BTO - Breeding Birds of the Wider Countryside: Rook

ROOK
Corvus frugilegus

Conservation listings

Europe: no SPEC category (favourable conservation status in Europe, not concentrated in Europe)
UK: green

Long-term trend

UK: moderate increase

Distribution maps

Maps and statistics from British and Irish
atlases can be viewed here.

Status summary

Relatively few rookeries fell within CBC plots, but an index calculated from the available nest counts shows a shallow, long-term increase (Wilson et al. 1998). The trend is confirmed by the results of the most recent BTO rookeries survey, which identified a 40% increase in abundance between 1975 and 1996 (Marchant & Gregory 1999). This increase has been associated with an increase in brood size and probably reflects the species' adaptability in the face of agricultural change. BBS sightings suggest decrease in England since 1994, but increase in Scotland and a shallow increase in the UK as a whole; BBS also holds data from nest counts, but no indices from these are available.

Table of population changes for Rook

Source	Period (yrs)	Years	Plots (n)	Change (%)	Lower limit	Upper limit	Alert	Comment
BBS UK	9	1994-2003	1012	8	0	17
BBS England	9	1994-2003	793	-10	-18	-2
BBS Scotland	9	1994-2003	96	52	15	101
BBS Wales	9	1994-2003	68	5	-26	49
BBS N.Ireland	9	1994-2003	52	24	-16	83

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 34 1968-2002 14 Curvilinear 4.15 eggs 3.93 eggs -0.22 eggs Small sample

Brood size 34 1968-2002 90 Linear increase 2.33 chicks 2.81 chicks 0.48 chicks

Daily failure rate (eggs) 34 1968-2002 37 None

Daily failure rate (chicks) 34 1968-2002 58 None

Laying date 34 1968-2002 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., Marchant, J.H., Crick, H.Q.P., Noble, D.G., Balmer, D.E., Beaven, L.P., 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. (2005) Breeding Birds in the Wider Countryside: their conservation status 2004. BTO Research Report No. 385. BTO, Thetford. (http://www.bto.org/birdtrends) Pages maintained by Susan Waghorn and Iain Downie: Last updated 18 January, 2006