The British Trust for Ornithology
DIPPER
Cinclus cinclus
Dipper © Tommy Holden
Conservation Listings

Unlisted/Green
Biodiversity Steering Group Conservation Concern List

Long term trend
UK: Fluctuating with no long-term trend
Status Summary
The WBS trend shows that Dipper populations have fluctuated considerably over the last 30 years. The species is a good indicator of acidity and other water pollution (Ormerod & Tyler 1989, 1990), so the trend warrants careful monitoring. Breeding performance has improved strongly over time as laying dates have become earlier, perhaps because of climate change (Crick & Sparks 1999). Although the change in nestling-stage failure rates is relatively minor, the decline for the 20-day egg stage (16 days incubation + 4 days laying) is from 41% down to 7%.
Table of population changes for Dipper
Source Period
(yrs)
Years Plots
(n)
Change
(%)
Lower
limit
Upper
limit
Alert Comment
WBS waterways 24 1975-1999 37 -14 -36 13    
  10 1989-1999 38 -11 -24 3    
  5 1994-1999 36 -2 -11 9    
BBS Scotland 6 1994-2000 21 20 -35 123   Small sample
The Breeding Bird Survey is jointly funded by BTO, JNCC and RSPB
Table of productivity information for Dipper
Variable Period
(yrs)
Years Mean
annual
sample
Trend Predicted
in first year
Predicted
in last year
Change Comment
Clutch size 31 1968-1999 78 None        
Brood size 31 1968-1999 149 Linear increase 3.49 chicks 3.96 chicks 0.47 chicks  
Daily failure rate (eggs) 31 1968-1999 108 Curvilinear 0.026 nests/day 0.0034 nests/day -0.0226 nests/day  
Daily failure rate (chicks) 31 1968-1999 85 Curvilinear 0.005 nests/day 0.006 nests/day 0.001 nests/day  
Laying date 31 1968-1999 65 Linear decline day 108 day 101 -7 days  
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. (http://www.bto.org/birdtrends)

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This page last updated: 21 April, 2008

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