Ringing has finished for winter 06-07. Here are the winter's totals, with previous years with reasonably comparable methodology shown for comparison. If you have difficulty with column alignment use a non-proportional font such as Courier 10.
Remember retraps are not counts of individual birds – an individual may apear in the retrap count more than once. However, an individual can only be counted once on any one day.
Winter 06-07 05-06 04-05 03-04
new retrap new retrap new retrap new retrap
Blackbird 42 60 78 79
14 35 18 29
Blackcap 3 1
1 0
Blue tit 45 55 80 47
16 13 14 5
Brambling 25 10 11 4
3 0 1 0
Bullfinch 1 0 0 1
0 0 0 0
Chaffinch 155 132 160 246
38 25 25 29
Coal tit 3 10 7 7
0 3 0 0
Dunnock 53 45 70 54
43 90 68 46
Fieldfare 0 1 3
0 0 0
Goldcrest 2 17 7 12
0 7 1 3
Goldfinch 3 3 2 18
0 0 0 2
Great tit 17 14 22 9
1 4 4 2
Greenfinch 13 29 105 39
0 0 4 2
Grey 1
Partridge 0
House 20 42 23 24
sparrow 9 25 6 9
Linnet 1 6 10 2
0 0 0 0
Long 4 12 13 12
tailed tit 1 5 7 5
Redwing 1 5 6
0 0 0
Reed 21 11 82 30
bunting 0 4 9 7
Robin 26 22 33 39
24 44 34 26
Skylark 2 7 0 5
0 1 0 0
Song Thrush 3 4 6 2
0 1 5 0
Sparrowhawk 0 0 0 1
0 0 0 0
Starling 1 0 0 5
0 0 0 0
Treecreeper 0 2 1
0 0 0
Tree 23 3 4 12
sparrow 3 0 0 1
Woodpigeon 1 0 1 1
0 0 0 0
Wren 14 9 29 10
3 8 23 0
Yellow- 225 128 309 261
hammer 75 46 58 44
705 232 628 311 1062 277 920 210
New Retrap New Retrap New Retrap New Retrap
In addition we added whoosh netting on rape bait at a new site this winter. Here we caught 2 new greenfinch, 387 new linnet and 104 retrap linnet. We intend to continue this in future years
Comments :
Overall a modest increase in new bird numbers and a drop in retraps. The drop in retraps is probably simply a consequence of the low catches last year, following two very good seasons.
I suggest you don't read too much into the data, especially for species where numbers are low. Natural variation will be compounded by our inability to repeat methodoly consistently from year to year for many reaons such as variations in weather, labour availability, success of wild bird cover. For instance methodological factors affected :
sparrow numbers in 05-06, boosted by an extra effort in my steading;
linnet, greenfinch and reed bunting, boosted in 03-04 and 04-05 by the success of wild bird cover in those years.
It is interesting to compare brambling and tree sparrow. Both have seen record catches this season. This is a complete surprise for brambling, as reports from all over the UK suggest it has been a poor year for migrants from Scandinavia / Russia (mild with plenty food there). However, brambling are very mobile, and we have just been lucky. By contrast tree sparrow are pretty sedentary. I am hopeful that the increased catch represents a real increase in population (at one site). Fingers crossed
In general, this season got off to a very slow start except for yellowhammer. I was pretty certain that there was loads of natural food availbale, and that I was seeing plenty chaffinch around, but not at the feeding stations. Yellowhammer are more attuned to cereal seed, so with fields being effectively cleaned (a dry harvest and easy autumn, leading to a high proportion of autumn sowings) would be more attracted by the feeding stations. Late on good numbers of birds appeared at the feeding stations, suggesting there had indeed been good supplies of natural food which were becoming exhausted.
In that context, I am pleased with this year. I suspect numbers have recovered after a very poor year last year. I am particularly pleased at the recovery in Yellowhammer. Chaffinch have shown only a small improvement, but I am not sure there was much to worry about with them. They are adaptable, abundant nationally, and the BTO suggested absence from feeders (in favour of natural food), rather than low numbers even last year when numbers were so low. They are also much more difficlt to re-trap than yellowhammer. Low catches might suggest a large reservoir of birds that have been caught once and learnt to stay away.
Blackbird catch may be down because fewer birds have visited from the continent. The same might be true of Goldcrest. The only other species I feel worth commenting on is Greenfinch. It is impossible to read anything into the very poor catch this year. We have been deafened with greenfinch calls on occasion and not caught any. They are there, but for some reason they don't want to help
It is this sort of anomaly that persuades me to say - don't read too much into the data.
Many thanks to all concerned.
Mike.