs by injection with formalin, so that the gulls continue to incubate the eggs for many weeks. Direct control of adult birds is seldom practised because it often entails disturbance of other nesting birds.
Treatment of oiled birds
Oil spills claim an increasing number of birds at sea and to a lesser extent in rivers, lakes and estuaries. Most seriously affected are seabirds, especially those attempting to nest and feed near industrial areas and shipping lanes. As Ranwell and Hewett (1964, p195) note, ‘oil is not a normal part of a bird’s habitat and birds do not appear to have developed any capacity to avoid it or to recognise polluted from unpolluted areas’. Where a spill occurs in a confined area it might be possible to set up buoys with bang-type scarers but otherwise there is little that can be done except to try to limit the amount of oil spilled in the first place.
Oiled birds preen vigorously in an attempt to clean their feathers. The oil swallowed slowly poisons them, while the remaining external oil destroys the waterproofing of the plumage so that the birds become wet and cold and easily die of exposure. Once beached, oiled birds starve or are killed by predators.
It is difficult to treat oiled birds and the success rate is low. Brief notes are given in the leaflet ‘Oiled Seabirds First Aid’ while details are contained in the booklet. ‘Recommended Treatment of Oiled Seabirds’. Both publications are available from the Nature Conservancy Council and the Royal Society for the Protection of Birds. The following points are basic:
- When approaching or handling an oiled bird, disturb it as little as possible. Approach it from the seaward side, whether it is on the beach or floating in the water. Avoid chasing it, if possible. Use a wide net attached to a pole to aid capture.
- Hold the caught bird to keep the wings from flapping. Wipe the bill clean and enclose the body in a cloth with head and feet projecting. An old piece of sheet about 200-300mm (9-12″) square with a 50mm (2″) hole in the middle for the head is ideal. This helps immobilise the bird and keeps it from taking in more oil by preening.
- Place the wrapped bird in a cardboard box at least 450mm (18″) on a side, well lined with newspaper and/or rags for warmth. Never use a straw lining. Keep the flaps down so the bird is in the dark, but make holes or leave gaps for ventilation. Treat the bird gently and calmly.
- Cleaning should only be attempted after the bird has excreted oil it has taken internally and its general condition has clearly improved. Take the bird as soon as possible to the local RSPCA Inspector (listed in the telephone book) or someone else with experience in treating oiled birds. If three hours or more pass from the time of capture, feed the bird uncooked filleted white fish in finger-sized strips. Give it no other food or medicine. Force-feeding may be required and this should be done with great care; one person should hold the bird and open its bill while another inserts the fish; the bill should be held nearly upright and the throat gently stroked to prevent regurgitation.
