Constant Effort Ringing in 2017

Sat here in the howling wind and rain pondering what to do and where to go, got me reminiscing about the summer months of last year and some of the avian joys that I encountered. Not least of which was some of the birds that I met whilst carrying out a newly formed CES study at Goss Moor, Cornwall. 

What is a CES? 

CES is a BTO led study and stands for Constant Effort Ringing. More information can be found here: www.bto.org/volunteer-surveys/ringing/surveys/ces

The CES Scheme uses catches from standardised mist-netting to monitor key aspects of the demography of 24 common breeding songbirds. Around 130 sites are monitored through the breeding season, with twelve standard visits between May and August. Changes in the total number of adults caught provides a measure of changing population size, whilst the proportion of young birds caught forms an index of breeding success. Re-traps of adult birds ringed in previous years are also used to estimate annual survival rates.

I had been ringing on the Goss for about 3 years and decided that, whilst my results were good and the data valuable, I wanted to make the study of more use long term. Setting up a CES seemed the best way to do this to achieve useful long term data on a local and national scale. I opted to use 7 nets spanning 380 ft, with my ringing station centred in the middle of them. This meant that I could extract and process birds in a timely manner and let them on their merry way straight after. After talking with the wardens from Natural England I opted for this location as I knew from previous ringing sessions that there were Willow Tit in the area and both the BTO and Natural England both valued data on this declining species. It was also a good area for general Warbler populations and I was especially interested in studying Garden Warbler which is prolific on the Moor and is one of the few locations in Cornwall were the population is dense.   

Goss Moor is a 480 hectare National Nature Reserve (NNR) which is owned and managed by Natural England.

The Results 

8th of May

A selection of the first birds ringed on the newly formed CES

I was pleased with my first visit and processed more than I was expecting as species can be quite elusive at this time of year.

Long-tailed Tit x 2, Blackbird x 3, Willow Warbler x 6, Treecreeper x 2, Reed Bunting x 2, Goldcrest x 1, Garden Warbler x 1, Dunnock x 1, Chiffchaff x 3, Bullfinch x 3, Blackcap x 1, Robin x 3 and a Willow Tit.

Total = 29

18th of May

Slightly quieter as birds begin to settle on nests and are generally less active before young birds hatch. 

Robin x 1, Goldcrest x 1, Willow Tit x 1, Long-tailed Tit x 1, Chiffchaff x 1, Blackcap x 2, Bullfinch x 4, Willow Warbler x 6 and Garden Warbler x 3.

Total = 20

29th of May

This visit saw the first fledged young on the wing. All juvenile birds will be shown in brackets.

Garden Warbler x 4, Wren x 1 (1), Willow Warbler x 5, Song Thrush x 1, Robin x 2 (6), Goldcrest x 2, Dunnock x 1, Chaffinch x 3, Bullfinch x 4, Blue Tit x 2, Blackcap x 4 (1), Blackbird x 1, Long-tailed Tit x 2 (8).  

Total = 48

4th of June

Lovely to see recently fledged young out on the wing

Perhaps a bit too soon since my last visit but my circumstances dictated when I could carry out the session.

Long-tailed Tit x 1 (1), Bullfinch x 3, Wren x 1, Willow Warbler x 2, Treecreeper x 1 (2), Robin x 4 (1), Blackbird x (1), Chaffinch x 1, Chiffchaff x (2), Blackcap x (1) and a single Garden Warbler.

Total = 23

18th of June

Juvenile birds were starting to become much denser in this visit and made up over 50% of the birds processed.

Willow Warbler 5 (2), Wren (1), Robin 1 (6), Long-tailed Tit (1), Great Tit (1), Goldcrest 1, Chiffchaff (1), Chaffinch 1, Bullfinch 2, Blue Tit 1 (3), Blackcap 2 (7), Blackbird 1 (1), Garden Warbler (2).

Total = 39

1st of July 

61 juveniles were caught in this visit and seen large flocks of tits starting to flock together and rove around the Moor. 

Coal Tit 2 (8), Willow Warbler 5 (8), Robin 1 (2), Marsh Tit 1 (1), Long-tailed Tit 5 (12), Great Tit (10), Goldcrest 1, Blackcap 3 (3), Dunnock 2 (1), Chiffchaff 2 (4), Bullfinch 5, Blue Tit 2 (8), Garden Warbler (3).

Total = 90 

9th of July

This session saw the largest catch of the year with over 80% of the catch juvenile birds. 

Coal Tit (5), Blackcap 5 (49), Blue Tit 2 (8), Chiffchaff 2 (12), Swallow 1 (3), Bullfinch 7, Willow Warbler 5 (6), Robin (6), Long-tailed Tit (3), Great Tit 2 (4), Goldcrest (2), Garden Warbler (6), Dunnock (2), Wren 1 (10).

Total = 141

17th of July

The first juvenile Willow Tit of the year

Whilst not such a large catch as the last session over 90 % were juveniles during this visit.

Robin 1 (2), Dunnock (3), Wren (4), Willow Tit (1), Long-tailed Tit (1), Great Tit (1), Garden Warbler (6), Chiffchaff (3), Chaffinch (2), Bullfinch 5 (4), Blackbird (1), Blue Tit (3), Blackcap 1 (36), Coal Tit (4), Willow Warbler 2 (5).

Total = 85 

31st of July

Two more juvenile Willow Tits during session 9

Still a good session but had got quieter compared to the last few visits.

Coal Tit (2), Willow Warbler (6), Willow Tit (2), Robin (2), Great Tit 1 (4), Goldcrest 1, Dunnock 1 (1), Chiffchaff (5), Bullfinch 2, Blue Tit 1 (3), Blackcap 1 (6), Wren (2), Garden Warbler (1).

Total = 41

6th of August

Lotti (8), Willow Warbler 2 (5), Treecreeper (1), Sedge Warbler (2), Robin (4), Marsh Tit (1), Garden Warbler 1 (1), Dunnock (2), Coal Tit (2), Chiffchaff 1 (3), Blackcap 2 (4), Blue Tit 2 (3), Goldcrest 1 (2).

Total = 47 

20th of August

Nice to get to see a Tree Pipit up close and personal

Robin (4), Wren (1), Willow Warbler 1 (1), Tree Pipit (1), Sedge Warbler 1, Jay (1), Garden Warbler (2), Coal Tit (3), Chiffchaff (4), Bullfinch (3), Blue Tit 1 (2), Blackcap 1 (8), Great Tit (1), Swallow 1 (1).

Total = 37

28th of August

Goss Moor harbours good numbers of Bullfinch throughout the year

Blackbird (1), Marsh Tit (1), Long-tailed Tit 3, Great Tit 1 (3), Goldcrest 3 (3), Dunnock (1), Coal Tit (2), Chaffinch (1), Blue Tit (13), Robin (1), Bullfinch (3). 

Total = 36

A grand total of 636 birds processed which I was most pleased with. I hope that 2018 is another successful year for the breeding birds on the Goss Moor.