Contents of report
Breeding Bird Survey
Common Birds Census
Constant Effort Sites
Nest Record Scheme
Waterways Bird Survey
Alerts
Summary
What the categories mean
Return to BTO Home Page
.
LONG-TAILED TIT Aegithalos caudatus
 
Conservation Listings Long term trend

Unlisted/Green
Biodiversity Steering Group: Unlisted

UK: Fluctuating, long-term overall moderate increase
 
Status Summary
Both CBC and CES index trends show increases in Long-tailed Tit abundance since the mid-1980s, but the species tends to undergo large-scale fluctuations in numbers, probably because of the effects of winter weather. Improvements in nesting success at the egg stage, (19 days, comprising 13 days incubation + 6 days laying) from 54% to 85%, have accompanied the recent increase and the trend towards earlier laying can be explained by recent climate change (Crick & Sparks 1999).
 
 
Table of population changes for Long-tailed Tit
Source Period
(yrs)
Years Plots
(n)
Change
(%)
Lower
limit
Upper
limit
Alert Comment
CBC all habitats 30 1968-1998 129 53 13 111    
  25 1973-1998 137 -1 -21 22    
  10 1988-1998 147 29 17 44    
  5 1993-1998 159 -7 -13 -2    
CBC farmland 30 1968-1998 46 86 . .    
  25 1973-1998 48 11 . .    
  10 1988-1998 56 44 . .    
  5 1993-1998 59 -4 . .    
CBC woodland 30 1968-1998 61 -10 -39 53    
  25 1973-1998 66 -32 -50 -6 >25  
  10 1988-1998 76 13 -1 26    
  5 1993-1998 83 -10 -17 -3    
CES adults 14 1984-1998 72 31 . .    
  10 1988-1998 86 23 . .    
  5 1993-1998 96 0 . .    
CES juveniles 14 1984-1998 64 15 . .    
  10 1988-1998 77 40 . .    
  5 1993-1998 89 -6 . .    
BBS UK 5 1994-1999 587 15 3 29    
BBS England 5 1994-1999 517 3 -8 15    
BBS Wales 5 1994-1999 43 36 -17 120   Small sample
The Breeding Bird Survey is jointly funded by BTO, JNCC and RSPB
 
 
Table of productivity information for Long-tailed Tit
Variable Period
(yrs)
Years Mean
annual
sample
Trend Predicted
in first year
Predicted
in last year
Change Comment
Clutch size 30 1968-1998 31 Linear decline 7.62 eggs 6.72 eggs -0.9 eggs  
Brood size 30 1968-1998 26 Curvilinear 6.84 chicks 6.27 chicks -0.57 chicks Small sample
Daily failure rate (eggs) 30 1968-1998 49 Curvilinear 0.0316 nests/day 0.0085 nests/day -0.0231 nests/day  
Daily failure rate (chicks) 30 1968-1998 34 Linear increase 0.0074 nests/day 0.0159 nests/day 0.0085 nests/day  
Laying date 30 1968-1998 41 Curvilinear day 108 day 96 -12 days  
Percentage juveniles (CES) 14 1984-1998 78 Smoothed trend 99 productivity index 100 productivity index 1%  
Percentage juveniles (CES) 10 1988-1998 92 Smoothed trend 84 productivity index 100 productivity index 19%  
Percentage juveniles (CES) 5 1993-1998 103 Smoothed trend 104 productivity index 100 productivity index -4%  
 
   



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)

[ Welcome | Contents | Introduction | CBC | WBS | BBS | Heronries | CES | NRS | Alerts ]
[ Summary | Discussion | References | Help | BTO Home Page ]

© British Trust for Ornithology
BTO, The Nunnery, Thetford, Norfolk IP24 2PU
Tel: (+44) (0) 1842 750050 Fax: (+44) (0) 1842 750030 Email:

Last updated: 18 April, 2001

Page created by Susan Waghorn