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 1984-2018

Species Period
(yrs)		 Plots
(n)		 Change
(%)		 Lower
limit		 Upper
limit		 Alert Comment
Willow Warbler 34 89 -77 -82 -71 >50  
Willow Tit 34 16 -77 -90 -60 >50 Small sample
Lesser Whitethroat 34 38 -65 -81 -40 >50  
Reed Bunting 34 61 -65 -77 -51 >50  
Sedge Warbler 34 68 -55 -68 -40 >50  
Chaffinch 34 76 -52 -72 -20 >50  
Whitethroat 34 65 -51 -68 -30 >50  
Reed Warbler 34 59 -29 -48 -4 >25  

2. Table of alerts for CES adults 1993-2018

Species Period
(yrs)		 Plots
(n)		 Change
(%)		 Lower
limit		 Upper
limit		 Alert Comment
Greenfinch 25 44 -76 -84 -62 >50  
Willow Tit 25 14 -72 -87 -45 >50 Small sample
Willow Warbler 25 95 -64 -71 -58 >50  
Lesser Whitethroat 25 39 -62 -76 -47 >50  
Chaffinch 25 83 -61 -70 -52 >50  
Sedge Warbler 25 76 -55 -61 -45 >50  
Reed Bunting 25 68 -46 -61 -30 >25  
Whitethroat 25 74 -31 -47 -8 >25  
Garden Warbler 25 70 -27 -41 -8 >25  

3. Table of alerts for CES adults 2008-2018

Species Period
(yrs)		 Plots
(n)		 Change
(%)		 Lower
limit		 Upper
limit		 Alert Comment
Greenfinch 10 38 -71 -79 -59 >50  
Chaffinch 10 74 -59 -65 -53 >50  
Willow Warbler 10 90 -31 -38 -22 >25  
Sedge Warbler 10 75 -28 -36 -17 >25  

4. Table of alerts for CES adults 2013-2018

Species Period
(yrs)		 Plots
(n)		 Change
(%)		 Lower
limit		 Upper
limit		 Alert Comment
Greenfinch 5 35 -57 -67 -42 >50  
Chaffinch 5 70 -45 -52 -39 >25  
Whitethroat 5 80 -30 -40 -22 >25  

5. Table of population increases for CES adults 1984-2018

Species Period
(yrs)		 Plots
(n)		 Change
(%)		 Lower
limit		 Upper
limit		 Alert Comment
Wren 34 103 63 36 92    
Goldfinch 34 37 81 17 312    
Blackcap 34 96 131 92 181    
Chiffchaff 34 81 298 159 570    

 

This report should be cited as: Woodward, I.D., Massimino, D., Hammond, M.J., Barber, L., Barimore, C., Harris, S.J., Leech, D.I., Noble, D.G., Walker, R.H., Baillie, S.R. & Robinson, R.A. (2020) BirdTrends 2020: trends in numbers, breeding success and survival for UK breeding birds. BTO Research Report 732. BTO, Thetford. www.bto.org/birdtrends