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BTO Blueline
CARRION CROW
Corvus corone
Carrion Crow © Mike Weston
Conservation listings

Europe (C. corone/cornix): no SPEC category, secure
UK (C. corone/cornix): Green

Long-term trend
UK, England: rapid increase
 
Status summary
Carrion Crows have increased steadily since the 1960s (Gregory & Marchant 1996) and both the CBC and the BBS indicate that the increase is continuing. This trend has been associated with increases in nesting success and earlier laying (perhaps an effect of climate change: Crick et al. 1997) and probably reflects the species' adaptability to changing habitats and the exploitation of ephemeral food resources in intensive agriculture. Reduced control activities by gamekeepers may also have contributed (Marchant et al. 1990), as may the increase in roadside carrion.
 
CBC/BBS UK graph
 
Table of population changes for Carrion Crow
Source Period
(yrs)
Years Plots
(n)
Change
(%)
Lower
limit
Upper
limit
Alert Comment
CBC/BBS UK 33 1967-2000 516 104 67 170    
  25 1975-2000 636 62 40 103    
  10 1990-2000 1252 25 16 32    
  5 1995-2000 1945 12 6 17    
CBC/BBS England 33 1967-2000 428 104 67 160    
  25 1975-2000 527 60 33 94    
  10 1990-2000 1034 22 14 31    
  5 1995-2000 1602 8 2 14    
BBS UK 8 1994-2002 1712 15 10 21    
  8 1994-2002 104 -31 -47 -9 (>25)  
BBS England 8 1994-2002 1400 21 14 27    
BBS Scotland 8 1994-2002 147 3 -14 24    
  8 1994-2002 50 -59 -73 -39 (>50)  
BBS Wales 8 1994-2002 156 7 -7 24    
BBS N.Ireland 8 1994-2002 48 90 28 182    
BBS acknowledgement
 
CBC/BBS England graph
BBS UK graph
BBS England graph
BBS Scotland graph
BBS Wales graph
 
Table of productivity changes for Carrion Crow
Variable Period
(yrs)
Years Mean
annual
sample
Trend Predicted
in first year
Predicted
in last year
Change Comment
Clutch size 33 1968-2001 38 None        
Brood size 33 1968-2001 83 None        
Daily failure rate (eggs) 33 1968-2001 56 Linear decline 0.0163 nests/day 0.0028 nests/day -0.0135 nests/day  
Daily failure rate (chicks) 33 1968-2001 46 Linear decline 0.0068 nests/day 0.0022 nests/day -0.0046 nests/day  
Laying date 33 1968-2001 36 Curvilinear day 106 day 99 -7 days  
Clutch size graph
Brood size graph
Egg nest failure graph
Chick nest failure graph
Laying date graph
Insufficient data on CES
available for this species
 
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This report should be cited as:
Crick, H.Q.P., Marchant, J.H., Noble, D.G., Baillie, S.R., Balmer, D.E., Beaven, L.P., Coombes, R.H.,
Downie, I.S., Freeman, S.N., Joys, A.C., Leech, D.I., Raven, M.J., Robinson, R.A. and Thewlis, R.M. (2004)
Breeding Birds in the Wider Countryside: their conservation status 2003.
BTO Research Report No. 353. BTO, Thetford. (http://www.bto.org/birdtrends2003)

Pages maintained by Susan Waghorn and Iain Downie: Last updated 16 February, 2009