JNCC Report No. 642 Summary of evidence of aggregations of Balearic shearwaters in the UK up to 2013 Parsons. M.a, Bingham, C.b, Allcock, Z.c & Kuepfer, A.d November 2019 © JNCC, Peterborough 2019 ISSN 0963-8091 For further information please contact: Joint Nature Conservation Committee Monkstone House City Road Peterborough PE1 1JY www.jncc.gov.uk This report should be cited as: Parsons, M., Bingham, C., Allcock, Z. & Kuepfer, A. 2019. Summary of evidence of aggregations of Balearic shearwaters in the UK up to 2013. JNCC Report No. 642, JNCC, Peterborough, ISSN 0963-8091. EQA: This report is compliant with the JNCC Evidence Quality Assurance Policy https://jncc.gov.uk/about-jncc/corporate-information/evidence-quality-assurance/. Affiliations: a JNCC – Inverdee House, Baxter Street, Aberdeen, AB11 9QA b RSPB North Scotland Office - Etive House, Beechwood Park, Inverness, IV2 3BW c Marine Scotland Science - 375 Victoria Road, Aberdeen, AB11 9DB d SAERI - Stanley Cottage North, Ross Road, Stanley, FIQQ 1ZZ, Falkland Islands Summary Balearic shearwater Puffinus mauretanicus is listed on Annex I of the EU Birds Directive (2009/147/EC). The EU Birds Directive requires Member States to classify Special Protection Areas (SPA) for birds listed on Annex I of the Directive and for regularly occurring migratory species. Balearic shearwater breeds solely in the western Mediterranean, numbering some 3000 pairs; it is listed by IUCN as Critically Endangered. Movements after the breeding season bring birds into Atlantic waters, primarily off Iberia and western France but also into UK waters, especially those of the English Channel during June to October. Most breeding colonies are SPAs, as are major aggregations around the French coast. There are currently no SPAs for this species in the UK. The Statutory Nature Conservation Bodies (SNCBs) are seeking to identify important marine areas in the UK that are used by aggregations of Balearic shearwater, to inform their identification of areas that may be suitable for classification as SPAs under the EC Birds Directive (2009/147/EC) and according to the UK SPA Selection Guidelines (Stroud et al. 2001). In this report JNCC provides a summary of evidence (gathered up to and including 2013) from a number of sources on the size and distribution of aggregations, to help the SNCB to identify possible sites. The main finding of this study was that analyses of a number of data sources on seabird distribution at sea did not detect any regularly occurring hotspots (as defined by established and peer-reviewed techniques) for Balearic shearwaters in UK waters that would be appropriate for identification as SPA. These data sources include a long-term and extensive dataset of seabird records at sea (ESAS) from which we detected one small hotspot in UK waters that subsequently failed to meet the regularity test required by the UK SPA selection guidelines to qualify as a SPA. On a finer geographical scale, in only one season out of three recent seasons of bespoke systematic surveys for the species, in west Lyme Bay and around Portland, were densities high enough to be measured. This level of regularity of use would not satisfy the UK SPA selection guidelines. Systematic July-October observations from coastal watch-points around SW England over four years indicated mean passage rates of 1.0-2.8 bird per hour, indicating the species regularly passes through much of that coastline, though there were few records of birds engaged in feeding or other types of behaviour where they remained in the area very long that would justify any SPA classification. Small numbers were recorded from coastal watch-points in midwinter. We conclude, based on the evidence reviewed, that conservation effort for Balearic shearwater in UK waters would be more appropriately targeted at spatially dispersed measures to combat threats at sea. Contents 1 Introduction .................................................................................................................. 1 2 Species status and distribution .................................................................................. 1 3 Methods ........................................................................................................................ 2 3.1. European Seabirds At Sea (ESAS) boat-based surveys ......................................... 3 3.2. Marinelife boat-based surveys and other information .............................................. 5 3.3. SeaWatch SouthWest land-based surveys ............................................................. 7 3.4. Mid-winter land-based pilot survey of St Ives Bay, west Cornwall ........................... 8 3.5. JNCC/NE-commissioned systematic boat-based surveys ....................................... 8 4 Results ........................................................................................................................ 10 4.1. European Seabirds At Sea (ESAS) ....................................................................... 10 4.2. Marinelife boat-based surveys .............................................................................. 14 4.3. SeaWatch SouthWest land-based surveys ........................................................... 17 4.4. Mid-winter pilot survey of St Ives Bay, west Cornwall ............................................ 19 4.5. JNCC/NE-commissioned systematic boat-based surveys ..................................... 19 4.5.1. 2009 surveys ................................................................................................. 19 4.5.2. 2011 surveys ................................................................................................. 19 4.5.3. 2013 surveys ................................................................................................. 21 5 Discussion .................................................................................................................. 22 5.1. Results from other published analysis ................................................................... 22 5.2. Possible bias in evidence sources ........................................................................ 23 5.3. Assessment of strengths and weaknesses of data sources .................................. 25 5.4. Application of SPA selection guidelines ................................................................ 27 5.4.1. Population size and density ........................................................................... 28 5.4.2. Species range ................................................................................................ 29 5.4.3. Breeding success .......................................................................................... 29 5.4.4. History of occupancy ...................................................................................... 29 5.4.5. Multi-species areas ........................................................................................ 29 5.4.6. Naturalness ................................................................................................... 30 5.4.7. Severe weather refuges ................................................................................. 30 5.5. Use of bird-borne telemetry devices: state of knowledge and potential future applications ..................................................................................................................... 30 6 Conclusions ............................................................................................................... 31 7 References ................................................................................................................. 32 8 Acknowledgements ................................................................................................... 34 Summary of evidence of aggregations of Balearic shearwaters in the UK up to 2013 1 Introduction The Statutory Nature Conservation Bodies (SNCBs) are seeking to identify important marine areas in the UK that are used by aggregations of Balearic shearwater Puffinus mauretanicus, to inform their identification of areas that may be suitable for classification as Special Protection Areas (SPAs) under the EC Birds Directive (2009/147/EC), and according to the UK SPA Selection Guidelines (Stroud et al. 2001). In this report JNCC provides a summary of evidence from a number of sources, on the size and distribution of aggregations, to help the SNCB to identify possible sites. Balearic shearwater is listed on Annex I of the EU Birds Directive (EU 2009). The EU Birds Directive requires Member States to classify Special Protection Areas (SPA) for birds listed on Annex I of the Directive and for regularly occurring migratory species. There are currently no SPAs for this species in the UK. The objectives of this report are to summarise all pertinent information on numbers and distribution of the species, primarily in UK waters but set in the context of the species’ wider distribution. The emphasis is to assess this information to identify the location, size and regularity of occurrence of any aggregations, in the context of the obligations of Article 4 of the Birds Directive. Article 4 states that “Member States shall classify in particular the most suitable territories in number and size as special protection areas for the conservation of these [Annex I] species in the geographical sea and land area where this Directive applies”. The UK SPA Selection Guidelines (Stroud et al. 2001) assist in the delivery of this aim; the report’s findings are discussed