Scottish Birds 38:1 (2018)
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Contents Scottish Birds 38:1 (2018) 2 President’s Foreword J. Main PAPERS 3 Seabird population trends on the Shiant Isles, Outer Hebrides, 2000–15 P. R. Taylor, R. MacMinn, S. Marsh, M. de L. Brooke, M. Macdonald, P. Hughes, F. Donald, H. Docherty, A. Over, J. Beaton, D. Scridel, L. Robertson & N. Currie 15 Honey-buzzards in central Scotland: observations and comparisons from two study areas during 2017 C.J. McInerny, K.D. Shaw, A. Little, K. Little, K. Hoey, K. Gibb & B. Kerr 30 Regular breeding by a pair of Whooper Swans in Ayrshire, 1991–2017 G. Shaw 35 Oystercatchers in Mid Deeside, North-east Scotland, in 2009–17 - numbers, breeding and effects of cold spells D. Jenkins SHORT NOTES 41 Brünnich’s Guillemot, Anstruther, 2016: postscript R.Y. McGowan 42 Golden Eagles predating Meadow Pipit nests J.C. Bain & H. Insley 44 Seasonality of North-east Scotland’s Common Scoters N. Littlewood 45 An offset metal grid thwarts predators of birds nesting in nest boxes R. Summers OBITUARIES 47 Ian Langford (1956–2017) J. Threlfall & J. Howie 48 Jimmy Steele (1962–2017) J. Nadin & C. McGuigan ARTICLES, NEWS & VIEWS 51 Tag-n-Track - tracking technology used to change the public perception on the Lesser Black-backed Gull H.A. Douglas & H. Riley 56 NEWS & NOTICES 61 ARTIST PROFILES Colin Woolf & John Cox 63 Other nests re-use 64 Homes for House Martins - on an aircraft or at sea D.J. & A.S. Bates, L.J. & T.F. Rogers 66 An exceptionally large Short-eared Owl winter roost in Fife K.D. Shaw 67 Predator perplexed J. Cole 68 BOOK REVIEWS 70 RINGERS' ROUNDUP J. Bowler 76 Black-billed Cuckoo, Dale of Walls, 18 September 2017 - second record for Shetland R. Tallack 78 White-crowned Sparrow, Foula, Shetland, 8 October 2017 - fourth record for Scotland D. Atherton 80 Siberian Blue Robin, North Ronaldsay, Orkney, 8 October 2017 - third Scottish record T. Gale & L. Hooper 82 White-winged Scoter, Yell & Unst, 16–22 October 2017 - third Scottish record and first for Shetland D. Preston 84 Blackpoll Warbler, Lochmaddy, North Uist, 23 October 2017 - fourth Outer Hebrides record B. Rabbitts 86 Pied-billed Grebe, Loch of Spiggie, Shetland, November 2017 - first record for Shetland R. Riddington 88 Red-eyed Vireo, Deerness, 8 October 2017 - second record for Orkney A. Leitch SIGHTINGS 91 SCOTTISH BIRD SIGHTINGS 1 October to 31 December 2017 S.L. Rivers PHOTOSPOT BC Hen Harrier P. Garrity 38:1 (2018) Scottish Birds 1 President’s Foreword President’s Foreword The new and greatly improved SOC website is now live! I am sure you will agree with me that this is a great step forward. Jane Cleaver is to be congratulated for her huge effort and tenacity in seeing this through to fruition. As I write this, the team behind the latest local atlas, Birds in South-East Scotland, is finalising its analyses, species accounts, maps and all that is involved with its production. Following extensive fieldwork, there has been a prodigious amount of effort put into the project and I for one am certainly looking forward to getting a copy. The atlas is dedicated to the late Ray Murray, a past President of the SOC and a major moving force behind this and the previous atlas. I commend this new tome, which now Plate 1. James Main, Musselburgh, includes breeding and wintering birds and is sure to enhance Lothian, January 2018. © Doreen Main your birdwatching opportunities in this part of the world. We are looking forward to the 2018 Scottish Birdwatchers’ Conference on 17 March at the SRUC Barony Campus, Parkgate, Dumfries. This year’s programme is entitled “Donald Watson Centenary Special: a celebration of the Birds of Dumfries and Galloway.” Thanks to SOC Dumfries Branch, BTO Scotland and staff at Waterston House for all their hard work in organising this event. The winter is now well upon us but, even in January, we have not had any really hard weather in the South-East of Scotland. What we have had is an influx of Hawfinches, which are normally very rare but they have been appearing in a few unusual places and in one of their old habitats - the Hirsel at Coldstream in the Borders. As in the past four years, the SOC and the Isle of May Bird Observatory will be running a Young Birders’ Training Course in July 2018. This course has proved most popular and will once again sponsor six enthusiastic young birders to stay at the observatory for a week to learn ringing and ornithological skills. As is mentioned in the news and notices section, Dave Allan, Events Coordinator at Waterston House, retires at the end of March after 13 years of service. Dave has been a stalwart of the Club over that time and has organised highly successful art exhibitions as well as year-round guided walks for beginners. This has brought in new members and much more. He will be missed - especially by the regular weekend visitors! Best wishes to Dave and his wife Alison in their retirement. Best wishes to everyone for 2018 - and good birding! James Main, SOC President 2 Scottish Birds 38:1 (2018) Seabird population trends on the Shiant Isles, Outer Hebrides, 2000–15 Seabird population trends on the Shiant Isles, Outer Hebrides, 2000–15 P. R. TAYLOR, R. MACMINN, S. MARSH, M. DE L. BROOKE, M. MACDONALD, P. HUGHES, F. DONALD, H. DOCHERTY, A. OVER, J. BEATON, D. SCRIDEL, L. ROBERTSON & N. CURRIE The Shiant Isles host one of Scotland’s most important seabird colonies and are designated a Special Protection Area. Ahead of a Black Rat eradication on the islands undertaken during the winter of 2015/16, a full census of the seabird population was undertaken to establish a baseline from which any changes could be assessed. The census was undertaken between 13 and 22 June 2015. The survey team conducted counts from land or sea using standard methodologies to derive a total pre-eradication baseline seabird population for the Isles. Population trends since 1999–2000, the date of the last full census, vary significantly between species. Fulmar, Guillemot and Kittiwake have suffered significant decreases, of 65%, 45% and 46% respectively, over these 15 years. This has been particularly marked for Kittiwake and Guillemot on some of the individual islands. On the other hand, Shag, Puffin and Razorbill populations on the islands appear to have been relatively stable. The Great Skua population has increased by 46% since 2000. Introduction Globally, seabirds are the fastest declining group of birds (Croxall et al. 2012). This is reflected in Scotland where many Scottish seabird populations are suffering significant and long-term declines (JNCC, 2015). The declines have been attributed to a range of factors, including oceano- graphic changes related to climate change, changes in fisheries policy, severe weather events, increase in generalist predators and presence of invasive, non-native predators (Votier et al. 2004, Wanless et al. 2007, JNCC 2015). To better understand these declines, their drivers and possible remedies we need to properly monitor seabird populations. The Shiant Isles are one of the most important seabird colonies in Scotland, hosting around 10% of British and Irish Puffins Fratercula arctica, 7% of Razorbills Alca torda and 1.8% of Shags Phalacrocorax aristotelis (Brooke et al. 2002, Mitchell et al. 2004). The presence of a Manx Shearwater Puffinus puffinus bone in archaeological remains and preferred habitat for Storm Petrels Hydrobates pelagicus suggest that both Manx Shearwater and Storm Petrels may have once bred on the islands. However, neither species has been recorded breeding, though Storm Petrels with brood patches were captured in mist nets on the islands in 1971 (Brooke 1973). The lack of petrels is likely linked to the Shiants population of Black Rats Rattus rattus, known predators of eggs and chicks (Stapp 2002, Towns et al. 2006). Black Rats are believed to have arrived on the islands in the 18th century. The RSPB led an EU LIFE+ Project that undertook an island restoration project to remove the population of black rats from the islands through an eradication done during the winter of 2015/16. We undertook a comprehensive count of the islands’ seabirds to provide an estimated total population and understand seabird population trends. We also aimed to establish a population estimate prior to the eradication of rats, so that this can be used as a baseline figure in future studies. We visited the islands from 13 to 22 June 2015. This work has been complemented by seabird productivity estimates calculated by RSPB monitoring team, but this work will not be presented here. 38:1 (2018) Scottish Birds: 3–14 3 Seabird population trends on the Shiant Isles, Outer Hebrides, 2000–15 Survey site The Shiant Isles (12 in number) lie east of the Isle of Harris (Outer Hebrides) and are composed of three main islands: Garbh Eilean, Eilean an Tighe and Eilean Mhuire (Figure 1). To the west, there is a short chain of islets and sea stacks called the Galtachan, the two most prominent being Galta Mor (to the west) and Galta Beag (to the east). Garbh Eilean and Eilean an Tighe are dolerite intrusions and are poorly drained with acidic soils and are joined by a short tidal isthmus. The north and east slopes of Garbh Eilean hold two very large boulder screes that sit under large cliffs. These boulder fields hold a significant percentage of the auk and Shag populations and present a significant challenge to completing a population census (Figure 2). Eilean Mhuire is mainly composed of softer sedimentary rock with deeper and more fertile soil.