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WILLOW TIT Parus montanus
 
Conservation Listings Long term trend

Table 4/Amber
(25-49% Population decline)

Biodiversity Steering Group Conservation Concern List

UK: Rapid decline
 
Status Summary
Willow Tits have been in decline since the mid-1970s and the continuing decline in the CBC index through the 1990s following a brief pause through the later 1980s is replicated in the abundance trend from constant-effort ringing. The decline is unlikely to be due to nest predation and has only occurred in woodland and farmland, not in the species' preferred, wet, habitats (G.M. Siriwardena, unpubl.). Candidate causes for the decline include reductions in the availability of dead wood, woodland drainage and drying and reductions in woodland shrub layer density (Vanhinsbergh et al. 2001).
 
 
Table of population changes for Willow Tit
Source Period
(yrs)
Years Plots
(n)
Change
(%)
Lower
limit
Upper
limit
Alert Comment
CBC all habitats 30 1968-1998 32 -69 -82 -46 >50  
  25 1973-1998 31 -75 -86 -57 >50  
  10 1988-1998 20 -56 -69 -38 >50 Small sample
  5 1993-1998 18 -33 -45 -17 >25 Small sample
CES adults 14 1984-1998 25 -36 . . [>25]  
  10 1988-1998 29 -44 . . [>25]  
  5 1993-1998 29 -31 . . [>25]  
CES juveniles 14 1984-1998 35 -19 . .    
  10 1988-1998 40 -40 . . [>25]  
  5 1993-1998 40 -27 . . [>25]  
BBS UK 5 1994-1999 60 -42 -58 -18 (>25)  
BBS England 5 1994-1999 53 -40 -57 -15 (>25)  
The Breeding Bird Survey is jointly funded by BTO, JNCC and RSPB
 
 
Table of productivity information for Willow Tit
Variable Period
(yrs)
Years Mean
annual
sample
Trend Predicted
in first year
Predicted
in last year
Change Comment
Percentage juveniles (CES) 14 1984-1998 40 Smoothed trend 105 productivity index 100 productivity index -5%  
Percentage juveniles (CES) 10 1988-1998 44 Smoothed trend 101 productivity index 100 productivity index -1%  
Percentage juveniles (CES) 5 1993-1998 44 Smoothed trend 99 productivity index 100 productivity index 1%  
 

 

Insufficient data on clutch size
available for this species

 

 

Insufficient data on brood size
available for this species

 

 

Insufficient data on nest failure
available for this species

 

 

Insufficient data on nestling failure available for this species

 

Insufficient data on laying date
available for this species

 

   



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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Last updated: 17 April, 2001

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