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JACKDAW Corvus monedula
 
Conservation Listings Long term trend

Unlisted/Green
Biodiversity Steering Group: Unlisted

UK: Moderate increase
Woodland: Rapid increase
 
Status Summary
Jackdaws tend to have increased since the 1960s (Gregory & Marchant 1996), an increase that the BBS suggests to be continuing. As with Magpies, Rooks and Crows, the increase has been associated with improvements in breeding performance and probably reflects the species' generalist feeding habits, allowing exploitation of diverse and ephemeral food resources. In addition to increases in average brood size, declines in nest failure rates have been large: for the egg stage (21 days, comprising 17 days incubation + 4 days laying) failure rate fell from 16% to 5%, and for the chick stage (30 days) they fell from 31% to 11%. Overall, from egg-laying to fledging, the proportion of nests that fail has fallen from 42% to 16%. Typically in this species, the younger chicks of a brood perish quickly if food becomes limited, therefore the larger brood size (and probably the higher fledging success) is likely to be due to improved success at provisioning by parents (Henderson & Hart 1993).
 
 
Table of population changes for Jackdaw
Source Period
(yrs)
Years Plots
(n)
Change
(%)
Lower
limit
Upper
limit
Alert Comment
CBC all habitats 30 1968-1998 76 72 15 153    
  25 1973-1998 80 81 19 168    
  10 1988-1998 84 24 0 45    
  5 1993-1998 81 23 8 41    
CBC farmland 30 1968-1998 40 36 . .    
  25 1973-1998 41 55 . .    
  10 1988-1998 45 12 . .    
  5 1993-1998 43 20 . .    
CBC woodland 30 1968-1998 25 199 . .    
  25 1973-1998 27 113 . .    
  10 1988-1998 31 50 . .    
  5 1993-1998 30 13 . .    
BBS UK 5 1994-1999 1120 21 14 28    
BBS England 5 1994-1999 889 29 21 38    
BBS Scotland 5 1994-1999 90 4 -17 30    
BBS Wales 5 1994-1999 94 19 -3 46    
BBS N.Ireland 5 1994-1999 42 -7 -35 32   Small sample
The Breeding Bird Survey is jointly funded by BTO, JNCC and RSPB
 
 
Table of productivity information for Jackdaw
Variable Period
(yrs)
Years Mean
annual
sample
Trend Predicted
in first year
Predicted
in last year
Change Comment
Clutch size 30 1968-1998 40 None        
Brood size 30 1968-1998 75 Linear increase 2.75 chicks 3.08 chicks 0.33 chicks  
Daily failure rate (eggs) 30 1968-1998 48 Linear decline 0.0081 nests/day 0.0024 nests/day -0.0057 nests/day  
Daily failure rate (chicks) 30 1968-1998 45 Linear decline 0.0121 nests/day 0.0037 nests/day -0.0084 nests/day  
Laying date 30 1968-1998 20 Curvilinear day 113 day 110 -3 days Small sample
 
Insufficient data for CES
available for this species

 

   



The report should be cited as: Baillie, S.R., Crick, H.Q.P., Balmer, D.E., Bashford, R.I., Beaven, L.P., Freeman, S.N., Marchant, J.H., Noble, D.G., Raven, M.J., Siriwardena, G.M., Thewlis, R. and Wernham, C.V. (2001) Breeding Birds in the Wider Countryside: their conservation status 2000. BTO Research Report No. 252. BTO, Thetford. (http://www.bto.org/birdtrends)

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Last updated: Last updated: 9 April, 2001

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