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BLACKCAP
Sylvia atricapilla
 Blackcap © Colin Varndell
 

• Population
  changes

• Productivity
  trends

• Additional
  information
Conservation listings
Europe: no SPEC category (concentrated in Europe, conservation status favourable)
UK: green
Long-term trend
UK, England: rapid increase
UK population size
932,000 territories in 2000 (1988–91 Atlas estimate updated using CBC/BBS trend: BiE04, APEP06)
Status summary
Blackcap abundance has increased consistently since the late 1970s, a trend common to all habitats and evident from both the CBC/BBS and the CES indices, although the causes remain unknown. There have been no clear accompanying trends in productivity. The trend towards earlier laying may be a response to recent climate change (Crick & Sparks 1999). The more rapid increase in Scotland indicated by BBS suggests that climatic warming may be allowing this species to spread its range northwards. Numbers have risen widely in Europe since 1980 (PECBM 2006).
 

Population changes
CBC/BBS UK graph
 
Table of population changes for Blackcap

Source Period
(yrs)		 Years Plots
(n)		 Change
(%)		 Lower
limit		 Upper
limit		 Alert Comment
CBC/BBS UK 38 1967-2005 480 144 100 200    
  25 1980-2005 663 119 96 144    
  10 1995-2005 1335 52 46 58    
  5 2000-2005 1436 9 6 13    
CBC/BBS England 38 1967-2005 422 134 91 195    
  25 1980-2005 579 113 90 141    
  10 1995-2005 1157 47 40 53    
  5 2000-2005 1225 8 4 12    
CES adults 21 1984-2005 86 63 37 97    
  10 1995-2005 99 42 26 57    
  5 2000-2005 94 13 3 23    
CES juveniles 21 1984-2005 88 40 13 72    
  10 1995-2005 102 35 23 51    
  5 2000-2005 96 6 -4 21    
BBS UK 10 1995-2005 1229 52 45 60    
  5 2000-2005 1408 11 7 15    
BBS England 10 1995-2005 1062 46 39 53    
  5 2000-2005 1200 10 6 14    
BBS Scotland 10 1995-2005 35 142 75 209    
  5 2000-2005 42 18 -10 46    
BBS Wales 10 1995-2005 105 52 30 79    
  5 2000-2005 127 9 1 20    

BBS acknowledgement
 
CBC/BBS England graph
CES adult abundance graph
CES juvenile abundance graph
BBS UK graph
BBS Wales graph
 

Productivity trends
Table of productivity changes for Blackcap

Variable Period
(yrs)		 Years Mean
annual
sample		 Trend Modelled
in first year		 Modelled
in 2005		 Change Comment
Clutch size 37 1968-2005 35 None        
Brood size 37 1968-2005 41 None        
Daily failure rate (eggs) 37 1968-2005 46 None        
Daily failure rate (chicks) 37 1968-2005 36 None        
Laying date 37 1968-2005 36 Curvilinear May 20 May 9 -11 days  
Juvenile to Adult ratio (CES) 21 1984-2005 94 Smoothed trend 122 Index value 100 Index value -18%  
Juvenile to Adult ratio (CES) 10 1995-2005 107 Smoothed trend 102 Index value 100 Index value -2%  
Juvenile to Adult ratio (CES) 5 2000-2005 101 Smoothed trend 89 Index value 100 Index value 13%  

Clutch size graph
Brood size graph
Egg nest failure graph
Chick nest failure graph
Laying date graph
CES productivity graph
 

Additional information
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This report should be cited as:
Baillie, S.R., Marchant, J.H., Crick, H.Q.P., Noble, D.G., Balmer, D.E., Barimore, C., Coombes, R.H.,
Downie, I.S., Freeman, S.N., Joys, A.C., Leech, D.I., Raven, M.J., Robinson, R.A. & Thewlis, R.M. (2007)
Breeding Birds in the Wider Countryside: their conservation status 2007.
BTO Research Report No. 487. BTO, Thetford. (http://www.bto.org/birdtrends)

Pages maintained by Susan Waghorn and Iain Downie: Last updated 3 January, 2008