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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 36 1967-2003 493 113 72 163   Includes Hooded Crow
  25 1978-2003 658 52 30 79   Includes Hooded Crow
  10 1993-2003 1416 17 11 25   Includes Hooded Crow
  5 1998-2003 1670 7 2 12   Includes Hooded Crow
BBS UK 10 1994-2004 1795 11 6 17    
BBS England 10 1994-2004 1466 20 14 26    
BBS Scotland 10 1994-2004 150 -3 -19 16    
BBS Wales 10 1994-2004 169 -4 -17 11    

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 2003
Change Comment
Clutch size 35 1968-2003 36 None        
Brood size 35 1968-2003 82 Curvilinear 2.83 chicks 2.46 chicks -13.3%  
Daily failure rate (eggs) 35 1968-2003 54 Linear decline 1.57% nests/day 0.27% nests/day -82.8%  
Daily failure rate (chicks) 35 1968-2003 45 Linear decline 0.7% nests/day 0.19% nests/day -72.9%  
Laying date 35 1968-2003 34 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

BTO blue divider
 

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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., 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. (2006)
Breeding Birds in the Wider Countryside: their conservation status 2005.
BTO Research Report No. 435. BTO, Thetford. (http://www.bto.org/birdtrends)

Pages maintained by Susan Waghorn and Iain Downie: Last updated 11 November, 2008