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BTO Blueline
WHITETHROAT
Sylvia communis
Whitethroat © Tommy Holden
 

• Population
  changes

• Productivity
  trends

• Additional
  information

Conservation listings
Europe: no SPEC category (concentrated in Europe, conservation status favourable)
UK: green
Long-term trend
UK, England: rapid decline, followed by shallow increase
UK population size
945,000 territories in 2000 (1988–91 Atlas estimate updated using CBC/BBS trend: BiE04, APEP06)
Status summary
Whitethroat populations had been stable for a few years up to 1968 but, after a normal autumn departure for Africa, crashed by around 70% between the 1968 and 1969 breeding seasons. They fluctuated around their lower level until the mid 1980s, since when they have sustained a consistent shallow recovery. 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, just south of the Sahara Desert. Annual fluctuations in abundance, which are not shown in the smoothed trends, correlate to those in overwinter survival (Baillie & Peach 1992). Other trans-Saharan migrant warblers have shared similarly timed population changes in abundance (Siriwardena et al. 1998b). Productivity, as measured by CES, rose during the 1980s and has since fluctuated. It seems likely that habitat loss since the 1960s, particularly on farmland, will eventually limit the degree of recovery.
 

Population changes

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 England 36 1967-2003 317 -63 -75 -51 >50  
  25 1978-2003 408 48 15 82    
  10 1993-2003 867 41 30 49    
  5 1998-2003 1014 11 7 15    
CBC/BBS UK 36 1967-2003 363 -63 -75 -52 >50  
  25 1978-2003 468 43 14 82    
  10 1993-2003 996 41 31 50    
  5 1998-2003 1171 10 5 16    
WBS waterways 28 1975-2003 40 110 -2 269    
  25 1978-2003 42 194 52 384    
  10 1993-2003 57 84 40 118    
  5 1998-2003 52 22 0 38    
CES adults 19 1984-2003 58 -24 -44 -6    
  10 1993-2003 71 10 -9 32    
  5 1998-2003 65 24 11 38    
CES juveniles 19 1984-2003 63 -31 -53 -6 >25  
  10 1993-2003 76 -7 -27 15    
  5 1998-2003 72 52 26 80    
BBS UK 10 1994-2004 1024 39 31 48    
BBS England 10 1994-2004 887 39 30 48    
BBS Scotland 10 1994-2004 57 63 19 123    
BBS Wales 10 1994-2004 65 7 -16 34    

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
 

Productivity trends

Table of productivity changes for Whitethroat

Variable Period
(yrs)
Years Mean
annual
sample
Trend Modelled
in first year
Modelled
in 2003
Change Comment
Clutch size 35 1968-2003 25 None       Small sample
Brood size 35 1968-2003 59 None        
Daily failure rate (eggs) 35 1968-2003 36 None        
Daily failure rate (chicks) 35 1968-2003 44 None        
Laying date 35 1968-2003 17 Curvilinear May 26 May 20 -6 days Small sample
Juvenile to Adult ratio (CES) 19 1984-2003 73 Smoothed trend 74 Index value 103 Index value 35%  
Juvenile to Adult ratio (CES) 10 1993-2003 88 Smoothed trend 106 Index value 103 Index value -6%  
Juvenile to Adult ratio (CES) 5 1998-2003 83 Smoothed trend 86 Index value 103 Index value 17%  

 
Clutch size graph
Brood size graph
Egg nest failure graph
Chick nest failure graph
Laying date graph
CES productivity
 

Additional information

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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., 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. (2006)
Breeding Birds in the Wider Countryside: their conservation status 2005.
BTO Research Report No. 435. BTO, Thetford. (http://www.bto.org/birdtrends)

Pages maintained by Susan Waghorn and Iain Downie: Last updated 11 November, 2008