WICKEN FEN GROUP BULLETIN CCXXXIX JANUARY Secretary: Dr. C.J.R. Thorne, St. Catharine's College, phone

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1 WICKEN FEN GROUP BULLETIN CCXXXIX JANUARY 2016 Secretary: Dr. C.J.R. Thorne, St. Catharine's College, phone Cambridge CB2 1RL. 1. Ringing sessions, December 2015 January 2016 The last Bulletin covered WFG activities to December 6 th. There were a further 13 sessions in December, and 7 in early At the Piggeries there were sorties on December 10 th with a catch of 26 (10 new) including 3 Redwings, 2 Goldcrests and the Coal Tit and on December 12 th when the visit (in poor conditions, partly for the sake of a newbie who needed a lift, and partly to set nets for the next day) produced just 2 birds. The subsequent December 13 th session did deliver 41 birds (8 new) for the party of five ringers, but was tit-dominated (19 of the 41). Further Piggeries December visits were on the 16 th (44 birds, 8 new); 19 th (52 birds, 24 new, including a retrap Sparrowhawk); 20 th (20 birds, 9 new); 29 th (21 birds, 5 new) and 31 st (22 birds, 9 new). Redwings, in general, remained available, but the earlier immigrant Siskins, Goldcrests and Coal Tits had not been boosted further; and catches of those species were mainly retraps. Late December visits elsewhere were, on December 8 th to the Reedbed (catch of 28, including 15 Pied Wagtails and 3 Fieldfares); December 9 th to Gallops (catch of 24, 7 new, including 2 Goldcrests); December 15 th to Gallops (catch of only 5); December 18 th to the Reedbed (catch of 13, with 4 Pied Wagtails and 7 Starlings) and December 23 rd to Gallops (catch of 30, with 7 Redwings and a Siskin). All but one of the 7 visits in early 2016 have been to the Piggeries - on the 2 nd (catch of 10), on the 3 rd (catch of 32, 25 of them tits), on the 6 th (a large catch of 108 birds, with 53 Blue Tits, 8 Great Tits and 6 Long-tailed Tits), on the 9 th (catch of 15), on the 10 th (catch of 32) and on the 13 th (catch of 86, with 38 Blue Tits, 7 Great Tits and 5 Long-tailed Tits). The only non-piggeries 2016 session so far was to the Reedbed on January 6 th, when a lone Starling was apprehended. 2. Ringing totals for 2016 so far The ringing totals for 2016, to January 14 th, is 80 birds of 14 species. The breakdown is: Blue Tit 18 Goldfinch 3 House Sparrow 11 Long-tailed Tit 2 Chaffich 11 Redwing 2 Greenfinch 11 Dunnock 2 Reed Bunting 8 Bullfinch 2 Great Tit 4 Great spotted Woodpecker 1 Blackbird 4 Starling 1 3. Ringing totals for 2015 The final ringing total for 2015 was 3913 birds. The full details for this, and recent past, years, are: TOTAL Teal Mallard Heron Little Grebe Red-legged Partridge Marsh Harrier Sparrowhawk

2 Kestrel Hobby Water Rail Spotted Crake Moorhen Coot Ringed Plover Lapwing Jack Snipe Snipe Woodcock Redshank Green Sandpiper Black-headed Gull Common Tern Stock Dove Woodpigeon Collared Dove Turtle Dove Cuckoo Barn Owl Little Owl Tawny Owl Long-eared Owl Short-eared Owl Nightjar Swift Kingfisher Green Woodpecker Great spotted Woodpecker Lesser spotted Woodpecker Skylark Sand Martin Swallow (inc. hybrid) House Martin Tree Pipit Meadow Pipit Yellow Wagtail Pied/White Wagtail Wren Dunnock Robin Nightingale Redstart Whinchat Stonechat Wheatear Blackbird Fieldfare Song Thrush Redwing Mistle Thrush Cetti's Warbler Grasshopper Warbler Sedge Warbler Marsh Warbler Reed Warbler Great Reed Warbler Barred Warbler Lesser Whitethroat

3 Whitethroat Garden Warbler Blackcap Wood Warbler Chiffchaff Willow Warbler Goldcrest Firecrest Spotted Flycatcher Pied Flycatcher Bearded Tit Long-tailed Tit Blue Tit Great Tit Coal Tit Willow Tit Marsh Tit Nuthatch Tree Creeper Red-backed Shrike Jay Magpie Jackdaw Carrion Crow Starling House Sparrow Tree Sparrow Chaffinch Brambling Greenfinch Goldfinch Siskin Linnet Lesser Redpoll Mealy Redpoll Bullfinch Yellowhammer Reed Bunting Corn Bunting TOTAL SPECIES The 2015 ringing totals for Goldcrest, Siskin, Jackdaw and Coal Tit were all records for any one year. 4. Recoveries and controls Since the last Bulletin we have received 9 reports from the BTO of birds recovered or controlled: Blue Tit D ringed as pullus , WF Controlled , Kingfishers Bridge (2km N) Blue Tit D ringed as , WF Controlled , Kingfishers Bridge (2km N) Blue Tit Z ringed as , Thetford Controlled , WF (33km WSW)

4 Great Tit TS30264 ringed as pullus , WF Controlled , Kingfishers Bridge (2 km N) Great Tit Z ringed as 3F , WF Controlled , Kingfishers Bridge (2 km N) Reed Warbler Y ringed as 4F, , WF Controlled , Gosforth Park, Tyne and Wear (327 km NNW) Greenfinch TL11019 ringed as 5F , WF Controlled , Kingfishers Bridge (2 km N) Goldfinch Z ringed as 4, Sutterton, Lincs Controlled as 4F, WF (72km SSE) Reed Bunting D ringed as 3F WF Controlled as 4F Brook, Rutland (79km WNW) We are still awaiting news of Blackcap Madrid caught at Wicken on and Reed Warbler Brussels caught on ^^^^^^^^^^ Elderly (over 3 years old) retraps at the Fen since the last Bulletin have been: Dunnock L ringed , retrapped (4y 9m) Robin X ringed , retrapped (6y 5m) Robin X ringed , retrapped Robin Y ringed , retrapped Blue Tit X ringed , retrapped (5y 5m) Blue Tit X ringed , retrapped Blue Tit Y ringed , retrapped Blue Tit Y ringed , retrapped Blue Tit Y ringed , retrapped Great Tit L ringed , retrapped Great Tit TH47268 ringed , retrapped (6y 8m) Great Tit Y ringed , retrapped House Sparrow TK77864 ringed , retrapped (4y 4m) Chaffinch L ringed , retrapped Chaffinch X ringed , retrapped (6y 3m) Chaffinch Y ringed , retrapped Bird Observations, December 2015 January 2016 Greylag 258 on December 22 nd, 350 on December 27 th. Barnacle Goose 4 on December 26 th. Ross Goose In December. Shelduck between 2 and 7 at Burwell Fen in December. Wigeon 375 on December 22 nd ; 325 Burwell Fen on December 29 th. Gadwall 25 at Burwell Fen on December 29 th. Teal 155 on December 22 nd ; 269 on December 28 th. Mallard 220 on December 30 th. Shoveler 100 at Burwell Fen on December 19 th. Pintail On December 20 th. Tufted Duck 9 on December 22 nd. Goosander At Burwell Fen on December 9 th. Grey Partridge 18 at Burwell Fen on December 2 nd. Cormorant 29 on December 14 th. Bittern In December. Little Egret 2 on December 31 st.

5 Great White Heron One over on December 23 rd ; another on January 3 rd. Kite On December 19 th and 31 st. Hen Harrier At least 5 males and 2 ringtails in December; 4 males and 2 ringtails in January. Marsh Harrier 5 on December 12 th, 5 on January 2 nd. Buzzard 2 in December. Water Rail In December. Coot 63 on December 22 nd. Crane 16 over on December 16 th. Lapwing 1000 Burwell Fen on December 19 th. Golden Plover 1500 Burwell Fen on December 31 st. Black-tailed Godwit On December 9 th. Snipe 19 on December 1 st. Redshank On December 31 st. Woodpigeon Estimate of c3000 to roost on December 5 th. Short-eared Owl Maximum 4 at Burwell Fen in December; 2 in January. Peregrine On December 3 rd and (Burwell Fen) 11 th. 2 on January 8 th. Merlin Female on December 2 nd ; male on December 9 th and 18 th. One on December 26 th. Jackdaw c150 on December 14 th, perhaps 1000 on January 3 rd. Rook c500 on December 14 th. Carrion Crow 100+ on December 16 th ; c70 on December 18 th. Cetti s Warbler 4 in December. Starling estimate (?exaggerated) of Burwell Fen on December 19 th. Fieldfare 127 on December 16 th. Stonechat a pair on Tubney on December 31 st. Goldfinch c150 on December 2 nd ; 100+ on December 31 st Nesters report Carole Davies, in collaboration with others, has produced an excellent report. (Please note the year-on-year increase in the numbers of open nests found; reward for the ever-increasing skill and dedication of the nesters). Wicken Fen Nesting Group has been undertaking nest monitoring across the Fen since Most of the volunteers involved in nest finding and monitoring are also involved in the ringing activities of the group and, since nesting activity occurs at the busiest time for ringers (particularly with the Constant Effort Site monitoring now taking place at two sites across the Fen), the extra time for nest monitoring is limited. Nest recording is often time consuming, involving a number of regular visits to each nest location. For this reason, the nest monitoring is focussed on gaining a good set of data for a small range of species. The group would be pleased to welcome new members to the group who have an interest in the nesting activities of birds. After a fantastic nesting season in 2014 which combined a high productivity rate across all the species that were monitored with very low levels of predation, 2015 was a great disappointment, with poor productivity and high levels of predation. There was a substantial difference in the temperature in April and May across the two years which may have been the overriding factor in the differences in productivity. The average temperature in East Anglia in April 2015 was 9.2 degrees as compared to 10.7 degrees in 2014 and the average May temperatures were 11.6 degrees and 12.9 degrees respectively (as reported by the Met Office). The data collected by the nesting group is submitted to the BTO (British Trust for Ornithology). The BTO Nest Records Scheme monitors trends in breeding performance in order to identify species of birds which may be in decline due to problems at the nesting stage. These trends are updated each year and published in the BTO Birdtrends report which enables our data to be part of a wider picture ( Wicken Fen Group aims to ring as many of the pulli from successful nests as possible since the data from these birds are of high importance due to the fact that they are then birds of known age. The nesting activity across the Fen is divided into three sections with different members of the group taking the lead in each area. Small boxes Carole Davis and Hannah Ward There are more than 80 small nest boxes across the Fen, many of which are occupied by Blue Tits and Great Tits. These are sited mainly at St Edmunds Fen but with a small number also at Gallops and at the Reedbed pools. Carole Davis has been responsible for organising and monitoring the small nest boxes since There are also 26 small boxes at Anglesey Abbey which were monitored by Hannah Ward this year. Although the boxes at

6 Anglesey Abbey have been monitored in previous years, this was the first year that the pulli from the nests have been ringed. Large boxes Neil Larner and Chris Quy There are several large boxes spread at various locations across the Fen to encourage Barn Owls but which are also often used by Jackdaws and Stock Doves. As in previous years, Neil Larner and Chris Quy undertook most of the work on the large boxes which included a range of maintenance tasks prior to the breeding season as well as regular checks of the boxes during the breeding season. Open nests Ann Beeby and Carl Barimore The most difficult and time consuming challenge is the location of open nests of passerines. In 2015, the group again focussed on specific areas of the fen including parts of St Edmund s Fen and the short scrub at the far end of Monk s Lode. Carl Barimore (BTO Nest Records Organiser) and Ann Beeby spent many hours searching for, and monitoring, nests with the aim of providing complete nest records for each nest as well as ringing of the pulli if appropriate. Various members of the wider group assist with the ringing of the pulli which often need ringing at short notice. The group is developing a particular interest in finding and monitoring the nests of Chiffchaffs across St Edmunds Fen. Wicken Small Nest Box report 2015 As usual, this required some maintenance work to repair the boxes prior to the breeding season. Bernard Siddle helped with this work in the early part of the season. The nest boxes were emptied and repaired ready for the breeding season with weekly monitoring of the boxes carried out from early April until the last broods fledged. Of the 83 nests monitored, 50 reached egg laying stage, 23 Blue Tit nests and 27 Great Tit nests, producing 153 and 137 eggs respectively. As can be seen from Table 1 and Table 2, predation at the egg stage was high resulting in the loss of a substantial number of nests. Some nests were also lost at the pullus stage which is always more upsetting for the nest monitor, particularly with one set of nestlings which had been ringed and subsequently found to have died in the nest. We also had a couple of dead adults in nests, possibly due to a spell of very cold weather. In total, there were only six successful Blue Tit nests and five successful Great Tit nests across the Fen producing 44 fledged Blue Tits and 29 Great Tits. These results were mirrored in the preliminary report on the 2015 breeding season by the BTO which recorded productivity of Blue Tits (in terms of the number of fledglings produced), as -13.9% and of Great Tits as -15.6% as a percentage change relative to the five-year average ( Species Summary with Survival Rates Blue Tit E/P = survival rate from eggs to pulli; P/F = survival rate from pulli to fledged young; E/F = survival rate from egg to fledged young Year Nest Count Eggs Pulli Fledged E/P P/F E/F % 78.2% 45.3% % 89.4% 70.5% % 86.2% 69.6% % 61.1% 29.4% % 79.4% 50.0% % 98.2% 87.6% % 73.3% 28.8% Totals: % 84.7% 56.8% Species Summary with Survival Rates Great Tit Year Nest Count Eggs Pulli Fledged E/P P/F E/F % 100.0% 68.8% % 80.9% 48.4% % 78.0% 41.8% % 63.2% 22.5% % 73.7% 31.8% % 97.8% 78.0% % 60.4% 21.2% Totals: % 83.1% 45.1%

7 There were some interesting findings from nests which had been unsuccessful with birds moving from one nest to another. One nest had two separate female Great Tits on eggs at different times, both of which were predated. Presumably once a predator has located a nest, it may return at a later date. On another occasion, one Great Tit laid two eggs at the beginning of May, to be replaced by another Great Tit which then went on to have a successful brood. The general picture for Barn Owl productivity in East Anglia is that the ringing totals are 75% down on 2014 due to a crash in vole numbers ( It seems that, at Wicken Fen, productivity of Blue Tits and Great Tits which have nested in boxes mirrors to some extent that of Barn Owls. One hypothesis for this is that the tit boxes are predated by weasels when other prey such as voles is not available. Anglesey Abbey Nest Box report 2015 Seventeen of the twenty six boxes were used this year, six less than last year. Of the known outcomes, success was achieved by five out of eight Great Tits and by four Blue Tit nests out of ten boxes occupied. Last year it was five out of seven Great Tits and ten out of fifteen Blue Tit attempts. Sixty three chicks successfully fledged this year (84 in 2014) and for the first time these were ringed by the Wicken Fen Group. The intention has been to discover if birds considered sedentary do move from one site to another, but none has yet been recovered away from Anglesey Abbey. Wicken Big Nest Box report 2015 An additional Barn Owl box was erected early this year by the Badcock brothers, bringing the total monitored to nine. In contrast to the hugely successful 2014, when 21 young were ringed at Wicken Fen, this year has been reported as a disaster for Barn Owls, attributed to their main food source, field voles, being in very short supply. In the one successful Wicken box, three young were reared, possibly assisted by the neighbouring farmer supplying day old chicks to feed his owls. Only one other box showed sign of owl occupancy and that was by a single bird. Four Jackdaw boxes were erected in the outer barn on Burwell Fen in the hope of luring Jackdaws away from the owl boxes. This diversion was unsuccessful in that Jackdaws used the three Barn Owl locations in addition to two of the new boxes and two other locations. As a result, seventeen pulli were ringed, fourteen of these on the same evening which was double the 2014 total. Three Stock Dove nests were monitored, fledging five young, the same number and similar locations to last year. Common Terns on the raft at Pout Hall Corner produced three chicks for the third consecutive year. Open Nest report 2015 This year has seen a good range and number of open nests at Wicken, despite rather limited manpower for searching and checking. The spring was cool, but mostly dry with a few frosts in May. As usual, nests were found by searching and watching, often in combination. Nests were monitored to as high a standard as possible, with emphasis on establishing a definite outcome. We are grateful to several ringers for helping with pulli, as the totals show, and of course pulli ringed are valuable since they are of precisely known age and origin. Table 3 shows the total of nests recorded for each species from 2012 to 2015 including with ringing details for (These totals cannot be used as an estimate of the breeding population, since time spent and sites visited vary so much from year to year, but the figures are nonetheless interesting). The high number of Chiffchaff nests was in large part due to extra time and effort spent on this species, as part of the ongoing study of their breeding strategy on St Edmunds Fen. Early season nests were relatively easy to find, especially when the birds were building but, as the vegetation increased, the birds were frustratingly difficult to watch back to nests, or even to see if they were carrying food. This was despite lengthy periods watching on individual territories where a nest had already been monitored. Many early-season nests were notably prone to predation. This is not unexpected for blackbirds, where the early sites are very open. However, the high rate of predation of chiffchaffs at the laying stage or in early incubation meant that several of them built a replacement nest, and the knock-on effect from this was that there were very few true second-brood nests, probably only two pairs achieving 2 successful nests. It is difficult to assign blame for predation. Some nests were probably taken by Jays and other corvids, but it is tempting to blame weasels for most, since circumstantial evidence suggests the vole population was low, and these would normally be the weasels preferred prey. Five of the pulli ringed have already been re-trapped locally, four Chiffchaffs and one Willow Warbler. Three of the Chiffchaffs were from the same nest. It will be very interesting to hear whether CES (constant effort sites) figures show a productivity or recruitment that relates to the number of nests found. Wrens, for example, seem to have had a particularly successful nesting season.

8 Detailed records of all open nests monitored, with associated observations and other reports, are now stored in a Dropbox folder set up specifically for Wicken data. Another nest related activity this year has been a contribution to the development of a new section of the BTO s ringing website devoted to guidance on pullus ringing. Carole Davis, Alan Wadsworth and Ann Beeby have submitted information on Chiffchaff, Linnet & Bearded Tit to the BTO and we await further developments. The Group can now look forward to the nesting season of 2016, with various plans in an embryonic stage. Wicken Fen nests recorded, details for 2015 Mute Swan Mallard Pheasant Little Grebe Great crested Grebe Moorhen Coot Lapwing Woodpigeon Collared Dove Cuckoo one ringed in RW nest Great spotted Woodpecker Swallow pulli ringed in 3 nests Wren pulli ringed in a wide holed nest Dunnock Robin pulli ringed in 2 nests Blackbird Song Thrush Cetti s Warbler Sedge Warbler Reed Warbler Blackcap pulli ringed in one nest Whitethroat Chiffchaff pulli ringed in 8 nests Willow Warbler pulli ringed in 2 nests Bearded Tit Long-tailed Tit Chaffinch Goldfinch Linnet Bullfinch Yellowhammer Reed Bunting TOTALS Further CES 2015 data In the last Bulletin there was a simple summary of the 2015 St. Edmunds and Reedbed CES results. The St. Edmund s CES has only been running, in its present form (it replaced a venerable SSS system in 2014) for 2 years; while the Reedbed CES was in its fifth year in The latter has received a detailed analysis by Michael Holdsworth (this had been sent out earlier, but also forms an Appendix to this Bulletin). But a simple comparison for the two CES efforts might be of interest (the overall gain ^ or loss v symbols are the Secretary s conclusions - they have no statistical significance!).

9 St. Edmunds CES Adults Juvs Total Adults Juvs Total Great spotted Woodpecker Green Woodpecker Jay ^ Blue Tit v Great Tit v Cetti s Warbler Long-tailed Tit v Chiffchaff Willow Warbler Blackcap Garden Warbler Lesser Whitethroat Whitethroat Sedge Warbler ^ Reed Warbler ^ Tree Creeper Wren v Blackbird v Song Thrush Robin Dunnock Chaffinch Goldfinch Bullfinch ^ TOTALS Reedbed CES Adults Juvs Total Adults Juvs Total Sparrowhawk Woodpigeon Kingfisher Hobby Great spotted Woodpecker Carrion Crow Bearded Tit v Blue Tit v Great Tit v Cetti s Warbler ^ Long-tailed Tit v Chiffchaff v Willow Warbler v Blackcap Garden Warbler Lesser Whitethroat Whitethroat Grasshopper Warbler Sedge Warbler Reed Warbler Spotted Flycatcher Tree Creeper v Wren v Blackbird Song Thrush Robin Dunnock Chaffinch Goldfinch

10 Bullfinch Reed Bunting v TOTALS Miscellany Caroline has recently been awarded her (Oxford) PhD, for the raptor work she talked to us about at the 2015 indoor meeting; so she is now Dr. Brighton. Chantal Macleod-Nolan, newly at RSPB Sandy, has recently attended some ringing sessions, as has Filipa Goncalves, returned from distant parts. ^^^^^^^^^^ A seal was reported seen in Wicken Lode (even up as far as the landing stage near the Visitor Centre) on January 1 st. Although the bird list for the Fen is over 240 species, the mammal list is only 30 (excluding homo sapiens); this seal is an addition.