_________________________________________________________________________Swansea University E-Theses Habitat, home range, diet and demography of the water vole (Arvicola amphibious): Patch-use in a complex wetland landscape. Neyland, Penelope Jane How to cite: _________________________________________________________________________ Neyland, Penelope Jane (2011) Habitat, home range, diet and demography of the water vole (Arvicola amphibious): Patch-use in a complex wetland landscape.. thesis, Swansea University. http://cronfa.swan.ac.uk/Record/cronfa42744 Use policy: _________________________________________________________________________ This item is brought to you by Swansea University. Any person downloading material is agreeing to abide by the terms of the repository licence: copies of full text items may be used or reproduced in any format or medium, without prior permission for personal research or study, educational or non-commercial purposes only. The copyright for any work remains with the original author unless otherwise specified. The full-text must not be sold in any format or medium without the formal permission of the copyright holder. Permission for multiple reproductions should be obtained from the original author. Authors are personally responsible for adhering to copyright and publisher restrictions when uploading content to the repository. Please link to the metadata record in the Swansea University repository, Cronfa (link given in the citation reference above.) http://www.swansea.ac.uk/library/researchsupport/ris-support/ Habitat, home range, diet and demography of the water vole(Arvicola amphibius): Patch-use in a complex wetland landscape A Thesis presented by Penelope Jane Neyland for the degree of Doctor of Philosophy Conservation Ecology Research Team (CERTS) Department of Biosciences College of Science Swansea University ProQuest Number: 10807513 All rights reserved INFORMATION TO ALL USERS The quality of this reproduction is dependent upon the quality of the copy submitted. In the unlikely event that the author did not send a com plete manuscript and there are missing pages, these will be noted. Also, if material had to be removed, a note will indicate the deletion. uest ProQuest 10807513 Published by ProQuest LLC(2018). Copyright of the Dissertation is held by the Author. All rights reserved. This work is protected against unauthorized copying under Title 17, United States C ode Microform Edition © ProQuest LLC. ProQuest LLC. 789 East Eisenhower Parkway P.O. Box 1346 Ann Arbor, Ml 48106- 1346 Author’s declaration This work has not previously been accepted in substance for any degree and is not concurrently submitted in candidature for any degree Signed .............................. (candidate) Date ............ Statement 1 This thesis is the result of my own investigations, except where otherwise stated. Other sources are acknowledged with explicit references. A bibliography is appended. Signed-. ...............................Candidate) Date yj.k.j.J)............. Signed ........................ (supervisor) Date ................ Statement 2 I hereby give consent for my thesis, if accepted, to be available for photocopying and for inter-library loan, and for the title and summary to be made available to outside organisations. Signed ... (candidate) Date ........... Abstract Water vole (Arvicola amphibius ) ecology was studied at the National Wetland Centre Wales (NWCW), a National Key Site for water voles, consisting of a diversity of interconnected habitats, including ponds, ditches and reed-beds. A novel method of mapping the vegetation of the wetland landscape was devised, using patches of vegetation classified according to the dominant vegetation type (DVT). The richness and abundance of DVT patches was used as an index of diversity at the habitat level. This provided a basis for describing the matrix habitat, which underpins the study of water vole ecology at the patch-landscape scale. The practical application of the DVT mapping approach allows the stages of wetland succession to be monitored, identifies areas of high biodiversity and provides a baseline on which to monitor the distribution and movements of animal species. Implementation of this method reduces time and the need for specialist field surveyors, thereby facilitating efficient management practices if applied at a national level. An intensive four year study of a metapopulation of water voles on eight adjacent ponds in the NWCW wetland reserve revealed an important insight into the dynamics of wild populations in complex, non-linear habitats. Multi-annual fluctuations in population densities were observed, characterised by a peak density phase and a low density phase. Density dependent juvenile dispersal was characteristic of the water vole population. Female water voles in diverse pond habitats maintained intra-sexually overlapping home ranges, uncharacteristic of this species. During the breeding season, water voles selected the ponds with the highest habitat diversity (assemblage of DVTs) but were typically associated with the least diverse DVT patches within the vegetation mosaic. Temporal plasticity in niche partitioning was observed both between genders and between individual female water voles at NWCW. During the winter, Bramble (Rubus fruticosus) was the most important dominant vegetation type, providing a source of cover and protection from predation. Water voles selected 23 plant species (and 3 non-plant species) as food. Soft Rush (.Juncus effusus) a species with high nitrogen and calorific content was favoured particularly. The physical effects of water vole grazing and burrowing, combined with the large amounts of nitrogen- containing faeces deposited in latrines and underground burrows, has implications for wetland nutrient cycles. The effects of large scale vegetation clearance are described and holistic management recommendations are presented. Table of contents Title Page i Author’s declaration ii Abstract iii Table of contents iv List of tables and figures xii List of animals mentioned in the text xx List of animals mentioned in the text xxi Abbreviations xxii Acknowledgements xxiv Introduction 1 1. Habitats to Ecosystems 1 Habitats and plant communities 1 Ecological wetland succession 1 The importance of scale: from patches to landscapes 2 Biodiversity and ecosystem functioning 3 Grazers and ecosystems 3 2. Rodent Ecology 3 Cyclic population dynamics 3 Factors that constrain small mammal populations 4 Metapopulations and source-sink dynamics 5 Mammals: territory and home range 5 3. Water voles (Arvicola amphibius ) 6 General introduction to water voles 6 Early history of the water vole in Britain 7 Recent history of the water vole in Britain 8 Distribution of water voles in Britain 9 Water vole habitat preferences 10 Water vole life expectancy and survival 10 Water vole home ranges 10 Water vole territoriality and social behaviour 11 Water vole latrines 12 Water vole foraging behaviour 12 iv Water vole dispersal strategies 13 A note on American mink 14 4. Water vole conservation and management 15 Water voles - threats and conservation measures 15 Current techniques used to monitor water vole populations 16 Persistence of extant water vole populations 16 Evidence-based conservation 17 Implementation of monitoring data to advise management practices 17 5. Outline of Chapters 18 Methodology 21 1. Study site 21 1.1 Site history 21 1.2. Ponds 23 2. Vegetation surveys and habitat mapping 26 2.1 Vegetation surveys at the habitat level: ponds 27 2.2 Vegetation surveys at the patch level: Dominant Vegetation Types (DVT) 28 2.3 Statistical analysis of vegetation data 28 3. Live Trapping 29 3.1 Processing captured animals 30 3.2 Juvenile water voles 32 3.3 Water vole population densities 32 3.4 Recruitment and survival of water voles 32 3.5 Statistical analysis of population data 33 3.6 Water vole home range lengths (ORL) 33 3.7 Statistical analysis of water vole home range length 34 3.8 Water vole home range overlaps 34 3.9 Agonistic behaviour 3 5 3.10 Habitat utilisation (DVTs and water voles) 3 5 3.11 Statistical analysis of habitat utilisation data 3 6 4. Field surveys 37 4.1 Analysis of field surveys 40 4.2 Statistical analysis of field survey data 41 5. Elemental and energy content analysis 41 v 5.1 Plant samples 41 5.2 Faecal samples 42 5.3 Elemental analysis (Carbon: Nitrogen) 42 5.4 Bomb calorimetry (energetic and mineral content) 42 5.5 Statistical analysis of elemental and energetic content of forage 43 5.6 Nutrient loading of wetland soils 43 5.7 Statistical analysis of soil nutrients 44 Chapter 1 Water vole Habitat 45 1.1 Introduction 45 Current methods used to map habitats 45 Why map water vole habitats? 46 Water vole habitat requirements 46 Rationale 47 Aims 47 1.2 Results 48 1.2.1 Dominant Vegetation Types (DVT) 48 1.2.2 Length and area 57 1.2.3 DVTs as a measure of diversity at the habitat level 59 1.2.4 Habitat diversity (Dpond) - does size matter? 60 1.2.5 How well do DVTs reflect the plant species diversity of the ponds? 62 1.2.6 DVT plant species associates 63 1.2.7 DVT patch diversity(D dvt) 68 1.3 Discussion 70 1.3.1 Dominant vegetation types (DVT) 70 1.3.2 Length and area 71 1.3.3 DVTs as a measure of diversity at the habitat level (Dpond) 72 1.3.4 Habitat diversity (Dpond) - does size matter? 72 1.3.5 How well do DVTs reflect the diversity of the ponds? 73 1.3.6 DVT plant species associates and patch diversity (D d v t ) 74 1.3.7 How can the DVT method be implemented practically? 74 Summary 76 vi Chapter 2 Water vole Population Ecology 77 2.1 Introduction 77 Water vole population densities 77 Over-winter survival 77 Sex ratios in water voles 78 Rationale 79 Aims 79 2.2 Results 80 2.2.1 Trapping effort and capture success 80 2.2.2 Demography of the water vole meta-population 82 2.2.3 Sex ratio of adult water vole population 83 2.2.4 Pooled data: water vole population densities per year 83 2.2.5 Water vole population densities per pond 84 2.2.6 Seasonal population densities 86 2.2.7 Survival and recruitment o f adult water voles 88 2.2.8 Over-wintering water voles 97 2.2.9 Juvenile water voles 98 2.2.10 Life histories from repeat captures 100 2.3.