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CORN BUNTING Miliaria calandra
 
Conservation Listings Long term trend

Table 2/Red
(>=50% Population decline)
Biodiversity Steering Group Priority Species List

UK: Rapid decline
 
Status Summary
Corn Buntings declined rapidly from around 1973 to around 1986, after which the decline has continued but at a much reduced rate. The BBS also shows a continuing decline. Corn Bunting breeding performance has increased considerably over time (Crick 1997), and the best hypothesis as to the demographic mechanism behind the decline is probably that survival rates have fallen, but ring-recovery sample sizes do not permit this to be tested (Siriwardena et al. 1998b, 2000b). The decline is probably a result of the deleterious effects of agricultural intensification on seed availability in winter (Donald 1997).
 
 
Table of population changes for Corn Bunting
Source Period
(yrs)
Years Plots
(n)
Change
(%)
Lower
limit
Upper
limit
Alert Comment
CBC all habitats 30 1968-1998 24 -83 -91 -68 >50  
  25 1973-1998 22 -86 -93 -75 >50  
  10 1988-1998 15 -38 -63 7   Small sample
  5 1993-1998 15 -22 -41 19   Small sample
BBS UK 5 1994-1999 148 -26 -37 -13 (>25)  
BBS England 5 1994-1999 141 -22 -34 -8    
The Breeding Bird Survey is jointly funded by BTO, JNCC and RSPB
 
 
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
Clutch size 30 1968-1998 10 None       Small sample
Brood size 30 1968-1998 12 Curvilinear 3.09 chicks 3.7 chicks 0.61 chicks Small sample
Daily failure rate (eggs) 30 1968-1998 13 None       Small sample
Daily failure rate (chicks) 30 1968-1998 12 Linear decline 0.0367 nests/day 0.0109 nests/day -0.0258 nests/day Small sample
Laying date 30 1968-1998 15 Linear decline day 181 day 165 -16 days Small sample
 

Insufficient data on 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: 26 March, 2001

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