Scottish Birds published by the SCOTTISH ORNITHOLOGISTS’ CLUB Volume 35(1) March 2015 Scottish Birds Established in 1958. Published quarterly by: The Scottish Ornithologists' Club, Waterston House, Aberlady, East Lothian EH32 0PY. Email: mail@the-soc.org.uk Phone: 01875 871330 www.the-soc.org.uk www.facebook.com/ScotlandsBirdClub twitter.com/ScottishBirding Editors: Co-ordinating editor Ian Andrews Peer-reviewed papers Dr Stan da Prato Assisted by: Dr I. Bainbridge Dr M. Marquiss Dr J.B. Nelson R. Swann Articles , news and views Jimmy Maxwell Dr Stuart L. Rivers Harry Scott Editorial correspondence: c/o SOC, Waterston House, Aberlady, East Lothian EH32 OPY. Email: mail@the-soc.org.uk To advertise in Scottish Birds or obtain back issues, please contact Waterston House. Designed and typeset by: Pica Design, 51 Charlton Crescent, Aboyne, Aberdeenshire AB34 5GN. Email: picades@ifb.co.uk Printed by: Swallowtail Print Limited, Unit 2 Drayton Industrial Park, Taverham Road, Drayton Norwich, Norfolk NR8 6RL. Natural History Museum Library Scottish Birds is the quarterly journal for SOC members, and is published in March, June, September and December annually. Containing original papers relating to ornithology in Scotland, topical articles, bird observations, reports of rare and scarce bird sightings, alongside branch and Club-related news, our members tell us that Scottish Birds is one of the key benefits of belonging to the SOC. Its different sections have been developed to meet the wide needs of the birdwatching community, and the publication is renowned for its first-class photography. An archive of the journal is available on the SOC website, where links can be found to other Club publications including the Scottish Bird Report online. More about the SOC... On the one hand, a birdwatching club; Established in 1936, the Scottish Ornithologists’ Club (SOC) is Scotland’s bird club with 15 branches around the country and a growing membership of over 3,000. Through a programme of talks, outings, conferences and other events, it brings together like-minded individuals with a passion for birds, nature and conservation. On the other, a network of volunteers across Scotland, gathering vital, impartial information about our wild birds; The data we collect is made available to conservationists, planners and developers, and is used by organisations such as the RSPB, as one of the first points of reference in informed conservation planning. Club Headquarters can be found at Waterston House, Aberlady, overlooking the scenic local nature reserve. Housed within, is the George Waterston Library, the largest ornithological library in Scotland, and the Donald Watson Gallery - one of the jewels in the Waterston House crown, exhibiting wildlife art all year-round. Join us... As well as receiving Scottish Birds every quarter, SOC members have access to a programme of talks and outings across Scotland and affiliation to a local branch of the Club. New members will receive a welcome pack on joining, plus a thank you gift if paying their subscription by direct debit. Annual membership rates* Adult (aged 18 and over) £ 32.00 Family (2 adults & all juniors at same address) £ 43.00 Junior (aged 17 or under) £ 12.00 Student (in full-time education) £ 12.00 Unwaged (in receipt of state benefits) £ 12.00 Concession (pensioner) £ 24.00 Joint Concession (at same address) £ 31.00 Life £ 620.00 Life family (at same address) £ 930.00 For non-UK addresses, there is a £15 supplement to all categories to cover postage. * Rates valid until August 2015, subject to change thereafter Front Cover: Fulmar, Fair Isle, June 2014. © Rebecca Nason ISSN 0036-9144 For more information about the Club and its activities, including details of how to join, please visit www.the-soc.org.uk or contact Waterston House on 01875 871 330, or email membership@the-soc.org.uk 23 MIX Paper from responsible sources www.fsc.org FSC® Cl 13523 Scottish Charity Reg. No. SC 009859 Contents \ Scottish Birds 35:1 (2015) 2 President's Foreword C. Mclnerny PAPERS 3 The status of the Gannet in Scotland in 2013-14 S. Murray, M.P. Harris & S. Wanless 19 A review of the status of breeding Black-necked Grebes in Scotland M. Holling SHORT NOTES 26 Changes in numbers of wintering Slavonian and Black-necked Grebes in south-west Scotland P.N. Collin 28 A dead Osprey chick in a double-shelled egg J. Savory, D. Bennett &T. Lightley 30 Red-backed Shrikes breeding in Moray in 2013 M. Cook OBITUARIES 32 James Stewart (1926-2014) T. Delaney & K.S. Macgregor ARTICLES, NEWS & VIEWS 34 A year in the life of Mousa: island nature reserve jewel W. Miles 42 NEWS AND NOTICES 44 Bird Photography Code of Practice D, Tipling 48 Artist's Profile: Lucy Newton 50 I thought you knew! A. Hogg 54 BOOK REVIEWS 56 RINGERS' ROUNDUP 61 2014 - a record breaking year on Fair Isle D. Parnaby 67 Marsh Warbler in first-winter plumage - SBRC identification criteria M.S. Chapman on behalf of the Scottish Birds Records Committee 78 Booted Warbler, Torness, 11-23 October 2014 - first record for Lothian I.J. Andrews &M. Eden 82 Scarlet Tanager, Barra, Outer Hebrides, 6-9 October 2014 - the first Scottish record K. Gillon 85 Cetti's Warbler, Barra, Outer Hebrides, 12 October 2014 - the second Scottish record C. Scott 87 Black-billed Cuckoo, North Ronaldsay, 23 October 2014 - first record for Orkney M. Warren 89 Spotted Sandpiper, Inverallochy, October 2014 to January 2015 - first record for North-east Scotland P.A.A. Baxter, SJ. Baxter & M.B. Cowie SCOTTISH BIRD SIGHTINGS 92 1 October to 31 December 2014 S.L. Rivers PHOTOSPOT BC Water Rail D. Main NATURAL HISTORY MUSEUM LIBRARY 1 3 MAR 2015 35:1 (2015) Scottish Birds 1 President's Foreword President's Foreword The Club journal, Scottish Birds, has been running in its current format since June 2009. It is fantastic, with an excellent blend of scientific papers, notes, news and descriptions of Club activities, which together showcase the SOC and its members in a wonderful way. The editorial team, led by Ian Andrews, does a huge amount of work to create each issue and I am sure I speak for all members when I offer my fulsome thanks to them. Certainly, I eagerly look forward to the next issue and all copies are carefully stored on my bookcase! Of course a major part of a journal is the quality of the articles that it publishes, and the editors are very grateful to all authors for their submissions. Can I therefore, on behalf of the editors, make a request to members to consider contributing to Scottish Birds. The journal is very inclusive and welcomes all submissions. If you have an article or note, or anything that you think would be of interest to other members, please contact Waterston House. To update members on the conversion of the SOC to a Scottish Charitable Incorporated Organisation (SCIO): following support for this at the AGM, the Club’s solicitors Morton Fraser made an application to OSCR, the Scottish Charity Regulator, and we have recently received preliminary approval. More work still has to be done, but we are hopeful that the conversion will occur on schedule at the end of the financial year, in late March 2015. 1 thank Alan Fox for taking a leading role in this process. The Scottish Birdfair (Scotland’s Big Nature Festival) will be running again this year in May, but with a change in venue being held at Musselburgh, in East Lothian. The SOC will be present at this important event; please see the announcement section for details. Turning to bird recording, and the SOC Local Recorders’ network, I’d like to welcome Ian Ricketts as the new Local Recorder for the Outer Hebrides (see inside back cover for contact details). Moving to the Clyde branch I extend my thanks to Val Wilson for the work she does as Local Recorder, but also in running the grapevine. This daily email service passes on bird sightings to branch members and has been a great source of information. Val has recently upgraded the service to Mailchimp and the new messages look very professional. Perhaps other branches might consider using such a system; they are a great way to pass on information and to keep in touch with members. If any branches are interested, please contact Jane Cleaver at Waterston House who will be happy to help. As I write, we have just had the second fall of snow in Glasgow this winter. Such conditions change bird behaviour and movements. The brightness caused by the snow has resulted in Robins singing in my back garden through the night, and I watched the unusual sight this morning of a Pied Wagtail feeding on the busy pavement at Byres Road. Let us hope this cold snap does not last and that milder weather comes soon. Best wishes to all in 2015. Chris Mclnerny, SOC President Plate 1. Chris Mclnerny, Glasgow January 2015. CJ. Mclnerny. 2 Scottish Birds 35:1 (2015) Plate 2. Bass Rock, the world's largest Gannet colony, 23 June 2014. © S. Murray The status of the Gannet in Scotland in 14 S. Murray, M.P. Harris & S. Wanless All 16 Gannet colonies in Scotland were counted in 2013-14. Combined colony totals indicated that Scotland currently holds 243,505 apparently occupied sites (58% and 46% of the east Atlantic and world populations, respectively). Numbers were divided very unevenly between the colonies with Bass Rock (now the world’s largest colony), St Kilda and Ailsa Craig together holding 70% of the Scottish population. Gannets started to nest on Barra Head, Berneray in 2007 and breeding may now be regular on Roekall. Numbers at St Kilda, Sule Stack and Scar Rocks were stable, but all other colonies had increased, some spectacularly. Overall the Scottish population increased by 33% between 2003-04 and 2013 -14 at an average rate of increase of 2.9% per annum. Although the Gannet appears less vulnerable to climate change than many other UK seabirds, the proposed construction of major offshore wind farms close to colonies in the North Sea and the imminent ban on fishery discards, could pose future threats to this species. Introduction Decadal counts of the number of Gannets Morns bassanus at colonies in Britain and Ireland have been made since the 1980s (Murray ft Wanless 1986, 1997, Murray et al. 2006). At the time of the last census in 2003-04, Scotland had 14 gannetries containing 182,511 apparently occupied sites, which represented 58% of the total for the east Atlantic and 44% of the world populations, respectively (Murray et al. 2006). Numbers at most colonies were increasing and new gannetries had been founded at Sule Skeny (2003) and Westray (2003). However, the overall rate of increase of the Scottish Gannet population appeared to have slowed compared to the previous 20 years. Given that widespread declines of seabird species have been reported at Scottish colonies since 2000 (Miles 2013), the 2013-14 Gannet survey provided an ideal opportunity to assess the current status of one of Scotland’s most iconic species. 35:1 (2015) Scottish Birds: 3-18 3 The status of the Cannet in Scotland in 2013- 14 Methods Aerial surveys of St Kilda, the Flannan Isles, Sula Sgeir, Sule Stack and Sule Skerry were made in 2013 under contract to Scottish Natural Heritage (SNH) and full section-by-section details of these counts are given in Wanless et al. (2015). Further aerial surveys of Scar Rocks, Ailsa Craig, Hermaness, Troup Head and Bass Rock were made in 2014 in collaboration with the Royal Commission on the Ancient and Historical Monuments of Scotland (RCAHMS). Other observers counted Foula in 2013 and Barra Head (Berneray), Rockall, Westray, Hermaness (land and sea count), Noss and Fair Isle in 2014. The counts of the Bass Rock and Scar Rocks are documented in detail in Murray et al. (201 4b, c) and the current paper concentrates on the counts of colonies not detailed elsewhere and gives an overview of the state of the Scottish population in 2013-14. The 2013-14 survey was carried out using similar methods to those adopted in 1984-85 and refined in 1994-95 and 2003-04. Thus, where possible, colonies were photographed from the air and the numbers of apparently occupied sites (AOS, a site occupied by one or two Gannets irrespective of whether nest material was present) were counted. Although non-breeding birds in ‘club’ areas are easily distinguished when counts are made from the land or sea, they can cause problems during aerial surveys. In practice, most non-breeders fly off in response to the aircraft; those that remain are usually obvious due to (a) the irregular spacing of birds/pairs compared to site holders/nest holders, and (b) the lack of guano that makes the club areas less white than breeding areas. In 2013-14 visits were made to check colony boundaries and the locations of clubs at St Kilda, Flannan Isles, Sula Sgeir, Troup Head, Hermaness, Bass Rock and Ailsa Craig. Prior to the current survey counts were done by marking AOS either directly on colour prints, or after projecting colour transparencies onto a flat white surface. However, in 2013-14, digital cameras were used for the aerial surveys and the downloaded images were counted on computer screens using either Photoshop or Paint Shop Pro 7 software. This enabled images to be viewed at different magnifications and colour contrasts and each AOS was blocked out with a dot using the paintbrush option. Dot colour was changed after every 100 AOS to facilitate keeping a rough tally of the total and a tally counter was used to keep an accurate running score. Counts were made independently by two or more experienced counters, without knowledge of totals recorded by the other counters, to prevent subconsciously counting high or low because of prior information. Elsewhere, counts were made directly in the field, sometimes augmented by photographs taken from the sea or land. In these cases, the unit was the apparently occupied nest (AON, one or two birds at a site with nest material present). Sites with a chick, but no obvious nest, were included in this category. Neither count unit provides an unbiased estimate of the number of breeding pairs, nor is it strictly correct to equate occupied sites with pairs, as some sites may be held by a single bird for at least a year (Nelson 1978). The unavoidable lack of cross-colony standardisation makes it impossible to calculate a grand total for Scotland in terms of a common unit. Our estimates of the Scottish population, and the east Atlantic and world totals, are therefore, a combination of totals of AOS at the majority of colonies and a few counts of AON. No correction factors were applied to either unit, and for convenience the grand total, is expressed as AOS. Surveys were mainly carried out in June or July, except for Barra Head (May) and the Hermaness aerial survey (August). Replicate counts during this and previous censuses indicate that within and between observer errors are typically between 5-10% (Murray ft Wanless 1986, 1997). Differences between counts made in 2003-04 and 2013-14 of <10% could, therefore, potentially be due to observer error rather than real changes in numbers. Accordingly, changes of < 10% were assumed to indicate no significant overall change and an approximately stable population. For all colonies images were checked to pinpoint any major changes in colony extent or nesting density between surveys. Unless otherwise stated, counts from 2003-04 and 2013-14 are directly comparable. 4 Scottish Birds: 3-18 35:1 (2015) The status of the Cannet in Scotland in 2013- 14 To set the 2013-14 results in context, all counts since 1900 known to us can be found in the papers listed in the references and are plotted in Figure 2 (colonies established prior to 1930) and Figure 3 (colonies founded since 1930). Results All 14 g'annetries that were active in Scotland in 2003-04 were occupied in 2013-14, a new colony has become established on Barra Head (Berneray) and breeding on Rockall appeared to have become more regular (Figure 1). Below we present the 2013-14 counts in detail and summarise the current status of each colony in terms of changes since 2003-04 and in some cases over the longer term. Scar Rocks (established in the 1930s, numbers stable, colony probably full) An aerial survey on 23 July 2014 indicated that there were 2,376 AOS on Scar Rocks, a total that was almost identical to that in 2004 (2,394 AOS). Careful scrutiny of the images indicated that there is veiy little unoccupied, suitable nesting habitat left and the colony is probably at, or veiy close to, maximum capacity. Ailsa Craig (occupied since the 16th century, increasing) Counts by three observers of images taken on 16 June 2014, were highly consistent (range: 32,503- 33,132 AOS) and gave a mean total of 33,226 AOS (Table 1). At face value this suggested an increase of 22°/o since 2004. However, the 2004 count was unusual in that in contrast to most of the other Scottish gannetries, numbers on Ailsa Craig had declined since the previous survey in 1995. Inspection of the 2004 photographs revealed that the decrease seemed to be due to a decline in breeding density throughout the colony, most notably in the almost empty areas apparent within Section 9/10/11. The overall total for 2014 is very similar to the 1995 figure suggesting that the population has recovered from the 2004 decline (Table 1) (Plate 3). However, detailed comparisons of the section totals for 1995 and 2014 indicate that numbers in some areas remain low, notably sections 4 8t 5, 6 and 8 on the west side of the island. The most pronounced increase has occurred in sections 19 H 21 along the upper slopes at the southern edge of the colony. The reason for these marked differences is unknown. Some limited abstraction of boulder spoil has been carried out at both north and south quarries in recent years and Ailsa Craig has been free of rats since 1991 (Zonfrillo 2001). Both these operations could potentially have impacted on the Gannets, the former by possibly deterring recruitment to parts of the colony, the latter by making conditions in cliff top areas more attractive. However, Ailsa Craig has a long history of marked and unexplained fluctuations in numbers (Nelson 1978) so any interpretation of these changes must remain speculative. The colony’s difficult terrain makes detailed population studies challenging, but increasing the frequency at which aerial surveys are carried out might help resolve some of the uncertainties. Hermaness# Sule Skerry Sule Stack-^ \ SulaSgeir# Fiannan Isles Foula# #Noss Westray • Fair Isle St Kilda Troup Head Barra Head • Bass Rock • Ailsa Craig % X • T ^ ^Scar Rocks Figure 1. The locations of Gannet colonies in Scotland, 2013-14. Rockall is located 300 km west of St Kilda. 35:1 (2015) Scottish Birds: 3-18 5 The status of the Can net in Scotland in 2013- 14 Plate 3. Ailsa Craig, the gannetry from the south-west, 16 June 2014. © S. Murray Table 1. Counts (AOS) from aerial photographs of Ailsa Craig in 1995, 2004 and 2014. The count sections are shown in Murray & Wanless (1997). Count section 1 2 3 4 & 5 6 7 8 9,10 &11 ‘12 13 & 14 15 & 16 17 18 & 20 19 & 21 22 23 Total 5 August 1995 946 187 441 1877 2097 954 4300 11959 140 1994 2263 21 1439 3660 0 177 32455 6 June 2004 1009 85 245 1222 1333 809 2711 10338 157 1411 2279 38 981 4279 0 236 27133 16 June 2014 1374 59 269 1139 1578 1202 3279 12634 148 1845 2283 57 1138 5880 0 341 33226 Barra Head (Berneray) (established 2007, increasing) The first record of Gannets breeding on Barra Head was a bird on a nest on the south cliffs in 2007. Subsequent records have been one nest (2008), two nests (2010), four nests (mid-June 2011), two chicks near fledging (August 2012) and seven nests on 11 May 2014 (details from M. Forrest in litt., J. Love in litt.). 6 Scottish Birds: 3-18 35:1 (2015) The status of the Cannet in Scotland in 2013- 14 Rockall (colonised 1992, occupied intermittently, increasing) The first confirmed breeding on this wave-swept rock was of a single nest with an egg on 19 June 1992 (Belaoussoff 1993). There have been three further confirmed breeding records (nests and eggs found), the most recent on 1 June 2012 when there were four well-built nests, one with an egg and eight trace nests (Hancock in Murray et al. 2014a). N. Hancock, who was resident on the rock between 4 June and 17 July 2014, counted 28 occupied sites including three nests with eggs, 13 other well-built nests and 12 trace nests. Thus it would appear that Gannets now attempt to nest on Rockall in most years. However, successful breeding seems highly unlikely since the breeding sites are very vulnerable to bad weather. For example during a severe gale on 1 July 2014 waves broke over Hall’s Ledge (Plate 4) sweeping away all the nests, even those on the summit. While Gannets may persist in attempting to breed on Rockall the colony’s vulnerability to storms would seem to make it highly unlikely that it will ever produce chicks. Plate 4. Rockall, Nick Hancock (left) on Hall's Ledge, 4 June 2014. There were six Gannet nests on the summit, 12 on Hall's Ledge and 10 elsewhere, all were swept away in a severe gale on 1 July. © A. Smith 35:1 (2015) Scottish Birds: 3-18 7 The status of the Cannet in Scotland in 2013- 14 St Kilda (occupied since at least the 17th century, numbers stable, but space for expansion) Together the three components of the St Kilda gannetry (Boreray, Stac Li and Stac an Armin) have been the largest colony in the east Atlantic for the last 100 years. However, numbers have shown little overall change in the three aerial surveys carried out in 1994 (60,428 AOS), 2004 (59,622 AOS) and 2013 (60,290 AOS) (Plate 5). Despite the fact that there would appear to be plenty of unused, suitable nesting habitat the population seems to be stable and has been overtaken by Bass Rock (see below). Plate 5. Boreray, St Kilda. This group of breeding Gannets on the east face of Clagan na Rosgachan have grown from a single AOS in 1959 to 671 AOS in 2013. This is one of the few areas where numbers have increased over the last 50 years. © S. Murray Flannan Isles (established around 1969, increasing rapidly) An aerial survey made on 19 June 2013 found 5,280 AOS, an increase of 91% since 2004. The presence of veiy large numbers of non-breeding birds and plenty of apparently suitable nesting habitat, suggest the population will continue to grow rapidly. Sula Sgeir (occupied since at least the 1 6th century, increasing after a previous decline) An aerial survey made on 18 June 2013 found 11,230 AOS, an increase of 22% since 2004. The colony is the only one in the UK that is still exploited for food with c.2000 well-grown chicks (‘gugas’) harvested each year. In 2004 there was concern that numbers were declining, but the 2013 count indicates that the population is now increasing and there would appear to be ample space for further colony expansion. Sule Stack (occupied since at least the 18th century, numbers stable, colony probably full) An aerial survey made on 18 June 2013 found 4,550 AOS, almost identical to the count of 4,618 AOS in 2004. There have been no changes in numbers or colony extent since at least 1994 which suggests that the rock is fully occupied. 8 Scottish Birds: 3-18 35:1 (2015) The status of the Gan net in Scotland in 2013- 14 Plate 6. Hermaness showing the site of the 2003 winter landslide. Breeding Gannets on Soorie Face (left) were unaffected, but a large number of nests were destroyed in a summer landslide on Saito (right), 15 June 2010. © RCAHMS Sule Skerry (established 2003, increasing rapidly) Breeding was first confirmed in July 2003, when 15 pairs with eggs or chicks were found on the west side of Stack Geo (Blackburn ft Budworth 2004). In 2004, 57 AOS were counted from aerial photographs. The survey on 18 June 2013 indicated that the colony had increased 30- fold with a total of 1,870 AOS. Westray (established 2003, increasing rapidly) A count from the land on 16 June 2014 found 751 AON (Bell 2014), a 50-fold increase from 14 AON on 21-22 June 2004. In 2012 there were 623 nests (Meek 2013). Foula (established in the mid-1970s, probably increasing) A count made from the sea by S. Gear on 10 June 2013 found 1,226 AON. Checks made from the land on 7 July showed additional adult plumaged birds on other ledges although no obvious signs of breeding behaviour were noted. The 2013 count indicates that the colony has increased by 33°/o from 919 AON in 2004. However, the 2013 count was slightly lower than the total in 2007 (1,370 AON, SNH unpublished data.). This suggests that currently the colony may not be growing, but an aerial survey would be useful to check this. Hermaness (established around 1917, increasing) An aerial survey of the colony on 15 August 2014 achieved close to complete photographic coverage of the offshore skerries and the main cliffs. Two independent counts of the photographs gave totals of 25,609 AOS and 26,245 AOS respectively, and a mean of 25,927 AOS. Fortuitously, SNH staff had counted the colony earlier in the season (9 June- 17 July) using the same methods as in 2003 (a direct count of nests (AON) from fixed vantage points, supplemented by boat counts of areas hidden from the land). Their initial land/sea count was given as 27,033 (Heubeck et al 2014), but detailed comparison of the counts with those from the aerial survey showed that there had been double counting of some areas that were difficult to delimit from the land and sea and a corrected total of 24,885 AON was substituted (Pawley 2014). The aerial survey total would also have been higher had 35:1 (2015) Scottish Birds: 3- 18 9 The status of the Gannet in Scotland in 2013-14 we not been able to exclude the majority of non-breeders present on the cliffs, which are a well documented feature of this colony. This was mainly due to the ground checks made by J. Swale at the time of the land count, who scrutinized the air photographs for both non-breeding birds and hidden ground. This approach worked well, with each count in effect validating the other. Given this, we have used 25,580 AOS (the mean of the land count and the mean of the two aerial counts Table 2) as the colony total for 2014, a 64% increase over the 15,633 AON in 2003. Table 2. Counts of Hermaness (AON & AOS) from land and sea in 2003 & 2014 by SNH and an aerial survey in 2014, of AOS, by RCAHMS. Count section 26 June & 26-27 July 2003 9 June-17July 2014 15 August 2014 Method Land photographs & Land photographs & Aerial counts and sea counts counts and sea counts photographs Greing 109 141 141 Humla Stack 580 1175 1266 Humla Houl 629 1128 664 Burra Stack 641 930 1020 Clingra Stack 317 951 750 Flodda Stack 38 304 393 Neap North 1190 997 1526 Neap-Soorie 3873 6370 7315 Soorie-Geo Saito 2606 4410 3362 Neapna Stack 550 511 511 Soorie Stacks 60 83 83 Saito 1941 1984 2242 Tipta Skerry 0 0 289 Rumblings East 869 1767 2111 Rumblings West nc 95 176 Vesta Skerry East 1745 3457 3151 Vesta Skerry West 485 582 927 Total 15633 24885 25927 Mean for 2014 25580 Noss (established 1914, increasing) A whole colony count made from the land and sea in June 2014 found 11,786 AON (Denton et al 2014), an increase of 36% since 2003 (Table 3). The count follows well-established methodology in place since 1992 and each of the five counts made since then by SNH staff have shown progressive increases at both section and colony level. Table 3. Counts (AON) from land and sea of Noss in 2003, 2008 and 2014 by SNH. Count Section 8-14 June & 9-30 July 2003 June 2008 11 June to 2 July 2014 Cradleholm 4 8 41 Holmoless 93 115 126 Holmoless to Geordie's Holes 2008 2212 2254 Geordie's Holes 70 65 239 Rumblewick 355 384 379 Rumblewick Face 320 450 581 Cuddack's Geo 3 9 56 Noup South 2850 3048 3667 Noup East 709 860 937 Noup North 965 1124 1253 Rump South 885 938 1259 Rump North 387 537 793 Geo Heogatoug 3 17 201 Total 8652 9767 11786 Scottish Birds ; 3-18 35:1 (2015) 10 The status of the Gan net in Scotland in 2013- 14 Fair Isle (established 1974, increase since 2004, but may currently be declining) A land and sea count is carried out annually by Fair Isle Bird Observatory Trust staff. The 2014 count was 3,591 AON (Parnaby 8t Hatsell 2014). This represented a 92°/o increase over the 1,875 AON count for 2004, but was well down from the peak count of 4,085 nests recorded in 2011. This recent decrease would appear to be genuine, but Fair Isle is a difficult colony to count and switching to an aerial survey would help resolve uncertainties. Troup Head (established 1987, increasing rapidly) The Troup Head g'annetiy was photographed from the air on 30 June 2014. Photographic coverage of all the breeding cliffs was complete, apart from one small area that was subsequently checked during a field visit to identify club areas and non-breeding groups. Since this was the first aerial survey of this colony, boundaries of count sections were delimited to tie in with prominent, named coastal features and ideally should be used in future aerial surveys (Plates 7 ft 8). Two independent counts gave totals of 6,581 and 6,332 AOS respectively, a mean total of 6,456 AOS. The field visit highlighted that veiy large numbers of non-breeding club birds were present, particularly at the western end of the colony. Counts of these areas on the aerial photographs estimated that there were at least 1,816 club birds ashore at that time. Section counts were 1,278 AOS in A (Troup Head-Thirlet Point), 1,839 AOS in B (Thirlet Point-Mercury Heugh), 655 AOS in C and 2,684 AOS in D (Mercury Heug'h-Ignet Craig). The cliffs on either side of the currently occupied sections appear to offer ample space for further colony expansion and the Gannets are clearly colonising broad ledges that are occupied by Guillemots Uria aalge. Comparing the 2014 total with a land and sea count of 1,547 AON on 1 July 2004 suggests an increase of over 300%. However, due to the difference in counting units this value is likely to overestimate the increase. Other recent counts from the land and sea using AON are 1,810 AON on 23 May-26 June 2009 (http://jncc.defra.gov.uk/smp/), 2,787 on 7-9 June 2010 (D. Goulder/RSPB ft R. Mavor/JNCC) and 2,885 AON on 15 -25 June 2013 (Anderson 2013). Given the current size and complexity of the Troup Head gannetiy, switching to an aerial survey augmented by land checks to establish boundaries of the club areas would seem the most effective way of monitoring changes in numbers. Plate 7. Count sections A and B between Troup Head and Mercury Heugh. Note non-breeders on the upper grass slopes of section A, 30 June 2014. © RCAHMS 35:1 (2015) Scottish Birds: 3-18 11 The status of the Cannet in Scotland in 2013- 14 Plate 8. Troup Head count sections C and D between Mercury Heugh and Ignet Craig (not shown), 30 June 2014. © RCAHMS Plate 9. Bass Rock from the north-east. Jetty and landing top left, 23 June 2014. © S. Murray 12 Scottish Birds: 3-18 35:1 (2015) The status of the Gan net in Scotland in 2013- 14 Bass Rock (occupied since at least the 15th century, increasing) An aerial survey was carried out on 23 June 2014 in ideal conditions (Plate 2). Two independent counts gave 75,829 and 74,690 AOS respectively, a mean total of 75,259 AOS, indicating an increase since 2004 of 57°/o. This made the Bass Rock the world’s largest colony of Gannets (Murray et al 2014b), relegating St Kilda (60,290 AOS in 2013), and Bonaventure Island in Canada (47,669 AOS in 2011) to second and third places respectively (Chardine et al. 2013, Chapdelaine ft Rail 2014). There is now little suitable, unoccupied nesting habitat on the upper parts of the rock, but since 2009 large numbers have congregated on the rocks around the landing area (Plate 9) with many apparent pairs showing pre-breeding behaviour (M. Sheddan pers. comm.). Table 4. Summary of counts of Scottish Gannetries in 2013-14 and changes since the 2003-04 survey. The rate of change for the total Scottish population was calculated assuming that the combined colony counts had all been made 10 years apart. Colony Year AOS/AON Year AOS/AON % change % per annum change between counts Bass Rock 2004 48065 2014 75259 +57 +4.6 St Kilda 2004 59622 2013 60290 + 1 +0.1 Ailsa Craig 2004 27130 2014 33226 +22 +2.0 Hermaness 2003 15633 2014 25580 +64 +4.6 Noss 2003 8652 2014 11786 +36 +2.9 Sula Sgeir 2004 9225 2013 11230 +22 +2.2 Troup Head 2004 1547 2014 6456 +317 + 15.4 Flannan Isles 2004 2760 2013 5280 +91 +7.5 Sule Stack 2004 4618 2013 4550 -1 -0.2 Fair Isle 2004 1875 2014 3591 +92 +6.7 Scar Rocks 2004 2394 2014 2375 -1 0 Sule Skerry 2004 57 2013 1870 +3181 +47.4 Foula 2004 919 2013 1226 +33 +3.3 Westray 2004 14 2014 751 +5264 +48.9 Rockall 2004 no check 2014 28 7 ? Barra Head 2004 0 2014 7 new colony new colony Total 2003-04 182511 2013-14 243505 +33 +2.9 Table 5. Latest world population estimates of the Gannet. *France has two other colonies with a total of only three pairs. The Irish total is provisional. Number of Year Total % NE Atlantic % World Country colonies counted AOS/AON population population Source Scotland 16 2013-14 243505 58.4 46.3 This survey Ireland 6 2014 47754 11.4 9.1 Newton (2014) Wales 1 2009 39293 9.4 7.5 Murray (2009) Iceland 8 2013-14 37216 9.0 7.1 Gardasson (in press) France 1* 2014 21545 5.1 4.1 LPO (2014) England 1 2012 11061 2.6 2.1 RSPB (2012) Channel Isles. 2 2011 7885 2.0 1.5 E. Morgan/Alderney Wildlife Trust Norway 10 2013 6000 1.4 1.1 R.T. Barrett (pers. comm.) Faeroe Isles. 1 1996 2340 0.5 0.4 Skov et al. (2002) Germany 1 2014 656 0.1 0.1 J. Dierschke (pers. comm.) Russia 1 1998 35 <0.1 <0.1 Y.V. Krasnov (pers. comm.) NE Atlantic total 48 417290 Canada 6 2013 108404 20.6 Environment Canada, Canadian Wildlife Service (unpubl. data) World total 54 525694 100 100 35:1 (2015) Scottish Birds: 3-18 13 The status of the Cannet in Scotland in 2013-14 ooooooooooooo Figure 2. Counts of long-established (since before 1930) Scottish Gannet colonies between 1900 and 2014. 7,000 6,000 5,000 - is) 4,000 O < 3,000 2,000 1,000 Fair Isle Foula Flannan Isles Troup Head Scar Rocks Sule Skerry Westray 1930 1940 1950 1960 1970 1980 1990 Figure 3. Counts of Scottish Gannet colonies founded since 1930 up to 2014. 2000 2010 2020 14 Scottish Birds: 3-18 35:1 (2015) The status of the Gannet in Scotland in 2013- 14 Total numbers in Scotland The counts documented above were combined to provide an estimate of the total Scottish population in 2013-14. The overall total for colonies counted using AOS was 226,116 and the total for those counted using AON was 17,389 (Table 4). Combining these figures and expressing them as AOS (the dominant unit), gave a Scottish total of 243,505 AOS. Numbers were divided vexy unequally between the 16 colonies with the Bass Rock, St Kilda and Ailsa Craig together holding 70°/o of the Scottish population. Discussion After the last survey of Scotland’s Gannets in 2004, we speculated that the sustained period of increase throughout much of the 20th century might be coming to an end. Thus, while between 1984-85 and 1994-95 the Scottish population had increased by 27%, an average growth rate of 2.4% pa, by 2003-04 these values had declined to 6% and 0.6% pa, respectively (Murray et al. 2006). Much of this change was attributable to the situation in the three largest colonies, with numbers stable on St Kilda, a marked slowing of the rate of increase on Bass Rock and a decline of 16% at Ailsa Craig. Set against these findings, two new colonies had been established in Orkney (Sule Skerry and Westray) and many of the small to medium sized colonies were still increasing, in some cases rapidly. Whilst the cause (or causes) of these contrasting trends was uncertain, the observed patterns were consistent with density dependent effects. Thus, changes were most marked at the larger colonies where competition for resources would be expected to be greater, particularly if conditions were further exacerbated by reduced food availability as a result of climate change and/or fishing pressure (Davies et al. 2013). In addition, evidence from British and Irish ringing recoveries suggested that adult survival rate had decreased, which would also potentially reduce population growth rate (Wanless et al. 2006). However, the findings from the latest survey presented here, indicate that these concerns were unfounded since over the last decade the Scottish Gannet population has increased by 34% at an average rate of 2.9% pa. Of the three largest colonies only St Kilda has barely changed and indeed has been overtaken by Bass Rock, which is now the largest Gannet colony in the world. Numbers on Ailsa Craig have recovered and are now back to the level they were in 1995. A similar reversal of fortunes was also apparent at Sula Sgeir, with the 2013 total the highest of the four counts made here since 1985. This increase is particularly surprising given that up to 2,000 well grown Gannet chicks (‘gugasj continue to be killed under license each year. Without detailed data on the demography of Gannets at this colony an objective assessment of the impact of the guga hunt and associated disturbance is impossible (Beatty 1992). However, it seems unlikely that the increase is driven by the colony’s own production, but rather that it is due to immigration from neighbouring colonies, possibly St Kilda and Sule Stack, neither of which are currently increasing. Favourable conditions over the last decade are also evidenced by numbers at most of the small and medium sized colonies increasing at varying rates, a new colony being established on Barra Head, and even Rockall far out in the Atlantic, has seen the largest number of nests yet recorded on it. Only numbers at Sule Stack and Scar Rocks are unchanged, but all the evidence suggests that this is due to lack of nesting space rather than poor breeding conditions. Although totals at the Shetland colonies of Foula and Fair Isle were higher in 2013-14 compared to 2003-04, it appeared that numbers might in fact have peaked during this period and thus the populations are now declining. However, taken as a whole the changes apparent in Scottish Gannet colonies are very much in line with those anticipated by comparisons of foraging activity in 2000 and 2009, that indicated that conditions had become more favourable (Davies et al 2013). Thus, colony-specific trip durations were significantly shorter in 2009 particularly at the larger colonies and those in the North Sea. Improved conditions for Gannets contrasts markedly with the situation in many other Scottish seabirds where populations are declining and breeding failures are becoming more frequent (Miles 2013). While the cause, or causes, of these problems have not been fully ascertained, poorer 35:1 (2015) Scottish Birds: 3-18 15 The status of the Gannet in Scotland in 2013- 14 conditions as a result of climate change is a leading candidate (Russell et al 2014). However, ironically, while Gannets seem less sensitive to climate change and over-fishing than many other seabird species, they may be more vulnerable to some of the proposed ways of combating these problems. Thus, Gannets have been identified as being at risk of collision mortality at offshore wind farms (Cook et al. 2012) and the granting of recent planning consent for major developments in the Moray Firth (Plate 10) and on the Bell Rock Bank, are likely to overlap with foraging areas of birds from Troup Head and the Bass Rock, respectively. If these developments do go ahead they could, therefore, impact on these colonies, although the magnitude and nature of effects are currently highly uncertain. As well as potential changes associated with offshore renewables, imminent changes in fisheries practice as part of the reform of the Common Fisheries Policy and the end to pelagic and demersal discards, will remove a major source of prey for scavenging seabirds, including Gannets (CEU 2012). It seems likely that this will result in changes in behaviour, distribution and abundance of affected species (Bicknell et al. 2013). Thus, although Gannets currently seem to be one of the few seabird species that are increasing in Scotland, conditions may well change over the coming years making it particularly important to continue collecting data on abundance. Although it is possible to count the numbers of nests in small Gannet colonies from the land or the sea with reasonable accuracy, as numbers increase this becomes progressively more difficult. In most colonies it soon becomes impossible to view the entire colony from the land and counts have to be made from both the land and sea, which increases the risk that some areas are overlooked while others are counted twice. Most of the main Scottish colonies are now surveyed by aerial photography, which has several important advantages. Crucially it is usually possible to delimit discrete counting areas using natural features of the cliffs. If these areas are standardized (e.g. Troup Head) the approach enables detailed comparisons to be made between surveys and thus identify if the extent and/or density of the colony has changed. The value of this method is further enhanced by the advent of digital photography and associated software for viewing, manipulating and archiving images which in future will make it much easier to compare results from successive surveys. Given the high conservation importance of the Scottish Gannet population and potential concerns about the adverse effects of offshore wind farms and/or changes in EU discard policy, maintaining the long tradition of colony counts of this species using 21st century technology should be a top priority. Acknowledgements Our sincere thanks go to the many people who contributed to making this survey a success. We are well aware of the difficulties involved in just reaching some of the remote colonies, so are especially grateful to Sheila Gear for Foula, Miranda Forrest and John Love for Barra Head and Nick Hancock for his epic on Rockall. Although Gannet counting wasn’t the purpose of his stay, Plate 10. Beatrice Field, inner Moray Firth. Announced in 2014, this will be the core area of a 100 wind-turbine development, 28 February 2011. © S. Murray 16 Scottish Birds: 3-18 35:1 (2015) The status of the Cannet in Scotland in 2013- 14 Plate 11. Gannets surround the ruined medieval chapel on Bass Rock and even breed between its walls, 23 June 2014. © S. Murray he contributed a unique ornithological record to the history of the rock. From SNH we thank Jonathan Swale and Afra Skene for help in Shetland; from the RSPB, Chris Bell and Alan Leitch in Orkney and Crystal Maw at Ailsa Craig. From NTS, Susan Bain and Paul Sharman for their help on St Kilda. Jill Harden, Maggie Sheddan, Angus Smith, Duncan Goulder and Roddy Mavor all assisted in various ways. The aerial survey in 2013 was made under contract to SNH and we thank Andy Douse for facilitating this work. Finally, special thanks are due to our pilots, David Rutter in 2013 and Ronnie Cowan in 2014, whose skill and enthusiasm were vital to the success of the aerial surveys. Dave Cowley of RCAHMS made the flights in 2014 possible and without his support some of the key colonies would not have been surveyed. References Anderson, V. 2013. Gannet: Full colony count, Troup Head, 2013. Unpublished report, RSPB, Strathbeg. Beatty, J. 1992. Sula: The Seabird Hunters of Lewis. Joseph, London. Belaoussoff, S. 1993. Northern Gannet and Common Guillemot nesting on Rockall. British Birds 86: 16. Bell, C. 2014. Westray and Papa Westray, 2014 annual report. RSPB, Orkney. Bicknell, A.W.J., Oro, D., Camphuysen, C.J. ft Votier, S.C. 2013. Potential consequences of discard reform for seabird communities. Journal of Applied Ecology 50: 649-658. Blackburn, A. Et Budworth, D. 2004. A new gannetiy for the UK. Seabird Group Newsletter 96: 10. CEU 2012. Outcome of the Proceedings of the Agriculture and Fisheries Council of 12 June 2012, Brussels, Belgium. Interinstitutional File: 2011/0195 (COD), 14 June 2012, 11322/12, 78 pages. Chardine, J.W., Rail, J-F. Et Wilhelm, S. 2013. Population dynamics of Northern Gannets in North America, 1984-2009. Journal of Field Ornithology 84: 187-192. Chapdelaine, G. Et Rail, J-F. 2014. Northern Gannet - a sentinel species for the Gulf. 3rd edn. http://planstlaurent.qc.ca/en/state_monitoring/ monitoring_sheets.html. Cook, A.S.C.P., Johnston, A., Wright, L.J. Et Burton, N.H.K. 2012. A Review of Flight Heights and Avoidance Rates of Birds in Relation to Offshore Wind Farms. Crown Estate Strategic Ornithological Support Services. Project SQSS-02. www.bto.org/ science/wetland-and- marine/soss/proj ects. Davies, R.D., Wanless, S., Lewis, S. Et Hamer, K.C. 2013. Density-dependent foraging and colony growth in a pelagic seabird species under varying environmental conditions. Marine Ecology Progress Series 485: 287-294. Denton, A. Nisbet, C. Et Snell, K. 2014. Noss National Nature Reserve annual report 2014. Unpublished report, Scottish National Heritage, Lerwick. 35:1 (2015) Scottish Birds: 3-18 17 The status of the Cannet in Scotland in 2013- 14 Gardarsson, A. in press. Icelandic colonies of the Northern Gannet in 2013=2014. Bliki. Heubeck, M., Mellor, M., Denton, A., Nisbet, C, Pawley, E., Skene, A., Swale, J., Gear, S., Harper, N. 0 Ok ill, D. 2014. Shetland (excluding Fair Isle). Seabird Group Newsletter 127: 3-4. LPO 2014. https://sept-iles.lpo.fr/37-les-actualites/234-fou-de-bassan-de-la-reserve-naturelle- nationale-des-sept-iles-etat-de-la-population-en-2014. Mavor, R.A., Parsons, M. Heubeck, M. a Schmitt, S. 2005. Seabird numbers and breeding success in Britain and Ireland, 2004. Joint Nature Conservation Committee (UK Nature Conservation, No. 29), Peterborough. Meek, E. 2013. Seabirds in Orkney in 2012. Seabird Group Newsletter 122: 1=5. Miles, W.T.S. 2013. Long-term declines in Scottish seabird populations. Scottish Birds 33: 145=152. Murray, S. 2009. A count of the Grassholm gannetry in 2009. Countryside Commission for Wales Commissioned Report, Bangor. Murray, S. a Wanless, S. 1986. The status of the Gannet in Scotland 1984-85. Scottish Birds 14: 74=85. Murray, S. a Wanless, S. 1997. The status of the Gannet in Scotland in 1994=95. Scottish Birds 19: 10=27. Murray, S., Wanless, S. a Harris, M. P. 2006. The status of the Northern Gannet in Scotland in 2003=04. Scottish Birds 26: 17=29. Murray, S., Smith, I. a Smith, A. 2014a. Gannet and Guillemot breeding on Rockall, North Atlantic, Scottish Birds 34: 13=15. Murray, S., Wanless, S. a Harris, M.P. 2014b. The Bass Rock - now the world’s largest Northern Gannet colony. British Birds 107: 765-769. Murray. S., Harris. M.P. a Wanless, S. 2014c. An aerial survey of Northern Gannets Morus bassanus on Scar Rocks, southwest Scotland, in 2014. Seabird 27: 104-109. Nelson, J.B. 1978. The Gannet. Poyser, Berkhamsted. Newton, S. 2014. The 2013-2014 census of Gannetries in Ireland. Interim report to National Parks ft Wildlife Service of the Department of Arts, Heritage and the Gaeltacht. Pamaby, D. a Hatsell, C. 2014. Fair Isle seabird summary 2014. Seabird Group Newsletter 127: 4-6. Pawley, E. 2014. Hermaness and Keen of Hamer National Nature Reserves annual report 2014. Unpublished report, Scottish National Heritage, Lerwick. RSPB 2012. Shining a light on gannet numbers at RSPB Bempton cliffs, http://www.rspb.org.uk/ news/details.aspx?id=326575. Russell, D.J.F., Wanless, S., Collingham, Y.C., Anderson, B.J., Beale, C., Reid, J.B., Huntley, B. a Hamer, K.C. 2014. Beyond climate envelopes: bio-climate modelling accords with observed 25-year changes in seabird populations of the British Isles. Diversity and Distributions doi: 10. 1111/ddi. 12272. Skov, H., Upton, A., Reid, J., Webb, A., Taylor, S. a Durinck, J. 2002. Dispersion and vulnerability of marine birds in Faroese waters. Joint Nature Conservation Committee, Aberdeen. Wanless, S., Frederiksen, M., Harris, M.P. a Freeman, S.N. 2006. Survival of Northern Gannets Morus bassanus in Britain and Ireland, 1959-2002. Bird Study 53: 79-85. Wanless, S., Murray, S. a Harris, M.P. 2015. An aerial survey of Northern Gannet Morus bassanus colonies off NW Scotland in 2013. Scottish Natural Heritage Commissioned Report No. 696. Zonfrillo, B. 2001. Ailsa Craig before and after the eradication of rats in 1991. Ayrshire Bird Report 2000. S. Murray, Easter Craigie Dhu, Butterstone, Dunkeld PH8 OEY. Email: murraysurvey@yahoo.co.uk M.P. Harris & S. Wanless, Centre for Ecology & Hydrology, Bush Estate, Penicuik EH26 OQB. Email: swanl@ceh.ac.uk Revised ms accepted January 2015 18 Scottish Birds: 5-18 35:1 (2015) A review of the status of breeding Black-necked Grebes in Scotland A review of the status of breeding Black-necked Grebes in Scotland M. Holling In the early and mid-1970s the entire breeding population of Black-necked Grebes in Britain was in Scotland, with up to 19 pairs nesting in Scotland at that time. Regular breeding in England only began in 1977 and since the 1990s the proportion of Britain’s breeding Black-necked Grebes in Scotland declined relative to the number of pairs breeding elsewhere (reports of the Rare Breeding Birds Panel). Forrester et al. (2007) reviewed the status of Black-necked Grebes up to and including 2004 and at that time the species still bred in Scotland. However, 2004 was to be the last year that breeding was confirmed in the country. This paper looks at the decline and subsequent loss of Black-necked Grebe as a breeding species in Scotland. Sources of data The UK Rare Breeding Birds Panel (RBBP) monitors and reports the numbers of the rarest breeding birds in the UK and began collecting data on Black-necked Grebes Podiceps nigricollis when it was established in 1973. Their reports provide the only UK-wide assessment of the breeding population since that time. Early reports published in British Birds listed records as ‘county A, county B etc.’ so it is not clear from those reports in which county or even country the nesting occurred. Access to the RBBP records was permitted for the compilation of this paper, and the counties (recording areas in Scotland) in which breeding occurred are named here for the benefit of the ornithological record. Thus, in the first report of the RBBP (Sharrock et al. 1975) confirmed breeding was noted at three sites, all of them in Scotland: two in Fife (‘County A’) and one in Perth ft Kinross (‘County B’). Because of their rarity and susceptibility to disturbance, records of Black-necked Grebes have been subject to some suppression and reports have not always been submitted to county bird recorders nor even to the Rare Breeding Birds Panel. This has led to different numbers being published for a year or for a recording area, and even the Birds of Scotland project was unable to source all data at the time. One of the aims of this paper is to provide a definitive account of the changing status of the species in Scotland and to this end the author has sought to seek out all available sources of information. Much of these data came from the archives of the Rare Breeding Birds Panel, but additional data was provided by current SOC bird recorders reviewing their archives and by checking other published information, particularly the Scottish Bird Report (1968-2000) and local bird reports, where available, for the period under review. A number of people have been very supportive in this quest and they are acknowledged at the end of this paper. Inclusion of records in this review This review is only concerned with breeding Black-necked Grebes, using the standard criteria of confirmed, probable and possible breeding based on national Atlas surveys (such as Balmer et al. 2013), modified slightly so as not to include apparent passage birds or single birds present for only a few days even if at potential breeding sites. These are the criteria used in the annual reports of the Rare Breeding Birds Panel (e.g. Holling et al. 2014) and summarised below. 35:1 (2015) Scottish Birds: 19-25 19 A review of the status of breeding Black-necked Grebes in Scotland All records were assessed to use consistent definitions of breeding evidence as follows. Confirmed breeding records are those where there is good evidence that eggs have been laid and/or young have been seen. Probable breeding usually relates to the presence of at least one pair at a site for at least a week. A record of birds displaying (unless birds were only on site for a single day) would also be classed as probable breeding. Pairs present at a site for less than a week and where no other breeding behaviour was observed are classified as possible breeding. Black-necked Grebes frequently occur on apparently suitable water bodies in the spring, and sometimes display is recorded, but no further proof of breeding is recorded. Depending on the length of time such birds are recorded at a site, these records may be classed as possible or probable breeding, but in many instances reports of grebes seem not to have been followed up, so it is unclear whether pairs remained on site (and may therefore have bred) or whether they in fact moved on. Breeding Black-necked Grebes are specially protected by law, being on Schedule 1 of the Wildlife ft Countryside Act (1981) which means it is an offence to disturb them at or near the nest unless the observer has been granted a licence by the BTO or SNH. Conscientious birdwatchers will therefore take care to observe only from a distance, which could mean that incubating birds, hidden in vegetation, may be missed. In addition, once chicks are hatched, they tend to be led into denser vegetation and may not be visible until they are older and larger, or they may be predated and hence go unrecorded. Thus some pairs granted a status of only probable breeding may actually have laid eggs at the site. Productivity at many sites may also have been under-estimated. Breeding Black-necked Grebes in Scotland 1973 to 2014 Prior to 1973, confirmed breeding in Scotland had been recorded in six recording areas, documented in Forrester et al. (2007): Angus ft Dundee, Borders, Clyde, Fife, Lothian and Perth ft Kinross. During the 42 year period 1973-2014, Black-necked Grebes bred in five Scottish recording areas: Angus ft Dundee, Borders, Dumfries ft Galloway, Fife and Perth ft Kinross. An overview of the numbers and sites in each of these areas is detailed in Appendix A. Up until the mid-2000s, nesting in Scotland was still annual and confirmed breeding was recorded at seven main sites in four recording areas. The principal sites, where confirmed or probable breeding occurred on five or more occasions, are shown in Table 1. During the period 1973-2004, confirmed breeding was recorded from a further three sites, two of which were within the same four recording areas. Records of only probable or possible breeding came from an additional 12 sites, within three recording areas: Lothian, North-east Scotland and Perth ft Kinross. Table 1. Principal breeding sites for Black-necked Grebes in Scotland, 1973-2014. Site name Kilconquhar Loch Dupplin Loch Loch of Kinnordy Folly Loch Lindores Loch Bemersyde Moss Cogbrae Recording area Years when breeding was confirmed Total or at least probable years Fife 1973-2005 33 Perth & Kinross 1973-93 21 Angus & Dundee 1986-2000 15 Borders 1995-2005, 2009 12 Fife 1973-75, 1977-80, 1982, 1985-86 10 Borders 1992-95, 1997-2000, 2003 9 Perth & Kinross 1995-2002 8 In the early 1970s, breeding occurred regularly at 1-2 sites in Fife and one site in Perth ft Kinross. Confirmed breeding in Fife continued in most years until 2003, while in Perth ft Kinross the site was abandoned after 1993 to be replaced by another from 1995 until 2000. In the late 1980s a new breeding site was established in Angus ft Dundee and this site was still in use when, in the early 1990s, breeding began in Borders. By the end of that decade breeding was regular at two sites in the Borders and continued at one of these until 2004. Breeding in Angus ft Dundee ceased in 2002. 20 Scottish Birds: 19-25 35:1 (2015) A review of the status of breeding Black-necked Crebes in Scotland 20 18 16 14 ID CD 12.ti in O 10o3 Xl 8 I (X — * ui on Figure 1. The maximum total number of breeding pairs, number of sites and number of sites where breeding was confirmed for Black-necked Grebe in Scotland, 1973-2014. However, a new site in Perth 8t Kinross was colonised in 2003 and breeding also occurred in 2004. The last year of confirmed breeding by Black-necked Grebes recorded in Scotland was thus 2004. The peak number of sites occupied in the breeding season occurred in 1995 (seven) and subsequently began to decline (Figure 1). The total number of pairs never exceeded that at the start of the review (18-19 in 1973-74). Between 1973 and 2004 the maximum total number of pairs fluctuated between seven and 14. After 2004 pairs and single birds continued to appear in spring at former breeding sites. 100 mLryi ■nrnr -i—r- nrjr -rjr nrjf “TT -r-m "i ""i" TT “i — r NJ NJ NJ NJ NJ i i NJ (X IX (X (X IX