BTO - Breeding Birds of the Wider Countryside: Tree Sparrow

TREE SPARROW
Passer montanus

Conservation listings

Europe: SPEC category 3 (declining)
UK: red (>50% population decline)

Long-term trend

England: rapid decline

Distribution maps

Maps and statistics from British and Irish
atlases can be viewed here.

Status summary

Tree Sparrow abundance crashed between the late 1970s and the early 1990s. BBS data indicate increase since 1994, in England and in the UK as a whole, but it should be remembered that the current population level is still only about 3% of that of the 1970s. Clear range contractions occurred between the two breeding atlas periods (Gibbons et al. 1993), and have continued subsequently, with many local extinctions occurring during the 1990s. Components of agricultural intensification, such as reductions in winter stubble availability, are likely to be implicated in the decline. Breeding performance has improved substantially as population sizes have decreased, suggesting that decreases in productivity were not responsible for the decline. It is likely that survival was the more critical demographic measure, although ring-recovery analyses have produced equivocal results because of small sample sizes (Siriwardena et al. 1998b, 2000b). Following declines across western and northwestern Europe during the 1990s, the European status of this species is no longer considered 'secure'.

Table of population changes for Tree Sparrow

Source Period
(yrs) Years Plots
(n) Change
(%) Lower
limit Upper
limit Alert Comment

CBC/BBS England 35 1967-2002 77 -97 -99 -94 >50

25 1977-2002 75 -96 -99 -93 >50

10 1992-2002 100 -20 -65 0

5 1997-2002 119 22 1 54

BBS UK 9 1994-2003 133 52 24 85

BBS England 9 1994-2003 111 23 0 52

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 34 1968-2002 93 Curvilinear 4.71 eggs 5.19 eggs 0.48 eggs

Brood size 34 1968-2002 104 Linear increase 3.85 chicks 4.52 chicks 0.67 chicks

Daily failure rate (eggs) 34 1968-2002 121 Curvilinear 0.0072 nests/day 0.0031 nests/day -0.0041 nests/day

Daily failure rate (chicks) 34 1968-2002 87 Linear decline 0.0141 nests/day 0.0087 nests/day -0.0054 nests/day

Laying date 34 1968-2002 105 None

Insufficient data on CES
available for this species


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This report should be cited as: Baillie, S.R., Marchant, J.H., Crick, H.Q.P., Noble, D.G., Balmer, D.E., Beaven, L.P., Coombes, R.H., Downie, I.S., Freeman, S.N., Joys, A.C., Leech, D.I., Raven, M.J., Robinson, R.A. and Thewlis, R.M. (2005) Breeding Birds in the Wider Countryside: their conservation status 2004. BTO Research Report No. 385. BTO, Thetford. (http://www.bto.org/birdtrends) Pages maintained by Susan Waghorn and Iain Downie: Last updated 18 January, 2006