BTO - Breeding Birds of the Wider Countryside: Corn Bunting

CORN BUNTING
Emberiza calandra

Conservation listings

Europe: SPEC category 2 (declining)
UK: red >50% population decline, historical decline)

Long-term trend

UK, England: rapid decline

Distribution maps

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

Status summary

Following an earlier, historical decrease, Corn Buntings declined very steeply between the mid 1970s and mid 1980s, withdrawing then from large areas of their former range. Subsequently the decline has continued at a much-reduced rate. Corn Bunting breeding performance has increased considerably over this period (Crick 1997), and the demographic mechanism behind the decline is probably that survival rates have fallen. Ring-recovery sample sizes do not permit this hypothesis to be tested, however (Siriwardena et al. 1998b, 2000b). Any decrease in survival rates is probably a result of the deleterious effects of agricultural intensification on seed availability in winter (Donald 1997). With declines across much of its European range, this previously 'secure' species is now provisionally evaluated as 'declining'.

Table of population changes for Corn Bunting

Source	Period (yrs)	Years	Plots (n)	Change (%)	Lower limit	Upper limit	Alert	Comment
CBC/BBS UK	35	1967-2002	55	-87	-93	-79	>50
	25	1977-2002	63	-88	-94	-81	>50
	10	1992-2002	126	-45	-60	-30	>25
	5	1997-2002	149	-20	-32	-10
CBC/BBS England	35	1967-2002	53	-85	-94	-71	>50
	25	1977-2002	61	-88	-95	-78	>50
	10	1992-2002	120	-43	-58	-19	>25
	5	1997-2002	144	-16	-29	-3
BBS UK	9	1994-2003	139	-35	-45	-22	(>25)
BBS England	9	1994-2003	132	-31	-42	-18	(>25)

Table of productivity information for Corn Bunting

Variable Period
(yrs) Years Mean
annual
sample Trend Predicted
in first year Predicted
in last year Change Comment

Brood size 34 1968-2002 12 Curvilinear 3.09 chicks 3.44 chicks 0.35 chicks Small sample

Daily failure rate (eggs) 34 1968-2002 12 None Small sample

Daily failure rate (chicks) 34 1968-2002 11 Linear decline 0.0362 nests/day 0.0096 nests/day -0.0266 nests/day Small sample

Laying date 34 1968-2002 14 Linear decline day 180 day 165 -15 days Small sample

Insufficient data on clutch size
available for this species

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