CES alerts & population increases
  1. CES adults alerts – long term
  2. CES adults alerts – 25 years
  3. CES adults alerts – 10 years
  4. CES adults alerts – 5 years
  5. CES adults population increases of >50% – long term

1. Table of alerts for CES adults 1984-2017

Species Period
(yrs)		 Plots
(n)		 Change
(%)		 Lower
limit		 Upper
limit		 Alert Comment
Willow Warbler 33 90 -77 -82 -71 >50  
Willow Tit 33 16 -72 -90 -36 >50 Small sample
Lesser Whitethroat 33 38 -66 -81 -48 >50  
Reed Bunting 33 61 -64 -75 -51 >50  
Whitethroat 33 65 -55 -70 -34 >50  
Sedge Warbler 33 68 -53 -69 -39 >50  
Chaffinch 33 77 -41 -69 -4 >25  
Garden Warbler 33 65 -33 -57 -8 >25  
Reed Warbler 33 59 -27 -44 -7 >25  

2. Table of alerts for CES adults 1992-2017

Species Period
(yrs)		 Plots
(n)		 Change
(%)		 Lower
limit		 Upper
limit		 Alert Comment
Greenfinch 25 44 -69 -81 -56 >50  
Willow Warbler 25 96 -67 -72 -61 >50  
Willow Tit 25 14 -67 -87 -24 >50 Small sample
Lesser Whitethroat 25 39 -64 -77 -50 >50  
Sedge Warbler 25 75 -50 -60 -42 >50  
Chaffinch 25 84 -50 -62 -36 >25  
Reed Bunting 25 67 -46 -60 -29 >25  
Whitethroat 25 73 -32 -52 -4 >25  
Garden Warbler 25 70 -30 -44 -16 >25  

3. Table of alerts for CES adults 2007-2017

Species Period
(yrs)		 Plots
(n)		 Change
(%)		 Lower
limit		 Upper
limit		 Alert Comment
Greenfinch 10 40 -69 -78 -60 >50  
Chaffinch 10 76 -53 -60 -46 >50  
Willow Warbler 10 90 -33 -40 -26 >25  
Garden Warbler 10 67 -26 -34 -17 >25  

4. Table of alerts for CES adults 2012-2017

Species Period
(yrs)		 Plots
(n)		 Change
(%)		 Lower
limit		 Upper
limit		 Alert Comment
Greenfinch 5 35 -54 -66 -34 >50  
Whitethroat 5 81 -44 -53 -36 >25  
Chaffinch 5 73 -36 -44 -27 >25  
Willow Warbler 5 94 -30 -36 -22 >25  

5. Table of population increases for CES adults 1984-2017

Species Period
(yrs)		 Plots
(n)		 Change
(%)		 Lower
limit		 Upper
limit		 Alert Comment
Robin 33 96 53 32 81    
Wren 33 103 68 43 99    
Goldfinch 33 36 76 9 210    
Blackcap 33 95 103 72 149    
Chiffchaff 33 80 285 151 565    

 

This report should be cited as: Woodward, I.D., Massimino, D., Hammond, M.J., Harris, S.J., Leech, D.I., Noble, D.G., Walker, R.H., Barimore, C., Dadam, D., Eglington, S.M., Marchant, J.H., Sullivan, M.J.P., Baillie, S.R. & Robinson, R.A. (2019) BirdTrends 2019: trends in numbers, breeding success and survival for UK breeding birds. BTO Research Report 722. BTO, Thetford. www.bto.org/birdtrends