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Common Birds Census
Constant Effort Sites
Nest Record Scheme
Waterways Bird Survey
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Summary
What the categories mean
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PIED WAGTAIL Motacilla alba
 
Conservation Listings Long term trend

Unlisted/Green
Biodiversity Steering Group
Conservation Concern List

UK: Uncertain
Lowland England: Fluctuating after a moderate increase
Waterways: Moderate decline
 
Status Summary
Pied Wagtails are most abundant in northern and western areas that are not covered well by the CBC or WBS, but the two schemes show similar trends for birds that breed in lowland Britain. Abundance has been stable since the mid-1980s, but this stable period was preceded by a decade of decline that is most apparent in the WBS index, perhaps suggesting particular impacts of habitat influences specific to linear waterways. The CBC shows that a strong increase preceded this period of decline, such that populations have increased, overall, since 1966 and there have been no trends in breeding performance that could explain the population trends. Although average clutch size has declined a little and chick stage failure rates show little overall change, failure rates at the egg stage (17 days, comprising 13 days incubation + 4 days laying) have fallen from 26% to 19%. The long-term trend in abundance is similar to those shown by Wren and Long-tailed Tit, two other resident insectivores (Siriwardena et al. 1998a).
 
 
Table of population changes for Pied Wagtail
Source Period
(yrs)
Years Plots
(n)
Change
(%)
Lower
limit
Upper
limit
Alert Comment
CBC all habitats 30 1968-1998 84 70 24 139   Unrepresentative
  25 1973-1998 87 8 -18 46   Unrepresentative
  10 1988-1998 75 22 2 52   Unrepresentative
  5 1993-1998 76 5 -4 18   Unrepresentative
CBC farmland 30 1968-1998 58 69 . .   Unrepresentative
  25 1973-1998 59 9 . .   Unrepresentative
  10 1988-1998 59 20 . .   Unrepresentative
  5 1993-1998 62 7 . .   Unrepresentative
WBS waterways 23 1975-1998 67 -49 -62 -35 >25  
  10 1988-1998 70 -14 -28 7    
  5 1993-1998 73 -19 -27 -8    
BBS UK 5 1994-1999 907 18 9 27    
BBS England 5 1994-1999 687 20 10 30    
BBS Scotland 5 1994-1999 116 23 -1 53    
BBS Wales 5 1994-1999 80 9 -15 39    
BBS N.Ireland 5 1994-1999 21 -23 -64 64   Small sample
The Breeding Bird Survey is jointly funded by BTO, JNCC and RSPB
 
 
Table of productivity information for Pied Wagtail
Variable Period
(yrs)
Years Mean
annual
sample
Trend Predicted
in first year
Predicted
in last year
Change Comment
Clutch size 30 1968-1998 61 Linear decline 5.12 eggs 4.98 eggs -0.14 eggs  
Brood size 30 1968-1998 113 None        
Daily failure rate (eggs) 30 1968-1998 84 Linear decline 0.0176 nests/day 0.0123 nests/day -0.0053 nests/day  
Daily failure rate (chicks) 30 1968-1998 91 Curvilinear 0.015 nests/day 0.0125 nests/day -0.0025 nests/day  
Laying date 30 1968-1998 81 None        
 
Insufficient data on CES
available for this species
   




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Last updated: 15 March, 2001

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