SUFFOLK BIRDS I993
• 1992 Bird Report
• Winter Gulls
• Ringing Report
• Rosefinches
• Breeding Shelducks
• Rarities
3 o o 3 n
a o 3
3 0 1 i 3
West Area Recorder: Colin Jakes, Yewtree Cottage, 16,The Street, GAZELEY, NEWMARKET CB8 8RD Tel: 0638-750239
North-East Area Recorder: Dick Waiden, 21,Kilbrack, BECCLES NR34 9SH Tel: 0502-713521
South-East Area Recorder: Michael James, 296,Walton High Street, FELIXSTOWE IP 11 9EB Tel: 0394-276540
SUFFOLK BIRDS 1993 VOL. 4 2 incorporating the County Bird Report of 1992
Editor M . D. Crewe Assistant Editor P. W . M u r p h y Photographic Editor J . Levene
Published by SUFFOLK NATURALISTS' SOCIETY
Published by The Suffolk Naturalists' Society, c/o The Museum, High Street, Ipswich IP1 3QH Š The Suffolk Naturalists' Society 1994 All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, without prior permission of the Copyright owners.
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Printed by Healeys, 55 Fore Street, Ipswich, Suffolk IP4 1JL. 2
CONTENTS Page Editorial Mike Crewe Winter Gull Roosts in Suffolk Adam Bimpson 1992 Survey of Breeding Shelducks in Suffolk Mick Wright Weather trends and their effect on the County's avifauna, 1992 John Grant Common Rosefinch — First confirmed breeding in Suffolk Rex Beecroft Recent Additions to the Suffolk List Mike Crewe & Philip Murphy Submission of Records: Guidelines for Observers Steve Piotrowski The 1992 Suffolk Bird Report List of Contributors Earliest and latest dates of summer migrants Notes: Successful Breeding by Red-backed Shrikes Jean Garrod Red-footed Falcon stealing food from Kestrel Steve Piotrowski Leucistic Wheatear at Felixstowe Mike Crewe Rarities in Suffolk 1992 Mike Crewe Greenish Warbler Nigel Odin Rustic Bunting Rob Duncan Red-throated Pipit Mike Crewe White-throated Sparrow Will Brame Lesser Crested Tern Mark Cornish "Steppe" Shrike John Cawston Great Spotted Cuckoo J. R. Pilkington Black-headed Bunting A. Banwell Suffolk Ringing Report Mike Marsh
5 7 14 18 21 22 24 30 139 141 142 142 143 145 147 147 148 149 150 150 151 151 153
List of Colour Illustrations Piale No. 1. Shags Jack levette 2. Whcrstcad Strand Mike Crewe 3. Red-footed Falcon Jack Levene 4. Red-footed Falcon Steve Piotrowski 5. Rcd-lcggcd Partridge Stan Dumican 6. Golden Plover Jack Levene 7. Little Stint Jack tsvene 8. Orfordncss Mike Crewe 9. Curlew Stan Dumican 10. Caspian Tern Rob Wilson II. Terek Sandpiper Clive Naunton 12. Hoopoe Jack Isvene 13. Great Spotted Cuckoo Jack Isvene 14. "Steppe" Shrike Jack l^vene 15. Kingfisher Stan Dumican
Facing Page
Plate No.
Facing Page
24 24 25 25 56 56 56 57 57 80 80 80 81 81 81
16. 17. 18. 19. 20. 21. 22. 23. 24. 25. 26. 27. 28. 29.
112 112 113 113 136 136 137 137 137 160 160 161 161 161
Skylark Jack Levene Tawny Pipit Rob Wilson Song Thrush Stan Dumican Landguard Point Mike Crewe Marsh Warbler Derek Moore Dartford Warbler Rob Wilson Blackcap Rex Beecrofi Coal Tit Stan Dumican Pied Flycatcher Mike Crewe Serin Jack Levene Common Rosefinches Rex Beecroft White-throated Sparrow Jack Levene Rustic Bunting Jack Levene Sparrowhawk Mike Crewe
The copyright remains that of the photographers.
3
Notice to Contributors Suffolk Birds is an annual publication of records, notes and papers on all aspects of Suffolk ornithology. Except for records and field descriptions submitted through the County Recorder, all material should be original. It should not have been published elsewhere or offered complete or in part to any other journal. Authors should carefully study this issue and follow the style of presentation, especially in relation to references and tables. Where relevant, nomenclature (English and scientific) and order should follow Dr K. H. Voous's List of Recent Holarctic Bird Species. Manuscripts should be typed, double spaced, with wide margins, on one side of the paper only. They must be in the final form for publication: proofs of longer papers are returned to authors, but alterations must be confined to corrections of printer's errors. The cost of any other alterations may be charged to the author. In certain circumstances, the Editor may be able to accept papers on computer disc. Photographs and line drawings are required to complement each issue. Suitable photographs of birds, preferably taken in Suffolk, should ideally be in the form of 35mm transparencies. A payment of £10 will be made to the photographer for each photograph published and £5 for each drawing. Every possible effort will be made to take care of the original photographs and artwork. However, photographers and artists are reminded that neither the Editor nor the SNS can be held responsible in the unlikely event that loss or damage occur. Prints (6" x 4 " ) of most photographs are available to readers, at a cost of £1.50 per print, by sending a stamped, addressed envelope together with remittance to the Photographic Editor. Authors may wish to illustrate their own articles but this will be subject to the illustrations being of the standard required by the Editor, and the decision on such matters will rest with him. Material submitted for publication should be sent to the Editor no later than March 1st of each year. Authors of main papers may request up to five free copies of the journal. Suffolk Ornithological Records Committee: Chair: Dr Anne Brenchley Area County Recorders: Colin Jakes, Richard Waiden, Michael James Secretary: David Walsh Other Committee Members: Mike Crewe, Mike Marsh, Derek Moore, Dr. David Pearson, Steve Piotrowski, Brian Small, Geoff Welch, Malcolm Wright ADDRESSES Papers, notes, drawings and photographs: The Editor (Suffolk Birds), The Suffolk Naturalists' Society, c/o The Museum, High Street, Ipswich IP1 3QH. Records: Colin Jakes, Yewtree Cottage, 16 The Street, Gazeley, Newmarket CB8 8RD. Suffolk Ornithological Records Committee — information.The Secretary, SORC, c/o The Museum, High Street, Ipswich IP1 3QH.
4
Editorial
Adam
Kennedy
Suffolk goes Régional A look at the inside front cover of this journal will reveal a change in the ornithological map of Suffolk. The workload of the County Recorder has been growing ever bigger with the continued increase in the number of people becomimng interested in birdwatching and submitting their notes. Unfortunately, Philip Murphy has had to relinquish the post of County Recorder after an ali too brief speli. This situation left the County in dire straits, but in a good position to take a long hard look at the whole issue of bird recording in Suffolk. The outcome has been a three way split in the work load by the création of three separate recording areas in the County (see map). It is hoped that this division of labour will make it possible for the task of collating Suffolk's bird records, and corresponding with the County's observers, a whole lot easier. For those who know the County well enough, there should be no problem in dividing up observations and supplying them to the relevant Recorder(s). However, for those who are new to the County, or who visit on a casual basis, it may not be clear to whom any observations should be sent; for this, and other more technical reasons, Colin Jakes has agreed to accept any records from people who would otherwise be unsure where to send them. Thus, Colin Jakes' name will be appearing in various journals as being the County Recorder, but those observers who live in Suffolk and submit records regularly are requested to send their observations to the relevant Régional Recorders — note however, that any belated records for 1993 should stili be sent to Philip Murphy. The three Régional Recorders are as follows: West Area Recorder:
Colin Jakes, Yewtree Cottage 16 The Street, Gazeley, Newmarket, CB8 8RD
5
North-East Area Recorder:
Richard Waiden, 21 Kilbrack, Beccles, NR34 9SH
South-East Area Recorder:
Michael James, 296 Walton High Street, Felixstowe, IP 11 9EB
Apologies for the delay Editing Suffolk Birds has been a whole new experience for me and has come as something of a shock! Steve Piotrowski did an excellent job in raising this journal to become the best County bird report in the whole country — with an award to prove it! As the new Editor, I have mixed feelings about this as such a successful act is very hard to follow. I have learned a great deal during these first twelve months and, although the change of Editor has had a detrimental effect on the timing of publication (i.e. F m very late in getting it out), changes to the system should mean that we can get back on schedule for the next one. W h e r e a r e ali the common birds? I have deliberately chosen a common species to head this Editorial. The most important lesson I have learned during production of this report is that it is a real headache trying to write about common species. Few records are received at all of such species as Pheasant, Wren and House Sparrow and it is often difficult to comment on the status of such species — they may not be as common as we think. With this in mind, I should like to appeal to ali regular recorders to supply information on all common species in your area; try to keep an eye on them with a view to submitting any comments on their status which may be of interest in the production of this report. Nobody knows your local patch better than you do, so are there as many House Sparrows in your area as there were last year? Have you noticed any nesting in peculiar places? How do the numbers of Blue and Great Tits fluctuate from year to year in your area, and which species is the more common? A simple statement on each species at the end of the year (or preferably shortly before so as not to hold up the Bird Report!) will, after a few years, help to build up a useful set of data on the County's avifauna which can be used as a yardstick in the future.
6
Winter Gull Roosts in Suffolk Adam
Bimpson
Introduction The importance of Suffolk as a County for gulls has been well documented, both historically by Ticehurst (1932) and Payn (1978) and more recently through the County bird reports. Most of these data have concentrated either on breeding totals e.g. the importance of Orfordness with its Lesser Black-backed and Herring Gull colony, or specific records of unusual occurrences and scarce species. Little work had been attempted to obtain a year round picture of the numbers or distribution of Suffolk's gull population. 1993 saw an attempt to redress the balance with a continuation of the British Trust for Ornithology's (BTO) Winter Gull Roost Census. The information obtained is slowly building into a valuable source of information relating to the wintering gull population in the British Isles. The BTO Winter Atlas (Lack 1986) provides a good example of the use made of such information, although it can be difficult to ascertain patterns and trends that occur at County level when using data gathered on such a large scale. The Winter Gull Roost Census has been carried out in Suffolk once every decade since its commencement in 1953. It is usually during the first winter period (January-March) that the roosts have been counted, concentrating on January, thus providing a mid-winter population estimate. Previous surveys have produced a rather incomplete coverage of the County by mainly concentrating on the well known sites, thus leading to a fragmented knowledge of the wintering gull population. The coverage obtained in the 1993 survey has been the most complete to date with both coastal and inland waters being studied. This paper aims to provide an insight into the wintering populations of gulls within the County and to gauge their relative importance on the national scale. Methods Observers were asked to visit their allocated site just prior to sunset on any convenient date between January 21 st and 31 st 1993, but preferably during the weekend of 23rd/24th. Totals of gull numbers were collected as either actual or estimated figures, incorporating birds already present on the surface or in flight lines coming in to roost. Full instructions were given on the back of the official census cards. Other details were also collected includ-
ing site description (coastal sites are defined as those within five kilométrés of tidal waters), weather conditions and disturbance directly affecting the roost. A total of eighteen sites was surveyed covering the Stour, Orwell and Deben estuaries, coastal stretches and various inland sites. Fig. 1 shows the position of each roost site that was surveyed. For the purposes of this report, coastal sites have been divided into two catégories, with estuaries and the coastline being treated as distinct areas.
Figure 1:
1. STOUR 2. ORWELL
5. LOWESTOFT HARBOUR ESTUARIES-MULTIPLE SITES COVERED
6. WEYBREAD PITS
3. DEBEN
7. LACKFORD
4. SIZEWELL
8. CAVENHAM PITS
Results The aim of this paper is to summarise the most recent findings relating to the wintering gull population in Suffolk. Each species is discussed separately in terms of their past and present status and an attempt is made to place findings within the national picture. Table 1 gives the results for the 1993 census.
Black-headed Gull La rus ridibundus During the winter period, the Black-headed Gull forms almost 90% of the total gull population in Suffolk. Within the County, it is the roosts on the estuaries and at inland sites which hold the largest numbers with the former habitat being of slightly greater 8
importance. In contrast to this, the coastal roosts are utilised by less than 50% of the number occurring in either of the other two roosting habitats. However, this may have been due to the prevailing weather conditions which were very windy and may have displaced birds to sites providing the most shelter. When examined in more detail it becomes apparent that the Orwell Estuary is the single most important roost site for this species, holding just over 50% of the total number of Black-headed Gulls occurring in estuarine roosts. Inland, Lackford Wildfowl Reserve and Wey bread Pits form the main roosting areas, each holding similar numbers. The pattern of distribution of Black-headed Gulls is probably due to the species' catholic diet. Cramp et al. (1983) describes the Black-headed Gull as an adaptable species with an extensive diet which includes animal, plant and human waste. The utilisation of landfill sites and agricultural land provides an excellent example of this adaptability. It is perhaps hardly surprising that the Orwell comes out as the top roosting site, situated as it is in an intensive agricultural area and close to one of the main centres of human population. This estuary is also reasonably well sheltered and a source of more traditional food items for the gulls. Lack (1986) states that a strong relationship exists between areas of open freshwater, often of artificial construction e.g. reservoirs, and winter roosting behaviour and indicates that the increase of waters of human origin may be an important factor in the species' widespread distribution. Lackford Wildfowl Reserve has become an important roosting site for gulls as the freshwater factor is enhanced by the presence of a nearby landfill site that provides a readily available food source. The association of these two factors is also important for other gull species and is discussed later in this paper. Compared with the results obtained in 1983 (Bowes et al. 1984), the Black-headed Gull has shown a national increase of 44% in the last ten years. The distribution pattern appears to have remained fairly constant with coastal numbers being higher than those recorded inland. The Orwell Estuary was also the most important roosting area in Suffolk in 1983, although increases since then at this site are not as pronounced as those at Lackford Wildfowl Reserve where numbers have risen by over 50% since the 1983 census. Ringing data have shown that a substantial proportion of the wintering population originates from northern European breeding grounds, with recoveries coming particularly from the Baltic States, Russia and Finland. This is in line with national trends (Lack 1986) with up to two-thirds of the national wintering population originating from the Continent.
Common Gull Larus canus Although Suffolk's wintering population of this species is far smaller than that of the Black-headed Gull (only 9% of the total number of wintering gulls), it is nevertheless the second commonest wintering gull species in the County. The wintering distribution pattern is similar to that of the preceding species, with estuarine roosts predominating. Again, it is the Orwell Estuary which is of greatest importance, holding over 75% of the Common Gulls found during the survey. Coastal and inland roosts held just over 1,000 indivduals between them, three-quarters of which occurred inland. Unlike other gull species, the winter diet of the Common Gull is considerably more specialised, with earthworms Lumbricus spp.) and other terrestrial invertebrates forming a major part (Cramp et al. 1983; Lack 1986). All of Suffolk's main estuary systems are surrounded by agricultural land, providing ideal feeding areas for this species. This readily available food supply, and the relatively sheltered aspect of the estuaries, provide ideal conditions for wintering Common Gulls. The two main inland sites, Lackford Wildfowl Reserve and Weybread Pits, showed very similar wintering numbers with each locality forming the major inland roost for the west and north of the County respectively. Areas on the immediate coast hold lower numbers 9
than elsewhere, perhaps due to their being relatively exposed. The largest concentration at such a site occurs at Lowestoft Harbour, supporting 4% of the County's population. This site has always been a focus point for gulls due to the local fishing industry which provides a ready supply of offal. Since the 1983 census, Common Gull numbers have risen significantly (see Table 2), with a dramatic increase to over 6,000 individuals. The reasons for this increase are unlikely to include a massive expansion in the population, but could be due to a shift in the species' preferred wintering areas, perhaps due to changes in weather patterns. Increased observer coverage could also be a contributing factor, providing a more accurate estimate of the wintering population. The Common Gull is predominantly a winter visitor and passage migrant in Suffolk with only a handful of pairs breeding at a single site in the County. The origins of the wintering population are similar to those of the Black-headed Gull, although there is also a greater dispersal of the British breeding population with birds moving south from the main breeding centres in upland areas of northern England and Scotland (Lack 1986). H e r r i n g Gull Larus argentatus A preference for maritime habitats is displayed by the Herring Gull throughout the year, showing a greater reliance on the coast than is shown by either Black-headed or Common Gulls. This pattern is reflected within the County with coastal areas holding almost 70% of the wintering population; both the estuary and inland roost sites hold approximately equal numbers. During the survey, Sizewell attracted the largest number of Herring Gulls with Lowestoft holding a similar total to those at inland and estuary sites. The major attraction at Sizewell would appear to be the warm water outlet from the power station. It has been shown that such outlets attract marine invertebrates and other higher taxa due to the increased temperature of the water, providing more favourable breeding and feeding conditions, especially during winter. This allows species such as the Herring Gull to exploit a richer and more beneficial food source than would otherwise be available. The difference in roosting numbers between Sizewell and Lowestoft is surprising. Although food in the shape of fish offal may be more readily obtained in Lowestoft Harbour, the overall quantity may be insufficient to support a large number of gulls. This is perhaps because there has been a significant drop in the size of the fishing fleet and legislation has forced factory areas to be more stringent with the disposal of offal. One other possibility is that human operations around the harbour during the night create too much disturbance for the birds, causing them to roost offshore and thus be missed during the survey. Certainly, a correlation between feeding and roosting sites is evident when comparing the two main inland gull roosts. The single bird found at Weybread Pits represents a stark contrast with the total of 254 roosting at Lackford Wildfowl Reserve during the survey; the presence of an adjacent landfill site is surely responsible for the high total at Lackford. As with other gull species, the Herring Gull has shown an increase in wintering numbers. When compared with the 1983 survey results, a fourfold rise is seen on the coast with inland numbers increasing by 68%. The expansion in numbers at inland localities must undoubtedly be due to the increase in landfill sites and the utilisation of such sites by this species. The reasons for the significant increase on the coast are far less clear and are contrary to the drop in fishing activity. However, Sizewell was not covered during the 1983 survey and since this proved to be one of the most important sites during 1993, this must surely have a bearing on the results. Britain's Herring Gull population is swollen by an influx of birds from the northern Continent during the winter. Many individuals of these northern populations (particularly adults) are identifiable in the field and their origins are confirmed by ringing recoveries at landfill sites within Suffolk of individuals ringed in Scandinavia. The dispersal pattern of the County's breeding population is poorly understood. Cramp et al. (1983) states that 10
each colony has a reasonably well defined area of occurrence after post-breeding dispersal. However, it is unknown at present whether birds from the Orfordness colony winter in Suffolk or move elsewhere. Lesser Black-backed Gull Larus fuscus Up until fairly recently, the Lesser Black-backed Gull was rarely seen in Suffolk during the winter but migration patterns changed dramatically during the period covered by the Winter Gull Roost Census (Lack 1986). In Suffolk, a similar change has been observed with numbers not only increasing during the winter but also during the summer with the establishment of the Orfordness breeding colony in the late 1960s. (Payn 1978). The colony has undergone a very large increase during the last 15 years, but it has only been in the last decade that a marked change has been observed in the species' wintering behaviour. In Suffolk, wintering Lesser Black-backs are mostly confined to the inland roost at Lackford Wildfowl Reserve where around 82% of the total found in the County during the 1993 census occurred. Elsewhere numbers are much lower with the remaining 18% scattered throughout the other roost sites. The dominance of Lackford as a winter roost is no doubt due in part to the presence of the nearby landfill site as a source of food. It is also likely that birds have spread further east from other wintering areas in central England; Lack (1986) states that wintering Lesser Black-backs are more commonly found inland, with freshwater roost sites being very important. The change in the wintering behaviour of this species has been much more pronounced than any changes in the breeding population during the last decade. The Orfordness colony, now established, has remained relatively stable at 8,500 pairs for the last ten years, as documented in Suffolk Birds. However, the wintering numbers have increased dramatically from a handful of individuals in 1983 to the estimate of 265 in the 1993 census. A steady increase in the number of recorded wintering individuals can also be traced through the County bird reports for the last ten years. Ringing recoveries show that the majority of Suffolk's breeding population winters on the north-west African coast so the origin of the birds wintering in the County is, as yet, a mystery. It is most likely that these birds are originating from further north on the Continent, although the most northerly populations L. f . fuscus habitually migrate south-eastwards to winter in the Middle East and East Africa (Grant 1986). Great Black-backed Gull Larus marinus Although the wintering population of this species is well below that of the three commonest species, twice as many Great Black-backs were found during the census as Lesser Blackbacks. The presence at Lowestoft Harbour of almost three-quarters of the total wintering population of this species in the County is to be expected, given its strong preference for maritime roost sites with only 30% occurring away from the coast. It is the size and aggresive nature of the Great Black-backed Gull that makes it such a dominant component of any roost or feeding flock. As discussed previously, offal is not so readily available within the Lowestoft Harbour complex as was once the case; with this in mind, the presence of fairly large numbers of this species is perhaps surprising, although the dominance of this species may help to explain the relative scarcity of Herring Gulls at the site by way of competitive exclusion. This may also account for the larger number of Herring Gulls at Sizewell where Great Black-backs are less frequent. The river estuaries and inland sites are far less important for this species than the immediate coast with the Orwell and Stour estuaries and Lackford Wildfowl Reserve all attracting around 50 individuals during the census. Data from the Birds of Estuaries Enquiry (BoEE) counts reveal that the Aide/Ore estuary is the most important estuary in the County for this species; however; this estuary was not included in the roost census in 1993. This species does not breed in Suffolk and the wintering population is probably a mix 11
of northern European birds and individuals from further north in Britain. Lack (1986) suggests that most of the east coast winter population is derived from Norway and this idea is supported by ringing data from within Suffolk. Over the last ten years, numbers have increased but there is a difference in the geographical location of roost sites used during the two survey periods. In 1983, inland and coastal sites held nearly equal numbers (c. 150) but the 1993 census has shown the species to be more heavily dependent on coastal sites. This latter situation is perhaps more typical for this species and it may be that weather conditions affected the distribution of birds during the 1983 census period. O t h e r Species Just two other gull species were recorded during the 1993 census. The Kittiwake Rissa tridactyla is chiefly pelagic during the winter and although occasional individuals are blown inland during bad weather, only Lowestoft Harbour produced any birds during the census. With a small but increasing breeding population at this location, birds are now present there throughout the year with winter numbers offshore augmented by birds from more northerly breeding grounds. Three Mediterranean Gulls Larus melanocephalus were located during the 1993 census, all at Lowestoft. Although more individuals of this species are known to have been wintering elsewhere in the County, they were not found at the roost sites surveyed during the census. Conclusions Caution is needed when analysing the results as it was not possible to cover all known roosts in the County. Large gull roosts are known to exist on the Aide/Ore and Blyth estuaries and on Alton Water and thus the total number of gulls wintering in the County will be far greater than the survey suggests. However, in 1983 the census located a winter roosting population of gulls in Suffolk involving 37,160 individuals; the 1993 census recorded 73,124 individuals. From this it would appear that the wintering population has effectively doubled in the space of a decade. It is difficult to establish the true extent of the change which may in part be attributable to a much greater observer coverage. Further details may become apparent when the national findings are published. Table 2 shows the comparison between the two surveys. On the basis of the 1993 results, there are two sites of special interest — Lackford Wildfowl Reserve and the Orwell Estuary — which together form the most important areas for winter gull roosts in Suffolk. The Orwell Estuary was found to be holding 29% of the total number of all gulls recorded during the survey, the highest figure for any one single site (although the size of the site has to be taken into account when making direct comparisons). Lackford Wildfowl Reserve held 16% of the total number of gulls found, a significant' figure considering the site's inland location. From the findings presented here, it appears that Suffolk fits in well with the national picture, following many of the established trends and patterns, including the geographical location of roost sites and the natal origins of the wintering popualtions. Although largely based on the 1993 census, most of the established patterns are evident in previous documentation, primarily the Suffolk Bird Reports. The organised counting of roosting birds over a very short period i.e. one weekend, is a good way of estimating the total population as it limits the chance of duplication if birds subsequently move to other sites.
Table 1. Numbers of roosting gulls found in Suffolk during the January 1993 census. Black-headed Gull Common Gull Herring Gull Lesser Black-back Great Black-back Other species Totals
Estuaries
Coast
Inland
29,907 5,250 341 44 67 0
10,500 330 1,450 1 400 118
23,373 763 304 220 56 0
Total 63,780 6,343 2,095 265 523 118
35,609
12,799
24,716
73,124
Table 2. Comparison of gull numbers found in Suffolk during 1983 and 1993 censuses
Black-headed Gull Common Gull Herring Gull Lesser Black-back Great Black-back Other species
Estuary/Coast 1983 1993 20,000 40,407 30 5,580 400 1,791 0 45 150 467 202 118
1983 16,070 26 181 7 154 0
1993 23,373 763 304 220 56 0
Totals
20,782
16,438
24,716
48,408
Inland
Acknowledgements I should like to thank Mick Wright for supplying the data gathered during the survey and Mike Crewe for comments on the first draft of this paper. Sincere thanks must also go to the following people who all took part in the census work: N. Baker, T. Bamber, R. Biddle, M. Buckingham, S. Dudley, A. Easton, J. Garstang, J. Glazebrook, C. Jakes, W. Last, M. Marsh, N. Mason, S. Piotrowski, R. Plowman, B. Small, M . Wright. References Bowes, A., Lack, P. C. & Fletcher, M. R. 1984. Wintering gulls in Britain, Jan. 1983. Bird Study 31:161-170. Cramp, S. & Simmons, K. E. L. (eds) 1983. The birds of the Western Palearctic. Vol. m . Oxford University Press. Goudie, A. 1990. The human impact on the natural environment. Blackwell, Oxford. Grant, P.J. 1986. Gulls — a guide to identification. Poyser, Calton. Lack, P. 1986. The atlas of wintering birds in Britain & Ireland. Poyser, Calton. Ticehurst, C. B. 1932. A history of the birds of Suffolk. Gurney & Jackson, London. Adam Bimpson, 11 Butley Close, Ipswich 1P2 9TR
13
1992 Survey of Breeding Shelducks in Suffolk Mick
Wright
Introduction The British breeding population of Shelduck Tadorna tadorna has never previously been accurately determined. According to the National Waterfowl Counts (NWC) the wintering population has gradually increased since the 1960s. The NWC for the winter of 1991-92 shows that Shelduck totals peaked in January with a population of 84,017 and the numbers counted in March were around three-quarters of the peak (Cranswick et al. 1992). This figure is an underestimate as counts are conducted at only a selection of sites. The most recent estimate for the north-west European wintering population is 250,000 (Monval & Pirot 1989). The Wildfowl and Wetlands Trust (WWT) has conducted annual surveys on the River Severn since 1988 (Fox & Salmon 1988; Jones 1989; Delany 1991a, 1991b). The procedures used in these surveys were tested at a variety of breeding sites during two pilot seasons of fieldwork (1990 and 1991) before the final methodology was recommended for the 1992 national survey. The survey aimed to produce estimates of the breeding and non-breeding populations of Shelduck in Britain during 1992 and also to obtain an approximate estimate of breeding success. This paper documents the survey results for Suffolk.
Methods The survey was undertaken in two parts. Spring counts were carried out between April 25th and May 17th and summer counts between June 27th and August 2nd. The two counts were recorded on different coloured data forms. Shelducks are strongly territorial and maintain feeding territories if they have a nest nearby. The male defends the territory while the iemale incubates. This means that a carefully conducted count of birds on feeding territories can be strongly indicative of the number of pairs nesting in an area (Delany 1992). 14
Most Shelducks have taken up territory by the beginning of May and counts in the first ten days of May minimise under-recording of numbers due to nest failure and desertion. The count period extended over three weeks, so that at tidal sites the scope for selecting the best tide on which to count could be maximised. This also enabled counts undertaken for the Birds of Estuaries Enquiry/National Waterfowl Counts on May 17th to be included. At least one count between April 25th and May 17th was required although three were desirable. Counts were conducted within two hours either side of low tide. The spring count détails required were for five différent catégories; total numbers of birds, territorial maies and pairs, numbers in non-breeding groups and the number of pairs that were apparently territorial. Other information was collected that may have affected the accuracy of the counts such as the occurrence of heat haze, wind and human or other disturbances. Summer counts were carried out between June 27th and August 2nd with an emphasis on counting during the weekend of July 1 Ith and 12th so as to maximise the value of the counts of adults. At least two counts in July (one early in the month, the other late) were desirable. At tidal sites it was recommended to carry out the counts at high tide when juvenile Shelducks would be more likely to be closer to the shore. The summer count détails required were the total number of adults, number of young and creche sizes. In addition, observers were requested to record the presence of any moulting birds.
Results The input of man-power and résultant coverage attained by the survey were excellent. Counts of Shelduck were co-ordinated on all estuaries and at four main sites, adults and ducklings were counted over the weekend of July 1 Ith and 12th. In all, Shelduck were counted on seven estuaries and at nine freshwater sites. The maximum number counted during spring was 3,781 and the co-ordinated count on April 26th found 2,952. The results indicate that there were 1,129 pairs and an additional 140 territorial males in Suffolk; the co-ordinated counts carried out on the estuaries found 931 pairs and 92 territorial males (see Table 1).
Table 1: Summary of data.
Adults Pairs Territorial Males Non-breeders A d u l t s (July 1 I t h / I 2 t h ) D u c k l i n g s (July I l t h / 1 2 t h )
Co-ordinated C o u n t Totals 2952 931 92 999 709 705
Maximum Totals 3781 1129 140 1403 1277 1284
The number of birds considered to be non-breeders totalled 1403 with 583 (42%) being found on the Orwell. Thcre was also a high concentration of 261 on the Aide/Ore complex. The Orwell, with 1069 birds, held 28% of the Suffolk population during the breeding season. The inland site with the most birds was Livermere Lake with 137. The total number of adults and juveniles counted during the summer was 1277 and 1284 respectively. During the weekend of July l l t h and 12th, 709 adults and 705 ducklings were counted.
Table 2: Summary of Shelduck numbers during the breeding season in Suffolk, 1992. Spring C o u n t s Total N o . of Birds
Site N a m e ORWELL STOUR DEBEN ALDE/ORE/BUTLEY BLYTH ALTON WATER WALBERSWICK M I N S M E R E B.R. MINSMERE LEVELS LIVERMERE IXWORTH REDGRAVE ELVEDEN LACKFORD W.R. TOTALS
Terr. Maies
C M C M C M C M C M M M M M M M M M M
875 1069 429 517 795 795 432 692 421 421 14 59 30 3 137 10 2 9 23
34 50 30 32 21 21 6 25
C M
2952 3781
Summer Counts N-breed Groups
Pairs
437 583 117 138 154 154 116 261 175 175
5
202 245 141 156 310 310 155 203 123 123 7 14 9 1 45 5 1 3 7
92 140
931 1129
999 1403
— — —
_ 6 1
— —
Terr. Pairs 28 92 19 62 8 —
31 7
_ _ _
-
—
—
_
47 —
_ 3 4
5 117
Total Adults Juvs 75* 282 400* 558 57* 67 172* 277
252* 211* 287 229* 260 6* 282
—
—
176 0 9 4 0 79 4
43 0 19 16 0 84 0
—
—
6 5*
4 7*
709* 1277
705* 1284
KEY: C M * —
= = = =
Figures from co-ordinated count. M a x i m u m c o u n t figures. F i g u r e s f r o m target w e e k e n d c o u n t . N o information.
Discussion The latest estimate of the British breeding population of Shelduck is put at 12,000 nesting pairs and 26,000 non-breeders (Owen et al. 1986) although Delany (1992) considers the breeding population in Britain to be more than 15,000 pairs. The number of birds found in Suffolk is impressive and when compared with the national figures clearly shows it to be one of the most important counties for Shelduck in Britain. In 1992, Suffolk supported at least 9.5% of the breeding and 6% of the non-breeding national populations. During the spring of 1988 the Suffolk Wildlife Trust Estuaries Project co-ordinated a survey of the breeding waders and wildfowl on the Suffolk estuaries (Holtzer et al. 1989). This survey was essentially designed to provide an understanding of the numbers of wildfowl and waders breeding on the saltmarsh and wet grassland bordering the Suffolk estuaries. Although there are différences in the methodology and présentation of results between the 1988 and 1992 surveys, a comparison of the totals of pairs gives a useful indication as to the Shelduck breeding population in Suffolk (see Table 3).
Table 3. Number of breeding pairs of Shelduck located in the 1988 and 1992 surveys. Year
Blyth
Aide
Deben
Orwell
1988
72
202
126
114
17
531
123
155
310
202
141
931
1992*
Stour
Total
* F i g u r e s taken f r o m the c o - o r d i n a t e d c o u n t s .
The British breeding population is considered to have been increasing since at least the late 1980s (Stroud et al. 1991; Andrews et al. 1992). The figures in Table 3 would appear 16
to support this, although the refined methodology for the 1992 survey shows a significant increase in breeding numbers suggesting that the breeding population in 1988 was possibly much healthier than indicated. Summary The 1992 National survey of breeding Shelduck Tadorna tadorna received excellent coverage in Suffolk. The number of birds found was impressive, making Suffolk clearly one of the most important counties in Britain for this species with 9.5% of the breeding birds and 6% of the non-breeding birds. During spring, there was a maximum of 3,781 birds which included 1,129 pairs. The maximum number of adults found during the summer counts amounted to 1,277 and the number of ducklings totalled 1,284. The co-ordinated Shelduck counts on the estuaries recorded a total of 2,952 birds which included 92 territorial males, 931 pairs, 999 nonbreeders and 698 ducklings. The Orwell estuary supported 28% of the Shelduck population in Suffolk and Livermere Lake held the highest inland concentration. There is also evidence to suggest that some adults remained on the Stour and Orwell estuaries in order to moult. Acknowledgements I should like to thank Philip Murphy for his helpful comments and all the surveyors for their time and effort spent in the field. Fieldworkers: T . Bamber, R. C. Beecroft, M. Biddle, M. Buckingham, D. Clarke, M. Crewe, D. Finch, J. Garstang, J. Glazebrook, C. Jakes, W. Last, R. Leavett, B. McCarthy, S. Marginson, M . Marsh, N. Mason, A. Miller, M. Miller, P. Murphy, R. Noble, D. Ockleton, J. Partridge, R. Plowman, C. Waller, G. Welch, R. West, P. Wilson, M. Wright. References Andrews, J. & Carter, S. (1992) Britain's birds 1990-91: the conservation and monitoring review. BTO/JNCC, Thetford/Peterborough. Cranswick, P. A., Kirby, J. S. & Waters, R. J. (1992) Wildfowl and wader counts 1991-92. WWT, Slimbridge. Delany, S. N. (1991a) Shelduck on the Severn estuary April-August 1990. Report to NCC, WWT, Slimbridge. Delany, S. N. ( 1991b) Numbers, distribution and breeding success of Shelduck on the Severn estuary following the oil spill of 11 FebrMiry 1991. Report to Wetlands Advisory Service, WWT, Slimbridge. Delany, S.N. (1992) Pilot survey of breeding Shelduck in Great Britain & Northern Ireland 1990-1991. Internal Report, WWT, Slimbridge. Fox, A. D. & Salmon, D. G. (1988) Severn barrage development project. Task 3.7(i)h: Shelducks on the Severn estuary. Final report.WWT, Slimbridge. Holtzer, T. J., Beardall, C. H. & Dryden, R. C. (1989). Breeding waders and other waterfowl on Suffolk estuaries in 1988. Wader Study Group Bulletin No. 56 August 1989. Jones, T. A. (1989) Shelduck in the Severn estuary, May-August 1989. Internal Report, WWT, Slimbridge. Monval, J-Y. & Pirot, J-Y. (1989) Results of the International Waterfowl Census 1967-1986. IWRB Spec. Pubi. No.8, Slimbridge. Owen, M., Atkinson-Willes, G. L. & Salmon, D. G. (1986) Wildfowl in Great Britain (SecondEdition). CUP, Cambridge. Stroud, D. & Glue, D. (1991) Britain's Birds in 1989-90: the conservation and monitoring review. BTO/NCC, Thetford/Peterborough. M. T. Wright, IS Avondale
Road, Ipswich
IP3
9JT.
Additional reports of breeding Shelduck, principally from inland sites, that were not recorded as part of the survey work are detailed in the Systematic List — Ed. 17
Weather trends and their effect on the County's avifauna, 1992 John H.
Grant
January, February, March: In what was to become one of the driest winters of the century, local meteorologists amassed January records which graphically told the tale. At Broom's Barn, Higham, the month's total rainfall was only 1,96in, falling in measurable quantities on only eight days — the lowest number of days in January since 1964. At Levington, the month's total was 1.18in and the Ipswich area's ranged from 1.25in to 1.31 in. A cold front which moved across Suffolk on January 9th produced much of the month's rain in only a few hours; at Broom's Barn there was 0.86in and in Ipswich 0.69in fell. The mild weather perhaps explains why an Arctic and three Pomarine Skuas stayed for the winter as well as a Turtle Dove wintering in Lowestoft and an unseasonable Whimbrel on the Butley River. February continued the winter's drought and although the month began cold and raw, with a short-lived anticyclone centred over England, milder conditions soon moved in. By February 12th, south-westerly winds had raised temperatures to 11 °C (52°F), dipping back briefly during snow flurries on 18th and 19th. Overall, the period will most likely be remembered for its drought than its birds. The dearth of rain continued a recent pattern — the total deficit of rain at the East Anglian Daily Times weather station in Ipswich over the three years ending December 31st 1991 was 13.75in. Rarity hunters had little to lift the winter's gloom but, on the other side of the coin, the generally mild conditions meant there were good numbers of species such as Chiffchaff and Blackcap overwintering with us. In stark contrast to January and February's drought, the heavens opened in an unsettled March and Ipswich, for example, had measurable rain on 21 days. The general picture was of an often mild and spring-like month with temperatures above the long-term average of 9 ° C (48°F) on 21 days. As could be expected, such conditions triggered off a movement of our summer migrants and early arrivals included a Wheatear on 2nd, a Sand Martin on 7th, an exceptionally early Swallow on 16th, a Yellow Wagtail on 22nd and a Tree Pipit on 26th.
March 1992 was often mild and springlike. High pressure over France gave some notably warm days with maximum of 58° F (14°C) on the 17th. There were warm south-westerlies from the Bay of Biscay on several days.
18
May 1992 was a chiefly sunny and warm month and over England it was the second wärmest May since records began in 1659. Blocking anticyclones controlied the weather an on May 24th and 25th a max. of 82°F (28°C) was recorded in East Anglia.
Aprii, May, June: There is a condition suffered by Suffolk's birdwatchers which is known colloquially as Eastern Mange, induced at peak migration times by the merest hint of easterly in the wind. It renders its victims incapable of work and the only known cure is to spend long periods scouring the coast for the vagrants which invariably turn up at such times. Occasionally however, these occurrences lead on to the second, more serious stage of the affliction, Eastern Frenzy for which the only known cure is when the weather returns to the dreaded South-westerly Lethargy. Eastern Mange tends to be an autumn affliction but it was to break out as an epidemie during the spring of 1992 and a rainy Aprii gave a hint of things to come with an anticyclone over the North Sea giving east to south-east winds early in the month. However, it was not until late Aprii that Eastern Mange became rampant. A Red-footed Falcon, Britain's second-earliest Caspian Tern and a Serin started the outbreak, which set in with a vengeance during May and June as a procession of vagrants appeared during one of the iongest spells of winds with an easterly component that many of us could remember. Temperatures were as hot as the birds, with East Anglia being considerably warmer on May 24th and 25th than the likes of Madrid, Barcelona, Nairobi and Tenerife. Ipswich temperatures reached a sweltering 28°C (82°F). Birders were getting hot under the collar and the mange outbreak turned inexorably to frenzy as the rarity parade included three Cattle Egrets, Glossy Ibis, more Red-footed Falcons, Terek Sandpiper, Alpine Swift, Bee-eaters, Red-rumped Swallow, Great Reed Warbler, Common Rosefinches, and Whitethroated Sparrow. The latter brought an unexpected western flavour to the proceedings but perhaps involved a bird that had hitched a ride on a transatlantic container ship. Special mention must be made of the birds that appeared in south-east Suffolk at Landguard and Fagbury Cliff. During late May and early June, these two sites between them produced Suffolk's first Black-headed Bunting, the County's first and second spring Greenish Warblers and two Red-breasted Flycatchers — ali typicai overshoots from eastern Europe. Largely responsible for this unexpected purple patch was a huge blocking anticyclone which settled over Scandinavia. It produced sunny, warm weather and this particular strain of Eastern Mange had a healthy side-effect — its victims were roasted to a reddish hue!
July, August, September: Récupération from the spring's ailments was provided in an unsettled July which, although often warm, was dogged by downpours and a deficit of sunshine. Many places recorded 19
•
A shallow depression over the North Sea brought torrential rain and thunder on Sept. 21st, 1992. In the 48 hours ending ai 9 a. m. on Sept. 23rd, 1.20 inches of rain feil in places — well over half the normal for the entire month.
more than three inches of rain during the month, most falling in several hours on the night of 20th/21st. The deluge was, in many places, the heaviest since the infamous hail storm on August 23rd 1987, and its intensity was such that meteorologists estimated that two million tons of water feil on the 9,589 acres of Ipswich. In such conditions, far removed from our ideals of summer, it was perhaps not surprising that species such as Brent Goose, Wigeon and Pintail featured in the July records. " S u m m e r is taken by s t o r m " said the E A D T headlines as nearly ali areas reported the wettest August since 1987, with only two hot days on which temperatures reached or exceeded 27°C (80°F). Nevertheless, rainfall totals varied widely, with Halesworth recording a monthly total of 3.4in, whereas Haughley's total was a relatively meagre 1.96in. Deep depressions moving either to the north of East Anglia or right across it were responsible for the deluges. It is difficult to assess the precise effect of ail this on our birdlife, but August produced the expected crop of returning waders, including remarkable numbers of some species following severe storms on August 30th, but a rather sparse crop of seabirds and only one bird to set the rarity-hunter's puise racing — a Lesser Crested Tern at Minsmere. September followed the now established pattern of unsettled weather with above-average rainfall. Meteorologists theorised that this pattern may have been due to the éruption of the volcanic Mount Pinatubo in the Philippines on June 15th 1991. About 20 million tons of ash were ejected into the atmosphère and subsequently started to circuiate in the stratosphère. It was not until late September that autumnal specialities began to appear in earnest and it was interesting to note that, for the most part, their occurrences were almost certainly linked to a shallow depression over the North Sea which gave torrential rain and thunder on September 2Ist. The next day, for example, Yellow-browed Warbler, Icterine Warbiers, Barred Warbiers, Red-backed Shrike and peak falls of Chiffchaffs and Pied and Spotted Flycatchers occurred.
October, November, December October competes with May in terms of birdwatchers' anticipation, but in 1992 these two months were as chalk and cheese; sun-drenched May seemingly knee-deep in rarities, chilly October providing an interesting yet, by comparison, rather sparse selection of vagrants. It was one of the coldest Octobers on record; at Broom's Barn only 1974 was colder, whilst the average temperatures in the County were 2.5°C below the seasonal norm of 20
10°C (50°F). At the EADT weather station in Ipswich it was the eighth month in succession with above-average rainfall. The key to much of the month's avian activity was a large blocking anticyclone to the north-east of Britain which gave winds from a north to northeasterly point from October 3rd to 13th. It not only steered cold weather our way but also drifted Red-throated Pipit, Barred Warblers, Yellow-browed Warblers, Red-breasted Flycatcher, an eastern race Great Grey Shrike and a Rustic Bunting to the County. November saw the end of this system and a sequence of depressions and fronts which moved north-east from the Atlantic. This is the classic recipe for wet and windy weather, which duly arrived. It became the ninth consecutive month of above-average rainfall at many weather stations. At Broom's Barn, for example, it was the wettest November for 18 years. Mildness accompanied the rain, however and in Ipswich the long-term average minimum temperature of 9°C (48°F) was reached or exceeded on no less than 22 days. The Great Spotted Cuckoo which lingered from the end of October into November must have felt quite at home in such a mild spell. In contrast, December brought a generally cold close to the year and, although southwesterly gales occurred on 2nd and 18th, winds from the north-east and south-east predominated thereafter. However, it was not cold enough to trigger off a mass invasion of species forced out of Continental Europe and they were represented by an average showing. Nor was it cold enough to displace our most honoured guest, the male Dartford Warbler on Dunwich Heath. It doggedly stayed on through late December's chill and lingered long enough into the New Year to kindle just a glimmer of hope for the re-establishment of the species' breeding in Suffolk. The bird had so far taken what the weather could dish out — would 1993 see a female to make his wait worthwhile? John Grant, 39 School Road, Sudbourne, Suffolk IP12 2BE.
Common Rosefinch — First Confirmed Breeding in Suffolk H. R.
Beecroft.
The ringing of birds as part of a long term migration study has been carried out at Bawdsey for several years. During these activities on June 25th 1992, myself, Muriel Beecroft and Sqn. Ldr. (retd.) Derek R. Rothery heard an unfamiliar bird song coming from the top of a nearby Monterey Cypress Cupressus macrocarpa. The bird soon flew off into an area of mixed woodland and scrub. At 09.10 the same morning, a male Common Rosefinch Carpodacus erythrinus was caught in a mist net during a routine net round. The bird was a first-summer individual and showed no sign of the red colouring of the full adult male plumage which is usually not attained until the second breeding year. Our first impressions were therefore of a rather uninterestingly coloured finch, brown or heavily streaked brown above with faint whitish double wingbars, buffish underparts, also streaked brown and a noticeably bulbous bill. The habitat in the immediate area consisted of Monterey Cypress, Evergreen Oak Quercus ilex, Hawthorn Crataegus monogyna, Tamarisk Tamarix gallica, Bramble Rubus ulmifolius and Traveller's-joy Clematis vitalba. The occurrence of the male rosefinch was considered to have involved a passage migrant and routine ringing operations continued at the site. The Common Rosefinch proved to be our mystery songster and was again heard singing from a Monterey Cypress, some 15 metres from the ground on July 2nd. Song was again heard on July 16th, this time for a period of about five minutes. Although there had been no confirmed sighting of a second individual, we began to feel optimistic that the male was holding territory and had 21
attracted a mate. On July 2nd, the male showed signs of aggression in 'seeing o f f a passing Kestrel Falco tinnunculus. On July 23rd, an adult female Common Rosefinch was caught and ringed. We immediately suspended ringing at the site to avoid any disturbance to possible breeding activity. On July 30th, the male was heard singing and later that morning the adult male and two juvenile Common Rosefinches were caught about 100 metres south of the original song tree. We did not ascertain whether other juveniles were present. Apart from the obvious fresh juvenile plumage, the wingbars on the young birds were more prominent than on the adults with wider buff tips to the greater and median coverts. To avoid any unnecessary disturbance the nest had been neither sought nor found. This constitutes the first confirmed record of successful breeding of this species in Suffolk. Prior to 1992 there had only been two confirmed breeding records for the U . K . , both in the Highland District of Scotland — one in June/early July 1982 (Mullins 1984) and one in June 1990 (Gibbons et al. 1993). In 1992, the mini-influx of this species, particularly into east coast areas of Britain, resulted in the first English breeding reports, the complete extent of which has still to be fully established. Elsewhere in Suffolk in 1992 a second pair of Common Rosefinches commenced nest building on the edge of the Minsmere RSPB Reserve but the outcome is uncertain. The Bawdsey birds were not seen after July 31st 1992, coincidentally the same latest date as that recorded at Flamborough Head, Humberside in 1991 although breeding was not proven at the latter site in that year. Although migration studies continued at Bawdsey in 1993 there was no evidence that this migrant finch had returned to the site in that year. References: Gibbons, D. W., Reid, J. B. & Chapman, R. A. 1993. New Atlas of Breeding Birds in Britain and Ireland: 1988-1991. Poyser, London. Lassey, P. A. & Wallace, D. I. M. 1992. Breeding breakthrough by Scarlet Rosefinches. Birdwatching Sept. 1992:84-85. Mullins, J. R. 1984. Scarlet Rosefinch breeding in Scotland. Brit. Birds 77:133-135. H. R. Beecroft,
'Alcedo',
Hall Lane,
Witnesham,
Ipswich
IP6
9HN.
Recent Additions to the Suffolk List Mike Crewe
and Philip
Murphy
Two records have recently, and rather belatedly, been admitted to the Suffolk list, both having caused controversy over the way the records were handled and/or the length of time taken to assess them. The details below should hopefully put both records to rest and resolve any disputes! Semipalmated Sandpiper Much confusion was caused over the identity of a small stint which remained at Felixstowe Ferry from October 30th 1982 to April 14th 1983. Opinion wasdivided between Semipalmated Sandpiper (Calidris pusilla) and Western Sandpiper (C. mauri) with the majority of observers favouring the latter. The bird was submitted as a Western Sandpiper, but after consultation with American and Swedish wader identification specialists, the British Birds Rarities Committee (BBRC) accepted, and published, the record as being a Semipalmated Sandpiper (Rogers 1986). The reasons for this decision were given in a subsequent article (Grant 1986). Despite the outcome of BBRC's extensive consultations, the Suffolk Ornithological Records 22
Committee (SORC) considered that an element of doubt still existed concerning the bird's identification. Accordingly, the record was published by them as being either Western or Semipalmated Sandpiper (Murphy 1987). The situation remained unresolved until ten years after the bird's occurrence. In a detailed analysis of the bird's identification, Millington and Vinicombe (1992) finally resolved the years of confusion by clearly showing that the bird was a Semipalmated Sandpiper. SORC has accepted the conclusions of Millington and Vinicombe and the record is now published as being Suffolk's first Semipalmated Sandpiper. Lark Sparrow The occurrence of an American Lark Sparrow (Chondestes grammacus) at Landguard Point from June 30th to July 8th 1981 was one of the highlights of that year in Suffolk. The bird was initially placed into Category D of the British List whilst the pros and cons of genuine vagrancy were considered. However, controversy developed as it began to look as though the record would languish there forever. Despite the discovery that the species was scarce in captivity and occurred regularly on the East coast of America as an over-shooting spring migrant (e.g. LeGrand 1986 and others), no more was heard of the record. Trying to unravel the thinking of the British Ornithologists' Union Records Committee (BOURC) regarding this bird had only served to produce headaches for members of the SORC with much apparent confusion over what factors were or were not holding up the process. With this in mind, it is not considered possible to summarise all the events to date. Tim Inskipp, on behalf of the BOURC, revealed in a recent letter to the Suffolk County Recorder, that the Lark Sparrow was finally elevated to Category A of the British List after a request from within the BOURC (doubtless similar to the many other requests from outside the committee over the years!), based on additional information relating to its status in the wild and in captivity in North America. After recent circulation, its acceptance into Category A was based on three points: (a) evidence that the species breeds on the Atlantic coast of North America and occasionally makes sea-crossings there (e.g. now recorded in Bermuda). (b) it became clear that the species is very rare in captivity — not known in Britain, or Mexico (the most likely source of imports) and, although recorded in captivity in Belgium and The Netherlands, it was felt that a ship-assisted origin was more likely. (c) the Committee revised its policy towards birds arriving here with ship (but not human) assistance. It was also revealed that the presence of a Lark Sparrow in Norfolk in May 1991 did not materially affect the result. References Grant, P. J., 1986. Four problem stints. Brit. Birds 79:617-621. LeGrand Jr., H. E., 1986. The spring migration March 1-May 31, 1986. American Birds 40:459. Millington, R. & Vinicombe, K. 1992. The new approach in action: Felixstowe '82 revisited. Birding World 5:433-437. Murphy, P. W. (ed.), 1987. Suffolk Birds 1985. Suffolk Naturalists' Society. Rogers, M. J., 1986. Report on rare birds in Great Britain in 1985. Brit. Birds 79:545.
23
SUBMISSION OF RECORDS: GUIDELINES FOR OBSERVERS Steve
Piotrowski
In 1950, the Suffolk Naturalists' Society published Suffolk's first Bird Report as part of its 'Transactions'. It was edited by Dr P. R. Westall and many of the sentiments expressed in his first 'Editorial' ring true today. Part of the opening paragraph read: "This summary of the large numbers of individual records must, of course, depend on the field work of observers, who, on the whole, can find but little spare time for such purposes, and we hope this Report — made possible only by their efforts — will go far in helping to co-ordinate the work done, and providing as full a picture as possible of the birds of Suffolk, year by year. " There were 84 contributors to that report, a higher figure than might be expected because of the obvious novelty factor. Realistically, there were about 50 regular contributors to the reports in the 1950s. There followed a steady increase and by the 1990s the number of contributors had risen to about 300. Traditionally, records have been processed by the County Recorder, but with such a vast increase in the number of records submitted, this task has become almost a full-time occupation. From 1979 to 1991, we were fortunate to have such a willing worker as Bob Warren at the helm, but we were always aware that finding a successor, with the time available and relevant experience, would be difficult. It was for this reason that we sought the help of the Suffolk Biological Records Centre (SBRC) to computerise the records and Philip Murphy was persuaded to take on the position of County Recorder. However, the tools of modern technology are not without their teething troubles and, for ornithology, the computer-package used at the SBRC was not ideal. To help with inputting, we initially asked observers to submit their records in diary format, but improvements to the system now mean that we are able to process records in any form, with a preference for species order. We have now resolved the early problems and the intention of this paper is to provide guidelines to the degree of information required for each species in order to minimise the amount of time that County Recorders spend chasing up details of sightings. Detailed below is the full list of species that have been recorded in Suffolk up to and including January 1st 1994. Well-marked subspecies are also included. The list has been divided into sections according to the various status categories as defined by the British Ornithologists' Union (BOU). These categories are as follows: C a t . A: Species which have been recorded in an apparently wild state in Britain or Ireland at least once since Jan. 1st 1958. C a t . B: Species which have been recorded in an apparently wild state in Britain or Ireland at least once up to Dec. 31st 1957 but have not been recorded subsequently. C a t . C: Species which, although originally introduced by man, have now established a regular feral breeding stock which apparently maintains itself without necessary recourse to further introduction. Cai. D: Species which would otherwise appear in categories A, B or C except that; (Dl) there is a reasonable doubt that they have ever occurred in the wild state; (D2) they have certainly arrived with a combination of ship and human assistance, including provision of food and shelter; (D3) they have only ever been found dead on the tideline; (D4) species that would otherwise appear in Category C except that their feral populations may not be self-supporting. Species in Categories A, B and C form the standard British and Irish List and are detailed together in the list below. Species in Category D do not form part of the British and Irish list and are therefore included in the appendices of Suffolk Bird Reports and not in the main checklist. Some species on the British and Irish List occur both as wild birds and as feral populations; such species have recently been assigned dual status by the BOU. It should be remembered that the species below are arranged according to their national 24
1: Immature Shags at Lowestoft. Numbers of this species have increased dramatically in recent winters.
2: TheRi ver Orwell at Wherstead Strand is rapidly becoming a winter mecca for local birdwatchers.
I
|j| s
«
A «
^
.f
'
-fc
WtííM M,:* — 1
' j m ^ m '
¡fe,
^^^MbWW^iW • • ¿V - ? • > ~
Y / - ?
¡¡¡¡•jöRsSä w&mwasaas«-- • s.v ; „;.• ,
• - '-s'H» t
,Ï
sâlï-v»: *.<*: *
*
' ö S
3: This immature male Red-footed Falcon entertained a delighted crowd at Landguard during a record year for the species.
4: Red-footed Falcon with prey taken from Kestrel, Orfordness (see p. 142).
status; some species have a different status in Suffolk to their national status (especially in relation to feral populations and escapees) but it would be confusing to create another set of categories which would only be relevant in Suffolk. Each species in the list below has been given a Recording Code as a guide to the form of records that are required. These codes relate to the following key: Recording Code Key: A All records required. B Birds confirmed breeding or holding territory. C Counts of roosts, flocks or movements. D Detailed description, sketches, field notes and/or photographs necessary to support record: forms are available from the County Recorders. E/L Earliest and latest dates. I Inland records required. IN Notes required to support inland records. M Migration or weather movements. N Brief notes (how bird was identified, view, distance, etc.). W All winter records required.
The Suffolk List BOU Categories, B
&C
Red-throated Diver Gavia stellala Black-throated Diver Gavia arctica Great Northern Diver Gavia immer White-billed Diver Gavia adamsii Little Grebe Tachybaptus ruficollis Great Crested Grebe Podiceps cristaius Red-necked Grebe Podiceps grisegena Slavonian Grebe Podiceps auritus Black-necked Grebe Podiceps nigricollis Fulmar Fulmarus glacialis Cory's Shearwater Calonectris diomedea Great Shearwater Puffinus gravis Sooty Shearwater Puffinus griseus Man* Shearwater Puffinus puffinus Storm Petrel Hydrobates pelĂĄgicos Leach's Petrel Oceanodroma leucorhoa Gannet Morus bassanus Cormorant Phalacrocorax carbo Shag Phalacrocorax arislotelis Bittern Botaurus stellaris Little Bittern Ixobrychus minuius Night Heron Nyclicorax nyclicorax Squacco Heron Ardeola ralloides Cattle Egret Bubulcus ibis Little Egret Egretta garzella Great White Egret Egretta alba Grey Heron Ardea cinerea Purple Heron Ardea purpurea Black Stork Ciconia nigra White Stork Ciconia ciconia Glossy Ibis Plegadis falcinelli Spoonbill Platalea leucorodia Mute Swan Cygnus olor Bewick's Swan Cygnus columbianus Whooper Swan Cygnus cygnus Bean Goose Anser fabalis
Recording Code
Recording Code Pink-footed Goose Anser brachyrhynchus White-fronted Goose Anser albifrons Greenland White-front A. a.flavirostris
A N N D B,C B,C N N N B,C,IN D D N A D D A B,C A.IN A D D D D D D B,C,M D D D D A B.C A N N
f t Lesser White-fronted Goose Anser erythropus Greylag Goose Anser anser Snow Goose Anser caerulescens Canada Goose Branta canadensis Barnacle Goose Branta leucopsis Brent Goose Branta bemlcla Pale-bellied Brent Goose B. b. hrota Black Brant B. b. orientalis Red-breasted Goose Branta ruficollis Egyptian Goose Alopochen aegyptiacus Ruddy Shelduck Tadorna ferruginea Shelduck Tadorna tadorna Mandarin Aix galericulata Wigeon Anas penelope American Wigeon Anas americana Gadwall Anas streperĂ Teal Anas crecca Green-winged Teal A. c. carolinensis Mallard Anas platyrhynchos Pintail Anas acuta Garganey Anas querquedula Blue-winged Teal Anas discors Shoveler Anas clypeata Red-crested Pochard Netta rufina Pochard Aythya ferina Ring-necked Duck Aythya collaris Ferruginous Duck Aythya nyroca Tufted Duck Aythya fuligula Scaup Aythya marila Eider Somateria moltissima Long-tailed Duck Clangula hyemalis Common Scoter Melanina nigra Velvet Scoter Melanina fusca
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N A D A B,C N B.C A C,M,I N D D A N B,C,I N B,C,I D B.C B,C D B,C B.C.I A D B,C A B,C D D B,C A A A A A
Recording Code
Recording Code Goldeneye Bucephala clangula Smew Mergus albellus Red-breasted Merganser Mergus senator Goosander Mergus merganser Ruddy Duck Oxyura jamaicensis Honey Buzzard Pemis apivorus Black Kite Milvus migrans Red Kite Milvus milvus White-tailed Eagle Haliaeetus albicilla Marsh Harrier Circus aeruginosas Hen Harrier Circus cyaneus Montagu's Harrier Circus pygargus Goshawk Accipiter gentilis Sparrowhawk Accipiter nisus Buzzard Buleo buteo Rough-legged Buzzard Buteo lagopus Spotted Eagle Aquila clanga Osprey Parution haliaetus Kestrel Falco tinnunculus Red-footed Falcon Falco vespertinus Merlin Falco columbarius Hobby Falco subbuteo Gyr Falcon Falco rusticolus Peregrine Falco peregrinas Red Grouse Lagopus lagopus Black Grouse Tetrao tetrix Red-legged Partridge Alectoris rufa Grey Partridge Perdix perdix Quail Cotumix cotumix Pheasant Phasianus colchicus Golden Pheasant Chrysolophus pictus Water Rail Rallus aquaticus Spotted Crake Porzana porzana Little Crake Porzana parva Baillon's Crake Porzana pusilla Corncrake Crex crex Moorhen Gallínula chloropus Allen's Gallinule Porphyrula alleni Coot Fúlica atra Crane Grus grus Little Bustard Tetrax tetrax Houbara Bustard Chlamydotis undulata Great Bustard Otis tarda Oystercatcher Haematopus ostralegus Black-winged Stilt Himantopus himantopus Avocet Recurvirostra avosetta Stone Curlew Burhinus oedicnemus Cream-coloured Courser Cursorius cursor Collared Pratincole Glareola pratíncola Oriental Pratincole Glareola maldivarum Black-winged Pratincole Glareola nordmanni Little Ringed Plover Charadrius dubius Ringed Plover Charadrius hiaticula Kentish Plover Charadrius alexandrinus Greater Sand Plover Charadrius leschenaultü Dotterel Charadrius morinellus Golden Plover Pluvialis apricaria Grey Plover Pluvialis squatarola Sociable Plover Chettusía gregaria Lapwing Vanellus vanellus Knot Calidris canutus Sanderling Calidris alba
Semipalmated Sandpiper Calidris pusilla Litde Stint Calidris minuta Temminck's Stint Calidris temminckii White-ramped Sandpiper Calidris fuscicollis Baird's Sandpiper Calidris bairdii Pectoral Sandpiper Calidris melanotos Curlew Sandpiper Calidris ferruginea Purple Sandpiper Calidris marítima Dunlin Calidris alpina Broad-billed Sandpiper Limicola falcinellus Stilt Sandpiper Micropalama himantopus Buff-breasted Sandpiper Tryngites subruficollis Ruff Philomachus pugnax Jack Snipe Lymnocryptes minimus Snipe Gallinago gallinago Great Snipe Gallinago media Long-billed Dowitcher Limnodromus scolopaceus Woodcock Scolopax rusticóla Black-tailed Godwit Limosa limosa Bar-tailed Godwit Limosa lapponica Eskimo Curlew Numenius borealis Whimbrel Numenius phaeopus Curlew Numenius arquata Upland Sandpiper Bartramia longicauda Spotted Redshank Tringa erythropus Redshank Tringa totanus Marsh Sandpiper Tringa stagnatilis Greenshank Tringa nebularia Greater Yellowlegs Tringa melanoleuca Lesser Yellowlegs Tringa flavipes Green Sandpiper Tringa ochropus Wood Sandpiper Tringa glareola Terek Sandpiper Xenus cinereus Common Sandpiper Actitis hypoleucos Spotted Sandpiper Actitis macularia Turnstone Arenaria interpres Wilson's Phalarope Phalaropus tricolor Red-necked Phalarope Phalaropus lobatus Grey Phalarope Phalaropus fidicarius Pomarine Skua Stercorarius pomarinus Arctic Skua Stercorarius parasiticus Long-tailed Skua Stercorarius longicaudus Great Skua Catharacta skua Mediterranean Gull Larus melanocephalus Franklin's Gull Larus pipixcan Little Gull Larus minutus Sabine's Gull Larus sabini Black-headed Gull Larus ridibundus Slender-billed Gull Larus genei Ring-billed Gull Larus dehwarensis Common Gull Larus canus Lesser Black-backed Gull Larus fuscus Herring Gull Larus argentanis Yellow-legged Gull L. a. michahellis Iceland Gull Larus glaucoides Glaucous Gull Larus hyperboreus Great Black-backed Gull Larus marinus Kittiwake Rissa tridactyla Ivory Gull Pagophila ebúrnea Gull-billed Tern Gelochelidon nilotica Caspian Tern Sterna caspia Lesser-crested Tern Sterna bengalensis
C,M A A A A D D N D A A D N A A N D A B,C,M D A A D A D D B A N B A A D D D D B,C D B,C D D D D B,C,I D A A D D D D A B,C,1 D D N C C,I D B,C C,1 A
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D A N D D D A A,IN C,I D D D A A B,C D D A B,C,I A D A B,C D A B,C D A D D A A D A D C,I D D N N A,IN D A,IN A D A D B,C D D B,C B,C B,C D N N B,C B,C,I D D D D
Recording Code
Recording Code Sandwich Tern Sterna sandvicensis Roseate Tern Sterna dougallii Common Tern Sterna hirundo Arctic Tern Sterna paradisaea Sooty Tern Sterna fuscata Little Tern Sterna albifrons Whiskered Tern Chlidonias hybridus Black Tern Chlidonias niger White-winged Black Tern Chlidonias leucopterus Guillemot Una aalge Razorbill Alca torda Black GuillemotCepp/u« grylle Little Auk Alle alle Puffin Fratercula arctica Pallas's Sandgrouse Syrrhaptes paradoxus Feral Pigeon Columba livia Stock Dove Columba oenas Woodpigeon Columba palumbus Collared Dove Streptopelia decaocto Turtle Dove Streptopelia turtur Ring-necked Parakeet Psittacuh krameri Great Spotted Cuckoo Clamator glandarius Cuckoo Cuculus canorus Yellow-billed Cuckoo Coccyzus americanus Barn Owl Tyto alba Scops Owl Otus scops Snowy Owl Nyctea scandiaca Little Owl Athene noctua Tawny Owl Strix aluco Long-eared Owl Asia otus Short-eared Owl Asio flammeus Tengmalm's Owl Aegolius funereus Nightjar Caprimulgus europaeus Swift Apus apus Pacific Swift Apus pacificus Alpine Swift Apus melba Kingfisher Alcedo atthis Bee-eater Merops apiaster Roller Coracias garrulus Hoopoe Upupa epops Wryneck Jynx torquilla Green Woodpecker Picus viridis Great-spotted Woodpecker Dendrocopos major Lesser-spotted Woodpecker Dendrocopos minor Short-toed Lark Calandrella brachydactyla Woodlark Lullula arborea Skylark Alauda arvensis Shore Lark Eremophila alpestris Sand Martin Riparia riparia Swallow Hirundo rustica Red-rumped Swallow Hirundo daurica House Martin Delichon urbica Richard's Pipit Anthus novaeseelandiae Tawny Pipit Anthus campestris Tree Pipit Anthus trivialis Pechora Pipit Anthus gustavi Meadow Pipit Anthus pratensis Red-throated Pipit Anthus cervinus Rock Pipit Anthus petrosus Scandinavian Rock Pipit A. p. littoralis Water Pipit Anthus spinoletta Yellow Wagtail Motacilla ¡lava
B,C,E/L,I D B,C,E/L A D B,C,E/L,I D A D A,IN A,IN D A,IN N D B,C B,C B,C,M B,C B,E/L A D B,E/L D A D D A A A A D A B.E/L D D A D D N A A A A D A B.C.M A B.C.E/L B.C.E/L D B.C.E/L D D A D B.C.M D A.IN N N B.C.E/L
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Blue-headed Wagtail M.f.flava Grey-headed Wagtail M.f. thunbergi Ashy-headed Wagtail M.f. cinereocapilla Black-headed Wagtail M.f.feldegg Citrine Wagtail Motacilla citreola Grey Wagtail Motacilla cinerea Pied Wagtail Motacilla alba White Wagtail M. a. alba Waxwing Bombyàlla garrulus Dipper Cinclus cinclus Black-bellied Dipper C. c. cinclus Wren Troglodytes troglodytes Dunnock Prunella modularis Alpine Accentor Prunella collaris Robin Erithacus rubecula Thrush Nightingale Luscinia luscinia Nightingale Luscinia megarhynchos Bluethroat Luscinia svecica White-spotted Bluethroat L. s. cyanecula Black Redstart Phoenicurus ochruros Redstart Phoenicurus phoenicurus Eastem Redstart P. p. samamisicus Whinchat Saxicola rubetra Stonechat Saxicola torquata Siberian Stonechat S. t. maura/stejnegeri Wheatear Oenanthe oenanthe Greenland Wheatear 0. o. leucorhoa Desert Wheatear Oenanthe deserti White-crowned Black Wheatear Oenanthe leucopyga White's Thnish Zoothera dauma Ring Ouzel Turdus torquatus Blackbird Turdus merula Fieldfare Turdus pilaris Song Thrush Turdus philomelos Redwing Turdus iliacus Mistle Thrush Turdus viscivorus Cetti's Warbler Cettia cetti Grasshopper Warbler Locustella naevia River Warbler Locustella fluviatilis Savi's Warbler Locustella luscinioides Aquatic Warbler Acrocephalus paludicola Sedge Warbler Acrocephalus schoenobaenus Paddyfield Warbler Acrocephalus agricola Blyth's Reed Warbler Acrocephalus dumetorum Marsh Warbler Acrocephalus palustris Reed Warbler Acrocephalus scirpaceus Great Reed Warbler Acrocephalus arundinaceus Icterine Warbler Hippolais icterina Melodious Warbler Hippolais polyglotta Dartford Warbler Sylvia undata Subalpine Warbler Sylvia cantillans Barred Warbler Sylvia nisoria Lesser Whitethroat Sylvia curruca Siberian L. Whitethroat S. c. blythii Whitethroat Sylvia communis Garden Warbler Sylvia borin Blackcap Sylvia atricapilla Greenish Warbler Phylloscopus trochiloides Arctic Warbler Phylloscopus borealis Pallas's Warbler Phylloscopus proregulus Yellow-browed Warbler Phylbscopus inomatus
N D D D D A B,C A A D N B B D B,C D B.E/L D D A A D A A D A N D D D A B.C C.E/L B.C B.C.E/L B.C N A D D D B.E/L D D D B.E/L D D D D D D B.E/L D B.E/L B.E/L B.E/L,W D D D D
Recording Code
Recording Code Radde's Warbler Phylloscopus schwärzt Dusky Warbler Phylloscopus fuscatus Bonelli's Warbler Phylloscopus bonelli Wood Warbler Phylloscopus sibilatrix Chiffchaff Phylloscopus collybita Siberian Chiffchaff P. c. tristis Willow Warbler Phylloscopus trochilus Goldcrest Regulus regulus Firecrest Regulus ignicapillus Spotted Flycatcher Muscicapa striata Red-breasted Flycatcher Ficedula poma Collared Flycatcher Ficedula albicollis Pied Flycatcher Ficedula hypoleuca Bearded Tit Panurus biarmicus Long-tailed Tit Aegilhalos caudatus Marsh Tit Parus palustris Willow Tit Parus montanus Crested Tit Parus cristatus Coal Tit Parus ater Blue Tit Parus caeruleus Great Tit Parus major Nuthatch Sitia europaea Treecreeper Certhia familiaris Pendutine Tit Remiz pendulinos Golden Oriole Oriolus oriolus Isabelline Shrike Lanius isabellinus Red-backed Shrike Lanius collurio Lesser Grey Shrike Lanius minor Great Grey Shrike Lanius excubitor Steppe Shrike L. e. pallidirostris Woodchat Shrike Lanius senator Jay Garrulus glandarius Magpie Pica pica Nutcracker Nucifraga caryocatactes Jackdaw Corvus monedula Scandinavian Jackdaw C. m. monedula Rook Corvus frugilegus Carrion Crow Corvus corone BOU Category D White Pelican Pelecanus onocrotalus Greater Flamingo Phoenicopterus ruber Bar-headed Goose Anser indicus Muscovy Duck Cairina moschata Wood Duck Alx sponsa
D D D N B,W N B,E/L B,C A B,E/L D D A A B,C B A D B,C B B A A D N D A D A D D B,M B,C D B,C,M N B,C,M B,C,M
D N A A A
Hooded Crow C. c. comix Raven Corvus corax Starling Sturnus vulgaris Rose-coloured Starling Sturnus roseus House Sparrow Passer domesticus Tree Sparrow Passer montanus Red-eyed Vireo Viren olivaceus Chaffinch Fringilla coelebs Brambling Fringilla montifringilla Serin Serinus serinus Greenfinch Carduelis chloris Goldfinch Carduelis carduelis Siskin Carduelis spinus Linnet Carduelis cannabina Twite Carduelis flamostris Redpoll Carduelis flammea Mealy Redpoll C.f. flammea Arctic Redpoll Carduelis hornemanni Two-barred Crossbill Loxia leucoptera Crossbill Loxia curvirostra Parrot Crossbill Loxia pytyopsittacus Trumpeter Finch Bucanetes githagineus Common Rosefinch Carpodacus erythrinus Bullfinch Pyrrhula pyrrhula Hawfinch Coccothraustes coccothraustes Lark Sparrow Chondestes grammacus White-throated SparTow Zonotrichia albicollis Lapland Bunting Calcarius lapponicus Snow Bunting Plectrophenax nivalis Yellowhammer Emberiza citrinella Ciri Bunting Emberiza cirlus Ortolan Bunting Emberiza hortulana Rustic Bunting Emberiza rustica Little Bunting Emberiza pusilla Yellow-breasted Bunting Emberiza aureola Reed Bunting Emberiza schoeniclus Black-headed Bunting Emberiza melanocephala Corn Bunting Miliaria calandra
A D B,C,M D B A D B,C A D B,C B,C B,C B,C A,IN B,C N D D A D D D B,C A D D N A,IN B,C D D D D D B,C D A
Baikal Teal Anas formosa Chukar Alectoris chukar Bobwhite Colinus virginianus Snow Finch Montifringilla nivalis Red-headed Bunting Emberiza bruniceps
D N N D D
Notes: A total of 369 species has been accepted onto the full Suffolk List. In addition, a further four species which are on the British List have occurred in the County in the past but are not fully accepted on the Suffolk List. The species are marked in the list above with the following symbols: t t Not known to have occurred as a truly wild bird in Suffolk. ** Introduced into Suffolk and either did not fully become established or the population died-out. t Ă Vagrant brought into Suffolk by Man. A sighting of a bird not listed would constitute a new species for the County and full details would be required as specified in Recording Code D. Additional details may be required for any record considered by the Suffolk Ornithological 28
Records Committee to be out of context in terms of season, habitat or numbers. Records of birds in unusual plumage, such as albino or melanistic, are also required as well as notes detailing instances of uncharacteristic behaviour. Acknowledgements: I should like to thank the Suffolk Ornithological Records Committee for their assistance during the preparation of this paper and Mike Marsh, Mike Crewe and Howard Mendel for their comments on the draft. S. H. Piotrowski, 18 Cobham Road, Ipswich IP3 9JD.
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