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SUFFOLK BIRDS

1992

• 1991 Bird Report

• Ringing Report

• Hollesley Heath

• Long-tailed Skuas

• Rarities

• Breeding Waders


3

THE COUNTY OF SUFFOLK

I

4 , ,Gt. Yarmouth

Brey don Water

Watsonian vice-counties 2 5 (East Suffolk) and 2 6 (West Suffolk).

J0—K

TG 63 TM 62

Fritton Lake

Ml

I i\ I

—1 Lowestoft

I J T Î Beccles

Oulton

Broad

Brandon Thetford Little

Pose1

Southwold Halesworth

Mildenhall

Blythburgh

Livermere Walberswick Lackford Pits Minsmere

Framlingham 'Newmarket

I ITM

Bury St. Edmunds

11 S t o w m a r k e t Aldeburgh Gipping

Valley Woodbridge — ~J Orfordness

fer I

Haverhill Wolves W o o d

R. Stour Sudbury

I

Ipswich

Havergate Island

Hadleigh Alton

Water Felixstowe Landguard

¿f


SUFFOLK BIRDS 1992 VOL. 41 incorporating the County Bird Report of 1991

Editor S. H. Piotrowski Assistant Editor P. W. Murphy Photographic Editor J. Levene

Published by SUFFOLK NATURALISTS' SOCIETY

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Published by The Suffolk Naturalists' Society, c/o The Museum, High Street, Ipswich IP1 3QH Š The Suffolk Naturalists' Society 1993 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.

ISSB 0264-5793

Printed by Healeys, 55 Fore Street, Ipswich, Suffolk IP4 1JL.


CONTENTS Page Editorial. Steve Piotrowski Twenty years of the Common Bird Census on Hollesley Heath. Alan Miller A brief summary of the Eagle Owl's status in Europe and its possible implications for Suffolk and Britain. Jeff Martin The Long-tailed Skua in Suffolk. John Cawston Breeding waders and other waterfowl on the coastal marshes and saltings of Suffolk in 1988 and 1989. T. C. Holzer, C. H. Beardall, R. C. Dry den & R. B. West Weather trends and their effect on the County's avifauna, 1991. John H. Grant... The 1991 Suffolk Bird Report Rarities in Suffolk 1991. Steve Piotrowski Lesser Crested Tern. Howard Parsons Franklin's Gull. John Cawston Ring-billed Gull. Richard Walden Red-eyed Vireo. Peter Ransome Wilson's Phalarope. Alastair Riseborough Radde's Warbler. Rex Beecroft Radde's Warbler. John Glazebrook Dusky Warbler, Sir A. G. Hurrell Gull-billed Tern. Nigel Odin & Jim Askins Roller. Mike Crewe Arctic Redpoll. Brian Small Notes Kestrel preying on House Sparrow under car. Mike Marsh Rump colour of Desert Wheatear. Mike Crewe Migrant Northern Wheatears at Landguard Point. Nigel Odin Letters Golden Orioles. Mike Jeanes Herons and other animals. Audrey Morgan Bird-eating Mussels. Craig Fulcher Landguard Bird Observatory. Mike Crewe Suffolk Ringing Report. Mike Marsh

5 7 11 15

19 29 35 142 142 143 144 145 145 146 147 147 148 148 149 152 152 152 153 154 155 155 156 162

List of Colour Illustrations Plate No.

Facing Page

Plate No.

1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15.

24 24 25 25 56 56 57 57 57 80 80 80 81 81 81

16. 17. 18. 19. 20. 21. 22. 23. 24. 25. 26. 27. 28. 29. 30.

Cormorant Stan Dumican Bittern Jack Levene Spoonbill Jack Levene Shelduck Steve Piotrowski Eider Jack Levene Smew Jack Levene Spotted Crake Jack I-evenc Black-winged Stilt Jack Levene Sanderling Jonathan Clay Wilson's Phalarope Jack Levene White-winged Black Tem Jack Levene Mediterranean Gull Jack Levene Stock Doves Stan Dumican Brambling Jack Levene Immature Roller Robin Chittenden

Shore Lark Jack Levene Sand Martin Jack Levene Radde's Warbler Rex Beecroft Tawny Pipit Jack Levene Black-bellied Dipper Howard Vaughan Fieldfare Jonathan Clay Blackbird Jonathan Clay Song Thrush Jack Levene Lesser Whitethroat Jack Levene Yellow-browed Warbler Jack Levene Yellowhammer Jack Levene Jay Stan Dumican Red-eyed Vireo Rob Wilson Great Spotted Woodpecker Muriel Beecroft Turnstone-eating Mussel Craig Fulcher

The copyright remains that of the photographers.

Facing Page 112 112 112 113 113 136 136 136 137 137 137 160 160 161 161


Notice to Contributors Suffolk Birds is an annual publication of records, notes and papers on ail aspects of Suffolk ornithology. Except for records and field descriptions, submitted through the County Recorder, ali material should be original. It should not have been published elsewhere or offered in complete or in part to any other journal. Authors should carefully study this issue and follow the style of présentation, especially in relation to référencés and tables. Nomenclature (English and scientific) and order should follow The 'British Birds' List of the Birds of the Western Palearctic (1984). Manuscripts must 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 altérations must be confined to corrections of printer's errors. The cost of any other altérations may be charged to the author. In certain circumstances the Editor may be able to accept papers on computer dise. Photographs and line drawings are required to complément 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 effort possible 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 Photographie Editor. The author may wish to illustrate his own article but this will be subject to the illustrations being of the standard required by the Editor, and the décision on such matters will rest with him. Material submitted for publication should be sent to the Editor no later than February lst of each year. Authors of main papers may request up to five free copies of the journal.

Suffolk Ornithological Records Committee Malcolm Wright (Chairman), Rex Beecroft, Dr. Ann Brenchley, Brian Brown, John Cawston, Gerald Jobson, Mike Marsh, Derek Moore, Philip Murphy (County Recorder), David Pearson, Steve Piotrowski, Brian Small, Cliff Waller. ADDRESSES Papers, notes, drawings and photographs: The Editor (Suffolk Birds), The Suffolk Naturalists' Society, c/o The Muséum, High Street, Ipswich IP1 3QH. Records: Philip Murphy, The County Recorder, 24 Henstead Gardens, Ipswich IP3 9LN. Suffolk Ornithological Records Committee — information: Philip Murphy, 24 Henstead Gardens, Ipswich IP3 9LN.

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Editorial

Top Award Suffolk Birds 1991, dealing with the events of 1990, was officially recognised as the best annua] County Bird Report in Britain. It was placed first, ahead of 46 rival publications and we were presented with the coveted British Birds "Best Annual Bird Report of the Year Award. " T h e panel ofjudges, D r J . T. R. Sharrock, Dr R. J. Chandler and Robert Gillmor, made particular reference to the design and layout. Brian Small's drawings of Baird's Sandpiper and John Grant's review of the effect of the year's weather on the County's avifauna attracted favourable comment. The photographie talents of Stan Dumican and Jack Levene were also noted. There were, of course, many other contributors who did not get a specific mention in BB. They were, nevertheless, fundamental to our success.

Records Bob Warren's retirement as County Recorder was announced in Suffolk Birds 1991 and, as is so often the case, no one really appreciated the quantity of work involved until it was passed on to others. The Suffolk Biological Records Centre is housed in Ipswich Museum and has been fully operational since 1985. DĂźring the past seven years it has been closely involved in a number of important Suffolk Naturalists' Society (SNS) projects including County surveys on Butterflies, Orchids, Molluscs, Dragonflies and Mammals and the ongoing Breeding Bird Atlas Project. Data from such surveys are fed into the SBRC's computer and over the years a comprehensive picture of the status, distribution, population and habitat requirements of many species has been built up. To serve the best interests of ornithological recording, it was thought desirable to computerise ail bird records and to use the same computer programme as that used for other groups. This enables comparisons to be made, for example, of the distribution of Redstarts with that of established

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Oak woodland. It makes the analysis of data sets possible to determine, for example, whether a decline in Nuthatches is correlated with an increase in Grey Squirrels. However, the use of this new tool has not been without cost nor teething troubles. The latter is primarily due to the vast number of records submitted and the traditional way in which they are presented. A total of 21,000 records was inputted for the year 1991 at a cost of ÂŁ1,500, the enterprise jointly funded by the SNS and the Suffolk Ornithologists' Group.

Rarities/twitching One of the problems that ornithologists are faced with concerns the action that should be taken on the discovery of a rare bird. Previous issues of Suffolk Birds have given hints on how to take detailed descriptions but in the case of an extreme rarity it is important that confirmation is obtained. Most ornithologists have an instinctive desire to share their finds with others, but they should be aware that the grape-vine system is now so efficient that within hours of an observation the site could be swamped by thousands of potential observers — yes, twitchers. Usually, this will pose few problems unless the bird is on private land. Revealing the locality may then compromise your position with the landowner, disrupt a long-term study, such as a BoEE count or ringing project, and may lead to damage being caused to habitat and/or crops. I have been present at many mass gatherings at sites hosting rare vagrants and have seldom encountered misbehaviour. Twitching has been glorified in recent years and varies in degree from those who would only travel locally to see a new bird to the fanatical individuals who are prepared to get their tick at any cost. The privacy and livelihoods of other people are often secondary considerations. Whilst it is important not to be over cautious, twitchers must accept that it will not always be possible to release information on all rarities.

Rare breeding birds Rare breeding birds are already under too much pressure and, therefore, should not feature on the twitching agenda. Unfortunately, there are the selfish few who persistently whinge because they are not told the whereabouts of our most vulnerable species. Murmurings of complaint about Suffolk's River Warbler in 1984 still persist, despite there being few better cases for information being withheld. Thankfully, it is only a minority who believe they have some divine right to be informed of the presence of every bird and place the quarry's welfare last on their list of priorities.

Estuaries Our estuaries, and in particular the Orwell, have been the focus of attention since the Felixstowe Dock and Railway Company first submitted plans to destroy the Fagbury mudflats. Since that sad loss, developers have continued to nibble away at the edges, building a new marina at Shotley; extending existing marinas at Levington and Bourne Bridge, Wherstead and infilling a significant area of mud-flats for the expansion of the Port of Ipswich. As these ornithologically-rich areas disappear under concrete, the quieter spots on the estuary are, in consequence, subjected to increased pressures. Leisure pursuits such as power-boating, water-skiing and jet-skiing cause considerable disturbance, especially during the summer months. Other activities such as bait-digging and wildfowling have a detrimental effect on wintering shorebirds.

New Editor for Suffolk Birds I shall retire as Editor of Suffolk Birds upon the publication of this issue. My successor is Mike Crewe, formerly Editor of White Admiral and The Harrier, and I wish him every success in the future. I have received tremendous help from many quarters during my term as Editor. Assistant Editor, Philip Murphy, has been a tower of strength since I took on the job and the high standards set by Suffolk Birds could not have been achieved without his support.

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Twenty years of the Common Bird Census on Hollesley Heath by Alan

Miller

Introduction The question often asked is are numbers of various species increasing or decreasing? This can only be answered by continuai monitoring on a national scale. The Common Bird Census, organised by the British Trust for Ornithology, does just that and, by incorporating data from both the Waterways Bird Survey and 'Constant Effort' ringing sites, a detailed annual assessment can be made of the success of a large number of species. Somewhat surprisingly, only seven Common Bird Census schemes are currently operating in Suffolk and contributing to the national data. The census method is a useful tool when managing an area acting as a barometer to the health of the habitat and is used on a locai scale on a number of sites in the County. It would be even more useful if these sites joined the national scheme contributing to the overall data and would then be able to compare their own results with the national trends. The British Trust for Ornithology began the Common Bird Census scheme in 1962 at the instigation of the then Nature Conservancy Council. Its initial aim was to monitor bird populations on farmland where there was growing concern on the use of pesticides and the destruction of hedgerows. By 1964, other habitats particularly woodland were included enabling a broad cross section of habitat to be sampled on both national and locai level. Annually, around 200 plots are surveyed enabling population trends to be compared from year to year and the various changes monitored. Hollesley Heath is owned by the Home Office and has been managed as a nature reserve by the Suffolk Wildlife Trust since 1969. Its 16 hectares consists of mature Scots Pine Pinus sylvestris and Silver Birch Betula pendula woodland interspersed with open areas of uneven-aged Bell Heather Erica cinerea and Ling Calluna vulgaris and areas of pine, birch and Bracken Pteridium aquilinum scrub. Notified as a SSSI in 1987 it is part of one of the largest remaining fragments of the once extensive Sandling Heaths of the Suffolk coast. Ornithologically, the reserve is nationally important for Nightjars Caprimulgus europaeus and Woodlark Lullula arborea and locally important for Redstart Phoenicurus phoenicurus. 1


The Hollesley Heath Common Bird Census has been carried out since 1972, initially by the late Michael Cavanagh and Geoffrey St John Hollis, and since 1985 by Laurence Potter, Mervyn Miller and myself. Each season an average of 42 species is recorded holding breeding territories. A total of 51 species has bred since recording began and a further 13 species recorded during the census periods. Method The census method involves at least ten visits to the plot between March and July. The locations of singing males and other information, e.g. nest building and carrying food, relevant to the confirmation of breeding by each species, is plotted onto a visit map. This information is then transferred to individual species' maps and by the end of the season each individual bird's territory can be defined and the population size for each species calculated for the plot. Results The aim of this paper is not to look at all 51 species but to select a few key species and discuss their past and present status taking into account national and local trends and al so the effects of the site's management o ver the past twenty years. To maintain a lowland heath site, a regime of constant management is required to prevent natural succession turning the site into secondary woodland. Comparing aerial photographs taken twenty years ago with some taken in 1986 they show that, in spite of continual work, the canopy had closed over several areas changing the suitability of the site for some species. However, in 1987 the October storm changed the entire reserve, by destroying 60% of the mature woodland and opening up new areas. Since that time much volunteer effort has gone into clearing wind blown areas creating new heathland glades suitable for Nightjars and Tree Pipits. Also some windblown areas will be left to regenerate and the Common Bird Census will be one recording method which will enable us to see the resulting effect of these changes. Six species were chosed as examples of obvious changes occurring because of a local influence whether of natural origin or the result of site management work. TURTLE DOVE Streptopelia turtur From 1963 to 1979 the national trend for this species was of a slow but steady increase and at Hollesley this increase continued until 1981. From that time until the present day, with the exception of 1985, the trend at Hollesley and nationally has been one of decline. The change from hay crop to silage with its earlier mowings and therefore lower production of weed seeds is thought to be a major cause in the species' decline nationally and at Hollesley the neighbouring grassland was turned into arable in the mid-1980s consequently denying the birds their feeding area and reinforcing the theory as the reason for their reduction.

TURTLE DOVE -

HOLLESLEY HEATH

TURTLE DOVE - NATIONAL TREND

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NIGHTJAR Caprimuglus europaeus The Nightjar has been declining nationally since 1930 and now the Sandling heaths and forests hold a significant proportion of the national population. From 1972 through to 1983, Hollesley Heath held an average of three pairs but this was reduced to a single pair from 1984 until 1990 when the numbers rose again to three pairs. The loss of the birds in the 1980s can be explained in that in 1983 the Forestry Commission began harvesting the adjacent area of Rendlesham Forest immediately giving the species a larger area of suitable habitat. By 1990, the subsĂŠquent replanting had reached sufficient height to be unsuitable as a breeding area and the numbers on the heath again increased. It will be interesting to see if the same pattern occurs again, because in May 1992 this replanted area was severely attacked by Banded Pine Weevil and the whole area has been cleared, once again expanding their available breeding area. NIGHTJAR - HOLLESLEY HEATH

No national t r e n d available.

72 73 74 75 76 77 78 79 80 81 82 83 84 8 5 86 87 i

W R E N Troglodytes troglodytes The population of Wrens on Hollesley Heath has paralleled national trends with severe winter weather being the primary factor causing the fluctuations which occur. Indeed, the severe winter of 1978-79 wiped out the entire population of the reserve but within five years it was at its highest level since recording began. Following the 1987 storm, numbers again rose with the increase in suitable low scrubby habitat caused by the windblown trees only to fall yet again following the cold winter in 1990-91 WREN - HOLLESLEY HEATH

W REN - NATIONAL TRENI)

72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90

72 73 74 75 76 77 78 79 I

82 83 84 85 86 87 !

REDSTART Phoenicurus phoenicurus Nationally, the Redstart has shown a steady increase in numbers from its severe crash in the mid-1970s. However, while elsewhere it was flourishing, on Hollesley Heath the reverse was happening. It followed national trends by peaking between 1972 and 1980 when up to nine territories were recorded. However, numbers then began to decrease until the species had ceased to breed on the reserve by 1986. Initially no obvious cause was apparent, but the answer came literally from above in the guise of the October 1987 storm. In 1988, we had only just begun to get to grips with clearing some of the damage but

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by 1989 the main woodland was at least partially cleared and, low and behold, the Redstarts returned and the population is now back to four pairs. The answer appears to have been that the graduai closing of the woodland canopy over the years had meant that the site became less attractive to Redstarts which prefer a more open woodland. Had the storm not occurred this species could have been lost as a breeding bird for some considerable time since as it is doubtful as to whether such a radicai approach would have or could have been taken to preserve its breeding areas.

REDSTART -

HOLLESLEY HEATH

72 73 74 75 75 77 78 79 I

REDSTART — NATIONAL TRENI)

82 83 84 85 86 87 88 89 90

72 73 74 75 76 77 78 79 I

82 83 84 85 86 87 I

WILLOW WARBLER Phylloscopus trochilus The national population of this species has been remarkably stable over the past thirty years, with only minor fluctuations occurring. On Hollesley Heath, the numbers peaked in 1980 and have shown a steady decline ever since. This can be explained as a combination of two factors. Firstly, although nationally the numbers have remained steady there has recently been an unexplicable, yet noticeable, decline in Eastera regions. Secondly, because Hollesley Heath is a heathland site, management concentrates on the reduction of scrub to create more open heather/grassland areas and therefore the very nature of this management reduces suitable Willow Warbler habitat.

WILLOW WARBLER - HOLLESLEY HEATH

CHAFFINCH Fringilla coelebs Nationally, this species has been undergoing a shallow increase since its decline in the late 1950s. On Hollesley Heath this was mirrored up to 1983 since when numbers have been steadily declining and are now at a level equal to that of the 1970s. This would seem to be as with the Willow Warblers in that the management to increase the heathland area reduces the amount of scrub and consequently suitable breeding area for the species.

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CHAFFINCH - HOLLESLEY HEATH

CHAFFINCH — NATIONAL TREND

Conclusion Over the past twenty years Common Bird Census monitoring has provided a detailed record as to the fortunes of the birds on Hollesley Heath and has also contributed data to enable a national annual summary to be produced by the British Trust for Ornithology. Long term consistent monitoring such as this acts as an early warning system as to population changes and helps to pinpoint the cause whether it be of local or international origin. Whilst it would not be desirable or indeed practicable for large numbers of sites to be monitored in this way an increase in the number of plots in Suffolk would be welcomed by the British Trust for Ornithology. The monitoring on Hollesley Heath hits provided a useful data base for comparing species' success alongside the management regime employed. Reverting scrub back to heathland must change species' composition and the Common Bird Census is an effective way of recording these changes and also the long term effects of the 1987 storm. Acknowledgements Thanks are due to the aforementioned field workers and to the staff of the British Trust for Ornithology for all their help and guidance over the past twenty years. References Marchant, J. H . , Hudson R., Carter, S. P. and Whittington, P. A . , 1990. Population Breeding Birds. Tring.

Alan Miller, 64 High Corner, Butley,

Woodbridge,

Suffolk

Trends in British

IP12 3QF.

A brief summary of the Eagle Owl's status in Europe, and its possible implications for Suffolk and Britain by Jeff

Martin

The Eagle Owl Bubo bubo is the world's largest owl. The nominate race B.b.bubo is found in many parts of Europe, from Fenno-Scandia and the northern parts of Russia, down to northern Spain and the Mediterranean. There are several other races found in Europe, although the taxonomists cannot agree on the exact number. However, it seems that those which are found nearer to the Equator have a lighter coloured plumage than those found further north. In North and South America the genus Bubo is represented by the Great Horned Owl Bubo virginianusi, and, despite the différent English ñames of that owl and the Eagle Owl, Voous (1988) considered that there was little if no différence between them.

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Although the Eagle Owl is a widely but thinly distributed species in Europe, it is absent from much of the north-west including the British Isles where it is an exceptionally rare visitor. Dymond et al. (1989) state that there have been around 20 records, and all of these are from the 18th and 19th centuries, with the last acceptable record of a wild bird in Argyllshire in 1883. The Eagle Owl is a powerful predator capable of killing large prey such as dogs, hares and even small deer. Mikkola (1983) found that they often preyed upon other birds, and especially the Long-eared Owl Asio otis. He also found that the Tawny Owl Strix aluco, Common Buzzard Buteo buteo and Kestrel Falco tunninculus also feature strongly in its diet. However, in keeping with the majority of other owls much of its food consists of small mammals, and especially the Water Vole Arvicola terrestris, which Mikkola found was the most important prey item, accounting for 23.6% of prey items taken. Due to its ferocious feeding habits and its confliction with game interests, the Eagle Owl has been subjected to heavy persecution in the past. For example, Wardhaugh (1983) reported that between the years 1908 and 1915 at least 1,359 were reported shot in Norway alone and there are other examples in the literature of the persecution that has been, and continues to be, meted out to this owl. Mikkola (1983) thought it ' 'probable, but not certain ' ' that its absence from the British Isles is due to persecution by man and Voous (1988) considered that it probably became extinct here before the Middle Ages. In recent years the Eagle Owl has been afforded protection over much of its European range, which has led to a partial recovery of its numbers and an expansion of its range. In the winter months, the Eagle Owl may become mobile with mountain birds descending to lower altitudes (Mikkola 1983), and others wandering south over considerable distances (Voous 1988). An example of this was recorded in 1947 when on 16th September the London Evening Standard reported that a bird which was shot at Villeneuve-sur-Lot near Bordeaux, proved to be a Great Horned Owl (undoubtedly an Eagle Owl) which had flown from Sweden. "An aluminium plate on the bird's leg bore the inscription: Return Ricks Museum, Stockholm". Some of these wanderers have settled in parts of Europe where the species had previously been exterminated. For instance in the Baden — Warthenburg area of what was formally West Germany, a population of c200 pairs had been eradicated by 1930, yet by 1978 the owl had returned and the area held c l 2 pairs. In recent years there have been other reports reflecting an increase in the number of breeding pairs. From Luxembourg it was reported that breeding had ' 'resumed ' ' and that it ' 'May now be considered reinstated as a breeding species after a long absence" (Sharrock 1985). It was thought that during the previous 2-3 years there had been 3-4 broods a year in the Grand Duchy and for the second time a brood had been reared within the city's limits. It was considered that this breeding population in Luxembourg originated from birds which had been released in West Germany a few years before (Sharrock 1987). Further evidence that the Eagle Owl is increasing in Europe comes from Belgium where at Wallacie the population had risen from the two pairs first reported in 1982, to 14 pairs in 1988. The breeding records for 1982 were the first for 70 years (Sharrock 1989). Elsewhere the Eagle Owl is also considered to be flourishing. In Southern Andalucia, Spain, it was estimated that there were between 113 and 180 pairs in an area encompassing 4,000 sq km (Sharrock 1989) and in Czechoslovakia it was estimated that there were between 600 and 950 pairs in the years 1985-89 (Sharrock 1992). In Suffolk, the Eagle Owl is an extremely rare bird and like the rest of Britain there are no confirmed records of wild individuals this century. Neither Payn (1978) nor Ticehurst (1932) list the species, but Babington (1886) stated that Yarrell had reported in 1843 that it had been taken in Suffolk, although Babington had no first hand record of its occurrence. On November 22nd 1990, an Eagle Owl was found at 07.30 hours in a garden at Felixstowe (Piotrowski 1991). It had apparently arrived at that location overnight. Originally

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it was thought the bird was a Long-eared Owl, but after an inspection by Michael James, a local birdwatcher, it was correctly identified. The bird allowed a "close approach" to within 6-7 metres, but was gone by 13.00 hours the same day. It was not seen again, which is unusual, as birds which are used to human habitation tend to remain in that environment for some while, when they can often be relocated or observed for some time. For example, in June 1983 at Whetsted in Kent, an Eagle Owl (probably an escapee) was found and remained to give birdwatchers close views (Hume and Allsopp 1983). Elsewhere, following the great storm of October 15th/16th 1987, an Eagle Owl took up residence on Chichester Cathedral and over the next few days proceeded to devour the local populations of Grey Squirrels Sciurus carolensis, and feral Rock Doves Columba livia in the grounds of the cathedral (Prytherch and Everett 1989). It was considered that this individual was the one which had escaped from a local aviary which had been destroyed in the storm. Other sightings of Eagle Owls in Britain are normally preceded or followed by reports in the media of escapees, but on the occasion of the sighting at Felixstowe there was no such account. The fact that the Eagle Owl is increasing its range and numbers in Europe must heighten the chances of it arriving in, and perhaps eventually colonising, Britain, and it appears that it has tried in the not too distant past. In May 1941 there was a reliable report of two Eagle Owls on suitable habitat "somewhere in Britain" (Anon. 1941). For security reasons the author and location were not named, but the editorial stated that the finder was reliable, and considered the record to be authentic. Unfortunately the author was not able to prove breeding. We do not know whether the birds were introduced, or whether they arrived here naturally. If the Eagle Owl does invade Britain, it seems possible that Suffolk may be one of the first counties where this will be noticed, and Felixstowe may well be one of the areas to observe this. Some readers may not be aware that Felixstowe is situated at the mouth of the Rivers Orwell and Stour and that this area, along with some others in eastern England, is noted for the passage of migrating birds, including owls. The fact that the Felixstowe Eagle Owl behaved in a manner similar to that of other migrating owls should not be overlooked. Some Long-eared Owls which have arrived in this country have been exhausted and allowed a close inspection, such as the tired and approachable bird at Spexhall, Suffolk on November 1st 1982 (Moore 1983). Other sightings, such as the Long-eared Owl which arrived at Landguard Observatory on October 12th 1988, and appeared to be totally unconcerned as ringers passed within three metres of it (Piotrowski 1989) are representative of sightings of owls in this country which may lead isolated lives in remote parts of Europe, and so are unafraid of Man. Therefore, it may be that, in the future, we should expect the occasional Eagle Owl to arrive in Britain. However, unless they are marked in some way before their arrival and then recovered in this country, we shall be frustrated in our attempts to prove their wild origin due to the possibility that escaped birds may be involved. It may be that some have already arrived in the past but been mis-identified as Long-eared Owls. Certainly one other Eagle Owl of unknown origin was seen by this author perched on a gate to the south of Ipswich at 23.15 hours on Tuesday, October 22nd 1985. Although the possibility of migrant Eagle Owls reaching these shores may be greeted by some ornithologists with excitement, they could have a considerable harmful impact upon some of our fragile wildlife such as the Barn Owl Tyto alba and Red Squirrel Sciurus vulgaris both of which occur quite regularly in the Eagle Owl's diet (Mikkola 1983). The effect it may also have on some of our dwindling stocks of Water Vole (Jefferies et al. 1989), may also be significant. Although it was considered that the Felixstowe bird was"undoubtedly an escapee" (Piotrowski 1991), the point was also made that, strangely, there was no press announcement that an Eagle Owl had escaped as is normally the case with such valuable exotics, and

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the event was referred to as ' 'bizarre ' '. That this record should occur at a time when there had been a reasonable amount of overnight rain, and the winds had been blowing moderately from the north-east (Table 1), must also create further speculation as to the origins of this bird. Table 1

Weather conditions for November 26th and 27th 1990

Date Temperature Monday 26/11/90 8°C Overnight 5°C Tuesday 27/11/90 9°C (From data supplied by M. James)

Wind direction north-east north-east north-east

Wind speed (m.p.h.) 15 10 10

Conditions rain all day rain in morning

In view of the Eagle Owl's current status in Europe, its proven ability to migrate long distances and that the Felixstowe bird's behaviour was in keeping with that of some other migrating owls, it is this author's view that an open mind should be kept upon that interesting record, and that birdwatchers in Britain should keep a sharp eye out for this bird in the future, especially in late October and early November. It would also help if keepers of these impressive birds were to contact their county bird recorder when one is lost. It should be possible for them to communicate this information on a confidential basis if necessary. Perhaps colour ringing captive birds on a voluntary basis might be a responsible approach to monitoring sightings of Eagle Owls in Britain? It would also be helpful to know whether the Felixstowe Eagle Owl was in fact an escapee, and was subsequently recovered by its owner, hence its "disappearance". Acknowledgements: I should like to thank Mrs Tina Martin and Stanley Dumican, for their encouragement and useful comments on the first draft, and the late Eric Hosking for supplying useful historical information on the Eagle Owl in Europe. I am indebted to Dr Heimo Mikkola for his important comments and encouragement, and to Michael James for his valuable discussion and comment on the draft and for supplying the important weather data. I also thank Martin Sanford of the Suffolk Biological Records Centre for allowing access to the Centre's library. References: Anon., 1941. The Eagle Owl in Britain. Country Life. 3rd October, 1941. Babington, C. 1886. The Birds of Suffolk. Proc. of the Suffolk Inst, of Archaeology and Nat. History: 233. Dymond, J. N., Fraser, P. A. and Gantlett, S. J. M. 1989. Rare Birds in Britain and Ireland. Poyser, Calton. Hume, R. A. and Allsopp, K. 1983. Recent Reports. Brit. Birds 76:421-422. Jefferies, D. J., Morris, P. A. and Mulleneux, J. E. 1989. An enquiry into the changing status of the Water Vole Arvicola terrestris). Mammal Review, 19:111-131. Mikkola, H. 1983. Owls of Europe. Poyser, Calton. Moore, D. R. (Ed.) 1983. Suffolk Birds 1982. Suffolk Naturalists' Society, Ipswich. Payn, W. H. 1978. The Birds of Suffolk (2nd ed.). Ancient House Press, Ipswich. Prytherch R. and Everett M. 1989. N e w s and Comment. Brit. Birds 82:389. Piotrowski, S. H. (Ed.) 1989. Suffolk Birds 1989. Suffolk Naturalists' Society, Ipswich. Piotrowski, S. H. (Ed.) 1991. Suffolk Birds 1991. Suffolk Naturalists' Society, Ipswich. Sharrock, J. T. R. 1983. European News. Brit. Birds 76:421. Sharrock, J. T. R. 1985. European News. Brit. Birds 78:343. Sharrock, J. T. R. 1987. European News. Brit. Birds 80:13. Sharrock, J. T. R. 1989. European News. Brit. Birds 82:20, 328, 389. Sharrock, J. T. R. 1992. European News. Brit. Birds 85:453. Ticehurst, C. B. 1932. The Birds of Suffolk. Gurney & Jackson, Edinburgh. Voous, K. H. 1988. The Owls of the Northern Hemisphere. Collins, London. Wardhaugh, A. A. 1983. Owls of Britain and Europe. Blandford Press, Dorset.

J. R. Martin, 17 Moss Way, West Bergholt, Colchester, Essex C06

14

3LJ.


Skua in Suffolk Ca ws ton

Introduction: Autumn 1991 will long be remembered by seawatching enthusiasts for the remarkable influx of Long-tailed Skuas Stercorarius longicaudus off the coast of Britain. In September alone, over 3,250 were reported mainly from Britain's east coast (Birding World 4:304). These constitute record numbers of what was assumed to be a very scarce species in British waters only 15 years ago. Although most of the influx was witnessed from seawatching stations between Lothian and Humberside, Suffolk did not miss out and an impressive total of 37 birds was recorded (Table I). This paper illustrates the likely causes of the influx into the North Sea, describing the initial movement off the Suffolk coast and giving a brief history of the species occurrence in the county. History: Payn (1978) mentions six records during the 19th Century, but no details are given, so their validity may be questionable. It was not until 1961 that the County received its first well documented record with a bird at Minsmere on Aug. 29th. During the next 25 years there were five more records. Indeed, its scarcity during this period is reflected by the fact that between 1976 and 1979 all records of this species were considered by the British Birds Rarities Committee. During the 1980s, however, intensive seawatching and a better understanding of Longtailed Skua identification resulted in a large increase in the number of records, both nationally and in Suffolk. Between 1980 and 1986, Britain averaged about 200 birds a year (Dymond et al 1989). However, in Suffolk it was not until 1987 that a regular seawatching effort, principally based at Covehithe and Southwold, started to produce more sightings. Since then the species has occurred annually in the County as shown in the table below: No. of birds

1987 1

1988 6

15

1989 3

1990 1

1991 37


The influx of September 1991: As with any major movement of seabirds, the weather conditions were the vital key to such a massive influx of this delightful seabird. The Long-tailed Skua is a highly pelagic species and its usual post-breeding migration probably takes it in a southwesterly direction out of the Norwegian Sea and towards the deep waters of the Atlantic Ocean, passing well to the north and west of Scotland (Cramp et al 1985). However, on Sept. 5th a cold frontal system was stationed between Greenland and Norway and the associated bad weather along its length blocked an easy passage for the birds into the North Atlantic. During the day, the eastern end of the front began to move quickly down the North Sea in a southerly direction with strong northeasterly winds behind it. This action of the front opening like a gate before them, probably induced the rapid southerly movement of many hundreds of Long-tailed Skuas into the North Sea. Subsequently, over 700 Long-tailed Skuas were reported along Britain's east coast on Sept. 6th, but four hours of seawatching at Southwold that day could only muster two Arctic Skuas S. parasiticus, a single Pomarine Skua S. pomarinus, and two Sooty Shearwaters Puffinus griseus. Sept. 7th dawned quite bright and clear with only a moderate northerly breeze. This tended to suggest that a large movement of skuas was unlikely, although about 50 Gannets Sula bassana, 40 Fulmars Fulmarus glacialis and nine Sooty Shearwaters moving north off Southwold gave the observers there some reward for their early start. An observer stationed on the sea-cliffs further north at Corton, however, was more fortunate with two juvenile Long-tailed Skuas flying south during the early morning. Those birders, who remained at Southwold, still had a long wait ahead of them. Their patience was eventually rewarded at 16.00 hrs, when, whilst watching a magnificent Balaen Whale sp. Balaenoptera sp., a flock of 11 Long-tailed Skuas flew south offshore. All of the birds were juveniles apart from one adult. The quite calm conditions at the time resulted in the birds flying fairly high above the sea in a loose, slow-moving flock. Some of the birds would frequently dip down to the sea's surface and briefly settle on the water before bounding gracefully upwards to rejoin the rest of the flock. Remarkably, about one hour later a flock of 12 juveniles and one adult passed south off Bawdsey. This was almost certainly the same group as that seen off Southwold, but with one additional juvenile. Observers at Southwold then moved to Covehithe and, between 16.30 hrs and dusk, saw another 11 pass offshore. These consisted of three superb adults (two moving south and one north) and seven juveniles moving south. Another juvenile flew west inland over the observers' heads until it was lost from sight. Sept. 8th saw no Long-tailed Skuas recorded off Suffolk at all but, after such a large influx into the North Sea, it seemed likely that birds would linger during the autumn months. This proved to be the case with another nine off Suffolk during the next nine weeks up to Nov. 10th, the latter bird constituting the County's latest this century. The timing of the Suffolk influx fits in very well with records from the neighbouring counties of Norfolk (Table II) and Essex (Table III). Seven Long-tailed Skuas passed Cley, Norfolk, on Sept. 6th and in Essex at least 11 were seen on the 8th, the day after the Suffolk observations. Ten birds were in a single flock off Southend and consisted of nine juveniles, one adult and one sub-adult bird. Interestingly, over 25 birds passed Cley on Sept. 30th, but none were recorded off Suffolk. Although the prospect of another influx of this nature taking place in the near future would seem remote, it is expected that the continuing contemporary interest in seawatching will result in regular records of Long-tailed Skuas off the Suffolk coast. Anyone seawatching regularly and for long hours from mid-August to late September in strong northerlies or onshore winds will stand a good chance of seeing this exciting seabird.

16


Acknowledgements: Thanks to all observers who persevered on that long but memorable day of Sept. 7th and also to those whose regular seawatching effort helped build a more complete record of this species in Suffolk during autumn 1991. Thanks also to Philip Murphy, Steve Piotrowski and Nick Green for their comments on the draft.

References: Cramp, S. & Simmons, K. E. L. (Eds). 1985. The birds of the Western Palearctic. Vol. 4. Oxford University Press. Dymond, J. N . , Fraser, P. A. & Gantlett, S. J. M. 1989. Rare birds in Britain and Ireland.. Poyser. Cal ton. Green, N. G. (Ed.) 1992. Systematic List 1991. The Essex Bird Report. 71-72. Furness, R. W. 1987. The Skuas Poyser. Calton. Payn, W. H. 1977. The birds of Suffolk. Ancient House Publishing, Ipswich. Seago, M. J. (Ed) 1992. Classified Notes. Norfolk Bird & Mammal Report 1991:311.

John Cawston, 477 Hawthorn

Drive, Ipswich IP2 ORU.

17


Table I: Long-tailed Skua records from Suffolk 1991. Date Aug. 22nd Sept. 7th

Sept. 13th Sept. 15th Sept. 18th Sept. 19th Sept. 28th Oct. 8th Oct. 10th Oct. 27th Nov. 10th

Location Landguard Pt Corton Southwold Bawdsey Covehithe Covehithe Covehithe Covehithe Covehithe Aldeburgh Covehithe Landguard Pt Minsmere Southwold Aldeburgh Southwold

Direction S S S S N S S N N N N N S S

Nos. 2 2 11 13 1 2 10 1 1 1 1 1 1 1 1 1

N

Remarks juvs — SE blow juvs — early morning ad. + 10 juvs — 16.00 hrs ad. + 12 juvs — 17.00 hrs ad. \ 16.00 hrs ads > till juvs ) dusk juv. juv. ad. ad. juv. juv. juv. — quartering beach juv.

Table II: Long-tailed Skua records from Norfolk 1991 (Seago 1992). Date Sept. 6th

Sept. 28th Sept. 29th

Sept. 30th Oct. 19th

Location Cley Blakeney Pt Titchwell Winterton Cley West Runton Hunstanton Cley Holme

Nos. 7 5 5 6 5 9 3 25 + 2

Direction

Remarks

— —

— — — — — —

high inland

Table III : Long-tailed Skua records from Essex 1991 (Green 1992). Date Aug. Sept. Sept. Sept.

30th 5th 6th 7th

Sept. 8th

Sept. 9th Sept. Sept. Sept. Sept.

16th 21st 26th 28th

Oct. 3rd Oct. 11th Oct. 17th

Location Canvey seafront Canvey seafront Canvey seafront Southend Pier Canvey seafront Wakering Stairs Southend Pier Canvey seafront East Tilbury Southend Pier East Tilbury Southend Pier East Tilbury Canvey seafront Colne Pt Southend Pier Canvey seafront Canvey seafront East Tilbury Bradwell

Direction

Nos. 1 2 1 1 5 1 10 9 1 2 4 1 1 2 1 1 1 1 1 2

— — —

Remarks juv. juv. + sub-ad. ad.

— —

— — —

2 ads + 3 juvs ad. 7 juvs + 2 ads + 1 sub-ad. 7 juvs + 2 ads

— — — — — — — — — — — —

18

three ads ad. juv. ad. + sub-ad. juv. juv. sub-ad. ad. sub-ad. juvs


Breeding waders and other waterfowl on the coastal marshes and saltings of Suffolk in 1988 and 1989 T. C. Holzer,

*C. H. Beardall, R. C. Dryden & R. B. West

Summary This paper summarises the results of a survey of breeding waders, wildfowl, gulls and terns on coastal grazing marshes, shingle and saltmarsh along the extent of the North Sea coast of Suffolk in 1988 and 1989. A total of 4387 ha was surveyed and 1470 pairs of wildfowl, 1594 pairs of waders and 11,760 pairs of gulls and terns were recorded. The Suffolk coast is an important breeding area for waders. It supports 33 % of British breeding Avocets, and over 1 % each of Ringed Piover, Redshank and Oystercatcher.

Introduction The drainage of lowland grassland and the claiming of saltmarsh for agriculture and industry are an ail too familiar story in Britain. These changes in land use have been accompanied by a decline in their ornithological interest, particularly as a breeding habitat for wildfowl and waders. In 1982, the British Trust for Ornithology (BTO) surveyed the distribution of waders breeding on lowland grassland in England and Wales (Smith 1983). This study revealed very low densities of breeding waders on most sites, with large areas of grassland holding no waders at ali. Moreover, a significant proportion of the breeding waders was concentrated on relatively few sites. Populations of Snipe, Redshank, Lapwing and Oystercatcher predominated in the south east of England, with the latter three species concentrated on the coastal marshes of East Anglia and North Kent. The survey also highlighted the contracting range of Redshank since the 1930s. The BTO survey (Smith 1983) was primarily aimed at lowland grasslands and although no attempi was made to include areas of saltmarsh it was acknowledged that such areas may be of great importance for breeding waders. The significance of saltmarsh as a breeding habitat, particularly for Redshank, has since been established (Green et al 1984). This study also demonstrated that the methodology employed in previous surveys may have significantly underestimated breeding populations of Redshank. In 1985, Allport, O'Brien and Cadbury assessed the breeding populations of Redshank on 77 plots of saltmarsh throughout mainland Britain and the island of Muli. Particularly high densities were reported to breed on the Deben estuary in Suffolk. The above studies on selected sites of saltmarsh and grassland in Suffolk's coastal rĂŠgion have indicated that this area may be particularly important for breeding waders on a national scale (Smith 1983, Allport et al 1985) and yet a comprehensive picture on a locai basis does not exist. The present survey was designed to provide a detailed understanding of the distribution and densities of ali species of breeding waders and wildfowl on saltmarsh and wet grassland bordering the Suffolk coast. The survey will also enable an assessment of the relative importance of this rĂŠgion in a national perspective.

Methods Survey The survey covered ali areas of saltmarsh within Suffolk as well as the south side of the Stour (the south bank of the Stour is in Essex, but for the purpose of this survey the whole estuary is considered as one unit). Grassland adjacent to the coast was also surveyed as well as areas of shingle (principally Orfordness) and reed.

19


The location of these habitats was delineated on 1:10,000 maps for collecting field data. In total there were 114 plots ranging from 3 hectares to 219 hectares. Many of these areas were distinct from one another (see Figure 1). Those stretches of estuary between these plots were surveyed using 1:25,000 scale field maps. Recording was focused on waders and wildfowl, but surveyors were asked to include all species likely to attempt to breed on the outlined areas. The survey method employed was that devised by Green et al (1984). Five visits were made during the breeding season, between April and early June. Each plot was sub-divided into areas of homogenous habitat type and management and a route, which was repeated on each visit, was devised that approached every point to within 100 metres. Visits were not carried out in windy or rainy conditions. For each visit, the number and location of every bird was recorded on the field maps, noting obvious pairs, singing birds, birds with young and flocks. At the end of every visit information from the maps was translated onto a summary table for analysis. Analysis of field data Redshank: The mean of the total Redshank recorded before June lst (excluding those birds behaving as if with young or in flocks), was taken as the peak number of pairs with nests. Snipe: The mรกximum number of drumming or chipping birds on any one count was taken as the number of breeding pairs, so long as birds were present throughout April and early May. Birds drumming or chipping on only one date, and not observed on following visits, were noted as possible breeders but not included in the final data. All other species: The mรกximum number of birds recorded at any one date, excluding those in flocks, was halved to give the mรกximum number of pairs likely to be breeding. This method does not differentiate between non-breeding and breeding pairs (for example, Shelduck), both of which are included in the total breeding pairs recorded (Table 2). If a single bird, or pair of birds was observed in suitable breeding habitat on only one occasion it was recorded as a possible breeder but not included in the summary presented in this paper.

Results ln total 4387 hectares were surveyed of which 1124 hectares were saltmarsh, 2836 hectares grassland, 347 hectares shingle and 80 hectares reed (see Table 1). The number and location of each species recorded as breeding within the survey area are given in Table 2. Six species of wader, ten of wildfowl and seven of gulls and terns were recorded. The Alde complex (which includes the Alde/Ore and Butley rivers), was found to hold the largest populations of breeding waders and wildfowl but also accounted for about half the total area surveyed (see Table 1). The relative importance of each estuary for the principal species of wader is shown in Table 2. This table identifies the Blyth as being exceptionally important for Snipe, as well as holding the largest populations of Redshank and Lapwing. The low numbers of breeding waders on the Orwell and Stour reflect the lack of suitable habitat. The distribution of Redshank, Oystercatcher, Lapwing, Ringed Plover and Snipe amongst the various habitat/ management types is reported in Tables 3-7.

Discussion National perspective Smith (1983) identified the coastal marshes of East Anglia and north Kent as being particularly important for breeding Redshank, Lapwing and Oystercatcher. The present survey has shown the study area to hold 1.4% of the Redshanks and 1.4% of the Oystercatchers estimated to breed in Great Britain (based on population estimates reported by Piersma 1986). Whilst these species breed in other areas of Suffolk it is probable that the majority

20


are within the coastal region included in the study area. By contrast, Lapwing are widespread throughout the county and those found within the study area represent only 12% (Wright 1988) of the county's breeding population. The 309 pairs recorded represent 0.1 % of the Lapwings estimated to breed in Great Britain (based on Piersma 1986). For Ringed Plovers 1.0% of the British and 0.7% of the European temperate populations are represented in the study area (based on figures by Piersma 1986). In Britain, breeding Avocets are mainly restricted to East Anglia with strongholds predominately on nature reserves. Approximately 32.9% of the British population was recorded in the study area. Trends in the breeding population Nine of the plots surveyed in 1988 were visited during the 1981/82 Breeding Waders of Wet Meadows Survey (Smith 1983). During this intervening period these plots have experienced an overall decrease in the populations of Redshanks (—38%) and Oy stercatchers (—12%), whilst seeing an increase in breeding Lapwings ( + 3 0 % ) , (O'Brien 1989). It is too early to assess whether these trends are due to natural fluctuations in breeding populations, changes in management or part of a general decline. Ringed Plovers were surveyed in Suffolk in 1979 and 1985 (Piotrowski 1980, Waters 1985). Over this five year period Waters (1985) reported a decrease of 20% in the overall county population. Orfordness held the largest discrete population with 53 pairs in 1979 and 34 pairs in 1985. The present survey reported only 13 pairs to be breeding on Orfordness, a total decline of 75% in nine years. This decline has been attributed (Waters 1985 & 1988) to increased human activity and the expansion of the Orfordness gull colony. In contrast the Orwell population has increased from 17 pairs in 1985 (Waters 1985) to 32 pairs in 1988, half of which were in newly created areas of shingle at Fagbury (soon to be lost to the Felixstowe Dock development, see Beardall, Dryden & Holzer 1988). Distribution of breeding waders The distribution of breeding waders was to a large extent dictated by the availability of suitable habitat. For example, the Stour held 5.6% of the total wader population in 8% of the study area and the Blyth held 24% of the waders in 16% of the study area (Tables 1 & 2). REDSHANK Just under one third of the Redshank were found on the Blyth, predominately on grassland (diagram 1). However, throughout the entire study area the ratio was found to be almost equal with 49.1 % recorded from saltmarsh and 47.9% from grazing marsh, despite there being twice the area of grassland available (Table 3). The value of ungrazed saltmarsh as a habitat for breeding Redshank appears to be reflected in the results, (Table 3), which show that 45 % of all breeding pairs were recorded in this category, which itself only accounted for just over a quarter (27%) of the study area. A peak density of 81 prs/km 2 was recorded from one site, which compares favourably with the peak density of 78 prs/ km 2 reported by Allport et al 1985). The category of grazing marsh shown in Table 3 does not differentiate between 'improved marsh' and the traditional unimproved, ill-drained grassland sites — both are included in the total figure. This probably disguises the Redshank's apparent preference for the unimproved sites. For example, on the Aide complex, one area of traditional grazing marsh accounted for 61 % of all the pairs recorded from cattle-grazed marsh on this estuary, but the same site only contributed 17% of the cattle-grazed land area. This single location produced a density of 29 prs/km 2 whilst the remaining 83 % of cattle-grazed areas only recorded a density of 3.5 prs/km 2 . The peak density for a cattle-grazed grassland site was 50 prs/km 2 , which again was from a traditionaly managed grazing marsh area.

21


OYSTERCATCHER The Oystercatcher's ability to occupy a variety of coastal habitats is seen in the data,Table 4, with breeding pairs being recorded throughout the study area. The ungrazed saltmarsh category in Table 4 also includes areas of higher marsh, some with a free draining overlying shingle deposit now covered with a sparse vegetative cover. Also included are areas of rough grazed sea-wall habitat and it is these areas in the ungrazed saltmarsh category that the Oystercatcher appears to have exploited. Breeding densities vary however between habitats; the shingle spit of Orfordness recorded a breeding density of 28.2 prs/km 2 whilst the total saltmarsh throughout the study area averaged 24.8prs/km 2 and on grazing marsh the figure was 7.5 prs/km 2 . LAPWING In comparison with Redshank, the maximum density for Lapwing was 34 prs/km 2 , with the majority being found on cattle-grazed grassland, Table 5. The saltmarsh anomaly in Table 5 is probably explained by some late surveys (late May-early June) picking up adults that have brought chicks from neighbouring breeding habitat onto saltmarsh, particularly sheep grazed saltmarsh, to feed. RINGED PLOVER It might be expected that the number of breeding pairs of Ringed Plovers would reflect the distribution of shingle and sparsely vegetated habitat but this does not appear to be the case. For example, the Orwell, which only accounted for 1.5% of the shingle in the study area, held 29.9% of the total breeding population. Over 33% of breeding Ringed Plovers were recorded from saltmarsh habitats, (Table 6) and these appear to be freedraining areas with little vegetative cover, probably created by tidal action which had deposited shingle onto an already existing saltmarsh substrate. Population densities differ between sites. On the combined habitats of pure shingle and shingle deposits on saltmarsh, 8.1 prs/km 2 were recorded on the Orwell, 9.7 prs/km 2 on the Aide complex, 13.5 prs/km 2 on the Blyth and 18.8 prs/km 2 on the Stour. SNIPE Only very small numbers of Snipe were recorded (Table 2) and this is probably due in part to the survey methodology. Recording was carried out during early morning which was not conduci ve to recording maximum numbers of drumming Snipe. A later survey at one site, conducted during the evening, recorded more displaying Snipe than on the Breeding Wader survey visits. However, the findings of the survey are stili valid, indicating the geographical spread of the bird. Soft penetrable ground, required by this species, was generally unavailable over much of the study area. The Blyth estuary held 86% of the total pairs recorded but only accounted for 25% of the total grassland in the study area. It was noted that these areas were exceptionally wet possibly accounting for the relative importance of this estuary. AVOCET The Avocet holds a unique position in the U.K. conservation story and consequently has been much studied. However, this survey is the first time that a comprehensive census has been attempted to record ali the breeding sites in one of its East Anglian strongholds. The Avocet was recorded at 9 discrete colonies within the study area, varying in size from a single pair to 50 pairs. A record peak of 389 pairs was reported to have bred in the U.K. during 1988 (Spencer et al 1990) and of this total 128 pairs were within the study area (Table 2), which accounted for nearly a third (32.9%) of the U.K. population. Avocets were found breeding not only on saltmarsh, (30%), and brackish lagoons, (61 %), but were also on freshwater traditional grazing marshes, (9%), where low-lying areas had

22


filled with flashes of water creating a mosiac of small islands and pools which was then exploited by the Avocets as a breeding site. Distribution of gulls and terns LESSER BLACK-BACKED GULL & HERRING GULL The large number of gulls found on the Alde complex illustrates the importance of Orfordness as a breeding site. The colony has grown at a surprisingly rapid rate from an estimated 3 or 4 pairs of Herring Gulls and no Lesser Blacks in 1963 (Axell 1976) to 1500 pairs equally divided between the two species in 1976 (Axell 1976) and on to the estimated 7,500 Lesser Black-backed Gulls, 2,500 Herring Gulls and 30 Common Gulls recorded during the present survey. This colony is one of the largest in south-east England and accounts for 15% of the North Sea population of Lesser Black-backed Gulls. BLACK-HEADED GULL In contrast with the above two species the main Black-headed Gull colonies were found on selected areas of saltmarsh on the Deben, Blyth and Butley rivers, Figure 2. COMMON & SANDWICH TERN Most of the Common Terns and all of the Sandwich Terns were recorded on Havergate Island and Minsmere (RSPB reserves) where management helps secure their survival. LITTLE TERN A comprehensive survey of all the Little Tern colonies found in coastal Suffolk was conducted in 1989 (Wright, M, per. comms.) and the data from the Breeding Wader sites were included in this survey. In 1989, 222 pairs of Little Tern were recorded from 12 discrete sites, nine of these being within the present survey area, which accounted for 82% (183 pairs) of the Suffolk population. It was noted that all colonies were on shingle and at one site at least, which had 5 sub-colonies, there appeared to be a preference for 'clean' shingle of > 2 0 mm diameter. Conservation The present survey was essentially undertaken to provide a detailed understanding of the distribution and abundance of breeding waders and wildfowl in the coastal región of Suffolk. The information collected during the present survey provides a comprehensive baseline from which future comparable studies can gauge changes in breeding populations as well as in land use and management. The information is an essential conservation tool allowing informed arguments to be presented against insensitive development proposals which may degrade the valué of these important areas. It will also assist in formulating advice presented to landowners and managers (e.g. farmers, National Rivers Authority (NRA), local government), providing the potential to improve the valué of many sites for breeding birds. This information is particularly relevant in the light of the recent designation of the Suffolk river valleys as an Environmentally Sensitive Area (SRV-ESA), in which farmers receive subsidies in retum for management practices that are sympathetic to wildlife. The grasslands adjacent to both the Alde complex and Blyth lie within this ESA (designated by the Ministry of Agriculture, Fisheries and Food in 1988). The effectiveness of this designation in promoting and maintaining the wildlife valué of these areas will become apparent by repeating this study in the future.

23


ACKNOWLEDGEMENTS The authors wish to thank the twenty-one surveyors who kindly gave up their free time to collect the field data and the many farmers who gave us permission to survey their property. The survey was organised and co-ordinated by the Suffolk Wildlife Trust's Estuary Project. REFERENCES Allport, G., O'Brien, M. & Cadbury, C. J. (1986) Survey of Redshank and other breeding birds on saltmarshes in Britain 1985. Royal Society for the Protection of Birds (RSPB), Sandy. Axell, H. E. (1976) Suffolk Bird Report. ed. W. H. Payn. Suffolk Naturalists ' Society Transactions, 17:150-182. Beardall, C. H . , D r y d e n , R . C . & H o l z e r , T . J. (1988) The Suffolk Estuaries. Suffolk Wildlife Trust, Saxmundham, Suffolk. Green, R. E., Johnson, T. & Collins, D. (1984) An intensive survey of breeding Redshank on the Wash. Unpublished report, RSPB. O'Brien, M. (1989) Breeding waders of wet meadows survey, 1989. BTO News 161:7. Piersma, T. (1986) Breeding Waders in Europe. Wader Study Group Bulletin 4 8 (supplĂŠment). Piotrowski, S. (1980) Suffolk Ringed Piover Survey 1979. Suffolk Ornithologists ' Group Bulletin 43:1-9. Smith, K. W. (1983) The status and distribution of waders breeding on wet lowland grasslands in England and Wales. Bird Study 30:177-192. Spencer, R. et al. (1990) Rare Breeding Birds in the United Kingdom in 1988. Brit. Birds 83:353-390. Waters, R. (1985) BTO breeding Ringed Piover Survey 1985. Suffolk Ornithologists ' Group Bulletin 68:12-18. Waters, R. (1988) Ringed Plovers in Suffolk. In (West, R. B. & Wright, M. T. eds), Suffolk Estuaries Report 1988:22-34 Suffolk BTO. Wright, M. T. (1988) 1987 survey of nesting Lapwings in Suffolk. Suffolk Ornithologists' Group Bulletin 79:24-25.

T. C. Holzer, *C. H. Beardall, R. C. Dryden and R. B. West * Suffolk Wildlife Trust, Brooke House, The Green, Ashbocking, near Ipswich IP6 9JY.

24


Plate 1: Cormorant at Ixworth Thorpe. Inland gravel pits are attracting this species in increasing numbers.

Plate 2: Bittern at Minsmere. Only six booming males were recorded in 1991


S p o o n b i l l s w e r e p a r t o f a g r o u p T f five a t

B e ^ T i ^ T


TABLE 1: Distribution of habitats surveyed in 1988 and 1989 for each of the Suffolk coastal sites % OF TOTAL AREA OF HABITAT TYPE SALTMARSH

GRASSLAND

0

11.0

0

0

9.3 0

19.7 6.4 3.6 36.1

6.1 0.3

10.9 14.9 0 42.9 31.3 0 0 79.8

1/2 Kessingland 3 River Blyth 4/5/6 Minsmere Levels 7 Sizewell Belts 8 Aide Complex 9 River Deben 10 River Orwell 11 River Stour Total area surveyed (ha)

0 44.1 30.0 7.5 9.1 1124.4

SHINGLE

0 77.8 0.6 1.5 13.8 346.6

11.0 7.2 5.0 2836.3

Total area surveyed (ha) 312.2 692.5 194.2 101.0 1824.6 677.3 293.6 291.7 4387.1

REED

TABLE 2: Total breeding pairs of waders, wildfowl, gulls and terns for each of the Suffolk coastal sites in 1988 and 1989 Kessingland Species Levels Mute Swan Cygnus obr 6 Canada Goose Brama canadensis 12 Shelduck Tadorna tadorna 0 Gadwall Anas streperĂ 0 Teal Anas crecca 0 Mallard Anas platyrkynchos 18 Pintail Anas acuta 0 Shoveler Anas clypeata 1 Pochard Aythya ferina 0 Tufted Duck Aytha fuligula 3 Oystercatcher Haematopus ostralegus Avocet Recurvirostra avosetta Ringed Plover Charadrius hiaticula Lapwing Vanellus vanellus Snipe Gallinago galinago Redshank Tringa totanus Black-headed Gull Larus ridibundus Common Gull Lams canus Lesser Black-backed Gull Larus fuscus Herring Gull Larus argentatus Sandwich Tern Sterna sandvicensis Common Tern Sterna kirundo Little Tern Sterna albifrons

Blyth 13 11 72 15 10 103 0 21 0 6

Minsmere Sizewell Aide Levels Belts Complex 2 18 10 66 0 55 0 202 6 15 0 15 2 0 6 12 115 31 0 0 0 1 27 9 0 0 0 0 64 6

Deben

Orwell

Stour

11 38 126 4 2 17 0 9 0 9

9 11 114 1 0 21 0 3 1 17

12 55 21 0 0 29 1 2 0 4

Total 81 248 541 50 20 346 1 73 1 109

0

30

3

0

223

103

50

69

*

*

•

*

*

*

*

*

478 128

0 10 0 0

22 101 25 148

4 45 7 49

1 1 3 0

24 89 0 120

6 24 3 115

32 18 1 64

18 21 0 37

107 309 39 533

0 0

600 0

0 0

0 0

592 30

179 0

0 0

0 0

1371 30

0 0

0 0

0 0

0 0

7500 2500

0 0

0 0

0 0

7500 2500

0 0

0 1

0 0

0 0

63 112

0 0

0 0

0 0

*

*

*

*

*

*

*

*

63 113 183

* Rare British breeding species listed in Schedule 1 of the Wildlife and Countryside Act 1981 : location details witheld.

25


TABLE 3: Distribution of breeding Redshank on différent habitats and management types

TABLE 5: Distribution of breeding Lapwing on différent habitats and management types

% of area surveyed

% of total pairs of Redshank

SALTINGS Cattle grazed Sheep grazed Cattle & sheep grazed Ungrazed

0.9 1.4 0.8 23.7

1.1 2.0 1.0 45.0

SALTINGS Cattle grazed Sheep grazed Cattle & sheep grazed Ungrazed

0.9 1.4 0.8 23.7

0.1 0.2

Total

26.8

49.1

Total

26.8

0.3

33.9 5.9 1.4 20.9 2.0

58.3 4.1 4.7 13.9 2.4

64.1

83.4

% of area surveyed

GRAZING MARSH Cattle grazed Sheep grazed Cattle & sheep grazed Ungrazed Mown

33.9 5.9 1.4 20.9 2.0

28.9 2.0 4.0 9.0 4.0

GRAZING MARSH Cattle grazed Sheep grazed Cattle & sheep grazed Ungrazed Mown

Total

64.1

47.9

Total

9.4

3.0

OTHER HABITATS

OTHER HABITATS Shingle 8.1 Arable & other areas 1.3

TABLE 4: Distribution of breeding Oystercatchers on différent habitats and management types

% of total pairs of Lapwing

— —

16.8

TABLE 6: Distribution of breeding Ringed Plovers on différent habitats and management types

% of total % of area pairs of surveyed Oystercatcher

% of total % of area pairs of surveyed Ringed Plover

SALTINGS Cattle grazed Sheep grazed Cattle & sheep grazed Ungrazed

0.8 1.4 0.8 23.7

6.0 5.8 2.4 39.5

SALTINGS Cattle grazed Sheep grazed Cattle & sheep grazed Ungrazed

0.9 1.4 0.8 23.7

1.1 2.2 32.1

Total

26.8

53.7

Total

26.8

33.3

GRAZING MARSH Cattle grazed Sheep grazed Cattle & sheep grazed Ungrazed Mown

33.9 5.9 1.4 20.9 2.0

7.8

64.1

8.9

8.1 1.3

41.0 15.1

GRAZING MARSH Cattle grazed Sheep grazed Cattle & sheep grazed Ungrazed Mown

33.9 5.9 1.4 20.9 2.0

6.9 2.8 1.5 13.5

Total

64.1

24.7

Total

18.4 3.2

OTHER HABITATS Shingle Arable & other areas

OTHER HABITATS Shingle Arable & others areas

8.1 1.3

26

1.1 — —


TABLE 7: Distribution of breeding Snipe on different habitats and management types % of area surveyed

% of total pairs of Snipe

SALTINGS Cattle grazed Sheep grazed Cattle & sheep grazed Ungrazed

0.9 1.4 0.8 23.7

Total

26.8

GRAZING MARSH Cattle grazed Sheep grazed Cattle & sheep grazed Ungrazed Mown

33.9 5.9 1.4 20.9 2.0

49.0 6.1

Total

64.1

100

OTHER HABITATS Shingle Arabie & other areas

Orwell

8.1 1.3

— — — —

DIAGRAM 1 Distribution of breeding Redshanks. At each coastal site figures are given as a percentage of total pairs, from Table 2.

44.9 —

Minsmere

0.63

Kessingland 3.24

DIAGRAM 2 Distribution of breeding Oystercatchers. At each coastal site figures are given as a percentage of total pairs, from Table 2.

Sizewell 0.32

DIAGRAM 3 Distribution of breeding Lapwing. At each coastal site figures are given as a percentage of total pairs, from Table 2. Orwell 2.56

Sizewell 0.93

DIAGRAM 4 of breeding Ringed Plovers. At each coastal site figures are given as a percentage of total pairs, from Table 2.

27

DIAGRAM 5 Distribution of breeding Snipe. At each coastal site figures are given as a percentage of total pairs, from Table 2.


Figure 1: Location of survey sites

Figure 2: Location of Black-headed Gull colonies

28


WEATHER TRENDS AND THEIR EFFECT ON THE COUNTY'S AVIFAUNA, 1991 by John H. Grant (Based on the monthly reports by Ken Blowers, weather correspondent for the East Anglia Daily Times Co Ltd. )

WINTER: January, February,

March.

January: With rain on only 12 days, sunshine hours amongst the highest in Britain and temperatures often well above the long-term average maximum of 43°F (6°C), January's trends felt more like June's. But, rather surprisingly, there was a run of northern immigrants which lifted the mild-weather monotony. Basking in the sunshine — of which there were totals of 86 hours at Levington and 78 hours at Higham and Cavendish — were, for instance, a pair of Parrot Crossbills in the Brandon area, Arctic Redpolls in the King's Forest, two Rough-legged Buzzards around Butley Creek and an array of five species of grebe. More predictably, some species were enticed to linger a little longer than is usual by an early January spell which was the warmest for seven years: a Little Stint overwintered on Loompit Lake, Trimley, for example, and the total of 20 Chiffchaffs is the highest wintering population recorded in the County. By the end of the month, however, there was an intense anticyclone of 1,040 millibars over Scandinavia which gave an early indication of the wintry weather which was to strike Britain with a vengeance in February. February: Suffolk bore the brunt of an icy blast from the east as a result of the Scandinavian anticyclone, which by Feb. 5th had attained a central pressure of 1,055 millibars — and it was then that the snows arrived, continuing for much of the following four days. Temperatures were continually below 32°F (0°C) until Feb. 11th. RAF Wattisham's 13 inches of snow on Feb. 9th was Britain's deepest fall on that date and, in general, this vicious onslaught was Suffolk's heaviest snowfall since Feb. 15th 1979. The lowest temperatures in this cold snap occurred in the early hours of Feb. 13th, when a minimum air temperature of 17°F ( - 8 ° C ) and a grass minimum of 10°F ( - 12°C) were registered at the East Anglian Daily Times (EADT) weather station in Ipswich. The cold weather, with temperatures below the long-term day maximum of 44°F (7°C) lasted to Feb. 21st. At Higham, recording showed that it was the third coldest February since 1947 and the fourth coldest of the present century. Mortality among estuarine waders, particularly Redshank, hit the newspaper headlines. Corpses found on the estuaries between the Aide and the Stour included 574 Redshank, 240 Dunlin, 99 Shelduck and 54 Grey Plovers. The worst hit estuary was the Deben where the total of 448 dead Redshank is 42% of the site's average wintering population. Hindsight shows that this Arctic spell may well have had a similarly disastrous effect on at least three other species: Kingfisher, Goldcrest and Bearded Tit. They crashed alarmingly and the damage inflicted in less than a month may well take many years to be rectified.

29


Wildfowl displaced from the Continent, a region also gripped by harsh conditions with several inches of snow covering such exotic locations as Nice and Monaco, made forays into the frozen field well worthwhile. For example, 131 Scaup took shelter on the River Orwell and Landguard recorded a hard weather movement which included 26 Smew between Feb. 10th and 12th. Also fleeing from the worst of the weather in movements at Landguard during Feb. 9th to 11th were 226 Linnets and 642 Skylarks, both normally scarce at the site in winter. The see-saw effect of the weather continued at the end of the month when a sudden warming took place, thanks to a southerly airflow which raised temperatures to 59°F (15°C). Ipswich and Lowestoft became the warmest places in Britain . . . was spring really on its way? March: A Collared Dove's nest at Landguard, albeit abandoned, contained two eggs on Mar. 6th, but such hasty reactions to the end of the Big Freeze were few and far between. Spring arrivals were more sedate in their activities and interest centred more on species lingering after February's icy grip. Mild March saw temperatures which rose above the long-term average on no less than 24 days — a result of a southerly airflow from 2nd to 20th when East Anglia was often warmer than Madrid, Cyprus or Rome. On Mar. 13th there was unbroken sunshine and at Ipswich the temperature rose to 64°F (18°C). Consequently, many spring migrants chose this spell to make their arrival and winter visitors made their exodus.

SPRING: April, May,

June.

April: To complete the whole gamut of weather conditions experienced in only the first four months of the year, April provided wind and rain a-plenty. A cold north or north-easterly airflow persisted and the last day of the month was the wettest April day since 1904 in many parts of Britain. However, Britain was still parched by the two previous bone-dry summers and a dry winter — it would have taken several deluges of April's magnitude to ease the crisis in groundwater levels. In such conditions it was hardly surprising that some winter visitors, such a Black-throated Diver and Long-tailed Duck, continued to sit it out in Suffolk. Similarly, it was no surprise to see a mere trickle of spring migrants rather than the hoped-for flood. May: A persistent blocking anticyclone to the west and north-west of Ireland diverted active depressions well -away from East Anglia, allowing north and north-easterly winds to predominate for most of the month. Such conditions in May are virtually guaranteed to bring in a good assortment of rarities, but equally likely to halt the arrivals of many of our more common summer visitors.

30


These conditions were undoubtedly the root cause of an influx of 13 Temminck's Stints (Suffolk's highest ever spring total), a scattering of Wrynecks, together with Bluethroat, Ortolan Bunting and Hoopoe. Even scarcer species included Gull-billed Tern, Tawny Pipit and Red-rumped Swallow. These latter over-shots from warmer climes may well have felt more than a little out of place, for it was a dull month in terms of sunshine. The long-term average for May is 212 hours, but at Cavendish for example there were only 142.9 hours and Levington fared little better, at 156.6 hours. The relentless drought continued, however, and at Broom's Barn Experimental Station, Higham, it was the fourth driest May since 1948. June: In sharp contrast to May, June saw heavy rainfall — just when the holiday-makers, and perhaps some of our breeding birds, did not want it. The main upper airstream circulating over the northern hemisphere was displaced southwards during the month and the result was one of the worst Junes this century. Britain was often on the cold side of the jet stream and consequently temperatures were much below the seasonal average. At Higham, the mean air temperature of 61°F (16.3°C) was the lowest for more than 40 years and the number of days with measurable rainfall was the highest for at least 42 years. The gloom of the weather was lifted somewhat by such species as Common Rosefinch and White-winged Black Tern. A Great Grey Shrike of the Iberian race which remained near Lowestoft throughout the month must have felt distinctly cooler than normal.

SUMMER: July, August,

September.

July: In a word — unsettled. Sporadic spells of heavy rainfall caused flood chaos in some areas and one such downpour, on July 24th, produced 1.10 inches of rain at the EADT weather station in Ipswich — ranking as the heaviest 24-hour rainfall total since Dec. 24th 1989. Just six days after this July mini-monsoon south-easterly winds from the Continent pushed warm hot air into East Anglia and Ipswich achieved a temperature of 80° F (27 °C), a good illustration of the changeable nature of the month's weather. Such a mixture inevitably stirred up some ornithological interest and highlights of the month included a long-staying Black-winged Stilt, three Caspian Terns, Bee-eater and Alpine Swift. The Shore Lark which appeared must have been as unsettled as the weather, but the Great Grey Shrike settled down to lengthen its stay with us still further. August: If ever a month showed what a non-conformist lot birdwatchers are, it was this. The onset of autumn stimulates birders' dreams of riches to come — and while everyone else prays for an Indian summer, all we can do is hope for bad weather. August illustrates the point perfectly. Persistent anticyclones near the British Isles gave Suffolk one of its driest Augusts of the past 150 years. In many areas there was measurable rain on only four days and parts of East Suffolk recorded totals of less than a quarter of an inch. Temperatures, without being notably high, were continually warm and above the long-term average on 28 days. A combination of these factors led to a settled month in terms of weather and a relatively quiet month in terms of birds. At Landguard, for example, a mere trickle of migrants was noted and Suffolk's sea-watchers were for the most part left with unfulfilled dreams. Inevitably, as much by the law of averages as by anything else, a few rarities occurred, such as Suffolk's first Lesser Crested Tern, a Long-tailed Skua, Sabine's Gull, Honey


Buzzard and Purple Heron, but it was not a vintage spell. Even when a large blocking anticyclone produced a prolonged spell of easterlies, accompanying clear skies meant it was plain sailing for most birds and Suffolk groundings were unnecessary.

Aug. 24

Aug. 31

Simplified weather maps for Aug. 3, 24 and 31 show the flow of warm winds into Britain which gave temperatures at or above the month's average on 28 days.

September: Suffolk basked in one of its warmest Septembers on record. RAF Honington's meteorological office recorded an average daily maximum temperature of 69.5°F (20.8°C) — the highest since its records began 21 years previously. Correspondingly, sunshine hours were outstandingly high, with Levington Research Station's total of 185.3 hours being 36.7 hours above' the month's long-term average. Anticyclones dominated the weather for much of the month and produced winds between north-east and south-east. Combined with torrential rain near the month's end, this pattern inevitably produced an interesting month for birdwatchers.

32


Pick of the bunch was the Orfordness Roller, an appropriate visitor in such warmth and seawatchers were at last rewarded by a diverse crop of species, with Suffolk sharing in Britain's Long-tailed Skua invasion, for example. A good selection of passerines with easterly origins was topped by a Redstart of the eastern race samamisicus, which ensured that birdwatchers outnumbered the congregation at St Edmund's Church, Southwold.

WINTER: October, November,

December.

October: 1991 will probably be remembered by most people as the year in which the recent drought strengthened its grip. Certainly, October was another abnormally dry month — the fourth driest October of the century, in fact. For birdwatchers, however, interest centred on an intense anticyclone which became established to the west of Scotland for the last ten days of the month, feeding mainly dry but — significantly — south-east winds into East Anglia. Consequently, there was eastern promise and it became a promise which was fulfilled with two Radde's Warblers, a Dusky Warbler and a procession of Yellow-browed and Pallas's Warblers. The star bird, however, came from the opposite direction. A Red-eyed Vireo chose Britain's most easterly wood in which to break its journeying from the west and was, amazingly, the second of its species to achieve this feat.

Anticyclones dominateti the weather during the last two weeks of October. The first chart shows the colà northerly airflow from the Norwegian Sea on Od. 19 and the second map reveals the mild south-easterly airstream from the Continent on Oct. 27 which gave sunshine for the first day ofGreenwich Mean Time.

A flurry of sea-bird activity shortly before south-easterlies set in, associated with a Scandinavian low which fed a cold north-westerly airflow down across the North Sea, included a Black Guillemot, Little Auks, Puffins and a Storm Petrel. Ail in ail then, a mixed bag of wind directions and a varied selection of birds. November: At least four species, which are not usually associated with November in Suffolk, enlivened a month which was generally gloomy and often rather cold. Indeed, there was only a handful of notably sunny days throughout the month, making the occurrences of Barred Warbler, Tawny Pipit, Turtle Dove and Whitethroat ail the more surprising.

33


These species might more often be associated with the balmy days of early autumn, but here they were in an often turbulent month, with tornado winds hitting Dullingham, near Newmarket, and Kirton, near Felixstowe, on Nov. 12th. A week later a deep depression moved into the North Sea, creating strong winds after a brief respite of calm and foggy conditions.

Despite favourable conditions for sea-watching, however, there were few rewards, apart from a County record passage of Eiders, a tardy Long-tailed Skua, a scattering of Little Auks and a Leach's Petrel. Worthy of note, particularly in these days of drought, is the fact that the Felixstowe area — often the region's driest — proved to be the wettest in November. Levington Research Station recorded 3.31 inches of rain, with 1.01 falling on the 18th alone. December: We were soon back in the old routine as far as rainfall was concerned, however, as for the first 16 days most districts had no measurable rainfall. Not only was it dry — it was bitterly cold early in the month, with most places recording air frost on at least 11 nights. In Ipswich, minimum air temperatures of 19°F (—7°C) were noted on December 11th and 12th and at ground level temperatures of 15°F (—9°C) were recorded. As if to confound all of our theories and logic, a Whitethroat braved these harsh conditions to become the latest ever recorded in the County — on the 7th — and the Turtle Dove remained doggedly faithful to its Collared companions at Leathe's Ham, Lowestoft. More predictably, Brent Geese built up well and by the year's end, Suffolk's largest ever gathering of 5,000 had assembled at Falkenham, where there were also a Black Brant, two Barnacle and four Bean Geese. And so the year ended in what has become a familiar vein — in drought. The full longterm effects on our birdlife of this year-on-year lack of rain will make an interesting study in years to come. John Grant, 39 School Road, Sudbourne,

Suffolk IP12 2BE.

34

Suffolk Birds 1992 Part 1  

Volume 41

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