COMMISSION OF THE EUROPEAN COMMUNITIES SHOREBIRDS AND LARGE WATERBI RDS CONSERVATION d # W ffi b* ffi, ffib& a&\ fuTR \#&-"--s .*"&- PROCEEDINGS OF TWO WORKSHOPS HELD AT ST AIDAN'S COLLEGE, DURHAM, UNITED KINGDOM SEPTEMBER 17.18, 1983 5o). 7 COMMISSION OF THE EUROPEAN COMMUNITIES /SHOREBIRDS AND LARGE WATERBIRDS CONSERVATION~ z 0 ~ <( ...J ::::> PROCEEDINGS OF /,TWO- WORKSHOPS (.) a: HELD AT ST AIDAN'S COLLEGE, DURHAM, UNITED KINGDOM (.) SEPTEMBER 17-18, 1983,, Cl w t­ (.) a: t­ en w a: w en ::::> ...J <( z a: w t­ z a: 0 Edited by LL P.R. EVANS .J -~ Science Laboratories, University of Durham United Kingdom H. HAFNER Station Biologique de Ia Tour du Valat, Carmargue France P. L'HERMITE (Commission of the European Communities Directorate-General for Science, Research and Development, Brussels Belgium x cE £. ·. XXIII/ ;c.f' I I I I ( - 2 - L E G A L N 0 T I C E Neither the Commission of the European Communities nor any person acting on behalf of the Commission is responsible for the use which might be made of the following information - 3 - CONTENTS FOREWORD I. CONSERVATION OF SHOREBIRDS 7 Introduction 8 Session 1 - Habitat requirements and conservation problems in the breeding areas Populations and breeding schedules of waders in High Arctic Greenland H. MELTOFTE University of Copenhagen, Denmark 10 Recent population changes of waders in Finland and their causes 0. HILDEN University of Helsinki, Finland 13 The impacts of afforestation on breeding shorebirds and raptors in the Uplands of Britain D.R. LANGSLOW Nature Conservancy Council, Huntingdon, United Kingdom 17 Wet meadows in temperate Europe, threatened by agriculture A.J. BEINTEMA Research Institute for Nature Management, Leersum, The Netherlands 26 The breeding wader populations of the Western Isles of Scotland and the integrated development programme N.E. BUXTON Nature Conservancy Council, Inverness, United Kingdom 34 The impact of tourism on coastal breeding shorebirds in Western and Southern Europe: an introduction to general discussion M.W. PIENKOWSKI University of Durham, United Kingdom 36 Session 2: Shorebird moulting, refuelling and non-breeding areas: habitat requirements and conservation problems Identification of important sites for waders by coordinated counts C.J. SMIT I.W.R.B. Wader Research Group, Den Burg (Texel), The Netherlands 43 - 4 - Session 2: Shorebird moulting, refuelling and non-breeding areas: habitat requirements and conservation problems (cont.) Identification of relative importance of sites by studies of movement and population turnover M.W. PIENKOWSKI University of Durham, United Kingdom 52 Identification of refuelling sites by studies of weight changes and at deposition N.C. DAVIDSON University of Durham, United Kingdom 68 Barrage schemes - Predicting the effects of changes in tidal amplitude on wader populations P.M. MEIRE and E. KUYKEN Rijksuniversiteit Gent, Belgium 79 The effects of predators upon shorebird populations in the non-breeding season D.J. TOWNSHEND, University of Durham, United Kingdom 90 Is pollution a threat to shorebirds populations? P.R. EVANS University of Durham, United Kingdom 96 Creation of habitats and management of sites for shorebirds N.C. DAVIDSON University of Durham, United Kingdom 98 Summary of shorebird workshop 100 II. CONSERVATION OF HERONS, EGRETS AND OTHER LARGE WATERBIRDS 101 Introduction 103 Session 1 - Habitat requirements during the breeding season Purple heron colonies in the Camargue M.E. MOSER Station Biologique de la Tour du Valat, Camargue, Arles, France 104 Herons and egret colonies in Italy M. FASOLA Dipartimento di Biologia Animale, Pavia, Italy 114 European pelican populations and their conservation A.J. GRIVELLI Station Biologique de la Tour du Valat, Camargue, Arles, France 123 - 5 - Session 1 - Habitat requirements during the breeding season (cont.) Creation of a breeding site for tree-nesting herons in the 129 Camargue (Southern France) H. HAFNER Station Biologique de la Tour du Valat, Camargue, Arles, France Session 2: Habitat requirements during moult, migration and in the non-breeding areas Purple heron survival and drought in tropical West-Africa A.J. CAVE Institute for Ecological Research, Heteren, The Netherlands 136 The conservation of herons during migration and in the wintering areas: a review of present understanding and requirements for future research P.J. DUGAN Station Biologique de la Tour du Valat, Camargue, Arles, France 141 Cattle egret wintering in the Camargue D. BREDIN Station Biologique de la Tour du Valat, Camargue, Arles, France 155 Grey herons and fish farms in the Camargue, Southern France H. HAFNER Station Biologique de la Tour du Valat, Camargue, Arles, France 161 Grey herons at trout farms in England and Wales C.J. CADBURY and J. FITZHERBERG-BROCKHOLES R.S.P.B., The Lodge, Sandy, Bedfordshire, United Kingdom 166 CONCLUDING DISCUSSION 172 LlST OF PARTICIPANTS 174 INDEX OF AUTHORS 181 - 6 - FOREWORD This publication constitutes the proceedings of two workshops held at St Aidan's College, Durham (United Kingdom) on September, 17-18 1983, under the auspices of the Commission of the European Communities, as part of the first phase of the Third Environmental Research Programme. The workshops were convened by the contact group "Conservation of wild birds" to review recent developments concerning the conservation of shorebirds and of herons, egrets and other waterbirds. The first objective of the research activities on conservation of birds undertaken within the Environmental Protection R&D Programme is to provide the Council Directive no. 79/409/EEC of 2 April 1979 on the Conservation of Wild Birds with the necessary background information for its implementation and its application. In view of ensuring effective conservation, influence on the use or management of areas of particular habitats for specific migratory species at certain seasons, both inside and outside the Community may be required. It was the purpose of the two workshops to consider the habitat requirements of shorebirds, herons, egrets and other large waterbirds at different steps of their annual cycles. - 7 - I. CONSERVATION OF SHOREBIRDS - 8 - I N T R 0 D U C T I 0 N In recent years E.E.C. DG XI has commissioned several projects, partic­ ularly from IC BP, concerned with the identification of important specific sites for birds within the Member States. Sites have been selected largely on the basis of published information, and with particular reference to species and habitats named in the E.E.C. directive on conservation of birds. Most sites contain concentrations of breeding or wintering birds. With highly migratory species, such as many waders (shorebirds), safe­ guarding of species requires that we look outside E.E.C. Member States, particularly during the breeding season. Although many waders occur in large numbers in only a restricted number of localities outside the breeding season, they are often well dispersed whilst breeding. To ensure effective conservation, we may thus have to influence the use or management of large areas of particular habitats at certain seasons, both inside and outside the Member States. It is the purpose of this volume to consider the state of knowledge on the habitat requirements of waders whilst breeding, when refuelling during migration, whilst moulting, and in other non-breeding areas. Such knowledge is an essential basis for habitat management. We also need to keep in mind the question of at what season is the population of a particular species regulated~ for this will indicate where to concentrate conservation efforts. P. R. EVANS * * * * * * * * * - 9 - SESSION 1 HABITAT REQUI~ENTS AND CONSERVATION PROBLEMS IN THE BREEDING AREAS - 10 - POPULATIONS AND BREEDING SCHEDULES OF WADERS IN HIGH ARCTIC GREENLAND H. MELTOFTE Zoological Museum, University of Copenhagen Summary Waders are the dominating birds of the high arctic tundra of Greenland both regarding population densities and number of species. Of ten species of waders breeding regularly in Green­ land, eight have their main distribution in the high arctic part. Ringed Plover Charadrius hiaticula, Turnstone Arenaria interpres, Knot Calidris canutus, Dunlin Calidris alpina,San­ derling Calidris alba, and Red Phalarope Phalaropus fulicarius are the most abundant. Their living conditions in high arctic Greenland are characterized by extremely low and often sparse vegetation, moderate snow cover and short, cool summers. Large local, regional and annual differences occur, however, and the breeding phenologies and population densities of waders vary markedly in accordance with these differences. A strong negative correlation exist between the onset of egg-laying and the snow cover in early June. Waders breed two weeks later in areas rich in snow than in areas with little snow, i.e. areas with low precipitation and/or areas where the snow is blown off by frequent winter storms. The critical fac­ tors are probably the feeding conditions prior to egg-laying, and in snow rich areas also increasing fox predation with in­ creasing snow cover. Breeding densities are best correlated with the local oc­ currence of snow-free land with vegetation cover in early June, and even here the feeding conditions prior to egg-laying may be the most decisive factor. Although large local anomalies occur, there is a general northwards decrease in snow cover within the high arctic Greenland, and correspondingly a decrease in vege­ tation cover. This means that the earliest wader populations to breed are found in the extreme north, while the population den­ sities are low here due to low productivity. Also in the more productive southernmost parts of high arctic Greenland, the wa­ der populations are low, here due to extensive and long-lasting spring snow cover. The optimal conditions are found in between, where the combination of moderate snow cover and reasonable ve­ getation cover allow waders to breed relatively early and in high numbers. Compared to other arctic areas, the population densities of waders in high arctic Greenland are moderate to low (1-7 pairs per kilometre square in most census areas).