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BTO Blueline
MERLIN
Falco columbarius

Merlin © G H Higginbotham
 

• Population
  changes

• Productivity
  trends

• Additional
  information
Conservation listings
Europe: no SPEC category (favourable conservation status in Europe, not concentrated in Europe)
UK: amber (historical decline)
Long-term trend
UK: probable increase
UK population size
1,300 pairs in 1990–94 (Rebecca & Bainbridge 1998: BiE04, APEP06)
Status summary
Having declined substantially over the past two centuries, Merlin shows indications of a recent doubling of population (Rebecca & Bainbridge 1998). This increase may be associated with an increased use of forest edge as a nesting habitat (Parr 1994). Because of its recent population upturn, the species has been moved from the red to the amber list. It remains much too scarce, however, for annual population monitoring via BBS: dedicated observers and specialised field methods are required, as described by Hardey et al. (2006). Submissions to the Rare Breeding Birds Panel fall well short of the estimated UK total population but show an average of 1.86 young fledged per occupied territory during 1996–2004 (Holling & RBBP 2007a). Breeding performance has tended to improve since the 1960s, probably linked to the declining influence of organochlorine pesticides (Crick 1993). Hatching rates in the southeast Yorkshire Dales were consistently higher than had been recorded in earlier studies in Northumberland (Wright 2005).
 

Population changes
Annual breeding population changes for this species are not currently monitored by BTO
 

Productivity trends
Table of productivity changes for Merlin

Variable Period
(yrs)		 Years Mean
annual
sample		 Trend Modelled
in first year		 Modelled
in 2006		 Change Comment
Clutch size 38 1968-2006 38 None        
Brood size 38 1968-2006 55 Linear increase 3.52 chicks 3.79 chicks 7.8%  
Daily failure rate (eggs) 38 1968-2006 26 Linear decline 0.67% nests/day 0.24% nests/day -64.2% Small sample
Daily failure rate (chicks) 38 1968-2006 29 Linear decline 0.94% nests/day 0.24% nests/day -74.5% Small sample

 
Clutch size graph
Brood size graph
Egg nest failure graph
Chick nest failure graph

 

Insufficient data on laying date
available for this species

 

 

Insufficient data on CES
available for this species

 
 

Additional information
BTO blue divider
 

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This report should be cited as:
Baillie, S.R., Marchant, J.H., Leech, D.I., Joys, A.C., Noble, D.G.,
Barimore, C., Grantham, M.J., Risely, K. & Robinson, R.A. (2009).
Breeding Birds in the Wider Countryside: their conservation status 2008.
BTO Research Report No. 516. BTO, Thetford. (http://www.bto.org/birdtrends)

Pages maintained by Iain Downie, Mandy T Andrews and Laura Smith: Last updated 18.02.2009