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Breeding Bird Survey
Common Birds Census
Constant Effort Sites
Nest Record Scheme
Waterways Bird Survey
Alerts
Summary
What the categories mean
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DIPPER Cinclus cinclus
 
Conservation Listings Long term trend

Unlisted/Green
Biodiversity Steering Group
Conservation Concern List

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 37% down to 5%.
 
 
Table of population changes for Dipper
Source Period
(yrs)
Years Plots
(n)
Change
(%)
Lower
limit
Upper
limit
Alert Comment
WBS waterways 23 1975-1998 37 -16 -41 11    
  10 1988-1998 40 -15 -31 3    
  5 1993-1998 38 -5 -17 9    
BBS UK 5 1994-1999 44 28 -14 92   Small sample
BBS Scotland 5 1994-1999 21 33 -26 138   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 30 1968-1998 79 None        
Brood size 30 1968-1998 151 Linear increase 3.49 chicks 3.95 chicks 0.46 chicks  
Daily failure rate (eggs) 30 1968-1998 109 Linear decline 0.0225 nests/day 0.0023 nests/day -0.0202 nests/day  
Daily failure rate (chicks) 30 1968-1998 86 Curvilinear 0.0052 nests/day 0.0068 nests/day 0.0016 nests/day  
Laying date 30 1968-1998 65 Linear decline day 108 day 101 -7 days  
 
Insufficient data on CES
available for this species
   




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Last updated: 15 March, 2001

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