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BTO Blueline

JAY
Garrulus glandarius
 

• Population
  changes

• Productivity
  trends

• Additional
  information
Conservation listings
Europe: no SPEC category (favourable conservation status in Europe, not concentrated in Europe)
UK: green
Long-term trend
UK, England: fluctuating, with no long-term trend
UK population size
160,000 territories in 2000 (1988–91 Atlas estimate updated using CBC/BBS trend: BiE04, APEP06)
Status summary
The UK Jay population remained stable in the species' preferred woodland habitat until the late 1980s, after which the population began to decline. This decrease followed an earlier decline on farmland CBC plots (Gregory & Marchant 1996). Long-term trends are stable overall, and the CBC/BBS index has recorded some increase in the recent ten-year period. No trends are known in breeding performance.
 

Population changes
CBC/BBS UK graph
 
Table of population changes for Jay

Source Period
(yrs)		 Years Plots
(n)		 Change
(%)		 Lower
limit		 Upper
limit		 Alert Comment
CBC/BBS UK 39 1967-2006 284 1 -19 25    
  25 1981-2006 386 -2 -15 13    
  10 1996-2006 704 11 5 18    
  5 2001-2006 756 4 -4 10    
CBC/BBS England 39 1967-2006 252 -6 -26 20    
  25 1981-2006 339 -8 -21 7    
  10 1996-2006 610 5 -3 14    
  5 2001-2006 648 5 -1 13    
BBS UK 11 1995-2006 628 9 1 18    
  10 1996-2006 652 11 4 19    
  5 2001-2006 756 5 -2 11    
BBS England 11 1995-2006 543 1 -7 9    
  10 1996-2006 561 5 -3 11    
  5 2001-2006 648 6 -1 11    
BBS Wales 11 1995-2006 65 24 -4 48    
  10 1996-2006 69 17 -6 36    
  5 2001-2006 79 0 -11 16    

BBS acknowledgement
 
CBC/BBS England graph
BBS UK graph
BBS England graph
BBS Wales graph
 

Productivity trends
Table of productivity changes for Jay

Variable Period
(yrs)		 Years Mean
annual
sample		 Trend Modelled
in first year		 Modelled
in 2006		 Change Comment
Brood size 38 1968-2006 10 None       Small sample

 

 

 

Insufficient data on clutch size
available for this species
Brood size graph

 

 

Insufficient data on egg stage failure
available for this species

 

 

Insufficient data on nestling failure
available for this species

 

Insufficient data on laying date
available for this species

 

 

Insufficient data on CES
available for this species

 
 

Additional information
BTO blue divider
 

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This report should be cited as:
Baillie, S.R., Marchant, J.H., Leech, D.I., Joys, A.C., Noble, D.G.,
Barimore, C., Grantham, M.J., Risely, K. & Robinson, R.A. (2009).
Breeding Birds in the Wider Countryside: their conservation status 2008.
BTO Research Report No. 516. BTO, Thetford. (http://www.bto.org/birdtrends)

Pages maintained by Iain Downie, Mandy T Andrews and Laura Smith: Last updated 18.02.2009