ISSN 1393 – 6670 The 2015 National Survey of Breeding Hen Harrier in Ireland Irish Wildlife Manuals No. 93 The 2015 National Survey of Breeding Hen Harrier in Ireland Ruddock, M., Mee, A., Lusby, J., Nagle, T., O’Neill, S. & O’Toole, L. Golden Eagle Trust, Irish Raptor Study Group & BirdWatch Ireland Citation: Ruddock, M., Mee, A., Lusby, J., Nagle, A., O’Neill, S. & O’Toole, L. (2016). The 2015 National Survey of Breeding Hen Harrier in Ireland. Irish Wildlife Manuals, No. 93. National Parks and Wildlife Service, Department of the Arts, Heritage and the Gaeltacht, Ireland. Keywords: Hen harrier, Circus cyaneus, Special Protection Area (SPA), national survey, population estimates, pressures, productivity, habitats Site list: 004160; 004161; 004162; 004165; 004167; 004168. Cover photo: © Marc Ruddock The NPWS Project Officer for this report was: David Tierney; [email protected] Irish Wildlife Manuals Series Editors: R. Jeffrey & F. Marnell © National Parks and Wildlife Service 2016 ISSN 1393 – 6670 Ireland Hen Harrier Survey 2015 ____________________________ Contents Contents .......................................................................................................................................................... i Executive Summary ...................................................................................................................................... iii Acknowledgements ...................................................................................................................................... iv 1.0 Introduction.............................................................................................................................................. 1 1.1 Surveys of the hen harrier in Ireland .................................................................................................. 2 2.0 Methods .................................................................................................................................................... 5 2.1 Objectives.............................................................................................................................................. 5 2.2 Survey design and implementation .................................................................................................... 5 2.3 Defining survey areas .......................................................................................................................... 6 2.4 Hen harrier field surveys ..................................................................................................................... 9 2.5 Data recording and data entry ...........................................................................................................13 2.6 National and regional population estimates, population change and breeding density ...............14 2.7 Population estimates, population changes and habitat composition within SPAs.........................16 2.8 Breeding outcomes and habitats utilised...........................................................................................17 2.9 Pressures ..............................................................................................................................................18 2.10 Other research ...................................................................................................................................20 3.0 Results......................................................................................................................................................21 3.1 Survey implementation, coverage and data submission ..................................................................21 3.2 Survey effort and observations ..........................................................................................................23 3.3 National and regional population estimates, population change and breeding density ...............26 3.4 Population estimates, population changes and habitat composition within SPAs.........................42 3.5 Breeding outcomes and habitats utilised...........................................................................................44 3.6 Pressures ..............................................................................................................................................48 3.7 Other research .....................................................................................................................................53 4.0 Discussion ...............................................................................................................................................55 4.1 Survey implementation, coverage and data submission ..................................................................55 4.2 Survey effort and observations ..........................................................................................................57 4.3 National and regional population estimates, population change and breeding density ...............59 4.4 Population estimates, population changes and habitat composition within SPAs.........................64 4.5 Breeding outcomes and habitats utilised...........................................................................................66 4.6 Pressures ..............................................................................................................................................68 4.7 Other research .....................................................................................................................................73 4.8 Conclusions & recommendations ......................................................................................................74 Ireland Hen Harrier Survey 2015 ____________________________ 5.0 Bibliography & Relevant Literature ...................................................................................................... 79 Appendix 1. 10km square map produced for use during surveys............................................................ 89 Appendix 2. 10km square map produced from orthophotography for use during surveys .................. 90 Appendix 3. 10km square map produced from habitat map derived from Moran & Wilson-Parr (2015) for use during surveys ................................................................................................................................. 91 Appendix 4. Mullaghanish to Musheramore Mountains SPA .................................................................. 92 Appendix 5. Stack’s to Mullaghareirk, West Limerick Hills & Mount Eagle SPA ................................... 96 Appendix 6. Slievefelim to Silvermines Mountains SPA ........................................................................... 99 Appendix 7. Slieve Aughty Mountains SPA ............................................................................................ 102 Appendix 8. Slieve Bloom Mountains SPA .............................................................................................. 105 Appendix 9. Slieve Beagh SPA .................................................................................................................. 108 Appendix 10. The numbers of each pressure codes recorded and total number of pressure records (Pressure Index 1) and standardised (Pressure Index 2 = total number of pressures / total number of visits to square) within 500m and 2km of hen harrier territories and/or suitable hen harrier breeding habitats within SPAs .................................................................................................................................. 111 Appendix 11. The population projection model displaying predictions for inside and outside the SPAs and nationally ............................................................................................................................................. 114 Appendix 12. Records collated in 2015 from other species showing distribution maps plotted at 10km square resolution ........................................................................................................................................ 115 Ireland Hen Harrier Survey 2015 ____________________________ Executive Summary The hen harrier (Circus cyaneus) is a protected raptor, listed in Annex I of the EU Birds Directive and as such, Member States are obligated to protect and conserve the species. These obligations involves key actions to designate Natura 2000 sites, also known as Special Protection Areas (SPAs) and also to undertake monitoring of hen harriers nationally, regionally and within the designated areas. The fourth national survey of hen harriers in Ireland was undertaken in 2015 and was preceded by surveys in 2010; 2005 and 1998-2000. Similar to previous surveys the aims were to quantify the size and distribution of the breeding population and examine changes since the previous national surveys. The survey effort and participation increased since 2010 with more than 7000 hours observational effort undertaken by 259 fieldworkers, largely via volunteer networks. In 2015, an estimated 108 – 157 breeding pairs of hen harrier were recorded. This is lower than the population estimates in 2010 (128 – 172); similar to the estimate in 2005 (132 – 153) and marginally higher than the population 1998 – 2000 (102 – 129). This represents a decline of 15.6% in the number of confirmed breeding pairs since 2010 and an 11.4% increase in the number of possible pairs. The distribution of the confirmed breeding