Wider Countryside Report Header
BTO Blueline
Main WCR menu image Site navigation menu item Results overview menu item Other info menu item BTO website menu item
BTO Blueline
MUTE SWAN
Cygnus olor
Mute Swan © Mike Weston
 

• Population
  changes

• Productivity
  trends

• Additional
  information
Conservation listings
Europe: no SPEC category (concentrated in Europe, conservation status favourable)
UK: amber (>20% of European breeding population)
Long-term trend
UK, England: rapid increase
UK population size
28,000–30,000 adults in 1990 (Delany et al. 1992: APEP06); 23,900–25,600 pairs in 2000 (updated using CBC/BBS trend: BiE04); 28,600–35,200 birds in Britain in 2002 (Rowell & Spray 2004)
Status summary
Mute Swan populations, which had been fairly stable since the 1960s, have increased progressively since the mid 1980s, perhaps reflecting warmer winter weather and the replacement of anglers' lead weights, which had earlier caused many casualties, with non-toxic alternatives (Rowell & Spray 2004, Ward et al. 2007). WBS plots, likely to be a preferred habitat for breeding swans, show a more moderate rate of increase than CBC/BBS. Winter trends as measured by WeBS have shown a parallel upturn (Austin et al. 2008). 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.
 

Population changes
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 39 1967-2006 80 199 33 473    
  25 1981-2006 117 139 64 277    
  10 1996-2006 234 7 -9 25    
  5 2001-2006 254 -14 -25 -4    
CBC/BBS England 39 1967-2006 69 181 13 560   Small CBC sample
  25 1981-2006 100 132 56 255   Small CBC sample
  10 1996-2006 201 1 -15 18    
  5 2001-2006 215 -7 -17 9    
WBS waterways 31 1975-2006 45 52 -1 152    
  25 1981-2006 47 33 3 89    
  10 1996-2006 55 2 -13 23    
  5 2001-2006 48 -7 -17 6    
BBS UK 11 1995-2006 213 10 -7 40    
  10 1996-2006 221 6 -10 24    
  5 2001-2006 254 -12 -23 -2    
BBS England 11 1995-2006 182 1 -18 21    
  10 1996-2006 190 1 -16 15    
  5 2001-2006 215 -6 -20 2    

BBS acknowledgement
 
CBC/BBS England graph
WBS UK graph
BBS UK graph
BBS England graph
 

Productivity trends
Table of productivity changes for Mute Swan

Variable Period
(yrs)		 Years Mean
annual
sample		 Trend Modelled
in first year		 Modelled
in 2006		 Change Comment
Clutch size 38 1968-2006 22 Curvilinear 5.89 eggs 5.64 eggs -4.2% Small sample
Brood size 38 1968-2006 38 None        
Daily failure rate (eggs) 38 1968-2006 30 Curvilinear 0.61% nests/day 1.41% nests/day 131.1% Small sample
Daily failure rate (chicks) 38 1968-2006 25 None       Small sample
Laying date 38 1968-2006 13 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
 

Additional information
BTO blue divider
 

BTO Home | JNCC Home
 © British Trust for Ornithology. Charity No 216652 (England and Wales).Charity No SC039193 (Scotland)
Company Limited by Guarantee No 357284 (England and Wales).
Registered Office: The Nunnery, Thetford, Norfolk IP24 2PU, UK.
Terms and Conditions | Privacy Statement          Email:


This report should be cited as:
Baillie, S.R., Marchant, J.H., Leech, D.I., Joys, A.C., Noble, D.G.,
Barimore, C., Grantham, M.J., Risely, K. & Robinson, R.A. (2009).
Breeding Birds in the Wider Countryside: their conservation status 2008.
BTO Research Report No. 516. BTO, Thetford. (http://www.bto.org/birdtrends)

Pages maintained by Iain Downie, Mandy T Andrews and Laura Smith: Last updated 18.02.2009