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MUTE SWAN
Cygnus olor
Mute Swan © Mike Weston
Conservation listings

Europe: no SPEC category, secure
UK: Amber (>20% of European breeding population)

Long-term trend
UK: moderate increase
 
Status summary
Mute Swan populations have increased progressively on both WBS and CBC plots since the mid-1980s, perhaps reflecting warmer winter weather and the replacement of anglers' lead weights with non-toxic alternatives (Gibbons et al. 1993). CBC/BBS data indicate that a rapid increase has occurred, but may be less representative of the whole population than WBS figures.The reductions in breeding performance, although statistically significant, may be to some extent artefacts of the relatively small and perhaps unrepresentative annual samples in the 1990s. The recent change of conservation listing from Green to Amber is unconnected with its UK trend.
CBC/BBS UK graph
Table of population changes for Mute Swan
Source Period
(yrs)
Years Plots
(n)
Change
(%)
Lower
limit
Upper
limit
Alert Comment
CBC/BBS UK 33 1967-2000 55 241 34 671    
  25 1975-2000 67 173 12 373    
  10 1990-2000 131 71 33 130    
  5 1995-2000 202 27 5 66    
CBC/BBS England 33 1967-2000 47 192 43 651    
  25 1975-2000 58 145 24 306    
  10 1990-2000 113 53 28 107    
  5 1995-2000 175 8 -2 26    
WBS waterways 25 1975-2000 44 73 18 165    
  10 1990-2000 56 49 31 80    
  5 1995-2000 61 22 11 37    
BBS UK 8 1994-2002 170 22 3 44    
BBS England 8 1994-2002 145 -12 -25 4    
BBS acknowledgement
CBC/BBS England graph
WBS UK graph
BBS UK graph
BBS England graph
Table of productivity information for Mute Swan
Variable Period
(yrs)
Years Mean
annual
sample
Trend Predicted
in first year
Predicted
in last year
Change Comment
Clutch size 33 1968-2001 19 Linear decline 5.86 eggs 5.1 eggs -0.76 eggs Small sample
Brood size 33 1968-2001 33 None        
Daily failure rate (eggs) 33 1968-2001 26 Curvilinear 0.0078 nests/day 0.0431 nests/day 0.0353 nests/day Small sample
Daily failure rate (chicks) 33 1968-2001 20 Linear increase 0.0005 nests/day 0.003 nests/day 0.0025 nests/day Small sample
Laying date 33 1968-2001 12 None       Small sample
Clutch size graph
Brood size graph
Egg nest failure graph
Chick nest failure graph
Laying date graph
Insufficient data on CES
available for this species
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This report should be cited as:
Crick, H.Q.P., Marchant, J.H., Noble, D.G., Baillie, S.R., 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. (2004)
Breeding Birds in the Wider Countryside: their conservation status 2003.
BTO Research Report No. 353. BTO, Thetford. (http://www.bto.org/birdtrends2003)

Pages maintained by Susan Waghorn and Iain Downie: Last updated 16 February, 2009