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TREE SPARROW Passer montanus
 
Conservation Listings Long term trend

Table 3/Red
(>=50% Population decline)

Biodiversity Steering Group
Priority Species List

UK: Rapid decline
 
Status Summary
Tree Sparrow abundance crashed between the late-1970s and the mid-1980s; abundance was comparatively stable beforehand and has remained so subsequently, as the BBS confirms. Clear range contractions have also occurred (Gibbons et al. 1993). Breeding performance has improved, suggesting that it has not driven the decline, for example failure rates at the egg stage (16 days, comprising 12 days incubation + 4 days laying) fell from 10% to 5%. It is likely that survival may have been more critical demographic rate, although ring-recovery analyses have produced equivocal results because of small sample sizes (Siriwardena et al. 1998b, 2000b). Features of agricultural intensification such as reductions in winter stubble availability are likely to be implicated in the decline.
 
 
Table of population changes for Tree Sparrow
Source Period
(yrs)
Years Plots
(n)
Change
(%)
Lower
limit
Upper
limit
Alert Comment
CBC all habitats 30 1968-1998 60 -95 -98 -88 >50  
  25 1973-1998 55 -94 -98 -87 >50  
  10 1988-1998 22 -58 -80 -27 >50  
  5 1993-1998 15 -30 -54 -6 >25 Small sample
CBC farmland 30 1968-1998 40 -94 -98 -86 >50  
  25 1973-1998 35 -93 -97 -86 >50  
  10 1988-1998 17 -63 -84 -38 >50 Small sample
  5 1993-1998 12 -36 -64 -6 >25 Small sample
BBS UK 5 1994-1999 132 11 -10 36    
BBS England 5 1994-1999 112 9 -12 36    
The Breeding Bird Survey is jointly funded by BTO, JNCC and RSPB
 
 
Table of productivity information for Tree Sparrow
Variable Period
(yrs)
Years Mean
annual
sample
Trend Predicted
in first year
Predicted
in last year
Change Comment
Clutch size 30 1968-1998 93 Linear increase 4.77 eggs 5.36 eggs 0.59 eggs  
Brood size 30 1968-1998 104 Linear increase 3.83 chicks 4.49 chicks 0.66 chicks  
Daily failure rate (eggs) 30 1968-1998 122 Curvilinear 0.0069 nests/day 0.003 nests/day -0.0039 nests/day  
Daily failure rate (chicks) 30 1968-1998 88 None        
Laying date 30 1968-1998 106 None        
 
Insufficient data on CES
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: 21 March, 2001

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