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
SEDGE WARBLER
Acrocephalus schoenobaenus
Sedge Warbler © Tommy Holden
 

• Population
  changes

• Productivity
  trends

• Additional
  information

Conservation listings
Europe: no SPEC category (concentrated in Europe, conservation status favourable)
UK: green
Long-term trend
UK: fluctuating, with no long-term trend
UK population size
321,000 territories in 2000 (1988–91 Atlas estimate updated using CBC/BBS trend: BiE04, APEP06)
Status summary
Detailed analysis of BTO data sets has shown that much of the year-to-year variation in population size is driven by changes in adult survival rates which, in turn, are related to changes in rainfall on their wintering grounds, just south of the Sahara Desert, in the West African Sahel (Peach et al. 1991). The smoothed CBC/BBS and WBS trends show four troughs in population, related to years of poor West African rainfall, with a low point in 1984–85. The CES, which provides the biggest Sedge Warbler sample, shows the most recent three of the same troughs and also illustrates the large year-to-year fluctuations that occur in this species. Daily nest failure rates at the egg stage have almost halved. CES productivity data show a steep fall in the 1980s, followed by further shallow decrease.
 

Population changes

CBC/BBS UK graph
 
BBS acknowledgement
 
CBC/BBS England graph
WBS UK graph
CES adult abundance graph
CES juvenile abundance graph
BBS UK graph
BBS England graph
BBS Scotland graph
 

Productivity trends

 
Clutch size graph
Brood size graph
Egg nest failure graph
Chick nest failure graph
Laying date graph
CES productivity graph
 

Additional information

BTO blue divider
 

BTO Home | JNCC Home
BTO, The Nunnery, Thetford, Norfolk IP24 2PU, UK.
 © British Trust for Ornithology (Registered Charity Number 216652).
Terms and Conditions
| Privacy Statement          Email:


This report should be cited as:
Baillie, S.R., Marchant, J.H., Crick, H.Q.P., Noble, D.G., Balmer, D.E., 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. (2006)
Breeding Birds in the Wider Countryside: their conservation status 2005.
BTO Research Report No. 435. BTO, Thetford. (http://www.bto.org/birdtrends)

Pages maintained by Susan Waghorn and Iain Downie: Last updated 11 November, 2008