The British Trust for Ornithology
Haematopus ostralegus

Oystercatcher © Tommy Holden

Conservation Listings

Table 4/Amber (Wintering population)
Biodiversity Steering Group: Unlisted

Long term trend
UK Waterways: Stable after rapid increase
Scotland: Stable
Status Summary
Oystercatchers increased along inland waterways between 1974 and 1986, as the species colonised inland areas in England and Wales (Gibbons et al. 1993). Thereafter, the WBS index stabilised, so showing a pattern parallel to that in winter abundance revealed by WeBS (Musgrove et al. 2001). The increase in nest failure rates for the 27-day egg stage (25 days for incubation + 2 days for laying) is from 30% to 43% and probably results from the spread of the species into less favourable areas. The trend towards earlier laying can be partially explained by recent climate change (Crick & Sparks 1999).
Table of population changes for Oystercatcher
Source Period
Years Plots
Alert Comment
WBS waterways 24 1975-1999 23 110 73 164    
  10 1989-1999 29 0 -18 30    
  5 1994-1999 31 4 -5 16    
BBS UK 6 1994-2000 231 -8 -17 2    
BBS England 6 1994-2000 103 11 -8 34    
BBS Scotland 6 1994-2000 117 -13 -24 1    
The Breeding Bird Survey is jointly funded by BTO, JNCC and RSPB
Table of productivity information for Oystercatcher
Variable Period
Years Mean
Trend Predicted
in first year
in last year
Change Comment
Clutch size 31 1968-1999 105 None        
Daily failure rate (eggs) 31 1968-1999 112 Linear increase 0.0131 nests/day 0.0204 nests/day 0.0073 nests/day  
Laying date 31 1968-1999 47 Linear decline day 137 day 130 -7 days  
Insufficient data on brood size
available for this species
Insufficient data on nestling failure
available for this species
Insufficient data on CES
available for this species

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This report should be cited as:
Baillie, S.R., Crick, H.Q.P., Balmer, D.E., Beaven, L.P., Downie, I.S., Freeman, S.N., Leech, D.I., Marchant, J.H.,
Noble, D.G., Raven, M.J., Simpkin, A.P., Thewlis, R.M. and Wernham, C.V.
(2002) Breeding Birds in the Wider
Countryside: their conservation status 2001. BTO Research Report No. 278. BTO, Thetford. (

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This page last updated: 21 April, 2008

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