C.J.R. Thorne, 12 February 2006

The Wicken Fen (Bird Ringing) Group has been in continuous operation for 38 years, having been established in 1968.  Since that year over 73,000 birds of 96 different species have been ringed at Wicken Fen; 375 of these have subsequently been reported away from the Fen (61 of them abroad). 

The Group, at 31 December 2005, numbered 35 members and 12 registered "friends"; the total of 47 represents another increase in membership, being the highest since 1979. This increased membership is reflected in another increase in activity at the Fen during the year.  Ringing operations were conducted on 120 days, involving 2940 member- (man- & woman-) hours.  Ringing sessions were held in every month, with the majority of sessions (70 out of 118) being carried out on St. Edmund's Fen (Compartments 30-34).  39 sessions were at the Reedbed (Compartments 51-53), while 9 were at North Field (Compartment 21).  

The 2005 ringing total was 2908 birds, of 44 different species.  These totals were an increase on the previous year, and in fact represented the highest total since 1984 .  In addition to the 2908 “new” birds in 2005, there were 2348 handlings of “retraps” (birds already bearing rings), 458 of them originally ringed in years earlier than 2005.  Several species topped the 100 mark, the highest scores being Greenfinch 777, Blue Tit 377, Great Tit 228, Reed Warbler 226, Blackcap 134,  Chaffinch 125, Wren 107, Chiffchaff 93, Robin 92, Blackbird 87, Long-tailed Tit 79 and Sedge Warbler 73.  The several unusual or noteworthy species ringed during the year were 3 Sparrowhawks, 1 Kestrel,  3 Woodpigeons, 1 Turtle Dove, 2 Collared Doves, 1 Cuckoo, 11 Kingfishers, 2 Green Woodpeckers, 18 Great spotted Woodpeckers, 6 Cetti’s Warblers, 1 Grasshopper Warbler, 2 Coal Tits, 3 Jays, 1 Brambling, 2 Linnets and 1 Redpoll.  These totals represent record numbers for several species – Great spotted Woodpecker (18 being almost double the previous record of 11), Greenfinch, Blue Tit, Great Tit, Chaffinch, Chiffchaff, Redwing and Fieldfare.  The Kingfisher total (11) is the highest since 1977; the Lesser Whitethroat (28) is the highest since 1987 and the Goldcrest (38) is the second highest ever.   The Greenfinches, Blue and Great Tits and Great spotted Woodpeckers were mainly caught at nut and seed bait suspended in suitable areas during the Winter.

The recent major change in the relative abundance of Willow Warblers and Chiffchaffs has continued to be seen at the Fen.  Ringing totals emphasise this: in 1997 Willow Warblers outnumbered Chiffchaffs in the ringing totals (117 to 72), in 2002 numbers were approximately equal (33 to 39), but in 2005 Willow Warblers were very much the minority species of the two (25 to 93).  But another warbler has recolonised the Fen – the six Cetti’s Warblers ringed in 2005 (the first for several years) being an adult female and five young birds.

The Group's nest-boxes were successful in 2005, 44 of the year’s Blue Tits and 52 of the year’s Great Tits being ringed as nestlings in the boxes.  These represented 6 and 8 broods of each species respectively.

The Group received notification of six Wicken-ringed birds being recovered away from the Fen during 2005; a Great Tit got to Norfolk, two Reed Warblers to Suffolk and three Greenfinches to Essex and Norfolk, all rather modest movements.  But during the year, Wicken Fen also welcomed several birds that had been ringed elsewhere – a Reed Warbler from Sussex, a Reed Bunting from Thetford, a Blue Tit from Mildenhall, a Blackcap from Humberside and a Greenfinch from Norfolk.  We also caught a Sedge Warbler wearing a French ring and a Blackbird a Dutch ring – but the foreign Ringing Schemes are slow at replying, so we have yet to learn the precise origin of these birds.

Some elderly birds were retrapped at the Fen during 2005 – a Robin and a Long-tailed Tit both 7 years and 6 months after ringing (these are each Wicken Fen longevity records), a Dunnock at 7 years 4 months (also a record), a Blue Tit at 6 years 8 months (equals the record), a Great Tit and a Chaffinch each at 6 years 0 months, a Blackbird at 5 years 8 months, a Bullfinch at 5 years 2 months, a Great spotted Woodpecker at 4 years 2 months (another record), a Sparrowhawk at 3 years 9 months and a Wren at 3 years 2 months.

During the winter of 2005-06, the Group organised the third successive quartet of “simultaneous site sessions”.  For these, 3 different areas of the Fen are baited with nuts and seed, and birds netted at each site at the same moments on 4 days in December and January.  By this means, we were able to show that Tits and Greenfinches can move both speedily and regularly around the Fen, with individual birds appearing at the different sites (which are between 0.8 and 1.7 km apart) within a short space of time on a single day, and regularly over longer periods.  In summer 2005 we also continued (for the 36^th successive year) our “standard sites sessions”.  These enable us to monitor the breeding population of birds at the Fen.  The Group also put on a “bird-ringing demonstration” for the public on 31 July 2005.

Various ornithological projects (leading to degree qualifications) in conjunction with the University of Cambridge, Anglia Ruskin University and other academic institutions, have been either initiated (a Tit nestbox comparison between Wicken Fen and the Cambridge Botanic Garden;  feeding ranges of Hen Harriers) or continued (breeding strategies of Reed Warblers).  Scientific papers have been published, using Ringing Group data (long-term catching statistics as a way of assessing bird populations; bird biometrics as a possible indication of medium-term climatic variation).

The Secretary has maintained his production of regular Bulletins (5 in year 2005), keeping Members and Friends informed, not only of ringing activities, but also of general bird observations at Wicken Fen.  He also produced monthly summaries of the Group’s activities, which are displayed in the Thorpe Building.   Anyone interested in joining the Group is welcome to contact him, Dr. Chris Thorne,  at St. Catharine’s College, Cambridge, CB2 1RL (phone 01954-210566, email cjrt@cam.ac.uk).