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Breeding Bird Survey
Common Birds Census
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BLUE TIT Parus caeruleus
 
Conservation Listings Long term trend

Unlisted/Green
Biodiversity Steering Group Conservation Concern List

UK: Shallow increase
 
Status Summary
Blue Tit populations have increased in parallel with those of Great Tits, with two brief pauses in the long-term upward trend. The recent changes in the BBS index show fluctuations but no clear trend. Winter food provision by humans and access to nest boxes that are safe from predation may have contributed to the population increase. However, a decline in productivity revealed by the CES may indicate developing problems for the population. (The improvement in failure rates at the egg stage (22 days, comprising 14 days incubation + 8 days laying) is only minor, having fallen from 10% to 6%.)
 
 
Table of population changes for Blue Tit
Source Period
(yrs)
Years Plots
(n)
Change
(%)
Lower
limit
Upper
limit
Alert Comment
CBC all habitats 30 1968-1998 216 35 21 48    
  25 1973-1998 222 17 8 27    
  10 1988-1998 211 4 0 8    
  5 1993-1998 220 8 5 11    
CBC farmland 30 1968-1998 93 33 . .    
  25 1973-1998 93 18 . .    
  10 1988-1998 93 11 . .    
  5 1993-1998 94 14 . .    
CBC woodland 30 1968-1998 84 30 . .    
  25 1973-1998 90 15 . .    
  10 1988-1998 97 0 . .    
  5 1993-1998 103 5 . .    
CES adults 14 1984-1998 93 11 . .    
  10 1988-1998 106 10 . .    
  5 1993-1998 115 12 . .    
CES juveniles 14 1984-1998 92 -24 . .    
  10 1988-1998 105 -17 . .    
  5 1993-1998 114 -16 . .    
BBS UK 5 1994-1999 1613 7 3 11    
BBS England 5 1994-1999 1324 5 1 9    
BBS Scotland 5 1994-1999 118 9 -9 29    
BBS Wales 5 1994-1999 120 11 -3 28    
BBS N.Ireland 5 1994-1999 44 35 -5 90   Small sample
The Breeding Bird Survey is jointly funded by BTO, JNCC and RSPB
 
 
Table of productivity information for Blue Tit
Variable Period
(yrs)
Years Mean
annual
sample
Trend Predicted
in first year
Predicted
in last year
Change Comment
Clutch size 30 1968-1998 86 None        
Brood size 30 1968-1998 137 None        
Daily failure rate (eggs) 30 1968-1998 138 Linear decline 0.0048 nests/day 0.0029 nests/day -0.0019 nests/day  
Daily failure rate (chicks) 30 1968-1998 118 None        
Laying date 30 1968-1998 120 None        
Percentage juveniles (CES) 14 1984-1998 96 Smoothed trend 164 productivity index 100 productivity index -39%[>25*]  
Percentage juveniles (CES) 10 1988-1998 110 Smoothed trend 147 productivity index 100 productivity index -32%[>25*]  
Percentage juveniles (CES) 5 1993-1998 118 Smoothed trend 135 productivity index 100 productivity index -26%[>25*]  
 

 

   



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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