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WHITETHROAT Sylvia communis
 
Conservation Listings Long term trend

Unlisted/Green
Biodiversity Steering Group
Conservation Concern List

UK: Rapid decline followed by shallow recovery since early 1970s
Linear waterways: Moderate recovery
Scrub (CES): Moderate decline
 
Status Summary
Whitethroat populations crashed in the late 1960s because of drought in their wintering grounds (Winstanley et al. 1974) and have since remained stable, although there is some evidence of recovery in farmland. Inter-annual fluctuations in abundance are related to over-winter survival (Baillie & Peach 1992), like the major crash. Other trans-Saharan migrant warblers have shared similarly timed population changes (Siriwardena et al. 1998b). Productivity measured by the CES shows a recent decline which may be associated with a recent decline in average clutch size.
 
 
Table of population changes for Whitethroat
Source Period
(yrs)
Years Plots
(n)
Change
(%)
Lower
limit
Upper
limit
Alert Comment
CBC all habitats 30 1968-1998 118 -57 -68 -39 >50  
  25 1973-1998 117 32 3 72    
  10 1988-1998 115 41 22 63    
  5 1993-1998 120 23 14 32    
CBC farmland 30 1968-1998 65 -43 -55 -24 >25  
  25 1973-1998 63 100 58 152    
  10 1988-1998 70 59 34 83    
  5 1993-1998 73 28 17 43    
CBC woodland 30 1968-1998 29 -82 -89 -63 >50  
  25 1973-1998 29 -57 -70 -27 >50  
  10 1988-1998 28 -11 -32 12    
  5 1993-1998 31 1 -18 20    
WBS waterways 23 1975-1998 39 63 -19 197    
  10 1988-1998 52 139 69 226    
  5 1993-1998 62 51 35 72    
CES adults 14 1984-1998 56 -31 . . [>25]  
  10 1988-1998 68 -24 . .    
  5 1993-1998 78 -16 . .    
CES juveniles 14 1984-1998 60 -39 . . [>25]  
  10 1988-1998 71 -38 . . [>25*]  
  5 1993-1998 81 -32 . . [>25*]  
BBS UK 5 1994-1999 932 6 0 14    
BBS England 5 1994-1999 813 7 0 14    
BBS Scotland 5 1994-1999 53 3 -27 45    
BBS Wales 5 1994-1999 56 7 -18 38    
The Breeding Bird Survey is jointly funded by BTO, JNCC and RSPB
 
 
Table of productivity information for Whitethroat
Variable Period
(yrs)
Years Mean
annual
sample
Trend Predicted
in first year
Predicted
in last year
Change Comment
Clutch size 30 1968-1998 26 Curvilinear 4.59 eggs 4.53 eggs -0.06 eggs Small sample
Brood size 30 1968-1998 61 None        
Daily failure rate (eggs) 30 1968-1998 37 None        
Daily failure rate (chicks) 30 1968-1998 46 None        
Laying date 30 1968-1998 17 None       Small sample
Percentage juveniles (CES) 14 1984-1998 71 Smoothed trend 133 productivity index 100 productivity index -25%[>25]  
Percentage juveniles (CES) 10 1988-1998 83 Smoothed trend 140 productivity index 100 productivity index -28%[>25*]  
Percentage juveniles (CES) 5 1993-1998 94 Smoothed trend 140 productivity index 100 productivity index -28%[>25*]  
 
   




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Last updated: 15 March, 2001

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