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JACKDAW
Corvus monedula
Jackday © Tommy Holden
 

• 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: moderate increase
UK population size
555,000 territories in 2000 (1988–91 Atlas estimate updated using CBC/BBS trend: BiE04, APEP06)
Status summary
Jackdaws have increased in abundance since the 1960s (Gregory & Marchant 1996), and more recent BBS data suggest that the increase is continuing in all UK countries. As with Magpie, Rook and Carrion Crow, the increase has been associated with improvements in breeding performance and probably reflects the species' generalist feeding habits, which allow it to exploit diverse and ephemeral food resources. A minor decrease in average brood size has been countered by substantial declines in nest failure rates during the egg and chick stages. Overall, from egg-laying to fledging, the proportion of nests that fail has fallen by about two-thirds. Typically in this species, the younger chicks of a brood perish quickly if food becomes limited. Increases in fledging success are therefore likely to be due to improved parental provisioning success (Henderson & Hart 1993).
 

Population changes

CBC/BBS UK graph
 
Table of population changes for Jackdaw

Source Period
(yrs)
Years Plots
(n)
Change
(%)
Lower
limit
Upper
limit
Alert Comment
CBC/BBS UK 39 1967-2006 489 92 30 206    
  25 1981-2006 728 62 20 124    
  10 1996-2006 1514 25 14 39    
  5 2001-2006 1648 9 4 16    
CBC/BBS England 39 1967-2006 389 79 15 184    
  25 1981-2006 577 56 18 110    
  10 1996-2006 1195 27 19 35    
  5 2001-2006 1299 12 6 17    
BBS UK 11 1995-2006 1427 28 17 41    
  10 1996-2006 1474 24 14 36    
  5 2001-2006 1648 9 3 15    
BBS England 11 1995-2006 1127 32 23 43    
  10 1996-2006 1162 27 19 36    
  5 2001-2006 1299 12 7 18    
BBS Scotland 11 1995-2006 99 8 -9 34    
  10 1996-2006 101 4 -11 29    
  5 2001-2006 107 -2 -16 19    
BBS Wales 11 1995-2006 131 34 -14 120    
  10 1996-2006 136 29 -13 104    
  5 2001-2006 155 8 -9 28    
BBS N.Ireland 11 1995-2006 66 58 11 94    
  10 1996-2006 71 50 16 72    
  5 2001-2006 83 8 -2 26    

BBS acknowledgement
 
CBC/BBS England graph
BBS UK graph
BBS England graph
BBS Scotland graph
BBS Wales graph
BBS N Ireland graph
 

Productivity trends

Table of productivity changes for Jackdaw

Variable Period
(yrs)
Years Mean
annual
sample
Trend Modelled
in first year
Modelled
in 2006
Change Comment
Clutch size 38 1968-2006 43 Linear increase 4.35 eggs 4.57 eggs 4.9%  
Brood size 38 1968-2006 91 Curvilinear 2.69 chicks 2.6 chicks -3.2%  
Daily failure rate (eggs) 38 1968-2006 54 Linear decline 0.76% nests/day 0.2% nests/day -73.7%  
Daily failure rate (chicks) 38 1968-2006 52 Linear decline 1.26% nests/day 0.24% nests/day -81%  
Laying date 38 1968-2006 23 Curvilinear Apr 23 Apr 18 -5 days Small sample

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

 

 

Insufficient data for CES
available for this species

 

Additional information

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This report should be cited as:
Baillie, S.R., Marchant, J.H., Leech, D.I., Joys, A.C., Noble, D.G.,
Barimore, C., Grantham, M.J., Risely, K. & Robinson, R.A. (2009).
Breeding Birds in the Wider Countryside: their conservation status 2008.
BTO Research Report No. 516. BTO, Thetford. (http://www.bto.org/birdtrends)

Pages maintained by Iain Downie, Mandy T Andrews and Laura Smith: Last updated 18.02.2009