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Front Cover: Peregrine by Orwell Bridge Su Cough


SUFFOLK BIRDS V O L . 58 A review of birds in Suffolk in 2007

Editor Nick Mason

Greatly assisted by Philip Murphy (Systematic List) Adam Gretton (Papers) Trevor Kerridge (Photos) Tony Howe (Artwork)

Published by S U F F O L K N A T U R A L I S T S ' SOCIETY in collaboration with SUFFOLK ORNITHOLOGISTS' GROUP


2009 Published by The Suffolk Naturalists' Society, c/o The Museum, High Street, Ipswich IP1 3QH Š The Suffolk Naturalists' Society 2008 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.

The SNS is a Registered Charity No. 206084.

ISSN 0264-5793

Printed by Healeys Printers Ltd, Unit 10-11, The Sterling Complex, Farthing Road, Ipswich, Suffolk IP1 5 AP.

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CONTENTS Page Editorial and Review of the Year: Nick Mason 5 Red-throated Divers Gavia stellata: Wintering Red-throated Divers, Thorpeness, Suffolk 2000/01-2008/09 David Thurlow 9 North Warren RSPB Reserve: management and wildlife review through 2008: Rob Macklin, Dave Thurlow 22 Black Kites Milvus migrons: The Black Kites in Suffolk 2008 - the full story: IVill Brame 27 Peregrine Falcon Falco peregrinus: Back breeding at last: Rod Plowman 29 Turtle Dove Streptopelia turtur: Report on the 2008 SWT Survey: Steve Piotrowski . 30 Common Blizzard Buteo buteo: colonising the north-east of the county: Peter Dare . 34 Tony Marshall: a fond farewell Derek Moore 36 The 2008 Suffolk Bird Report: Introduction 38 Systematic List 40 Appendices 154 List of Contributors 159 Gazetteer 161 Earliest and Latest Dates of Summer Migrants 163 A Guide to Recording Birds in Suffolk 164 Rare Birds in Suffolk 2008: David Walsh 168 Suffolk Ringing Report 2008: Andrew Gregory 171 Regional Review: Adam Gretton 179 List of Plates Plaie No.

1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18.

Facing

Black Kite Sean Nixon Black Kite James Kennerley Great Egret Sean Nixon Female Goosander Stuart Read Little Grebe Alan Tate Osprey Bill Bastón Osprey Bill Bastón Red-footed Falcon Alan Tate Peregrine Chicks Bill Bastón Dotterei Bill Bastón Purple Sandpiper Sean Nixon Curlew Sandpiper Sean Nixon White-rumped Sandpiper Chris Mayne Little Gull Sean Nixon Glaucous Gull Peter Ransome Nightjar Bill Bastón BarnOwl Bill Bastón Short-eared Owl Chris Mayne

Facing

Piate

Page

Page

No.

40 40 40 40 40 41 41 41 41 80 80 80 80 81 81 81 81 81

19. 20. 21. 22. 23. 24. 25. 26. 27. 28. 29. 30. 31. 32. 33. 34. 35. 36.

Tawny Owl Bill Bastón Ring Ouzel Bill Bastón Robin Bill Bastón Shorelark Bill Bastón Desert Wheatear Stuart Read Treecreeper Rebecca Nason Common Redstart Bill Bastón Black Redstart Sean Nixon Bluethroat Sean Nixon Richard's Pipit Stuart Read Yellow-browed Warbier Sean Nixon Radde's Warbier Bill Baston Waxwing Peter Ransome Cetti's Warbier Alan Tate Yellowhammer Bill Baston Com Bunting Stuart Read Twite Chris Mayne Brambling Bill Baston

Front c o v e r : P e r e g r i n e b y O r w e l l B r i d g e Su

Gough

The copyright remains that of the photographers and artists 3

81 120 120 120 120 120 121 121 121 121 160 160 160 160 161 161 161 161


Suffolk Birci Report 2008

Notice to Contributors Suffofk 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 recorders, 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 présentation, especially in relation to references and tables. Where relevant, nomenclature and order should follow the latest published for The British List by the British Ornithologist's Union and available on their web site at www.bou.org.uk. English names should follow the same list. Contributions should, if possible, be submitted to the editor by e-mail or on a CD/DVD and written in Microsoft Word. If typed, manuscripts should be 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. Photographs and line drawings are required to complément each issue. Suitable photographs of birds, preferably taken in Suffolk, can be either digital or in the form of 35mm transparencies. A payment of £12 will be made to the photographer for each photograph published and £12 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. Authors may wish to illustrate their papers, 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 or her. Material submitted for publication should be sent to the editor no later than March 1 st of each year. Authors of main papers may request up to five free copies of the journal. Any opinions expressed in this Report are those of the contributor and are not necessarily those of the Suffolk Naturalists' Society or the Suffolk Ornithologists' Group.

Suffolk Ornithological Records Committee: Chair: Steve Piotrowski. Area County Recorders: Colin Jakes, Andrew Green, Scott Mayson (2009 onwards). Bird Report Editor: Nick Mason. Secretary: Justin Zantboer. Other Committee Members: Steve Abbott, Richard Drew, Lee Gregory, Brian Small, Roger Walsh and Malcolm Wright. BBRC correspondent: Dave Walsh.

ADDRESSES Papers, notes, drawings and photographs: The Editor ( S u f f o l k Birds), The Suffolk Naturalists' Society, c/o The Museum, High Street, Ipswich IP1 3QH. Records: See inside front cover. Suffolk Ornithological Records Committee - correspondence: The Secretary, SORC, c/o The Museum, High Street, Ipswich IP1 3QH.

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Suffolk Birci Report 2008

Editorial and Review of the Year Nick Mason It is easy to listen to anecdotal comments about birds, whether they are common or rare, and to take away ideas that a species is either doing well or declining quickly. In some cases it may be accurate. The only way, however, to know about the county-wide health of different bird species is by proper bird recording. This can be by BBS squares which over a number of years will give an accurate idea of that particular kilometre square. The WeBS counts have been going for more than 40 years and give a year by year account of the numbers of wildfowl and waders on an estuary or waterbody. Good solid data. From time to time we have species-specific surveys such as that for Ringed Plover in 2007. This, of course, is leading me to the British Bird Atlas run by the BTO. The immediate take-up was very good and, at the end of 2008, showed that an amazing number of tetrads had been already completed or started. Some 10-kilometre squares are almost complete (all 25 tetrads surveyed). These areas tend to be on the coast or in areas where there are good numbers of birders. However, as mentioned last year, there is a need for counters in the west of the county towards Haverhill. Just as a reminder, Mick Wright is co-ordinating the effort in Suffolk and he can be contacted on 01473 710032 or by email at mickwright@btinternet.com. One of the species about which I hear so many anecdotal stories, mostly negative, is Turtle Dove. Steve Piotrowski's article on the 2008 Suffolk Wildlife Trust/Suffolk Ornithologists Group survey in this Report goes some way to putting these comments into perspective. At the end of the Atlas period we should have an even better idea of this bird's status. I am often tempted to go to Malta to help those trying to stop the atrocious slaughter of Turtle Doves as they pass through those islands. I know that one has to be careful when comparing other cultures but surely these things can't continue in an EU state in the 21st century? Steve, in his article, mentions how the farming community is likely to influence the fate of this species in Suffolk. Perhaps more of us could try to encourage farmers to include foraging areas on their land? Often this could be field corners near suitable breeding habitat. In his warbler section James Brown mentions the under-recording of some species, especially Goldcrest and Willow Warbler. Hopefully this will be addressed in the Atlas as each tetrad is covered. In the case of Goldcrest I should hope that this would be a species for which all recorders would enter Roving Records as it can sometimes go unrecorded by those with less than 100% hearing. When writing species' accounts the authors include a 'strapline' on their relative status in Suffolk, which we try to keep up to date. There is also mention of their current conservation status. There are three of the latter - Green, Amber and Red. It is worth explaining them. The Red list is for species of the highest conservation priority needing urgent action. The criteria are that they are one of these:• globally threatened • have shown an historical decline in the UK (1800-1995) • show a severe (more than 50%) decline in the UK breeding population over the last 25 years • show a severe (more than 50%) contraction of their UK breeding range over the last 25 years There are 52 species on the Red list which now includes Cuckoo and Yellow Wagtail. Recently Wood Lark and Stone-curlew, because of targeted conservation action, have been moved from Red to Amber based on tight statistical criteria. The Amber list contains 126 species and is based on these criteria:• unfavourable European conservation status • historical population decline, but recovering 5


Suffolk Birci Report

2008

• a 25 to 49% decline in UK population over 25 years • a 25 to 49% contraction of the UK breeding range over 25 years • a 25 to 49% decline in the UK non-breeding population over 25 years • a rare breeder with between one and 300 pairs in the UK • a rare non-breeder with less than 900 individuáis • is localized with at least 50% of the UK breeding or non-breeding population in ten or fewer sites • is internationally important with at least 20% of the European breeding or non-breeding population in the UK As mentioned, the statistics are tight with, for instance, Nightingale showing a 4 9 % decline and so being on the Amber list. There is a Green list, thank goodness, which is for species with no apparent conservation concerns. There are 68 species currently on it which now includes Peregrine and Sparrowhawk. These lists are put together by the leading UK conservation organizations and can be found on the RSPB website, for example. The above lists are based on data gathered from ail sorts of sources which includes your records, if submitted. Here is another reminder that your records should be sent to the Area Recorders. Their ñames and contact détails are on the front inside cover of this Report. Colin Jakes takes records from the west, Andrew Green from the north-east and Scott Mayson from the south-east. The map of these areas is also in the front. Where possible records should be sent on the spreadsheet obtainable from SOG, on their website. Paper records are also welcome, however.

Purple Héron Peter Beeson

Records from BINS and other bird networks are not normally accepted as bona fide. Such records do need to be submitted in the normal way. On the other hand, BINS continues to be a force in Suffolk birding for those keen to see the rarer species and goes from strength to strength. Most of the birders I know, who don't subscribe, seem to have been on the website to find out the latest news. We are lucky with the folk who are prepared to put themselves out to write the species reports and the ringing report. They often have full-time jobs and produce some 6


Editorial and Review of the Year excellent, detailed pieces. At least four of them are Lizards! I am pleased to list them ail here:Derek Beamish, James Brown, John Davies, Andrew Easton, Steve Fryett, John Grant, Andrew Green, Andrew Gregory, Chris Gregory, Peter Kennerley, Rob Macklin, Philip Murphy, Mark Nowers, Phil Whittaker, James Wright and Malcolm Wright. For this Report I was extremely grateful to John Grant, Gi Grieco and Phil Whittaker who stepped in late in the day to cover the Swans and Geese section. Thankyou. As usuai this Report would not be the same without the experienced input of Philip Murphy. He checks many of the records and ensures that a consistent standard is maintained. As last year, Laurie Forsyth did an excellent job of proof-reading the species accounts. This year, I am pleased to say, he had less to find but his eagle-eyes did spot a few errors! Again we have a mixture of articles. Dave Thurlow has to be admired for the time and effort he puts in to his seawatching and his report on the wintering Red-throated Diver is interesting and thorough. Dave and Rob Macklin have put together a piece on North Warren. Each year we hope to include such an article on an important birding site in Suffolk. Will Brame has courageously put the 2008 Black Kite saga into perspective. Rod Plowman has done us a short piece on his experiences watching the Peregrines on the Orwell Bridge, which led in 2008 to the first breeding in Suffolk for 200 years. As mentioned above, Steve Piotrowski has put together a full report on the 2008 Turtle Dove survey. Peter Dare has sent us a short piece on the establishment of a breeding population of Common Buzzards in the north-east area. Lastly Derek Moore gives us a positive obituary ofTony Marshall, a birding type we see so rarely these days. We hope that you enjoy the articles and welcome any suggestions for future Reports. Tony Howe gathered most of the art work and Trevor Kerridge the photographs. Peter Beeson and Su Gough have produced most of the artwork while Nick Andrews has done sketches of the Desert Wheatear and the Citrine Wagtail. We have eight photographers who have work in the Report. We are keen to encourage a wide range of artists and photographers to submit their work. Bill Baston's stuff is fantastic but so is some of yours! One of Bill's photos is of the celebrity Tawny Owl from Christchurch Park which appeared in the media. I was tempted to use one of Bill's pictures that shows a rusting New Age Travellers truck on Upper Hollesley Common. A Redstart nested in one of the holes in the bumper causing spĂŠculation that 1 might leave a few more such vehicles around the Common! We have, however, used a photo of the Redstart itself. There has to be mention, in a report such as this, of the continuing success of the Suffolk Community Barn Owl Project. There are a number of people involved and one of the special outcomes of such a project is that it brings others in - people who may not naturally have become involved in conservation or even with our natural history. Congratulations are due for the way that the project has claimed people's imagination. On the practical side, the project had been a big success too. You can see in our Ringing Report for 2008, later in this ĂŠdition, the number of ringed birds using the boxes. There are often further benefits from conservation action and, in this case, one of them is the number of Stock Doves that have found a suitable hole in which to nest.

Brief review of the year The weather in 2008 followed a similar pattern to the year before. There were some promising periods in spring with some early nesters getting a good start. However, the summer was mostly wet and cloudy with no consistent periods of fine, dry weather for rearing young. Many young birds suffered in late June and July. In January one of the most interesting finds was the Ross's Goose. This is the same bird that has been seen in Norfolk with the Pink-footed Goose flocks for a couple of years. It is currently a Category D species but the bird does have potential as it appears each winter with 7


Suffolk Birci Report 2008 the Pink-footed Geese that are hopefully going to become more common in Suffolk. These birds were also reported at the end of the year. The LesserYellowlegs remained for much of January and February and returned again on December 5th. There were more Firecrests noted as wintering at the beginning of the year. The same two Penduline Tits were reported from three locations in the north-east area, between February and Aprii. They, however, are stili awaiting ratification by BBRC at the time of going to print. In Aprii the birds that got the pulses racing were the Black Kites. For such a cosmopolitan bird the records of this species in Suffolk are surprisingly low. They did, however, bring with them a certain amount of angst! On the breeding front the Cranes bred again, unsuccessfully, at Lakenheath Fen and Peregrines bred for the first time in Sulfolk in 200 years on the Orwell Bridge. The Spectacled Warbler found on May 1 Oth at Westleton Heath was, for some, the bird of the year, and would have been for several others if it had hung around! There was a Thrush Nightingale at Minsmere between June 5th and 8th. In August, especially, there were some interesting wader sightings. A Kentish Piover was at Minsmere, briefly, on 25th and Suffolk's second Pacific Golden Piover, an adult, graced Havergate on 3rd. The Semipalmated Sandpiper seen at Minsmere on July 18th stili awaits full BBRC acceptance. There was an adult Citrine Wagtail at Landguard on August 29th, but this was another bird that did not stay long. In September the big event was the movement of Honey Buzzards, especially near the coast. For most of us a view of a Rustie Bunting in Suffolk, would perk us up. Unfortunately the one ringed at Landguard on September 24th was not seen again. On November 2nd a Red-flanked Bluetail was ringed at Hollesley, Suffolk's fourth. The Desert Wheatear at Easton Bavents from November 4th to lOth was Suffolk's third and presumably the first for our younger birders? There were good numbers of Waxwings around towards the end of the year with the largest flocks being at Rendlesham.

8


Suffolk Birci Report 2008

Wintering Red-throated Divers, Thorpeness, Suffolk, 2000/01-2008/09 Dave Thurlow Introduction Suffolk waters have long been recognized as important for wintering Red-throated Divers (Dare, 1998). Indeed, Babbington (1884-86) reported the bird to be "an abundant species about Aldeburgh". In recent winters much survey work has been undertaken on wintering sea birds in the southern North Sea, or Southern Bight (e.g. dti, 2006). This has resulted in the discovery of up to 10000 Red-throated Divers wintering in the Greater Thames area, which includes the Suffolk wintering population (Fig 1 ). These birds largely originate from Scottish and Scandinavian breeding populations along with some from as far away as Greenland (Hemmingsson, 2002). In addition, in the south-eastern North Sea area (Fig 1 ), up to 36000 winter off the Wadden Sea (Laursen and Essink, 2005). Figure 1. Map showing main wintering areas of Red-throated Divers, southern and central North Sea based on aerial survey work.

Context and Importance of the southern North Sea The southern North Sea is comprised of shallow turbid waters, influenced by the mixing of the North Atlantic water and fresh water inputs from the rivers Thames, Rhine and Scheidt (Stienen et al., 2007). It is rieh in fish and is recognized as an important feeding area for seabirds. It has also been long recognized as a major flyway, the funnel aspect of this part of the North Sea acting as a corridor with its entrance/exit being the Dover Strait (e.g. Cawston and Ling, 1998). An estimated 1 -1.3 million seabirds pass through the Dover Strait each year, with 40-100% of the North Sea flyway population of Great Skua and Little Gull, 30-70% of terns and Lesser-black backed Gulls and 10-20% of Red-throated Divers (Stienen et al., 2007). Thorpeness, on the east Suffolk coast certainly has potential to observe these movements. Since 2000, as part of compiling a sea bird data base, Red-throated Diver movements have been regularly logged from the Sizewell-Thorpeness Cliffs. The aims of this paper are (1) to summarize and describe these movements; (2) to assess the influence of tidal conditions on of these movements; (3) try and put the Thorpeness counts into context with the recent survey work in the Southern Bight. 9


Suffolk Birci Report 2008 Methods Winter watches (November to February) were carried out on 631 dates, totaling 1229 hours, during 2000/01 to 2008/09 from Ness House, situated to the north ofThorpeness on the Thorpeness/Sizewell cliffs. The majority of watches were carried out at around dawn and lasted typically 1.5 hours. When time permitted longer watches were carried out, either for the entire day or split between morning and afternoon sessions. Effort was more or less even over the months (typically 20 days, 30 hours) although during January 2002 and February 2005 watches were only carried out on two dates. A Leica APO 77mm telescope was used with a 32X wide angle eyepiece. Counts and flight direction of divers were recorded as well as the timings of any notable, or peak, movements. To summarize annual and seasonal abundance, data are presented as birds per hour to try and reduce the effect of different levels of observation throughout the study. Where presented, monthly and annual maximum day counts are the combined total of birds flying north and south; hence it should be borne in mind that these totals may involve duplication. To assess the impact of the state of the tide on diver movements, the following methodology was used. Only movements larger than 200 divers with a single peak unidirectional movement were analyzed. As the vast majority of peak movements lasted under an hour, each movement was assigned to an hourly time period in which time span the movement occurred in (07:00-08:00 etc.). This was then plotted against high tide time for northerly movements and low tide for southerly movements. High/low tides are for the Minsmere Sluice and were obtained from the WXTide 32 programme (which gives tide times for Lowestoft; Minsmere Sluice is plus 70 minutes). The data are also presented in bar chart form with the actual number of movements in relation to high or low tide. Results (1) Seasonal and annual abundance of wintering Red-throated Divers, Thorpeness Annual variation in abundance over the winters of 2000/01 to 2008/09 is summarized below (Fig 2), expressed as birds per hour. Figure 2. Annual variation over the winters of 2000/01 to 2008/09 expressed as birds per hour. Winter 2000/01

Fig2a.

Fig 2b.

300

300

250

250

200 Birds per hour

Winter 2001/02

200 Birds per hour

_ * North

150

I North

• South

I South

100

50 +•

0 Nov

Dec

Jan

Nov

Feb

Dec

Jan

Feb

Month

Month

A number of general points can be deduced from these graphs. Firstly, diver numbers can vary greatly between winters as indicated by the rates of movement. Secondly numbers can also vary quite markedly during the months of an individual winter although do tend to peak 10


Wintering Red-throated Divers, Thorpeness, Suffolk,

2000/01-2008/09

in December and January. Finally, southerly flights tend to be much more frequent than northerly flights. The first two observations outlined above have also been noted in aerial surveys of the Greater Thames (dti report, 2006). Fig 2c.

Fig2d.

Winter 2002/03

Winter 2003/04

400 350 300 250 Birdsper hour

200

150 100

50

Nov

Dec

Jan

Nov

Feb

Í1 Jan

• South

Feb

Month

Month Fig2e.

Dec

»North

Fig 2f.

Winter 2004/05

Winter 2005/06

200

Birdsper

250

hour

200

«North • South

Nov

Dec

Jan

Nov

Feb

Month Fig 2g.

150

Dec

Jan

Feb

Month

Winter 2006/07

Fig 2h.

Winter 2007/08

250

r

200 + 100

150 i Birds

Birds per

per hour

hour

50

I II

• North

• North

100

• South

• South

50

I Nov Dec Jan Feb

Nov Dec Jan Feb

Month

Month

11


Suffolk Birci Report 2008 Fig2i.

350

Winter 2008/09

y

- —

300 4— |

250

200 j

150

f

*N°rth

100 :

«South

Birdsper hour

I Nov Dec Jan Feb Month

The maximum day counts at Thorpeness during 2000/01 to 2008/09 are presented in Table 1:Table 1. Cumulative peak day counts at Thorpeness during the winters 20001/02 to 2006/07. Winter 2000/01 2001/02 2002/03 2003/04 2004/05 2005/06 2006/07 2007/08 2008/09

Peak cumulative day count 3,561 (605N, 2,956S) 3,760 (2,728N, 1,032S) 2,843 (2,743N, 100S) 4,710 (3,995N, 715S) 2,137 (1,382N, 7 5 4 S ) 1,764 (93N, 1,671S) 805 (52N, 753S) 2,726 (310N, 2,416S) 3,294 (2,854N, 440S) -

Dee 2000 Dee 2001 Dee 2002 Jan 2004 Nov 2004 Jan 2006 Dee 2006 Jan 2008 Dee 2008

(2) General characteristics of diver movements For this study, all days with counts of over 200 individuai diver sightings were analyzed. There were 214 such occasions involving 177170 divers (ofwhich 47,988 (27%) flew north and 129182 (73%) flew south). Table 2 presents the data in terms of wind and flight directions. Table 2. Flight direction in relation to wind direction. Included are 10 movements where no overall flight direction was obvious. Wind Direction No. ofdavs (2 = 214) Flight Direction % North South No direction

North Ind. NE & NW 60

East

45 45 10

25 38 37

8

12

South Ind. SE & SW 103 14 84 2

West

Cairn

36

7

17 78 5

38 62


Wintering Red-throated Divers, Thorpeness, Suffolk,

2000/01-2008/09

This table again illustrate the higher frequency of southerly flights compared to northerly flights along with a possible link between flight direction and wind direction; it has long been recognized that some species of seabird do seem to show a preference for flying into the wind [e.g. Gannets and auks (Cooke, 2006)]. Two basic types of movement were observed at Thorpeness. The first involved a unidirectional movement with a distinct peak of activity. In such movements birds flew in singles or extended cluster flight flocks (terminology from Heppner, 1971), mostly low over the sea. Birds were mainly at medium to distant ranges (1-3+ km). Although the timing of the peak activity could occur anytime during the day, most were within one to two hours of sunrise; the small number occurring later in the day may be a result of watches being biased towards early morning. These movements occurred in all types of weather conditions with the exception of wind strengths of near gale or above or during heavy rain. An example of such a movement occurred on December 13th 2007 when 2231 divers flew south between 07:30 and 08:55. It is these movements that are analyzed for the influence of tidal conditions (see methods). The second type of movement observed, again unidirectional, differed from above in that it lasted the best part of a morning. Either there was no obvious peak, with birds moving continuously throughout the watch or there were two or more obvious peaks, or pulses, involving several hundred or even up to a thousand birds. These peak movements were characterized by spectacular cluster flocks with birds often flying well above the sea and at close to medium range. Typically these movements occurred in wind strengths of force 4 or below often on clear bright days. An example of such a movement occurred on January 12th 2008 when 2416 divers flew south between 07:55 to 10:40 with pulses of 250 birds between 08:30 to 09:00, 990 birds between 09:10 to 09:30 and 600 birds from 10:10 to 10:25. At least some of these movements are considered to be weather related. A possible example of a weather induced movement/influx occurred at Thorpeness on Jan 1 st to 4th 2004. Strong southerly winds and drizzle were associated with a low pressure over the North Sea and English Channel on Jan 1st. On Jan 3rd 2,805 Red-throated Divers flew south between 07:40 and 14:45 with c.1000 between 08:00 and 09:15 and 900 birds between 11:40 and 13:00. On the following day the highest day count so far logged at Thorpeness occurred with 3995 birds flying north between 07:30 and 15:15 (including 195 from 09:00-09:30, c.760 from 09:45 and 10:15, c.2,000 from 10:25 to 10:50 and c.750 from 11:30 to 11:55). Additionally 715 flew south during the day. The same low pressure system also resulted in a county record count of Little Gull on Jan 2nd with 1002 flying south off Thorpeness, presumably displaced from and returning to wintering grounds further south. (3) An assessment of the effect of tidal conditions on Red-throated Diver movements The offshore flood tidal stream in Suffolk is virtually due south and the ebb flood stream due north (Pye and Blott 2006). Flood tidal velocities are at a maximum five hours before high tide, 0.67 m/sec (or 2.4km/hr) on spring tides and 0.31 m/sec (or 1.1 km/hr) on neap tides). On the ebb tide, maximum velocities are one hour after high tide being 0.72 m/sec (or 2.6 km/hr) on spring tides and 0.36 m/sec (or 1.3 km/hr) on neap tides. Tidal conditions may affect divers in two ways. Firstly, birds may be subjected to tidal drift. Tidal drift is assessed below based on tidal data and times of peak movements (see methods). Secondly tidal conditions may concentrate prey items, especially along the offshore sandbanks; during the study large numbers of Kittiwake were often noted feeding off the Sizewell Bank, which extends to Thorpeness, along with Great-crested Grebes. Red-throated Divers, especially when not feeding, are likely to be drifted by currents and wind. It is hence reasonable to assume that after a period of southerly drift (on a flood tide) divers may compensate by flying north and conversely compensate after drifting north on an ebb tide by flying south This is confirmed by the analysis (Fig. 3). The data show a strong correlation between northerly unidirectional movements and high tide (Fig. 3a, R2 = 0.73) 13


Suffolk Birci Report 2008 and a weaker but nevertheless significant corrélation between southerly movements and low tide (Fig. 3b, R2 = 0.43). Figure 3. Assessment of tidal drift Fig 3a. Northerly flights relative

to

Fig 3b. Southerly flights relative to

High Tide Times

Low Tide times

400 600 80010001200140016001800

200 400 600 800 1000120014001600

High Tide Time

Low Tide Time

2

2

R = 0.7307

R = 0.4340

Fig 3c. Peak northerly movevments irt relation to high tide (HT)

Fig 3d. Peak southerley movements in relation to Low Tide (LT> 50 45 40 £

35

¡

30

Ol 8 25 E 'S 20

E 'S

i

15

in A m « i ebb to N flood to S Tidal State

flood to S ebb to N Tidal State

The bar Charts (Figs. 3c,d) show that most northerly movements (66%) occurred within an hour either side of high tide, while most southerly movements (63%) were made at low water and as the tide started to flood. As it was of interest to know whether movements at other Suffolk watch points also show a relationship with the state of the tide, data from Kessingland (P Read, pers. comm.) were also analysed. Kessingland is watched on a daily basis, with watches commencing on more or less a fixed time and typically lasting 45-90 minutes (P Read, pers. comm.). The start time for winter watches was usually 09:00, i.e. one and a half hours later than at Thorpeness. This makes direct comparison of data difficult. To assess if Kessingland movements are related to the state of the tide, the watch start time for all unidirectional movements of over 100 divers was plotted against high/low tide times (Fig 4). From the graphs, it would appear that northerly movements were related to high tide times (Fig 4a). Southerly movements were not correlated with tides (Fig 4b). 14


Wintering Red-throated Divers, Thorpeness, Suffolk,

2000/01-2008/09

Figure 4. Kessingland: Assessment of tidal drift Fig4a. Kessingland: northerly flights

Fig4b. Kessingland: southerly flights

relative to High Tide times

relative to Low Tide times

High Tide time (hrs)

Low Tide t i m e {hrs)

R 2 = 0.0935

R2 = 0.5259

It is interesting to note that southerly flights showed a stronger corrĂŠlation to the state of the tide than did northerly flights, the converse of the results at Thorpeness. Discussion and summary (a) Diver population size The European breeding population of Red-throated Divers is estimated at 7158 to 10502 pairs while the Russian population is estimated at 50000 to 100000 pairs (Hagemeijer & Blair 1997)). The vast majority of the European population winters in the southern North Sea and the offshore area from the Wadden sea. The concentration of divers wintering in the Baltic sea (up to 26000) are thought likely to be Russian birds (Hemmingsson, 2002). The current estimated wintering population of Red-throated Divers in the UK is 17000, with the Greater Thames holding 44% (O'Brien et al., 2008) 1 . Recent aerial survey work (Table 3) suggests that the Greater Thames wintering population may be as high as 15000 in some years. Table 3. Estimated wintering population of Red-throated Divers in the Greater Thames (2002/03 to 2005/06). Data from Wetland Bird Survey Reports (BTO). Date of count January 2003 February 2004 January/February 2005 February 2006

Estimated pop. 11,089 7,668 6,437 7,998

Lower limit 8,115 5,041

Upper limit 15,154 11,725

6,609

9,661

Both land based counts (e.g. Thurlow, 2009 and Dare, 1998) and recent aerial surveys (e.g. dti, 2006) have shown that the northern sector of the Greater Thames along the Suffolk coast regularly holds large numbers of divers during the winter. These studies also show that diver numbers in Suffolk can vary markedly between winters and also during the months of an individual winter. Table 4 shows the seasonal estimâtes of significant counts within sub-sectors of the Thames (TH) area during 2004/05 (dti, 2006) which include the Suffolk coast, along with the peak day count from Thorpeness (TN) during the same period. 15


Suffolk Birci Report 2008 Table 4. Seasonal counts from Thames sub-sectors and peak day counts from Thorpeness. TH data from dtl 2004/05 data. Period Oct 23rd - Nov 2Ist Nov 22nd - Dec 31 st Jan l s t - F e b 9th

TH sub-sector

Estimate

TH5 TH4 TH5 TH4

642 1,779 840 1,167

Confidence Limits Lower Upper 476 807 2,374 1,068 552 1,279 510 1,716

TN peak day count 476 2,137 1,393

Geographically, TH5 is approximately Gorleston to Dunwich and TH4 is approximately Dunwich to Harwich. A key factor in these variations is likely to be the seasonal variation and mobility of fish stocks (dti, 2006). Herring and Sprat are likely to be the most important prey items of wintering divers (Dare 1997). The North Sea stock of herring is dominated by autumn spawners (Cefas, 2008) of which there are three groups: the Buchan group (Orkney, Shetland and east coast of Scotland), the Banks or Central North Sea group and the Downs Group (Southern Bight and east English Channel). The Downs group arrive on spawning grounds between November and February. Larvae then drift with plankton to arrive at nursery grounds. The most important nursery grounds are in the eastern North Sea (i.e the Wadden Sea offshore area) but significant nursery areas are also found in the Greater Thames and Wash areas. Herring stocks are considered to be weak with ail recruitment classes since 2001 the weakest since the late 1970's. This weak recruitment is thought to be linked to climate change (C Darby, pers.comm.). Sprat is most abundant in the shallow waters of the southern North Sea, including the Greater Thames area (International Council for the Exploration of the Sea - ICES). The most important Sprat spawning areas are the inner German Bight and the English east coast (ICES). Sprat is sustained by the zooplankton community, which is known to be decreasing in the northern North Sea, but as yet, not in the southern North Sea (Fishery Resources Monitoring System, 2006). Sprats move into the waters off Suffolk to North Kent during November to February (Dare and Read, 2005). Being a short lived species, Sprat biomass present in a given winter is obviously dependant on recruitment for that year. Over the last 10 years it has been relatively stable although recruitment in 2004 was well above average and in 2006 it was well below (Fishery Resources Monitoring System, 2006). This may explain the high diver movement rates in the winter of 2004/05 and the low rate in 2006/07. However, the recorded decline of Herring, Sandeel and Norway Pout in the North Sea may increase the fishing pressure on Sprat (Fishery Resource Monitoring System, 2006), with consÊquences for wintering divers. At present though, Sprat is a minor species for fisheries in Suffolk waters (C Darby, pers. comm. ). A co-ordinated study of Herring and Sprat biomass and diver abundance would be of great value. These variations make it difficult to give a wintering population estimate for Suffolk. The Covehithe study gives an estimate of 500-1,500 divers (Dare, 1998), while the Thorpeness data suggests a range of 800-3000 divers. A review of the Kessingland data (P Read, pers. comm.) gives a range of 200-1300 divers (but note also comments on diver distribution given below). However, in the recent revised estimate of numbers of wintering Red-throated Divers (O'Brien et al., 2008), the mean population estimâtes (2001 to 2006) for survey blocks TH4 and TH5 is 687 and 702 respectively. Land based counts to date at Kessingland, Covehithe and Thorpeness would all suggest these are underestimates. Clearly, further work is needed to substantiate the size of the Suffolk's wintering diver population. A discrepancy of aerial counts compared to land counts was also noted at Holme Bird Observatory, with land based counts also higher (Cooke, pers. comm.). 16


Wintering Red-throated Divers, Thorpeness, Suffolk,

2000/01-2008/09

(b) Diver movements There are a number of potential factors which could be the cause of the observed diver movements off Thorpeness : (1) Passage birds i.e. birds flying south to southerly wintering grounds and the return passage north. It is possible some of the movements observed during November and February may relate to passage; however, movements during these months did not differ in character from those observed in December/January so passage movements could not be 'filtered' out. (2) Returning birds displaced by adverse weather or birds moving ahead of adverse weather. (3) Birds flying to and from favoured nighttime raft areas. During the study period there was no evidence of birds flying from a nighttime raft area at dawn and returning at dusk. (4) Birds flying to favoured feeding locations or in response to the discovery of shoals of fish [fidai activity may especially cause periodic concentration of food resources (Mclntyre, 1978)]. (5) Birds compensating for fidai drift - away from feeding sites. (6) Birds displaced by disturbance. This was observed on an occasionai basis with disturbance caused by fishing boats/motor yachts or close container ships and involved flights of up to 300 divers. Similar disturbance is also noted at Covehithe and Kessingland (Dare and Read, pers. comm.). Although the tidal drift analysis presented above is quite basic and also possibly subjective in its selection of movements to include and exclude, it would appear that tidal drift can explain some of the movements observed from Thorpeness 2 . Such drift is also noted in Common Scoter (Brown & Grice, 2005). Dare (1996) cites various studies where early morning movements are considered to be compensating for tidal drift. Divers are most likely to drift during the night. In addition, some studies on Great Northern Diver (Mclntyre, 1978 and Ford and Gieg, 1992) showed that divers spend about 50% of daylight hours in maintenance, sleeping and drifting when they would also be likely affected by currents. Even when feeding, divers will be subject to drift unless they consistently dive and swim into the current. However, many movements remain difficult to interpret. It is likely that some involve birds moving between feeding locations, perhaps from favoured rafting areas far offshore (Brown & Grice, 2005) or ^ birds moving inshore due to foui weather conditions. Certainly, the Thames aerial surveys have shown divers present up to 40km offshore and in deeper waters than previously recognized. The Wadden Sea surveys have shown divers present offshore out to a f f i ' ' s'u^Gixj^ the 26 meter depth contour (Laursen and Essink, 2005). Such inshore/offshore movements are also noted among other seabirds, e.g. Kittiwake (Dare, pers. comm.). In an East Anglian context, a new initiative is the setting up of a network of sea watch sites which should in time provide valuable data with regards to diver movements 3 . As well as birds moving inshore, it is also probable that influxes from both the Greater Wash Area (geographically from the East Yorkshire coast south of Flamborough Head to the Norfolk/Suffolk border) and near continent (Belgium and French coasts), and perhaps even 17


Suffolk Birci Report 2008 the Wadden Sea offshore area (Denmark, Netherlands and German coasts), may play a part during periods of inclement weather. The huge movement of 3995 divers flying north and 715 south on January 4th, 2004 has already been described as probably relating to weather conditions. A similar movement of divers was noted off Covehithe on January 23rd 1994, when 2724 flew south between 09:30 to noon including puises of 515, 569 and 462 divers in ten minute periods. This was also interpreted as a weather induced movement in response to westerly gale/severe gale winds off the east coast north of The Wash (Dare. 1998). The link between wind direction and flight direction (Table 2) may play a part in diver movements at Thorpeness or it may just be an illusionary link; wind with a southerly direction element is the most frequent (52% of days) and divers correcting for northerly tidal drift. Although movements can often be related to the state of the tide, some of the movements flying into the wind are probably in response to rough weather. (c) Diver distribution The peak monthly counts from Thorpeness (2000/01-2007/08) seem to be consistently higher than those from the Covehithe study of 1994-96 (Dare, 1998) and from Kessingland (P Read, pers.com. ) which, if anything, is watched more intensively than Thorpeness. This may suggest that the bulk of wintering divers in Suffolk often occur from Sole Bay southwards to Orfordness. This may also explain the prĂŠdominance of southerly flights off Thorpeness - birds correcting for northerly tidal drift by flying back south 'to where they want to be'. The 2004/05 aerial survey (dti 2006) also seemed to show a higher density of divers south from Thorpeness to Orfordness than to the north of Thorpeness. As already noted, it is difficult to directly compare data from Kessingland with Thorpeness and during the study period, watch times for movements of over 100 divers coincided on only four occasions (Table 5). Table 5. Comparison of counts from Thorpeness (Th) and Kessingland (Ke). Date 04.01.04 30.11.04 01.12.04 12.01.08

Start time 07:30 09:40 07:15 07:35 07:20 07:30 07:55 08:55

End time 15:15 12:10 08:45 08:15 08:25 08:15 11:25 10:25

Th Ke Th Ke Th Ke Th Ke

North 3,995 1,499 75 40 2 8 57 213

South 715 89 1,208 100 1,254 102 2,416 2

Both the movements on November 30th and December 1 st 2004 at Thorpeness were interpreted as compensating for tidal drift, and the fact that virtually no south bound divers were recorded at Kessingland would seem to support this view on local diver distribution (at least for 2004). The huge movement on January 4th 2004 is interpreted as a weather-induced long shore movement and hence was also noted off Kessingland. The movement on January 12th 2008 was similarly interpreted at Thorpeness as a long shore weather movement (peaks of 250 divers from 08:30-09:00, c.990 from 09:10-09:30 and c.600 from 10:10-10:25) compensating for strong Southerly winds on January 11 th, but was not reflected at Kessingland. With a low tide time of 07:07 hrs (Minsmere Sluice), perhaps the state of the tide influenced this movement? (d) Divers and wind farms Recent aerial surveys were undertaken to assess the risk impact on seabirds of proposed offshore wind farms within the Southern North Sea. The main identified risks of wind farms 18


Wintering Red-throated Divers, Thorpeness, Suffolk,

2000/01-2008/09

to divers (and seabirds in general) are direct collision with the rotor blades or tower (especially during the night or periods of poor visibility) and avoidance of wind farm areas resulting in reduced areas for resting or foraging (Stienen et al., 2007). Currently, five developments have been approved for the Greater Thames Estuary: Thanet, London Array, Gunfleet Sands TWA, Gunfleet Sands II and Greater Gabbard (BWEA - British Wind Energy Association). The Greater Gabbard development is to be 23 km from the Suffolk coast covering 150 km 2 (Contractors Unlimited). Expected completion is 2010/11 when it will be the largest offshore wind farm in the world (Guardian Oct 2008). However, potentially larger is The London Array, currently the world's largest proposed offshore wind farm with a potential of 341 turbines spread over 245 km 2 . Because the aerial surveys revealed the presence of large numbers of wintering Red-throated Divers, the London Array will be limited initially to a first phase of 175 turbines to assess the impact on wintering divers (Guardian, Dec 2006). This first phase is expected to be completed in 2012 (Times, Oct 2008). (e) Proposed Outer Thames Estuary Special Protection Area (SPA) Natural England is currently progressing the Outer Thames Estuary as a potential SPA, with the qualification being that it regularly supports more than 1% of the British Population of wintering Red-throated Divers. The total area will be 393,734 ha and off the Suffolk Coast will extend out to the 12 nautical mile zone. Natural England identify the main risks to divers as being displacement due to disturbance from wind farm sites, entanglement in static fishing gear and impacts on prey species due to dredging and dumping activities. Consents for such activities would be subject to appropriate assessment and control under SPA provisions. Thus it is vital to carry on collecting data on wintering divers. As well as countbased studies such as the aerial surveys and land-based counts, it would also be useful to collect data, from along the entire Suffolk coast, on bird behavior during the day (feeding, maintenance, drifting) in relation to location and tidal /weather conditions. Only if we fully understand how birds are utilizing the Thames Estuary can we hope to assess the impact wind farms and other activities may or may not have on wintering divers. Notes 1. This estimate is derived from compiling data from UK nearshore marine areas (aerial surveys, county bird records and Wetland Bird Survey counts (O'Brien et al., 2008). For each site only one data source was used in the following order of preference: aerial surveys, county bird records and Wetland Bird Survey counts. Only counts during January and February were used when diver numbers are at their peak. 2. Since June 2005, Norfolk Ornithologists Association at Holme began to collect systematic records of birds seen from the shore (Cooke, 2006). It is planned to establish a net work of seawatch sites so that results could be compared. To date four sites are contributing data: Holme NOA and Weybourne in Norfolk and Kessingland and Thorpeness in Suffolk. It is hoped that coordinated data collection from the network of sea watch sites will allow for a similar or more rigorous analysis at this and the other sites in the future (Cooke, pers. comm.). 3. The network of seawatch sites should over time provide a valuable data set of seabird movements off the East Anglian coast. With regard to divers, so far the data confirm that divers are more abundant at the most southern site of the network (i.e. Thorpeness). The highest count recorded at Holme was 459 on January 12th 1997 while the highest count recorded off Norfolk is 820 past Sheringham on January 29th 1992 (NOA Annual Report, 2006). Also of interest was a marked increase in diver abundance off Holme in the winter of 2006/07 - with a sudden increase in the final week of 2006 and peaking in the first ten days of 2007 (Cooke, 2008). Rates per hour in ten-day periods reached just over 100 compared to a typical rate of around five per hour. Other seabirds at Holme also showed a marked increase in numbers during the 19


Suffolk Birci Report 2008 same period (Cormorants, large Auks, Kittiwakes and Little Gulls). This sudden and atypical influx was interpreted as a concentration of seabirds in response to a sudden and large increase in food items. It is interesting to note that during the same period, diver abundance at Thorpeness was unusually low while at Kessingland the abundance was consistent with previous years (Cooke, 2008). Acknowledgements I am indebted to Dr. Peter Dare, Professor Fred Cooke and Paul Read for comments on the manuscript and also to the last for providing data relating to Red-throated Diver movements off Kessingland. I would also like to thank Chris Darby (Cefas) for information on Herring and Sprats. However, any errors in the presentation of data and incorrect conclusions drawn from any such inaccuracies are mine and mine alone. References O'Brien, S.H.; Wilson, L.; Webb, A.; Cranswick, P.A. 2008. Revised estimate ofnumbers of wintering Red-throated Divers Gavia stellata in Great Britain. Bird Study, vol 55 No. 2, July 2008. British Trust for Ornithology. Brown, A. and Grice, P., 2005. Birds in England. T & A D Poyser. Cawston, J.M. and Ling, S„ 1988. Seabirds andSeawatching in Suffolk 1987. Suffolk Birds 37. Centre for Environment, Fisheries & Aquaculture Science (Cefas). 2008. Herring in the North Sea (ICES Division IV, Vlld and lila). Cooke, F., 2006. Seawatching at Holme Bird Observatory 2005. Norfolk Ornithologists' Association Report 2005. Cooke, F., 2008. Seawatching at Holme Bird Observatory 2007. Norfolk Ornithologists Association Report 2007. Dare, P.J., 1998. Movements and Abundance of divers off Covehithe, Suffolk, 1994-96. Suffolk Birds 46. Dare, P.J. and Read, P, 2005. Pomarine Skuas over-wintering off the Suffolk Coast 19932005. Suffolk Birds. Dti, May 2006. Aerial surveys of waterbirds in Strategie wind farm areas: 2004/05 Final Report. Fishery Resources Monitoring System. Marine Resource Fact Sheet, Sprats - North Sea, 2006. Ford, T.B. and Gieg, J.A., 1992. Wintering behavior of the Common Loon. Journal of Field Ornithology (page numbers 22-29) vol 66 no. 1. Hagemeijer, W.M. and Blair, M.J., 1997. The EBCC Atlas of European Breeding Birds. T & A D Poyser. Hemmingsson, E., 2002. Ringing of Red-throated Diver Gavia stellata Black-throated Diver Gaviaarctica in Sweden. Newsletter, Diver/Loon Specialist Group, Wetlands International, vol.4. Natural England. New Marine Natura 2000 sites - Special Areas of Conservation and Special Protection Areas, www.naturalengland.org.uk Mclntyre, J., 1976. Wintering Behavior of Common Loons. Dept of Biology, Syracuse University, Syracuse, New York. Pye, K. and Blott, S.J., May 2006. Coastal processes and Morphological Change in the Dunwich-Sizewell Area, Suffolk, UK. Journal of Coastal Research. Snow, D.W. and Perrins, C.M., 1998. The Birds of the Western Palearctic. Concise Edition. Oxford University Press. Stienen, E.W.M.; Van Waegenberge,J.; Kuijken, E.; Seys, J., 2007. Trapped within the Southern North Sea; the potential impact of offshore windfarms on Seabirds. In de 20


Wintering Red-throated

Divers, Thorpeness, Suffolk,

Lucas, M et al. (Ed) 2007. BĂŹrds and windfarms: pp. 71-80.

2000/01-2008/09

risk assessment

and

mitigation.

Website and internet references BWEA - UKWED offshore wind farms. www.bwea.com. BTO. Webs2005/05 report. www.bto.org. Contractors Unlimited - news. Greater Gabbard Wind Farm. www.contractorsunlimited.co.uk. Guardian. Worlds biggest offshore wind farm approved for Thames estuary. www.gaurdian.co.uk. Guardian. UK to boost wind power generation by a third. www.gaurdian.co.uk ICES - Fishmap. www.ices.dk/marineworld/fishmap Laursen, K. and Essink, K. Offshore Area (page numbers 265-271). www.waddensea-secretariat.org. Times. Abu Dhabi buys 20per cent of London Array. Times Online UK SPAR Scientific Working Group. Meeting 2005/03, 5th October 2005. Approved Minutes, www.freemap.jp

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2008

North Warren & Aldringham Walks Nature Reserve 2008 Rob Macklin - RSPB Suffolk CoastArea Manager Habitat management notes by Dave Thurlow Introduction The reserve lies on the Suffolk Coast between the town of Aldeburgh and the village of Sizewell with its accompanying nuclear power station. There is a continuity of semi-natural habitats from Aldeburgh, through Sizewell Belts and marshes, across the Minsmere levels and Minsmere itself, Dunwich Heath and forest and through to Walberswick. This is what makes this area of the Suffolk Coast one of the best areas for wildlife in the UK, and the North Warren and Aldringham Walks complex is no exception. North Warren itself became the second RSPB reserve in the UK after a large part of the heath was acquired in 1939. At that time breeding birds included an impressive list of rare species, particularly Bittern, Marsh Harrier, Montagu's Harrier, Stone-curlew, Woodlark and Red-backed Shrike. The main reedbed and fen was purchased from the Sizewell Estate in 1972 followed by Church Farm Marshes in 1990. In 1997 a management agreement with Sizewell Estate brought another 177 hectares of land under conservation management and the reserve to its current size of 443 hectares. January to March The lower levels of the grazing marshes are shallow-flooded in winter, usually from midNovember to mid-March, which in turn attracts a whole range of wildfowl and waders. These marshes are a well known winter haunt of grey geese, particularly White-fronted Geese and Tundra Bean Geese, and monthly numbers of White-fronts peaked at 444 on January 26th, 350 on February 16th and 293 on March 9th. Tundra Bean Geese were much thinner on the ground, although five birds on January Ist increased to a regular flock of eight from January 20th to February 16th. A flock of ten Pink-footed Geese on January 2nd was somewhat unusual for this site. Large numbers of feral geese continued to use the reserve, particularly Greylag and Canada Geese, and these were joined by 160 Barnacle Geese on January 26th and a Redbreasted Goose on January 6th and March 9th. Duck numbers ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ peaked and

is bound to attract the attention of predators and 2008 brought an

Great White Egret Su Gough 22


North Warren <S Aldringham

Walks Nature Reserve 2008

immature Peregrine on January 13 th, two Merlins in January and an amazing peak roost count of 25 Marsh Harriers on January 12th. The main reedbed provided a tremendous winter spectacle with up to 30000 Starlings roosting here and attracting the attention of the resident Sparrowhawks as well as the Marsh Harriers. The marshes and reedbeds also hosted up to 12 Little Egrets and a Great White Egret, which also often turned up in full view on Thorpeness Meare. Wintering finches and buntings continued to be a feature of the area with new horse paddocks backing on to the south marshes attracting 40 Linnets on January 9th, 150 Chaffinches, 50 Greenfinches and 100 Goldfinches on February 2nd, then 25 Yellowhammers on February 16th. Management of the reedbed is a winter priority and in 2008 just under a hectare of reed was cut using brushcutters. This was then raked off the site; such management prevents scrub encroachment into the reedbed and prevents a litter layer from building up. In order to maintain open water within the reedbed a floating reed cutter (Truxor) was used to cut 1517 metres of dykes with the cuttings removed by the machine to the adjacent spoil banks. Grass Snakes have been observed using these piles of cut reed. This work ensures that the ditches remain open throughout the breeding season allowing fish to thrive and move freely around the reedbed - essential for feeding bitterns! Mid- to-late March brought in the first of the early migrants beginning with two Chiffchaffs on 14th, a very early Yellow Wagtail along the beach on March 24th and then a Firecrest, Black Redstart and four White Wagtails on March 30th. The last day of March turned up three more White Wagtails on the marshes, 3 Wheatears on the beach, a singing Sedge Warbler on the edge of the grazing marsh and three Willow Warblers at the "migrant mecca" of Thorpeness Common.

April to June In the mid-to-late 1990s the 20 hectare reedbed at the reserve underwent a radical transformation. The entire area was cleared of invasive scrub and lowered by 30cms with the resulting spoil used to make a bund around the edge. Sluices were installed which allowed water levels to be controlled. The results were immediate. Bitterns soon colonised the site and in 2008 up to four booming males were recorded although one of these subsequently moved on. Two nests were found and at least one of these was successful. They shared the

Cetti's Warbler 50/

4

15l 10r 5 n

0=1

2002 2003 2004 2005 2006 2007 2008 Year Cetti's Warbler 2002-2008 23


Suffolk Birci Report

2008

reedbed with two male and three female Marsh Harriers although two nests only managed to rear two young. The reedbed was kept very wet throughout the breeding season providing ideal conditions for Little Grebes, Reed Warblers, Sedge Warblers and Reed Buntings. Another species to colonise the reedbed and the edge of the marshes was Cetti's Warbler with 38 territories located, an astonishing fact considering there were none as recently as 2002. Migrants continued to trickle in throughout early Aprii including a Common Buzzard on Aprii 3rd and eight Sand Martins and five Swallows on Aprii 5th. Mid-April onwards saw a flood of summer visitors arriving with an early Nightingale and Common Whitethroat on Aprii 15th, three Firecrests on Aprii 23rd, two Cuckoos on Aprii 26th, Turtle Dove on Aprii 29th and a Ring Ouzel on Aprii 30th. Raptors were much in evidence throughout the spring with six Hobbies over the reedbed on Aprii 28th increasing to at least 20 on May 1 Oth, hawking for dragonflies and particularly St Mark's Flies! An Osprey flew south on May lst, both Red Kite and Buzzard were over the reedbed on May 23rd and a Montagu's Harrier flew through on June lOth. The Great White Egret remained on the reserve until Aprii 12th and four Egyptian Geese on the marshes on May 23rd were unusual. A Red-backed Shrike on May 28th was the only spring record and hints of an irruption carne with 10 Crossbills in the birch woods on June 20th. North Warren and Aldringham Walks can probably claim to have as much scrub as any reserve in the UK and this is borne out by the amazing number of breeding warblers that the site attracts. In 2008 some 224 pairs of Common Whitethroats, 128 pairs of Garden Warblers, 117 pairs of Blackcaps, 170 pairs of Chiffchaffs and 60 pairs of Willow Warblers were found breeding on the site. Lesser Whitethroat numbers were on the low side at just 23 pairs, while the reedbed and reed-fringed dykes attracted 102 pairs of Sedge Warblers and 101 pairs of Reed Warblers. Perhaps the reserve's greatest claim to fame is the number of breeding Nightingales, at 39 pairs in 2008, one of the highest densities in the UK. Nightingale

2000 20012002 2003 2004 2005 20062007 2008 Year

Nightingale 2000-2008 July to September July and August are notoriously quiet months here but 2008 was enlivened by a Spoonbill on south marsh on July 26th, a Short-eared Owl over north marsh on August 12th and a smattering of waders moving through. As the summer moved into early autumn many more migrants began passing through, perhaps the most spectacular being the raptors including three Honey Buzzards moving south-east, an Osprey flying south on September 13th, 24


North Warren & Aldringham

Walks Nature Reserve 2008

single Buzzards on September 19th and 20th and a Merlin over Thorpeness Common on September 7th. Out on the marshes a Great White Egret dropped in briefly on September 21 st, two Greenshanks on September 11th, a Wood Sandpiper from September 10th to 20th and 105 Ringed Plovers moving between the marshes and the beach on September 19th. The last Common Swift went through on September 15th, a Wryneck was in the sluice bushes, but elusive, on September 20th and small passerines included six Whinchats on September 11th, three Yellow Wagtails and four Redstarts on September 15th, 13 Wheatears on September 19th, occasional Pied Flycatchers, a Wood Warbler in the sluice bushes on September 20th and three Tree Pipits at Thorpeness Common on September 21 st. Siskins also began to move through the area in force with 300 over Thorpeness Common on September 20th and 100 north on September 21st. October to December In October and November the last of the grass cutting or "topping" is carried out on the marshes and the last of the 100 or so cattle are taken back to their winter quarters. At this time the marshes are looking superb, ready for the arrival of wintering wildfowl and also ready for next year's breeding season, principally for Lapwings and Redshanks. The boards at the main sluice are raised, water levels rise and the birds flock in. A Whooper Swan on October 27th was an unexpectedly early arrival although a few days later, on October 30th, a minimum of 420 Brent Geese and 14 Goldeneye flew south offshore. Geese on the marshes built up to 226 Canada Geese on October 14th, 251 Greylag Geese on November 2nd and these were joined by 59 White-fronted Geese on November 16th. Barnacle Goose numbers peaked at 250 on December 20th and this flock was joined by the "suspect" Red-breasted Goose on several occasions from November 16th. Duck numbers were slow to build up, but peaked at 1280 Wigeon, 178 Gadwall, 500 Teal and 80 Pintail on the WeBS count on December 14th while Shoveler numbers reached a respectable 202 on December 24th. Migrants were still moving through well into October with Thorpeness Common again proving the main attraction. A Yellow-browed Warbler was tracked down on October 24th, followed by a Ring Ouzel on October 26th and a Firecrest on October 31st, with two there on November 2nd. A flock of 10 Common Crossbills was found on the Warren on November

Woodlark

2000 2002 2002 2003 2004 2005 20062007 2008 Year Woodlarks 2000-2008 25


Suffolk Birci Report 2008 9th and disappointingly just one Snow Bunting was recorded on October 3 lst and December 2nd. In recent years numbers of Snow Buntings have declined dramatically and the regular flocks of 100 birds seem to be a thing of the past. Out on the heath both Exmoor and Dartmoor ponies were introduced to attempt to combat invasive scrub, particularly Birch. The heath at Aldringham Walks has now been entered into an Organic Higher Level Stewardship scheme which prevents us from carrying out any chemical control on scrub and bracken. The ponies were also used on the heath at the Warren, replacing Manx Loghtan sheep which suffered from frequent attacks by unruly dogs, resulting in three being killed in 2008. The outdoor pig units at Aldringham attracted large numbers of corvids with 254 Carrion Crows found there on December 21 st. These corvids spend a lot of time on the open heath where, coincidentally or not, Woodlark numbers have plummeted over the past ten years. The Suffolk Coast RSPB area team will continue to test new ideas on this site to get the habitats into the best possible condition. This approach should maintain this area as one of the top birding sites on the Suffolk Coast and in the UK.

26


Suffolk Birci Report

2008

The Black Kite in Suffolk 2008 Will Brame History Black Kites (Milvus migrans) are widespread globally with several races having been identified. They are predators and scavengers taking advantage of available food sources. They have a preference to be near water and are well known for scavenging fish. They appear to avoid damper and windier situations and, in northern Europe especially, avoid the sea and coastlines. In Suffolk, however, they are categorised as a rare passage migrant. Since the first record of Black Kite occurred in Suffolk in 1971 a further twenty-seven sightings have been reported up until the end of 2007. So Black Kites can be seen to be an irregular and rare wanderer to our county. Among those sightings just mentioned very few were of birds that remained within our boundaries for long with, normally, only the finders being able to enjoy them. So for most Suffolk birders a Black Kite was something seen abroad, often at close quarters, but rarely seen within their home county. 2008 Düring 2008 two individuáis that first frequented the Boyton/Butley/Gedgrave area between April 8th and 28th were warmly welcomed by Suffolk's birding fraternity. They gave most, if not all, visitors prolonged views of this much sought after and elegant raptor. There was an undoubted influx into the east of the country at the time. However, during their stay news was put out on the internet birding forums that prior to the Suffolk sightings ail four Black Kites held in captivity in the Zoological Society of London's Snowdon aviary in Regent's Park had escaped, when the cage was damaged in a storm, and were at large and were seen over Regent's Park at times. These escapees brought into doubt the origins of the birds seen in eastern England. SORC had to make a décision on both Black Kites reported to them assessing ali the evidence available including written descriptions, photographie evidence and information gleaned from correspondence with the Zoo and European experts. This took up two meetings! A brief summary appeared in "The Harrier" number 156. Bird 1 reported at Butley between April 8th and lOth was also seen in the north Suffolk areas of Ashby Dell, Herringfleet Marshes, Oulton and Castle Marshes on April 26th. This dark bird was typically mobile but did afford photographers the opportunity to capture images. Some of these, especially those by James Kennerley, clearly show ali the necessary features including the white lower scapulars enabling confirmation that the Boyton bird and that in the north of Suffolk were one and the same. Bird 2, seen on and off between April 9th and 28th, was a very bright individual strikingly différent from Bird 1. This gave food for thought to many of Suffolk's birders leading, at times, to some passionate debate. The body tones were very rufous with a pale grey head and rufous upperparts and a bright carpai bar giving rise to the question as to whether it could possibly be a hybrid. Some very impressive images captured by Sean Nixon shows this well. A photograph by Sean and one taken by James can be seen on the first page of plates opposite page 48. The hybrid theory was discounted after Brian Small forwarded Sean Nixon's photographs to Dick Forsman, the renowned raptor expert. Dick responded stating that this bird was a typical adult Black Kite and that the bright plumage and structure of the bird were in keeping with that species. When assessing these Black Kite records, therefore, the hardest décision for SORC was their provenance. Were they the real thing or the birds from London Zoo? Photographs of 27


Suffolk Birci Report 2008 the four from the Zoo showed that all were rather pale-headed and bright. They were of a Kite species. These individuals were, in fact, taken from the Cape Verde Islands to be part of a captive breeding programme to save the rare/near-extinct Cape Verde Kites, thought at the time to be a Red Kite subspecies. DNA testing, however, has shown that they were genetically closer to Black Kites. Evidence gathered by Peter Kennerley from the Zoological Society of London proves without doubt that Bird 1 did not originate from the Zoo as none of their four birds showed any distinguishing marks. On plumage dĂŠtails Bird 2 could have been one of the escapees but for photographie evidence. Sean Nixon's images show unequivocally that it had no rings on its tarsi. All of the London Zoological Society birds were ringed, three on both legs and one on one leg only. Based on ali the evidence before the committee both Black Kites were accepted by SORC as being wild birds and of natural origin.

28


Suffolk Birci Report 2008

Peregrine Falcon: Backing breeding at last Rod Plowman I first noted a Peregrine Falcon on the Power Station which used to stand on the opposite bank of the River Orwell to The Strand at Wherstead in 1988. Every year a Peregrine would come back, usually in September, and overwinter until the next spring. Having left no Peregrines would then be seen until the next autumn. But in 1991 the Power Station was demolished and the Peregrine took to roosting on one of three chimneys. These stood for about another four years until they too were blown up in November 1994. Over the next few years, one, or occasionally two, Peregrines overwintered in the area. By this time they had taken to roosting on the Orwell Bridge. In 1999 a nestbox was erected high up on one of the piers of the bridge, but it took until November 2004 before a Peregrine was seen sitting on top of the nest box. On a few occasions over the years I have seen Peregrines get caught up in the fine mesh netting around the top of the piers but always after a few minutes struggling they have managed to escape. One morning I arrived early at the bridge and saw a young Kestral which had fledged from a nest on one of the pillars caught up in the netting but it was not so lucky - it was dead! It was the winter of 2007 and two Peregrines were wintering on the Orwell Bridge but in spring they d i d n ĂŹ fly off. Instead they stayed around and displayed through the spring and info the early summer. Both birds were seen in and around the nestbox and actual mating was seen in the first two weeks of May 2007, sometimes on top of the nestbox or on one of the piers. No young birds appeared, however. The two Peregrines stayed ali winter and into the spring of 2008 when the birds were again seen displaying and mating on the nestbox. For the next few weeks lots of activity was seen around the box with birds coming and going in and out. It was now a case of keeping a daily watch to see if this year they had got their act together and were hopefully sitting on eggs. I arrived early at the Orwell Bridge on May 22nd 2008 to see three juveniles sitting on the edge of the nestbox flapping their wings. The two adult birds were sitting on the adjacent piers of the bridge calling continually to the youngsters to encourage them to take the plunge. Eventually one went and the adult birds joined the juvenile. For the next fifteen minutes the three birds flew around together with the adults calling frantically. I was also lucky enough to get some good d o s e up photos of the first bird to fledge as it sat for a while on the rocks on the sea wall under the bridge only a few metres away. [See front of June 2008 Harrier - editor], By mid-afternoon five birds were on the wing together. Next morning, May 23rd, the birds were flying around together when one of the juveniles crashed into the netting but luckily one of the adult birds realised one was missing so it took to flying around the pier calling loudly. This prompted the juvenile to have another go at freeing itself and after a struggle it did manage to escape. Over the next few weeks some amazing sights were seen as the adults brought in food for the juveniles, occasionally leaving it on the top of the nestbox or on one of the piers. After a week or two I was treated to some fantastic flying skills as the adults brought in food and the young birds took it from them in some amazing mid-air food passes.

29


Suffolk Birci Report 2008

Suffolk Turtle Dove Survey 2008 Steve Piotrowski Introduction There can be few birds that are thought of as so quintessentially English as the Turtle Dove (Streptopelia turtur). It has featured in poetry and folk songs as emblems of devoted love and utmost fidelity since Geoffrey Chaucer's day. It's beautiful soft and sustained purring was once a familiar sound of an English high summer, but it is now rarely heard around the villages and its loss is lamented by town and country dwellers alike throughout Suffolk. The Turtle Dove is Europe's only migratory dove, being one of the last summer arrivais, often not returning to its nesting habitat until June and departing again in September. These dainty little doves were once widely distributed throughout Suffolk, although the highest densities have always been reported on the coast and in The Brecks. Historically, the Turtle Dove was considered a common summer visitor, but it is now included in the Birds of Conservation Concern Red List, the UK population having fallen by over 68% between 1995 and 2007 (BTO Bird Facts), as shown in Figure 1. Figure 1: The population index of the Turtle Dove (with 95% confidence limits) 1965-2007

CBC/BBS UK 1966-2007 Turtle Dove 900 800 o 700 o TII 600 (O 500 Q O 400CM X 300 0) T3 200 c 1000 i 65

,

X

-_

'v

^ ^ --

. 70

i . . . i

\

--

% \ â&#x20AC;˘ \v-

1 1 1 1 1 1 1 I I 1 1 1 I 1 1 1 1 I 1 1 1 1 I 1 1 1 1 I 1 1 1 1 I 1 1 1 1 I

75

80

85

90

95

00

06

10

Year (Reproduced with permission from

www.bto.org/birdtrends2008/wcrturdo.shtml)

The reasons for such a steep decline are many. Drought and loss of forest and scrub in subSaharan Africa have reduced food sources in its wintering grounds. Since World War II, extensive use of herbicides and pesticides applied to arable crops and grassland has resulted in a massive rĂŠduction in weed seeds in its breeding areas. The grubbing up of tali, ancient hedgerows, which accelerated during the 1980s and early 1990s, reduced foraging and nesting opportunities. It is now one of Britain's farmland bird species thought most vulnerable to agricultural intensification and there are similarities in range contraction between the Turtle Dove and other seedeaters such as the Grey Partridge. The cooler, wetter summers experienced in Britain in recent years, possibly linked to climate change, have reduced breeding success. Work done by Stephen Browne, much of it in West Suffolk, has 30


Suffolk Turile Dove Survey 2008 shown that "in the 1960s each pair laid on average just under three clutches of eggs, and produced about two fledged young. In the 1990s this had decreased dramatically to about one and a half clutches per pair and just over one fledged young" (S. Browne 2003). On migration south each autumn, thousands of Turile Doves are shot as they cross the Mediterranean - over 100,000 are killed each autumn in Malta alone. Many thousands more are shot during the spring migration despite spring hunting having been outlawed throughout Europe since 1979, and in Malta since it joined the EU in 2004. Early Suffolk Bird Reports gave few indications of significant change in status and their abundance from the 1950s through to the mid-1970s was demonstrated by the huge premigration gatherings most often noted in early autumn. The highest counts for each of those decades were: 300 at Framlingham in August 1958, 500 at Staverton Park on May 31 st 1968 and about 360 at Levington in August 1975. Today, three-figure gatherings are non-existent. The Survey In 2008, Suffolk Wildlife Trust (SWT) and Suffolk Ornithologists' Group (SOG) instigated a countywide survey to try to establish how many Turtle Doves were returning to breed. The results of this survey were complemented by records from the first year's fieldwork for the BTO's Atlas Project. The quite simple survey methodology was promoted through thejournals of SWT (Suffolk Wildlife) and SOG (The Harrier). Détails were also posted on SWT's website. A press release was forwarded to media outlets to attract further interest. Those participating in BTO Atlas fieldwork were encouraged to submit their Turtle Dove records both to BTO and SWT. The survey was highlighted at the Suffolk Show and attendees to SWT's marquee were asked to pinpoint where and when they had seen and/or heard Turtle Doves in Suffolk by sticking an orange dot on a map of Suffolk mounted on a large display board. This display proved to be very popular, with 40 people pinpointing a total of 65 sites. Although a relatively small sample, it did show that the species was more than hanging on in Suffolk and was fairly well spread geographically. The Suffolk Show records were not used as part of the final analysis of the results. Figure 2: Records of Turtle Dove - summer 2008

+ BTO Bird Atlas

• swr/soG SWT/SOGandBTO Atlas

A TI 6

Jèx +

i ^ n r

T \ JJ > ,<++ •

31


Suffolk Birci Report 2008 Surveyors were asked to provide the date and exact location of where the birds were seen or heard including a six-figure Ordnance Survey grid reference. They were also asked to supply observations on feeding behaviour, food items as well as any post-breeding behaviour such as large gatherings. Results The Turtle Dove is one of Britain's favourite summer visitors and this is clearly seen from the surveyors' enthusiasm when reporting their sightings. The survey enlisted the help of 115 observers and Turtle Doves were found at 150 Suffolk sites (116 tetrads) with 232 individual birds being logged. A further 380 records were gleaned from the returns of the first summer of BTO Atlas work. A total of 17 undated records or those without an Ordnance Survey grid reference were omitted from the analysis. Figure 2 shows a large cluster of sites in north-central Suffolk extending almost unbroken through Framlingham and Woodbridge to the Felixstowe peninsula. There are also concentrations around Lavenham and Hadleigh and in the north-east in and around Halesworth extending north-westwards through The Saints. There is the predicted small concentration of records between Minsmere and Aldeburgh but, otherwise, records for the coast were unexpectedly sparse even though they would undoubtedly include passage migrants. Figure 3: Turtle Dove observation dates (first recorded date used for each site)

01-15Apr

16-30Apr 01-15May 16-31 May 01-15 June 16-30June 01-15July 16-31 July 01-15Aug 16-31 Aug

Date Figure 3 shows that the peak arrivals were between May 16th and June 30th.There were only 16 records in April, the earliest being at Fressingfield on 12th. There were surprisingly only three records for August and none for September. This is possibly due to many failed breeding adults already undertaking an early return to their West African wintering grounds and those that remained being silent and therefore less obvious at farmland localities? The behaviour notes included 56 references to "purring" birds and 33 to birds feeding under or close to bird feeding stations. Some observers encouraged birds to prolong their stay by scattering seed on the ground in selected areas. The range of food provided included: Sunflower hearts, Black Sunflower seeds, Niger seed and Wheat mix. On farms, most observations were made around the farmhouse, with surprisingly few reports of birds feeding in semi-natural farmland habitats such as grassland headlands and hedgerows. There were two observations of birds feeding around grain stores, although with less spilt grain and 32


Suffolk Turtle Dove Survey

2008

vermin-proof buildings, perhaps this is not too surprising. There were four référencés to birds picking up grit on the edges of roads. Although several observers noted birds sitting on téléphoné wires, there were no pre-migration gatherings reported, the largest flock being 11 at the British Sugar site at Bury St Edmunds. Only one nest was found. Discussion The Suffolk Turtle Dove survey has bucked the trend regarding coastal distribution compared to previous countywide surveys. Many single-species surveys show population concentrations on the coast in sites favoured by birdwatchers. Therefore, the lack of records in this area could well show a real contraction of range in the coastal région, Suffolk's former stronghold. There are many tali ancient hedgerows growing in central Suffolk and this may be why we have good population Clusters in that région. However, there are large gaps in south-west Suffolk, which is almost certainly due to a lack of coverage in that area. In retrospect, it would have been a valuable exercise to seek negative results as currently we are unable to distinguish between "no birds present" and "area not covered". There were no reports detailing breeding success, but 2008 will long be remembered as one of the wettest summers on record, which could explain the absence of such reports and the possible early exodus of Turtle Doves in August. The window for this survey was very small depicting a single, relatively poor breeding season. It will be interesting to see how the maps differ once we have four years of data available for the BTO Atlas. In conservation terms, it is difficult to conclude with certainty whether we are in a position to halt the rapid decline of this species as survival rates may be influenced by wintering conditions. However, the Turtle Dove in Britain would undoubtedly benefit from sympathetic management of hedgerows together with an increase in foraging habitats. There have been excellent advances in deploying new, tiered agri-environment schemes in Suffolk and such schemes may well hold the key to the species future in Britain. With the lack of suitable foraging areas, Turtle Doves may become increasingly reliant on bird feeding stations as was seen in this survey. However, they are far more timid than their close relative the Collared Dove and are reluctant to venture into urban environments. Therefore, its fate will be heavily influenced by the farming community. Acknowledgments The author acknowledges the contribution of the British Trust for Ornithology which has allowed the privileged use of Atlas data to Supplement records obtained from this survey. The BTO have also authorised the use of the trends graph, which was derived from data submitted as part of their Common Bird Census and Breeding Bird Survey projects. Mick Wright, as BTO Regional Représentative, has collected data and assisted with the processing. SWT/SOG's Turtle Dove survey got off to an excellent start due to sterling work by Celia Rhodes, who helped with the methodology and provided fact sheets, flyers and survey forms for potential participants. Oka Last has disseminated data on behalf of SWT and Margaret Regnault has completed data processing and cartographie work. Most of ali we must thank those members of SWT and SOG who completed the fieldwork and for submitting their survey returns. Thanks are due to Dorothy Casey, Celia Rhodes and Peter Lack for their comments on the draft.

33


Suffolk Birci Report 2008

Common Buzzards breedtng again in north-east Suffolk Peter J. Dare The Buzzard became extinct as a breeding species in Suffolk, and across much of England, towards the end of the 19th century as a resuit of intense persÊcution by game-rearing interests (Piotrowski 2003). Since about 1985, however, this raptor has been staging a dramatic recovery, spreading back rapidly eastwards from its West Country strongholds to recolonise many former haunts. A more enlightened attitude by landowners and gamekeepers towards this raptor has been an important factor in its recovery. Suffolk began to be resettled in 1999, after a lapse of 125 years, when a pair bred successfully in the west (Piotrowski 2003). This was the prelude to a rapid increase probably driven in part by further immigration from the west. By 2006 about 50 territorial pairs were reported in Suffolk of which about 25 pairs were confirmed as having bred (Gregory 2006). These were mostly in the Breckland and south-eastern districts. In north-east Suffolk breeding was apparently first confirmed in 2006 when I found pairs with young at two locations east of Beccles. One of the estate owners reported having seen birds in the previous year. The process of re-establishment in that area is being monitored by annual surveys. This note summarises the main features of this pioneering Buzzard population, and problems encountered, in the first three years of study, 2006-08. The rectangular survey area now covers 68 km 2 of arable farms, hedgerows with scattered mature trees, and substantial deciduous or mixed woodlands located between the valleys of the rivers Hundred and Blyth. In July 2006, after being alerted to the presence of Buzzards resident on two private estâtes in the northern part of this area, two pairs were observed there with newly-fledged young and one of their nests was discovered. A third pair appeared not to have young. In 2007, after field work was started in early spring, four Buzzard pairs were present in the same area, of which three bred successfully, and another pair (with old nest) was found nearer to the Blyth estuary. In 2008, when the survey was extended southwards to the Blyth valley, another three (possibly four) territorial pairs of Buzzards were discovered; giving an average density of approximately one pair per 8 km 2 . In 2008, six of the eight pairs bred successfully and fledged six (possibly 7) juveniles. For ail three years combined, the 11 known breeding attempts were ail successful. Two pairs apparently did not breed. Observed fledged brood sizes averaged 1.2 juveniles; only two pairs are known to have reared two. This average may be a slight under-estimate, however, as some youngsters might have been overlooked in dense cover. Thus, breeding performance overall is very encouraging - a high proportion of breeders and good success. For nesting, the Buzzards prefer woods that are least disturbed once the winter pheasantshooting season has finished. They also favour large, old and well-branched oak trees that are often close to rides and clearings, to enable easier access. Many woods that appear suitable from the outside were found to contain just a few old trees scattered among dense under-plantings of useless tali, slender ash or sycamore. Woods composed mainly of hornbeam likewise seem to be avoided. Of the six nests found, five were in old oaks and one in a part-grown non-native pine (Pinus sp.). Ail were placed on branches against the trunk or in a central fork some 40-50 ft above the ground and, being new, were quite small and inconspicuous. The 2008 field work to assess the wider population status began with the first fine weather in late February. This is when Buzzard pairs begin to soar and display above their combined hunting/breeding territories and (if necessary) to contest boundaries with neighbours. Frequent spells of sky-watching, from lanes and paths, eventually provided behavioural dues as to likely nesting woods. They also enabled me to detect itinÊrant Buzzards and small groups of passage birds that move through this part of Suffolk each year in March and Aprii 34


Common Buzzards breeding again in north-east

Suffolk

(Dare 2006). In March 2008, two or three 'new' pairs that appeared to be prospecting for territories moved on after a week or so. Searching for nests is left usually until June or July when any young will be well grown; partly to avoid disturbance during egg laying and early incubation in Aprii, but also because of access problems and the poor visibility up through dense tree foliage. Instead, evidence of breeding success has been obtained, around fledging time in late June and early July, by listening for the noisy hunger calls of juveniles. These can be audible from 400m. Parents become very dĂŠmonstrative at this time when one is in the vicinity of nests or fledged youngsters. Nests can then be more easily located from traces of 'whitewash' beneath. Few prey remains below nests have been found because the ground usually is smothered by rank herbage. In comparison with Buzzards in western counties, birds in this survey area are surprisingly unobtrusive, not only in winter but also for much of the breeding season. Territorial behaviour in spring seems to be less frequent and intense than that seen in western populations, perhaps reflecting the stili low density of recent settlers. Some pairs can range for 2 km from nests before encountering a neighbour. Hunting is done almost exclusively from perches in winter and is the prĂŠdominant method in other seasons. It is difficult to observe in Suffolk since birds are hidden in large trees, often across wide fields, and viewable only from roadsides and foot paths. A new type of hunting behaviour that I have seen repeatedly here in the breeding season involves hovering or hanging at great heights, perhaps of 100-150m, while facing into the breeze. Often such birds were detected only by chance. In hillier western country Buzzards often hover in the updrafts above windward slopes but at much lower levels. The extremely high hovering noted in my survey area would appear to be an adaptation which enables birds to scan the broad arable fields of the fiat Suffolk landscape. These early survey results thus show that Buzzards are re-establishing themselves rapidly in north-east Suffolk since the first pairs arrived, probably only four years ago. It is planned to continue monitoring this population each year and to extend the survey a short distance southwards from the Blyth valley where, despite a good distribution of woodlands, breeding Buzzards have not yet been reported. The hinterland to the west seems largely unsuitable. Acknowledgements My thanks to Colin Carter who first alerted me to the presence of possible breeding Buzzards in this area; to Derek Eaton for information about another pair; and to those estate owners who allowed me access to some woodlands. References Dare P J. (2006). Spring movements of Common Buzzards along the Suffolk coast. Suffolk Birds, 56: 27-38. Gregory C. (2006). The return of the Buzzard to Suffolk. Suffolk Birds, 56: 22-26. Piotrowski S. (2003). The Birds of Suffolk. Christopher Helm, London.

35


Suffolk Birci Report 2008

Tony Marshall 1918-2008 Derek Moore The words "He was a character and we won't see the likes of him again" is perhaps a bit over-used but certainly not in the case of Richard Vernon Antony Marshall. Many Suffolk birders will have at some time been confronted by Tony. To me he always seemed old - grey hair and moustache, dressed like a refugee from "Last of the Summer Wine" in old pvc coat, turned-over wellies and a cloth cap bought at the Oxfam shop in winter, and in summer often clutching his swimming gear as he returned from Minsmere beach. He was a familiar sight in Suffolk and to those he was not sure of recognizing he would use his stock phrase of "Do I know you?" delivered in a distinct toff's accent. Tony was the cousin of the late Arthur Marshall of the BBC's Call My Bluff and a man of the same ilk. Tony regularly roamed the Suffolk countryside even though he was a man of Essex and in particular Colchester. He once told me he was "The Black Sheep" of the family firm and this worked to his advantage as his colleagues bought him out so he could watch birds every day. Tony was very much an East Anglian. He had enormous knowledge about the region, its history, characters and most of all its good birding spots. He was especially knowledgeable about all the best places to get a cup of tea and where all the toilets were. He always knew the best places to go and thought trespassing was only meant for other people. Once when with him in the Brecks, he turned an aggressive gamekeeper into a simpering wreck after announcing, as only Tony could, that he was a personal friend of Lord Iveagh. He was a creature of great habit too. Each August he would be at the Harnser in Cley where he was pals with the late Richard Richardson and Liz Forster. In May it was the time to stay with Mrs Meredith in Rhayader in mid-Wales and of course by October he would be off to the Isles of Scilly where he stayed latterly at the Boathouse in St. Mary's. Tony was the only person to miss the Common Nighthawk in 1971 because he had to go for his tea - his reluctance to break his routine cost him dearly. Tony was also very much a Minsmere man and this is where we first met nearly 45 years ago. At that time Herbert Axell ruled in the manner of Robert Mugabe but Tony always managed to edge around him, and with his pal the late Kerry Cobb, was wicked in his humorous appraisal of the regime. It was Tony who nicknamed Joan Axell the "Rear Axell" alluding to her dominance over Herbert and it was Tony who pointed out quite correctly that she was the real power behind the throne. Tony loved scandal - 1 caught him eating his lunch on Dunwich cliffs once whilst reading the News of the World and puffing on his daily Woodbine. He took great joy in reading the scandalous articles. He was also an avid fan of The Archers and woe-betides anyone who called him between 7pm and 7.15pm. I met Graham Harvey, the natural history producer of the programme, once and he knew of Tony. Apparently the programme received regular letters from him pointing out when they had cocked up on the wildlife front. One letter in particular pointed out that Phil Archer could not have seen a Hen Harrier in Ambridge in July, so it must have been the much rarer Montagu's Harrier. He also loved counting birds and took part in many surveys. In fact he was a compulsive counter and once whilst birding was slow on the Isles of Scilly he took to counting breeds of dogs, and on another occasion I met him in Colchester where he told me he had been counting fat women and was currently on 17. Political incorrectness was one of Tony's great attributes. Tony was also generous in his efforts for nature conservation. He committed hours of effort at Fingeringhoe Wick Nature Reserve in Essex, scrub clearing and maintaining woodland habitat. He also donated funds for the building of the scrape there. 36


Tony Marshall

1918-2008

His humour and knowledge of many things made him a wonderful companion. He had a great appréciation of having fun whilst leading his life. Any who experienced "The Wall of Death" whilst driving with him around Abberton Reservoir will be reminded of his mirth at scaring the living daylights out of his passengers. He was a competent birder but in the old fashioned mode. He shunned a telescope until his latter years but did meticulously read journals like British Birds. Indeed he contributed many small notes and his Rooks somersaulting on wire describing the antics of these corvids on high tension wires near Colchester in 1960 is especially memorable. His sense of humour was wicked when discussing other birders. He was particularly scathing about anyone who took themselves too seriously. He affectionately gave many his own nicknames. Guess which Suffolk birder was "The Greasy Pole"? Once discussing the Mute Swans at Abberton Reservoir in the 1980's Tony pointed out the various pairs. "That pair over there are Joan & Bertie (the Axells)" he stated. "They are very belligerent and don't like contact with other swans". "Over there we have Kerry & Audrey (the Cobbs) and they sadly have been childless for many years. And finally that pair are Derek & Beryl and they have only just got the hang of breeding and they are not very good at it yet". Absolutely priceless! Tony was a child at heart - once I found him skateboarding with my children in the garden. He was also a fanatical gardener and once I discovered him in my garden pruning my shrubs. He scolded me for neglecting them. He considered wasting money a great sin. He never bought a colour TV set. I did not realize this until when I extolled the glory of a displaying Cock of the Rock on a David Attenborough programme whilst talking to him over the téléphoné. "What colour are they?" he retorted?" Once whilst on Berner's Heath in the Brecks Tony found a sleeveless pullover in Fair Isle style saturated on a barbed wire fence. He picked it up, put it in his bag and then washed it (I hope) and wore it for 30 years right up to his death. He of course always referred to the garment as "Berners". Tony never admitted to his âge but I always knew exactly how old he was. Once in The Isles of Scilly I noted Tony in the queue in the Post Olfice in Hugh Town. "Isn't it wonderful?" he shrieked "The Queen is paying me to go birding now". He was drawing his State Pension for the first time. He began to get very frail in his last years and many worried about him living on his own. He had become very deaf too. I called him shortly before he went into the Nursing Home. While we attempted to talk there was a noise in the background. "I'il have to go" barked Tony "The lady is here to see if 1 am dead yet". Even as things got more difficult he could stili see the fìinny side. Many will have seen Tony but few may have known him really well. He was a true character and maybe the last in our midst of his type. His presence wandering the East Anglian countryside will be sadly missed. He just missed his 90th birthday having spent the last couple of years in a Nursing Home where whilst comfortable he could not continue his routines. It was he who suggested to me years ago in a mirthful moment in a hide somewhere that there ought to be Nursing Home just for old birders. Here he suggested we could ali bore each other to death with tali stories until our time came. That was Tony ali over - able to laugh even about the ultimate journey.

37

Suffolk Birds 2008 Part 1  

Volume 58

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