The British Trust for Ornithology

ROOK
Corvus frugilegus

Rook © G H Higginbotham
Conservation listings

Unlisted/Green
Biodiversity Steering Group: Unlisted

Long-term trend
UK: Stable
Scotland: Moderate increase
N Ireland: Moderate increase
Status summary
As a colonial species, Rook is not monitored ideally by the CBC, but an index calculated from the available data shows a shallow, long-term increase (Wilson et al. 1998). This is supported by the results of the BTO Rook survey, which identified a 40% increase in abundance between 1975 and 1996 (Marchant & Gregory 1999). This increase has been associated with general improvements in nesting success and probably reflects the species' adaptability in the face of agricultural change.
 
 
Table of population changes for Rook
Source Period
(yrs)
Years Plots
(n)
Change
(%)
Lower
limit
Upper
limit
Alert Comment
BBS UK 6 1994-2000 999 6 -3 15    
BBS England 6 1994-2000 789 -7 -15 2    
BBS Scotland 6 1994-2000 99 73 30 132    
BBS Wales 6 1994-2000 63 3 -30 50    
BBS N.Ireland 6 1994-2000 46 63 13 136   Small sample
The Breeding Bird Survey is jointly funded by BTO, JNCC and RSPB
 
 
Table of productivity information for Rook
Variable Period
(yrs)
Years Mean
annual
sample
Trend Predicted
in first year
Predicted
in last year
Change Comment
Clutch size 31 1968-1999 14 None       Small sample
Brood size 31 1968-1999 96 Linear increase 2.33 chicks 2.76 chicks 0.43 chicks  
Daily failure rate (eggs) 31 1968-1999 39 Curvilinear 0.0152 nests/day 0.0229 nests/day 0.0077 nests/day  
Daily failure rate (chicks) 31 1968-1999 61 None        
Laying date 31 1968-1999 13 None       Small sample
 
Insufficient data on CES
available for this species




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This report should be cited as:
Baillie, S.R., Crick, H.Q.P., Balmer, D.E., Beaven, L.P., Downie, I.S., Freeman, S.N., Leech, D.I., Marchant, J.H.,
Noble, D.G., Raven, M.J., Simpkin, A.P., Thewlis, R.M. and Wernham, C.V.
(2002) Breeding Birds in the Wider
Countryside: their conservation status 2001. BTO Research Report No. 278. BTO, Thetford. (http://www.bto.org/birdtrends)

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This page last updated: 21 April, 2008

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