WINTER BIRD ABUNDANCE & DISTRIBUTION IN THE SRUWADDACON BAY AREA, CO. MAYO WINTER 2010/2011 PREPARED FOR EACS - ECOLOGICAL ADVISORY AND CONSULTANCY SERVICES OCTOBER 2011 WINTER BIRD ABUNDANCE & DISTRIBUTION IN THE SRUWADDACON BAY AREA, CO. MAYO WINTER 2010/2011 User is Responsible for Checking the Revision Status of This Document Rev. Description of Prepared By: Checked By: Approved By: Date: Nr. Changes 1 Issue to client GF GF GF 11/11/11 Client: EACS - Ecological Advisory and Consultancy Services, for Shell E & P Ireland Ltd. Keywords: Winter Bird Study, Sruwaddacon Bay area, 2010-2011 Abstract: This report records and assesses bird abundance and distribution in and around Sruwaddacon Bay, Co. Mayo during the winter period 2010/2011. It comprises data collected from bird surveys conducted between October 2010 and April 2011. Bird counts from high water and low water are presented and the results are discussed in the context of previous year’s survey findings. The numbers and activity of key species such as Light- bellied Brent Goose are assessed and the information from ring records is described. Numbers of Light-bellied Brent Geese once again reached nationally and internationally important numbers during the winter of 2010/11. A number of other wading bird (e.g. Curlew and Ringed Plover) species showed marked increases in their peak counts when compared with recent winters. Q:/LE09/548/02/Reports/Winter Birds 2010-11-1.doc TABLE OF CONTENTS PAGE 1 INTRODUCTION ....................................................................................................... 1 2 METHODOLOGY ........................................................................................................ 2 2.1 FIELD SURVEYS ........................................................................................................ 2 2.2 CONSERVATION EVALUATION ........................................................................................ 2 3 RESULTS .................................................................................................................. 5 3.1 BIRD USAGE OF THE STUDY AREA AT LOW WATER ................................................................ 5 3.2 BIRD USAGE OF THE STUDY AREA AT HIGH WATER ............................................................... 6 3.3 AVIAN ROOST AREAS IN THE STUDY AREA .......................................................................... 6 3.4 LIGHT -BELLIED BRENT GOOSE USAGE OF THE STUDY AREA ..................................................... 6 3.5 LIGHT -BELLIED BRENT GOOSE RINGING RECORDS ............................................................... 7 3.6 COMPARISON WITH PREVIOUS STUDIES .......................................................................... 15 3.7 SPECIES OF ELEVATED CONSERVATION CONCERN .............................................................. 17 3.8 RELATIVE IMPORTANCE OF THE SPECIES OF SPECIAL CONSERVATION INTEREST IN THE SPA AND LOCALLY OCCURRING ANNEX I SPECIES .............................................................................................. 20 3.9 GENERAL CONSERVATION EVALUATION .......................................................................... 20 4 SUMMARY AND CONCLUSIONS ............................................................................... 23 5 BIBLIOGRAPHY ...................................................................................................... 25 LIST OF APPENDICES Appendix 1: NPWS Site Synopses for Designated Sites Appendix 2: Field Schedule for Winter Bird Surveys 2010/2011 Appendix 3: Peak bird counts of the study area at low water and high water, October 2010 to April 2011 Appendix 4: Light-bellied Brent Goose Records from the study area during 2010/11 winter survey Q:/LE09/548/02/Reports/Winter Birds 2010-11-1.doc i/i LIST OF TABLES PAGE TABLE 3.1: PEAK BIRD COUNTS OCCURRING AT LOW WATER IN THE STUDY AREA ....................................... 9 TABLE 3.2: PEAK BIRD COUNTS OCCURRING AT HIGH WATER IN THE STUDY AREA ..................................... 10 TABLE 3.3: SUMMARY OF LIGHT -BELLIED BRENT GOOSE COUNTS IN THE STUDY AREA . .............................. 11 TABLE 3.4: CONSERVATION OBJECTIVE SPECIES OF THE BLACKSOD BAY /B ROADHAVEN SPA AND ANNEX I BIRDS KNOWN TO OCCUR IN THE GLENAMOY BOG COMPLEX C SAC. ....................................................... 21 LIST OF FIGURES PAGE FIGURE 2.1: AVIAN COUNT SECTIONS AND VANTAGE POINTS IN THE STUDY AREA ...................................... 4 FIGURE 3.1: LOCATION OF PRINCIPLE BIRD ROOST SITES IN THE STUDY AREA . ........................................ 12 FIGURE 3.2 LIGHT -BELLIED BRENT GOOSE FLOCK AT GLENGAD , MARCH 2011. ...................................... 13 FIGURE 3.3 LIGHT -BELLIED BRENT GEESE DRINKING AT SMALL STREAM AY GLENGAD , MARCH 2011 .............. 14 Q:/LE09/548/02/Reports/Winter Birds 2010-11-1.doc i/i Section 1 EACS - Ecological Advisory and Consultancy Services Winter Bird Survey in the Sruwaddacon Bay Area 1 INTRODUCTION Fehily Timoney & Company (FTC) was commissioned by EACS - Ecological Advisory and Consultancy Services, on behalf of their client Shell E & P Ireland Ltd. (SEPIL), to survey and report on bird usage of the Sruwaddacon Bay area, Co. Mayo during the 2010/11 over-wintering period. This survey forms part of ongoing ecological monitoring in relation to the Corrib Gas Project. The main study area includes Sruwaddacon Bay, Glengad and the eastern half of Rinroe Strand. Birds occurring in the portions of North Rossport Bay, and the western half of Rinroe Strand, visible from the survey vantage points were also noted. These areas lie within the Glenamoy Bog Complex candidate Special Area of Conservation (cSAC, Site code 00500) with the exception of the extreme westerly sections at Rinroe which lie within the Broadhaven Bay cSAC (Site code 00472). The study area forms part of the Blacksod Bay/Broadhaven Special Protection Area (SPA, Site code 004037) for birds. This SPA was advertised in June 2011 and has a site area of 8,314 ha (a 13% increase in area over the 7,367 ha for the SPA - previously designated under S.I. No. 31/1995). The SPA, which extends across three cSACs: Glenamoy Bog Complex; Broadhaven Bay; and the Mullet/Blacksod Complex (Site code 00470), encompasses the study area and inshore sections of Broadhaven Bay and Blacksod Bay and is known to support nationally important populations of a number of avian species. The site synopses for these designated sites are provided in Appendix 1. The study area also encompasses part of the Mullet/Blacksod Complex Ramsar site (7IE036). The aims of this study are: • To describe bird distribution and abundance across the study area from direct observation • To examine the influence of the tidal cycle on bird distribution and abundance • To determine the importance of the study area for over-wintering birds, with particular reference to species with populations of national importance and qualifying species, as well as Annex I species (E.U. Birds Directive 79/409/EEC) in the associated designated sites • To compare these collected data with information from previous seasons. Q:/LE09/548/02/Reports/Winter Birds 2010-11-1.doc Page 1 of 26 Section 2 EACS - Ecological Advisory and Consultancy Services Winter Bird Survey in the Sruwaddacon Bay Area 2 METHODOLOGY 2.1 Field Surveys Field surveys were carried out between October 6 th , 2010 and April 27 th , 2011 (see Appendix 2 for survey schedule). Surveys were completed on a near weekly basis with low water and high water surveys typically being completed on consecutive days. On three occasions the low water and high water surveys were completed in the same day, due to the timing of the tides or limitations imposed by prevailing weather conditions. Standard bird census techniques and survey protocol were used for this study (Institute of Environmental Assessment 1995, Sutherland 1996, Bibby et al. , 2000). Field surveys were undertaken using suitable optical equipment ( i.e. telescope and binoculars). A summary of the visit schedule and prevailing weather conditions on each survey occasion is available in Appendix 2 of this report. The aquatic bird surveys followed a similar methodology to that used for aquatic bird surveys in the area for the Corrib project since 2002/2003. An updated methodology, which included more frequent counts, was agreed in consultation with National Parks and Wildlife Service (NPWS) in March 2009 and has been used for aquatic bird surveys since that time. The Sruwaddacon Bay study area is divided into six discrete Count Sections in order to assess bird usage in different portions of the bay (see Figure 2.1). Section 1 comprises the outermost part of Sruwaddacon Bay ( i.e. the mouth), including Glengad and the eastern half of Rinroe Strand and Section 6 comprises the inner bay, near the Glenamoy River estuary. Supplementary data were also recorded at additional sites which were visible from vantage point 1. These include a portion of North Rossport Bay and the western half of Rinroe Strand (see Figure 2.1 for the location of these additional sites). For the purposes of data presentation, peak count data over the survey period were grouped into Outer Bay (Count Sections 1 & 2), Middle Bay (Count Sections 3 & 4) and Inner Bay (Count Sections 5 & 6) regions. Peak counts for the study area as a whole (including the supplementary count areas) are also presented for both low water and high water counts. The surveys were conducted at ‘low water’ ( i.e. during the period two hours before or