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BTO Blueline
CARRION CROW
Corvus corone
Carrion Crow © Mike Weston
 

• Population
  changes

• Productivity
  trends

• Additional
  information
Conservation listings
Europe (C. corone/cornix): no SPEC category (favourable conservation status in Europe, not concentrated in Europe)
UK (C. corone/cornix): green
Long-term trend 
England: rapid increase
UK population size
790,000 territories in 1990 (1988–91 Atlas: APEP06); 987,500 pairs in 2000 (updated using CBC/BBS trend)
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 an increase in roadside carrion.
 

Population changes
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 England 38 1967-2005 568 116 76 174   Includes Hooded Crow
  25 1980-2005 797 48 29 73   Includes Hooded Crow
  10 1995-2005 1662 15 7 24   Includes Hooded Crow
  5 2000-2005 1729 4 -1 10   Includes Hooded Crow
BBS UK 10 1995-2005 1929 12 5 18    
  5 2000-2005 2099 -3 -8 3    
BBS England 10 1995-2005 1575 17 8 25    
  5 2000-2005 1707 4 -1 8    
BBS Scotland 10 1995-2005 159 -2 -16 18    
  5 2000-2005 162 -19 -35 -4    
BBS Wales 10 1995-2005 184 16 0 40    
  5 2000-2005 218 0 -13 19    

BBS acknowledgement
 
BBS UK graph
BBS England graph
BBS Scotland graph
BBS Wales graph
 

Productivity trends
Table of productivity changes for Carrion Crow

Variable Period
(yrs)		 Years Mean
annual
sample		 Trend Modelled
in first year		 Modelled
in 2005		 Change Comment
Clutch size 37 1968-2005 34 Curvilinear 4.08 eggs 4.08 eggs -0.1%  
Brood size 37 1968-2005 80 Curvilinear 2.87 chicks 2.49 chicks -13.3%  
Daily failure rate (eggs) 37 1968-2005 51 Linear decline 1.59% nests/day 0.23% nests/day -85.5%  
Daily failure rate (chicks) 37 1968-2005 43 Linear decline 0.73% nests/day 0.16% nests/day -78.1%  
Laying date 37 1968-2005 32 Curvilinear Apr 16 Apr 5 -11 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
 

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