Merlin
Falco columbarius (Linnaeus, 1758)
ML
MERLI
3090
Family: Falconiformes > Falconidae
![Merlin, John Proudlock Merlin, John Proudlock](https://www.bto.org/sites/default/files/birdfacts/00119_Merlin_John%20Proudlock.jpg)
This small, dashing falcon, with the male blue-grey in colour and the female grey-brown, is one of our rarer breeding birds of prey.
The Merlin breeds during the summer months in our uplands, where it is estimated that there may be around 1,000 pairs.
During the winter months the upland breeding areas are vacated and at this time the Merlin can often be found frequenting saltmarshes, where it hunts small birds.
Exploring the trends for Merlin
Our Trends Explorer will also give you the latest insight into how the UK's Merlin population is changing.
trends explorerIdentification
Merlin identification is sometimes difficult. The following article may help when identifying Merlin.
Identifying Cuckoo
![Cuckoo. Photograph by Edmund Fellowes Cuckoo. Photograph by Edmund Fellowes](https://www.bto.org/sites/default/files/styles/related_content_view/public/bird-id/cuckoo-001498-edmund-fellowes.jpg?itok=t0onivoH)
Cuckoos are well-known birds, but their distinctive and eagerly awaited song can be confused with several other species. Despite their popularity, Cuckoos are rarely seen and, when they are, can easily be mistaken for a bird of prey. Let us help you pick out this iconic bird that was once believed to turn into a Sparrowhawk in the winter - neatly explaining it's silence and disappearance outside the breeding season.
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SONGS AND CALLS
Listen to example recordings of the main vocalisations of Merlin, provided by xeno-canto contributors.
Alarm call
Call
Develop your bird ID skills with our training courses
Our interactive online courses are a great way to develop your bird identification skills, whether you're new to the hobby or a competent birder looking to hone your abilities.
Browse training coursesStatus and Trends
Population size and trends and patterns of distribution based on BTO surveys and atlases with data collected by BTO volunteers.
CONSERVATION STATUS
This species can be found on the following statutory and conservation listings and schedules.
POPULATION CHANGE
Having declined substantially over the past two centuries, Merlin shows indications of a recent doubling of UK population (Rebecca & Bainbridge 1998). Because of its recent population upturn, the species was moved from the red to the amber list in 2002. 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. (2009).
A repeat survey of Merlin's British breeding status undertaken in 2008 found a non-significant decline of around 13% since the previous survey in 1993-94, with decline most noticeable in northern England (Ewing et al. 2011). The historical UK decline now warrants red rather than amber listing (Eaton et al. 2015).
Exploring the trends for Merlin
Our Trends Explorer will also give you the latest insight into how the UK's Merlin population is changing.
trends explorerDISTRIBUTION
Breeding Merlins prefer uplands, especially heather-dominated moorland. They are most abundant on the Scottish islands, in the northern and eastern Highlands of Scotland, the north Pennines and in northwest Ireland. In winter many of these areas are vacated, with Merlins generally preferring low-lying areas in winter, except in Ireland where many of the same breeding areas remain occupied.
Occupied 10-km squares in UK
No. occupied in breeding season | 703 |
% occupied in breeding season | 23 |
No. occupied in winter | 1641 |
% occupied in winter | 54 |
European Distribution Map
DISTRIBUTION CHANGE
Change in occupied 10-km squares in the UK
% change in range in breeding season (1968–72 to 2008–11) | +11.1% |
% change in range in winter (1981–84 to 2007–11) | +49% |
SEASONALITY
Merlins are recorded throughout the year but more obviously so during autumn migration.
Movement
Information about movement and migration based on online bird portals (e.g. BirdTrack), Ringing schemes and tracking studies.
RINGING RECOVERIES
View a summary of recoveries in the Online Ringing Report.
Foreign locations of birds ringed or recovered in Britain & Ireland
![Foreign locations of Merlin ringed or recovered in Britain & Ireland Foreign locations of Merlin ringed or recovered in Britain & Ireland](https://app.bto.org/ring/countyrec/images/amap3090.png)
Biology
Lifecycle and body size information about Merlin, including statistics on nesting, eggs and lifespan based on BTO ringing and nest recording data.
PRODUCTIVITY & NESTING
Exploring the trends for Merlin
Our Trends Explorer will also give you the latest insight into how the UK's Merlin population is changing.
trends explorerSURVIVAL & LONGEVITY
View number ringed each year in the Online Ringing Report
Maximum Age from Ringing ![]() |
12 years 8 months 17 days (set in 1989) ![]() |
Typical Lifespan ![]() |
3 years with breeding typically at 1 year |
Adult Survival ![]() |
0.62±0.11 ![]() ![]() |
Juvenile Survival ![]() |
0.23 (in first year) ![]() |
Exploring the trends for Merlin
Our Trends Explorer will also give you the latest insight into how the UK's Merlin population is changing.
trends explorerBIOMETRICS
Wing Length ![]() |
Adults | 221.6±12.3 | Range 198–236.5mm, N=20 |
Juveniles | 218.5±15.4 | Range 204-235mm, N=41 |
Body Weight ![]() |
Adults | 229±56.27 | Range 148–343g, N=20 |
Juveniles | 202±34.0182 | Range 144–255g, N=39 |
Feather measurements and photos on featherbase
CODES & CLASSIFICATION
Ring size ![]() |
D (males) E (females) |
Field Codes ![]() |
2-letter: ML | 5-letter code: MERLI | Euring: 3090 |
For information in another language (where available) click on a linked name
Research
Interpretation and scientific publications about Merlin from BTO scientists.
CAUSES AND SOLUTIONS
Causes of change
The main causes of change are uncertain.
Further information on causes of change
Recent population increases may be associated with an increased use of forest edge as a nesting habitat (Parr 1994, Little et al. 1995, Rebecca 2011, Lusby et al. 2017). Breeding performance has tended to improve since the 1960s, probably linked to the declining influence of organochlorine pesticides (Crick 1993, Newton 2013). Hatching rates in the southeast Yorkshire Dales were consistently higher than had been recorded in earlier studies in Northumberland (Wright 2005). Submissions to the Rare Breeding Birds Panel fall well short of the estimated UK total population but show an minimum of 1.86 young fledged per occupied territory on average during 1996-2004 (Holling & RBBP 2007a), and a minimum of 1.53 young per territory on average during 2005-2008 (Holling & RBBP 2008, 2009, 2010a, 2010b). Full details of the minimum number of young fledged across all territories reported to the RBBP were not published after 2008, but where data are available productivity can be highly variable between years and particularly across different regions. In 2015, for example, no young fledged from 13 pairs in Meirionnydd and only one from 23 pairs in Northumberland, but 164 young fledged from 50 nests in a Durham study area, giving an overall average of 1.91 fledged young per nest across these three areas (Holling & RBBP 2017). A study in Ireland found that nest success was positively linked to the proportion of foraging habitat close to the nest site (Lusby et al. 2017). On Langholm moor in SW Scotland, Hen Harrier and Merlin numbers increased during periods of grouse moor management and more nesting attempts were successful; this was believed to be due to predator control (Ludwig et al. 2020a).
A decline observed during a thirty year (1984-2014) study in south-east Scotland was attributed to changes in land use management in the breeding area (Heavisides et al. 2017).
Information about conservation actions
The causes of change for this species are unclear and hence further research is needed before evidence-based conservation solutions can be proposed.
In the meantime, actions to maintain and, where appropriate, to restore foraging habitat in breeding areas would be prudent. A study in Ireland found that nest success was positively linked to the proportion of foraging habitat such as moorland, heathland, peat bogs and natural grassland close to the nest site (Lusby et al. 2017). Keepering that remains within the law can also benefit harrier populations by increasing their prey and reducing levels of their nest predators, especially crows and foxes (2020a).
Links to more information from ConservationEvidence.com
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