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BTO Blueline
WHITETHROAT
Sylvia communis
Whitethroat © Tommy Holden
Conservation listings

Europe: SPEC category 4, secure
UK: Green

Long-term trend
UK, England: rapid decline (followed by shallow increase)
 
Status summary
Whitethroat populations, which had been stable up to 1968 and departed as normal that autumn, crashed by around 70% between the 1968 and 1969 breeding seasons. They fluctuated around their lower level until the mid 1980s, since when a shallow recovery has occurred. Recovery has been most apparent along linear waterways. In a pioneering study, Winstanley et al. (1974) linked the 1969 crash to droughts in the Whitethroat's wintering grounds in the western Sahel. Annual fluctuations in abundance (not shown in the smoothed trend) correlate to those in overwinter survival rate (Baillie & Peach 1992). Other trans-Saharan migrant warblers have shared similarly timed population changes (Siriwardena et al. 1998b). Productivity, as measured by CES, shows a moderate decline during the period of population recovery, which may be associated with a minor reduction in average brood size.
 
CBC/BBS UK graph
 
Table of population changes for Whitethroat
Source Period
(yrs)
Years Plots
(n)
Change
(%)
Lower
limit
Upper
limit
Alert Comment
CBC/BBS UK 33 1967-2000 319 -65 -75 -50 >50  
  25 1975-2000 380 45 16 80    
  10 1990-2000 735 41 29 56    
  5 1995-2000 1143 12 7 16    
CBC/BBS England 33 1967-2000 279 -65 -73 -51 >50  
  25 1975-2000 332 49 14 90    
  10 1990-2000 641 44 29 66    
  5 1995-2000 995 12 8 17    
WBS waterways 25 1975-2000 40 81 -8 219    
  10 1990-2000 57 128 69 198    
  5 1995-2000 63 21 8 34    
CES adults 17 1984-2001 57 -32 . . [>25]  
  10 1991-2001 70 -18 . .    
  5 1996-2001 71 -19 . .    
CES juveniles 17 1984-2001 62 -38 . . [>25]  
  10 1991-2001 75 -28 . . [>25]  
  5 1996-2001 77 -22 . .    
BBS UK 8 1994-2002 978 30 22 38    
BBS England 8 1994-2002 851 36 27 45    
BBS Scotland 8 1994-2002 53 12 -20 57    
BBS Wales 8 1994-2002 61 -7 -27 20    
BBS acknowledgement
 
CBC/BBS England graph
WBS UK graph
CES adult abundance graph
CES juvenile abundance graph
BBS UK graph
BBS England graph
BBS Scotland graph
BBS Wales graph
 
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 33 1968-2001 26 None       Small sample
Brood size 33 1968-2001 60 Curvilinear 4.25 chicks 4.16 chicks -0.09 chicks  
Daily failure rate (eggs) 33 1968-2001 36 None        
Daily failure rate (chicks) 33 1968-2001 45 None        
Laying date 33 1968-2001 17 Curvilinear day 146 day 145 -1 days Small sample
Percentage juveniles (CES) 17 1984-2001 73 Smoothed trend 137 productivity index 101 productivity index -27%[>25]  
Percentage juveniles (CES) 10 1991-2001 87 Smoothed trend 136 productivity index 101 productivity index -26%[>25]  
Percentage juveniles (CES) 5 1996-2001 90 Smoothed trend 119 productivity index 101 productivity index -16%  
 
Clutch size graph
Brood size graph
Egg nest failure graph
Chick nest failure graph
Laying date graph
CES productivity
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This report should be cited as:
Crick, H.Q.P., Marchant, J.H., Noble, D.G., Baillie, S.R., 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. (2004)
Breeding Birds in the Wider Countryside: their conservation status 2003.
BTO Research Report No. 353. BTO, Thetford. (http://www.bto.org/birdtrends2003)

Pages maintained by Susan Waghorn and Iain Downie: Last updated 16 February, 2009