An assessment of the success of agri- environment schemes at increasing breeding success of lapwing in the Avon Valley, Hampshire. A thesis submitted in partial fulfilment of the requirements for the degree of Master of Science and the Diploma of ImperialCollege London Alison Nicholls 1 Contents List of acronyms..................................................................................................................................4 Abstract...............................................................................................................................................5 1. Introduction............................................................................................................................6 1.1 Introduction to the problem................................................................................................6 1.2 Study site............................................................................................................................7 1.3Study aims and hypotheses..................................................................................................9 2. Background...........................................................................................................................10 2.1 Agri-environment schemes...............................................................................................10 2.2 The lapwing (Vanellus vanellus).......................................................................................12 2.3 Habitat...............................................................................................................................14 2.4 Predation...........................................................................................................................16 3. Methods.................................................................................................................................19 3.1 Nest finding......................................................................................................................19 3.2 Hatch date.........................................................................................................................19 3.3 Productivity.......................................................................................................................20 3.4 Habitat quality...................................................................................................................22 3.5 Predator densities..............................................................................................................23 3.6 Landscape features............................................................................................................24 4. Results....................................................................................................................................25 4.1 Distribution and productivity............................................................................................25 4.1.1 Temporal analysis of distribution.............................................................................25 4.1.2 Temporal analysis of productivity............................................................................27 4.1.3 Probability of success ….........................................................................................28 4.2 Site selection.....................................................................................................................29 4.2.1 Presence of breeding lapwing..................................................................................29 4.2.2 Management of fields..............................................................................................32 4.2.3 Pair densities............................................................................................................33 4.3 Habitat and daily survival.................................................................................................34 4.3.1 Habitat variables and daily survival rates of nests...................................................34 4.3.2 Habitat variables and daily survival rates of broods................................................36 4.4 Predator densities and daily survival................................................................................38 4.4.1 Predator densities and daily survival rates of nests.................................................39 4.4.2 Predator densities and daily survival rates of broods..............................................41 4.5 Landscape features............................................................................................................42 4.5.1 Landscape features and daily survival rates of nests...............................................43 4.5.2 Landscape features and daily survival rates of broods............................................44 4.5.3 Landscape features and predator densities...............................................................45 5. Discussion..............................................................................................................................46 5.1 Distribution of lapwing over time in the Avon Valley......................................................46 5.2 Habitat...............................................................................................................................48 5.3 Predation...........................................................................................................................53 5.4 Implications for management...........................................................................................56 5.5 Limitations........................................................................................................................57 5.6 Suggestions for future research........................................................................................58 6. Conclusion.....................................................................................................................................59 References.........................................................................................................................................60 Useful websites..................................................................................................................................65 Appendix...........................................................................................................................................66 2 Figures Fig 1.3 Field sites.................................................................................................................................7 Fig4.1.2.1 Number of lapwing pairs per site per year........................................................................25 Fig 4.1.2.2 Number of lapwing nests hatched per site per year.........................................................26 Fig 4.1.2.3 Number of lapwing broods fledged per site per year.......................................................26 Fig 4.1.3 The relationship between the probability of a nest hatching and probability of a brood fledging in 2010................................................................................................................29 Fig 4.2.1.1 Mean sward height (cm) on fields where lapwings were present and absent..................30 Fig 4.2.1.2 Proportions of grass coverage and bare ground (arc-sine transformed) on fields where lapwing are present and absent......................................................................................31 Fig 4.2.2 Proportion of fields with birds present under each management type................................32 Fig 4.2.3 Relationship between bare ground coverage on the field and density of breeding lapwing pairs......................................................................................................................................34 Fig 4.3.1 Relationship between mean sward height and mean daily survival rate of nests...............36 Fig 4.3.2 Relationship between standard deviation of sward height and daily survival rate of broods .....................................................................................................................................38 Fig 4.4.1.1 Cause of failure of nests...................................................................................................39 Fig 4.4.1.2 Relationship between Gull density and 1-nest failure rate..............................................40 Fig 4.4.2 Relationship between gull density and daily survival rate of broods.................................42 Fig 4.5.2 Relationship between length of woodland border (km) and daily survival rates of both nests and broods.....................................................................................................................44 Fig 4.5.3 Relationship between boundary score and corvid density..................................................45 Tables Table 2.2 Nest success: as taken from Mayfield (1975)....................................................................13 Table 2.4 Common Lapwing clutch and brood predators in the UK.................................................17 Table 3.3 Causes of nest failure as taken from Chamberlain and Crick (2003)................................21 Table 3.4 weighted livestock units as taken from Chesterton (2006)................................................22 Table 4.1.1 Numbers of pairs present, nests hatched, broods fledged