The British Trust for Ornithology
MERLIN
Falco columbarius

Merlin © G H Higginbotham
 
Conservation Listings

Table 2/Red (Historical decline)
Biodiversity Steering Group Conservation Concern List
Long term trend
UK: Probable increase
 
Status Summary
Having declined substantially over the past two centuries, there are indications that it has increased recently (DETR 2000), perhaps associated with an increased use of forest edge as a nesting habitat (Parr 1994). Breeding performance has tended to improve since the 1960s, probably linked to the declining influence of organochlorine pesticides (Crick 1993).
 
Annual breeding population changes for this species
are not currently monitored by BTO
Table of productivity information for Merlin
Variable Period
(yrs)		 Years Mean
annual
sample		 Trend Predicted
in first year		 Predicted
in last year		 Change Comment
Clutch size 31 1968-1999 41 None        
Brood size 31 1968-1999 58 None        
Daily failure rate (eggs) 31 1968-1999 29 Linear decline 0.007 nests/day 0.0028 nests/day -0.0042 nests/day Small sample
Daily failure rate (chicks) 31 1968-1999 30 Linear decline 0.0095 nests/day 0.0031 nests/day -0.0064 nests/day Small sample
 

 

Insufficient data on laying date
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. (http://www.bto.org/birdtrends)

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