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SKYLARK Alauda arvensis
 
Conservation Listings Long term trend

Table 3/Red
(>=50% Population decline)
Biodiversity Steering Group
Priority Species List

UK: Rapid decline
 
Status Summary
The Skylark declined rapidly from the mid-1970s until the mid-1980s, when the rate of decline slowed; the BBS shows, however, that the decline is continuing in England. Considerable research effort at the BTO and elsewhere in recent years has indicated that the most likely cause of the decline is the increase in the winter-sowing of cereals, which restricts opportunities for late-season nesting attempts because of vegetation height and may reduce over-winter survival by reducing the available area of stubbles (Wilson et al. 1997, Donald & Vickery 2000). Breeding performance per attempt has increased during the decline (Chamberlain & Crick 1999, Siriwardena et al. 2000b). For a general review of the effects of agricultural practice on Skylark population trends see Chamberlain & Siriwardena (2000).
 
 
Table of population changes for Skylark
Source Period
(yrs)
Years Plots
(n)
Change
(%)
Lower
limit
Upper
limit
Alert Comment
CBC all habitats 30 1968-1998 121 -53 -62 -45 >50  
  25 1973-1998 121 -54 -62 -47 >50  
  10 1988-1998 106 -14 -23 -2    
  5 1993-1998 107 -11 -17 -5    
CBC farmland 30 1968-1998 85 -51 -60 -42 >50  
  25 1973-1998 84 -53 -60 -44 >50  
  10 1988-1998 81 -19 -26 -11    
  5 1993-1998 81 -13 -18 -7    
BBS UK 5 1994-1999 1354 -16 -20 -13    
BBS England 5 1994-1999 1051 -20 -24 -17    
BBS Scotland 5 1994-1999 194 -13 -22 -3    
BBS Wales 5 1994-1999 78 13 -4 32    
BBS N.Ireland 5 1994-1999 28 -9 -36 30   Small sample
The Breeding Bird Survey is jointly funded by BTO, JNCC and RSPB
 
 
Table of productivity information for Skylark
Variable Period
(yrs)
Years Mean
annual
sample
Trend Predicted
in first year
Predicted
in last year
Change Comment
Clutch size 30 1968-1998 43 Linear increase 3.34 eggs 3.69 eggs 0.35 eggs  
Brood size 30 1968-1998 75 Linear increase 3.13 chicks 3.45 chicks 0.32 chicks  
Daily failure rate (eggs) 30 1968-1998 52 None        
Daily failure rate (chicks) 30 1968-1998 61 None        
Laying date 30 1968-1998 23 Curvilinear day 146 day 148 2 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: Last updated: 9 April, 2001

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