AVON BIRD REPORT 2012 AVON ORNITHOLOGICAL GROUP October 2013 2 Avon Bird Report 2012 CONTENTS Advert and Avon Ornithological Group (AOG) Front cover Editorial H.E. Rose 3 From the Recorder J.P. Martin 4 Submission of Records 7 Photographs R.M. Andrews 8 Review of 2012 R.J. Higgins 9 Migration Summary 14 Weather Report for 2012 R.L. Bland 15 Contributors of Records 18 Systematic List 19 Swans and geese A.D. Scott 20 Ducks N.L. Milbourne 26 Game birds R. Mielcarek 38 Divers to grebes R.J. Higgins 40 Raptors B. L. Lancastle 49 Water Rail to Common Crane R.J. Higgins 58 Waders H.E. Rose 62 Skuas and gulls J.P. Martin 79 Terns and auks R. Mielcarek 87 Doves to woodpeckers D. Nevitt 91 Shrikes to warblers M. Bailey 102 Waxwing to Tree Sparrow R.L. Bland 118 Wagtails to Corn Bunting K.J. Hall 129 Escaped and released birds and hybrids R. Mielcarek 144 Bird Survey Data 147 Avon Ringing Report 2012 M. Bailey & E. Drewitt 149 Nightingale Survey 2012 R.L. Bland 156 Breeding Water Rails at CVL in 2012 M. Dadds 157 The Spring Migration of 2012 H.E. Rose 161 Migration Watches along the Severn Estuary, 1966-2005 R.L. Bland 165 Fifty years ago – Autumn Migration on Steep Holm in 1962 P.J. Chadwick 168 Unusual Ornithological Events in the Avon area 2006-2012 A.H. Davis 169 One Flock G. Warren 172 Gazetteer 173 Index of Species Accounts 175 Advert Back cover Typeset in WORD 2007 and printed by Healeys, Ipswich ISSN Number – 0956-5744 Front cover: Hoopoe at Sand Bay, Oct. 30th, photographed by Rob Cross. Rear cover: Map of the Avon area computer generated by S. Godden, Dept. of Geography, University of Bristol. 3 Editorial Are our bird populations declining? There is a shown in other contexts to be at least a guide to the general impression in some circles that the answer health and well-being, or otherwise, of a wildlife to this question is a definite ‘yes’. Certainly some population. local breeding activity is at a low ebb at the moment. And as can be seen from the Red and Amber But of course the more ornithologists that are active, Conservation Status data given in the Systematic the more birds will be seen. Hence, it is perhaps not List of this Report, nationally a substantial proportion surprising that the two graph lines rise more or less of all UK species are showing worrying reductions. in parallel. Rather speculatively I decided to see if But others are doing well with greatly increased there was any significant collation between these productivity including for example Great Spotted two sets of data by looking at an adjusted ratio to Woodpecker and Goldfinch, and there is always give a ‘status figure’ for the total bird diversity / going to be some ups and downs in any part of the populations in each year in the Avon area. Clearly animal kingdom. the number of species seen will not increase linearly with the number of observers, so some kind of With these thoughts in mind, while I was going adapted ratio was needed. I came up with one through some old records I was able to extract the (basically I used a smoothed out version of the data to construct the diagram below. The time scale square-root of the observer count leaving the is 1950 to the present, and the thin continuous graph species count unaltered) and it gave the dotted line in the diagram gives an estimate of the number graph in the diagram below. If this means anything of active ornithologists in the Avon area over this at all it shows a fairly constant rate over the past period. This data was calculated by counting the sixty three years with perhaps the ‘best’ period being number of contributors listed in each edition of this the late 1980s and early 1990s, and it will be Report (and its predecessors) published during the interesting to see if the rise in the last couple of period. These figures range from 36 in 1950 to 470 years is sustained. However, it should be noted that in 2003 and the graph shows a fairly steady increase the drop in the dotted graph over the past fifteen until the early 1990s, a rapid increase to 2000 with years coincided with the large increase in the fairly constant numbers since then. This rapid rise a number of observers, and so this needs to be taken decade or so ago coincided with the improved into consideration when analysing the data. But quality of this Report including the use of colour and speaking generally, I believe this exercise shows the detailed coverage of every species. The thick that our bird populations are faring reasonably well graph line in the diagram gives the number of and that overall there has been no major fall, or rise, species recorded in each year during the period. during this period; only that some years were better About 162 species are recorded every year in the than others which is to be expected. Some species Avon area, so only the excess over this figure is have fared badly, a few even becoming locally illustrated in the graph. This excess ranged from ten extinct during the period – Red-backed Shrike and in 1953 to 62 in 1989 and 68 in 2011. Although the Cirl Bunting for example – whilst others have gone number of species recorded, that is the bio-diversity from being very rare to relatively common, and these of our avifauna, is a crude estimate, it has been include Little Egret and Collared Dove. 1950 1960 1970 1980 1990 2000 2010 Number of observers Number of unusual species Adjusted ratio 4 Avon Bird Report 2012 As usual we have a number of reports and papers Ken Hall for part three of the passerines which add to our understanding of the dynamics of Rupert Higgins again for his excellent the avifauna in our area, and these begin with the Review of the Year, and the divers to grebes 2012 Ringing Report written as usual by Mike Bailey and the rails to Crane sections and Ed Drewitt. Our first main paper is by Mark Brain Lancastle for the raptor section Dadds, he has been studying Water Rails at CVL John Martin for the gull section and all his and his paper adds greatly to our understanding of work associated with the Recorder’s this species in Avon. Secondly, there are three Committee papers describing different aspects of migration in Nigel Milbourne (with some help from Mark our area, one for spring and two for autumn over the Ponsford) for the duck section past half century. Thirdly, Andy Davis has produced Dave Nevitt for the pigeon to woodpecker a further instalment in his series of papers detailing section the unusual occurrences in our area (he also Tony Scott for the swans to Shelduck provided helpful comments on the systematic list), section and Richard Bland has given an account of the Keith Vinicombe for helpful comments on disastrous breeding season for our Nightingales in the systematic list and some photographs. 2012. We end with a first - Geoffrey Warren’s poem, when did you last see a poem in a bird report? Thanks are also due to all those who provided photographs, some of which are quite exceptional, It is again a pleasure to acknowledge with thanks all names are given with the photo captions. Finally, the hard work and long hours put in by many thanks are due to Richard Mielcarek for the game observers, editors and computer specialists to birds, terns and hybrids sections (he is also a produce this Report. Without observers there would member of the editorial committee), help with the be no Report, and so first our thanks goes to all administration of the work of the Recorder’s those who went out into the field, recorded their Committee, and most important the final production sightings and submitted them to us, please do keep of this Report ready for the printers. them coming. Details on how to submit records are given on page 7. The activities of the Editor’s and Recorder’s Committees are overseen by the AOG Executive Many hours have been spent in front of computer Committee whose members are appointed by our screens ordering and collating the electronic files sponsoring organisations – Bristol Naturalists which has made the work of producing this Report Society and Bristol Ornithological Club. In 2012 the so much easier (and more accurate), amongst members of this committee were Richard Belson others we thank Richard Bland, Nick Hawkridge, (chairman) and Jane Cummings (treasurer) John Martin and Richard Mielcarek for this. As well appointed by the BOC, and Richard Mielcarek as to the authors listed above, our thanks also go to (secretary) and the Editor appointed by the BNS. the following who contributed to this Report, except Any comments that you may have about this Report for the first and last listed they are all members of – complimentary or otherwise – should be the editorial committee – some are new and our addressed to a member of this committee. It is especial gratitude goes to them for agreeing to take provided free to members of the BNS and BOC, on their tasks. details on how to become a member of either of Richard Andrews, our photographic editor these organisations are given on the inside front Mike Bailey for part one of the passerines cover of this Report. and the Mallard drawing on page 164 Richard Bland for the weather report, collation of the survey data and part two of the passerines Harvey Rose (Editor) Address for e-mails – [email protected] From the Recorder While 2012 might mainly be remembered for its fine run of rarities including: our fourth record and lousy cold and wet summer the year actually got off fifth individual Black-winged Stilt, at CVL on April to a fine start with its only new species for our area, 10th (relocating from Dorset); third Red-throated the two brief and elusive Penduline Tits at PW Pipit, at New Passage on 22nd; third Laughing Gull, Nature Reserve, on Jan.