Assessment of the Distribution and Abundance of Kingfisher Alcedo Atthis and Other Riparian Birds on Six SAC River Systems in Ireland
Total Page:16
File Type:pdf, Size:1020Kb
Assessment of the distribution and abundance of Kingfisher Alcedo atthis and other riparian birds on six SAC river systems in Ireland Prepared by Sinéad Cummins, Jennifer Fisher, Ruth Gaj McKeever, Laura McNaghten & Olivia Crowe A report commissioned by the National Parks and Wildlife Service and prepared by BirdWatch Ireland June 2010 Address for correspondence: BirdWatch Ireland, Unit 20, Block D, Bullford Business Campus, Kilcoole, Co. Wicklow. 1 Table of contents Summary ....................................................................................................................................................... 3 Introduction.................................................................................................................................................... 4 Methods......................................................................................................................................................... 4 Study location............................................................................................................................................ 4 Coverage................................................................................................................................................... 5 Field methods............................................................................................................................................ 5 River properties......................................................................................................................................... 7 Habitat .................................................................................................................................................................. 7 Pressures and threats........................................................................................................................................... 7 Potential sources of bias....................................................................................................................................... 7 Analyses.................................................................................................................................................... 8 Results........................................................................................................................................................... 8 Coverage................................................................................................................................................... 8 Detectability............................................................................................................................................. 10 Habitat, pressures & threats ................................................................................................................... 11 Riverine Habitats................................................................................................................................................. 11 Bank Habitats ..................................................................................................................................................... 14 Surrounding Habitats .......................................................................................................................................... 14 Pressures & Threats ........................................................................................................................................... 14 Riparian bird distribution & abundance................................................................................................... 15 Kingfisher distribution within river systems ............................................................................................. 19 Relative abundance ............................................................................................................................................ 19 Territories............................................................................................................................................................ 21 Habitats............................................................................................................................................................... 28 Bank & River suitability ....................................................................................................................................... 29 Predators................................................................................................................................................. 29 Discussion ................................................................................................................................................... 31 Distribution of Kingfisher territories ..................................................................................................................... 31 Distribution of Kingfishers across the six main systems surveyed in 2010 ......................................................... 31 Bankside and surrounding habitats..................................................................................................................... 32 Pressures and threats......................................................................................................................................... 32 Abundance and distribution of other waterways bird species ............................................................................. 32 Recommendations for future monitoring, and protection of the Kingfisher.......................................................... 33 Acknowledgements ..................................................................................................................................... 33 References .................................................................................................................................................. 33 Appendices.................................................................................................................................................. 35 Appendix 1a. Habitat key & recording form. ........................................................................................... 35 Appendix 1b. Pressures and threats key. ............................................................................................... 36 Appendix 2. River coverage descriptions ............................................................................................... 37 Appendix 3. Further details on river coverage in 2010. ..........................................................................45 Appendix 4. Recommendations for future boat-based surveys of riparian birds.................................... 47 2 Summary • Six river systems, namely the Barrow, Blackwater (Munster region), Boyne, Clare, Moy and Nore, all designated as Special Areas of Conservation (SAC) formed the basis for this survey. • Observers aimed to cover all the main channels along with all tributaries feeding into the main system (both SAC and non SAC). Three visits were made to each system between 15 March – 1 Jun 2010. • In addition, two smaller systems, the Gill (Co. Leitrim) and the Ilen (Co. Cork) were surveyed by NPWS Conservation Rangers. • Most fieldwork was carried out between 08:00 and 18:00, and all waterways bird species seen or heard were recorded. Observations by boat or on foot involved collecting birds and habitat data every 500m. • Grid references of the locations of any Kingfishers seen or heard were noted as were the locations of any nest holes deemed active, inactive or unknown. • A maximum length of 941 km divided into 2,004 sections was covered across the eight river systems. The Blackwater (Munster) system surveyed was the longest river system surveyed (265 sections totalling 218km) while the Ilen in Cork was the shortest in total length surveyed (25 sections totalling 12km). The average length of river system surveyed was just less than 119km. • A total of 25 waterways bird species were recorded, with the highest total of 21 species on both the Blackwater (Munster) and Boyne systems. Sand Martin Riparia riparia was the most abundant species on both systems, with Mallard Anas platyrhynchos also plentiful. • Vertical nesting banks of 1-2m in height were more common on sections with Kingfishers, as expected and overall the proportion of banks on sections with Kingfishers was greater, in particular banks greater than 10m in length. • A total of 16 – 22 territories were identified on the Nore (densities of 0.10-0.14 territories/km) and 15-19 territories on the Boyne (densities of 0.09-0.12 territories/km). On the Moy and Clare systems densities ranged from 0.11-0.12 territories/ km to 0.07-.0.08 territories/km respectively. Lowest densities were recorded on the Barrow (0.04-0.08 territories/km) and Blackwater (Munster) systems (0.05 territories/km). • The territories identified using both boat and walked transect methodologies along the six chosen river systems surveyed in 2010 will inform the Special Protection Area designation process, with regards to Kingfisher (Alcedo atthis). • Supplementary information on other waterways species, in particular the location of breeding colonies of Sand Martin, should also prove useful. 3 Introduction One of the most important features of Ireland’s waterways is the biodiversity that they support, and many are designated under the Birds * and Habitats Directives** (i.e. Special Protection Areas and Special