scoomids MOORLAND FORUM 16 301,_41., Ant UNDERSTANDING PREDATION A review bringing together natural science and local knowledge of recent wild bird population changes and their drivers in Scotland Centre for LJL UNIVERSITY OF BTO CUNIVERSITY Ecology & Hydrology vy STIRLING 610 Lrx4,ng okr fry berk OF ABERDEEN IIIIUO•C NC•0••••• &IC C OUNCIL Gill Ainsworth (University of Aberdeen), John Calladine (BTO Scotland), Blaise Martay (BTO Scotland), Kirsty Park (University of Stirling), Steve Redpath (University of Aberdeen), Chris Wernham (BTO Scotland), Mark Wilson (BTO Scotland) &Juliette Young (CEH Edinburgh) UNDERSTANDING PREDATION A review bringing together natural science and local knowledge of recent wild bird population changes and their drivers in Scotland Gill Ainsworth (University of Aberdeen), John Calladine (BTO Scotland), Blaise Martay (BTO Scotland), Kirsty Park (University of Stirling), Steve Redpath (University of Aberdeen), Chris Wernham (BTO Scotland), Mark Wilson (BTO Scotland)& Juliette Young (CEH Edinburgh) Page 1 of 382 CONTENTS CONTENTS ........................................................................................................................................................................... 2 INTRODUCTION ................................................................................................................................................................ 9 ACKNOWLEDGEMENTS .............................................................................................................................................. 11 EXECUTIVE SUMMARY ............................................................................................................................................... 14 Overall aims ...................................................................................................................................... 14 Study approach ................................................................................................................................. 14 Participants holding local and scientific knowledge ......................................................................... 15 Common ground on conservation evidence, drivers of population change and conservation- management techniques .................................................................................................................. 15 Areas of divergent understanding and possible reasons .................................................................. 16 Synthesis of knowledge bases .......................................................................................................... 17 Future collaboration and work ......................................................................................................... 18 Report structure ................................................................................................................................ 19 UNDERSTANDING PREDATION – SUMMARY REPORT ................................................................................. 20 1. INTRODUCTION ........................................................................................................................................................ 20 Background ....................................................................................................................................... 20 Aims and objectives of the project ................................................................................................... 21 Focal species ..................................................................................................................................... 22 Structure of the reporting ................................................................................................................. 23 2. REVIEWING METHODS .......................................................................................................................................... 23 2.1 Social science methods ............................................................................................................... 23 Questionnaire design .................................................................................................................... 23 Classifying stakeholder groups...................................................................................................... 24 Workshop and seminar programmes ........................................................................................... 24 Comparison of knowledge ............................................................................................................ 24 2.2 Natural science methods ............................................................................................................ 24 Population trends of predators and wild bird prey ...................................................................... 24 Review of natural science literature ............................................................................................. 25 3. HOW DO STAKEHOLDERS GAIN AND USE KNOWLEDGE? ..................................................................... 25 4. POPULATION TRENDS OF WILD BIRDS AND THEIR PREDATORS IN SCOTLAND ....................... 26 4.1 Natural science review of population change for terrestrial wild birds and their predators in Scotland ............................................................................................................................................ 26 Page 2 of 382 Population trends of predatory mammals.................................................................................... 27 Population trends of predatory birds ........................................................................................... 27 4.2 Stakeholder perceptions of population trends for wild birds and their predators .................... 28 4.3 Population trends of wild birds and their predators in Scotland – comparison of stakeholder knowledge and natural science findings ........................................................................................... 28 5. DRIVERS OF POPULATION CHANGE OF WILD BIRDS, INCLUDING THE ROLE OF PREDATION ............................................................................................................................................................................................... 31 5.1 Natural science review of drivers of population change for wild birds and their predators ...... 31 Difficulties of assessing the relative importance of population drivers ....................................... 31 FOCAL SPECIES – BLACK GROUSE .................................................................................................. 31 FOCAL SPECIES - CURLEW ............................................................................................................. 32 FOCAL SPECIES – GOLDEN PLOVER ............................................................................................... 33 FOCAL SPECIES – GREY PARTRIDGE .............................................................................................. 34 FOCAL SPECIES - LAPWING ............................................................................................................ 34 FOCAL SPECIES - OYSTERCATCHER ................................................................................................ 35 UPLAND GAMEBIRDS .................................................................................................................... 36 UPLAND WADERS .......................................................................................................................... 36 OTHER UPLAND BIRDS .................................................................................................................. 36 LOWLAND GAMEBIRDS AND WILDFOWL ..................................................................................... 36 LOWLAND WADERS ...................................................................................................................... 37 OTHER LOWLAND BIRDS ............................................................................................................... 37 RAPTORS AND CORVIDS ................................................................................................................ 37 5.2 Stakeholder understanding of drivers of population change for wild birds ............................... 37 Environmental and human drivers of population change ............................................................ 37 Predator species perceived to drive population change .............................................................. 38 5.3 Drivers of population change for wild birds in Scotland and the role of predation – comparison of stakeholder knowledge and natural science findings .................................................................. 41 6. CONSERVATION-MANAGEMENT OPTIONS................................................................................................... 44 6.1 Natural science review of the evidence for the success, or otherwise, of conservation- management options ........................................................................................................................ 44 PREDATION MANAGEMENT .......................................................................................................... 44 HABITAT AND FOOD SUPPLY ......................................................................................................... 47 COMBINED MANAGEMENT