Merlin (Falco columbarius)

Merlin (Falco columbarius)

Quick Facts

  • Scientific Name: Falco columbarius
  • Family: Falconidae (Falcons)
  • Size: 24–33 cm (9.5–13 inches)
  • Wingspan: 50–62 cm (20–24 inches)
  • Weight: 125–300 g (4.4–10.6 oz) — females considerably heavier than males

Conservation Status

  • IUCN Status: Least Concern (global)
  • UK Status: ⚠️ Red List — Species of High Conservation Concern
  • Population Trend: Recovering after a serious 20th-century decline, but remains on the Red List with around 1,150 breeding pairs in the UK

Worldwide Distribution

The Merlin has a wide circumpolar range across the Northern Hemisphere:

  • Breeds across upland Britain — primarily northern England, Wales, and Scotland
  • Found across Scandinavia, Iceland, Russia, and across northern North America
  • UK breeding birds are largely resident; the population is boosted in winter by migrants from Iceland
  • In winter, birds disperse to lower ground, coastal marshes, and farmland across much of Britain

Spotting Difficulty Rating

🔍🔍🔍🔍 (4/5 — Difficult)

  • Britain’s smallest bird of prey — easily overlooked or mistaken for a large thrush in flight
  • Extremely fast and low-flying; often gone before it registers
  • Breeding birds restricted to upland moors — requires targeted searching
  • Winter birds more widespread but still easily missed among open coastal and farmland habitats

Habitat and Behaviour

The Merlin is Britain’s smallest bird of prey — a compact, dashing falcon not much bigger than a Blackbird, yet one of the most formidable aerial hunters on the upland moor. The male is a beautiful slate-blue above, with warm orange-buff underparts streaked in black and has a neat dark tail band. The female is larger and is brown above with heavily streaked cream underparts, blending perfectly against moorland and heath. The Merlin has a characteristic silhouette: short, pointed wings, a square-cut tail, and flies with a rapid, direct wingbeat interspersed with brief glides.

Built for speed and low-level pursuit, the Merlin hunts by flying fast and low across open ground, using the contours of the landscape to ambush prey, then accelerating into a fierce tail-chase that can twist and turn for hundreds of metres before the quarry is caught — or escapes. Meadow Pipits are the staple prey on breeding grounds, but Skylarks, finches, and other small birds are all taken.

Unusually for a falcon, the Merlin does not build its own nest. On upland moors it typically uses a scrape among deep heather; elsewhere it may commandeer an old crow’s nest in a tree or on a crag. The female incubates the clutch of three to five eggs while the male hunts and delivers food, and the pair are famously aggressive in defence of their territory — readily mobbing and driving off birds far larger than themselves, including Ravens and Buzzards.

In winter, Merlins abandon the high ground and move to coasts, estuaries, and open farmland, where they hunt wader flocks and finch flocks with the same relentless intensity they bring to the summer moors.

Cultural History

No other British bird carries quite the same weight of aristocratic association as the Merlin. In the rigidly hierarchical world of medieval falconry, each rank of society was assigned its appropriate bird, and the Merlin was designated the falcon of ladies. The Book of Saint Albans (c.1486), one of the great manuals of noble pursuits, set out the hierarchy explicitly: “An Eagle for an Emperor, a Gyrfalcon for a King; a Peregrine for a Prince, a Saker for a Knight, a Merlin for a Lady.” Small, swift, and intensely spirited — qualities that evidently appealed — the Merlin was carried on the wrist by noblewomen across medieval and Tudor Europe as a mark of status and refinement.

Mary, Queen of Scots, was among its most devoted admirers. An ardent falconer even during her long imprisonment in England, she was reportedly permitted by Elizabeth I to fly her Merlins on occasional hawking excursions. Catherine the Great of Russia was also recorded as a Merlin falconer.

In the wider folklore of upland Britain, the Merlin shares something of the Ring Ouzel’s quality — a creature of the wild high places, seen at the margins of the inhabited world. Its appearance over a moor was simply part of the natural order of things, as expected and as unremarkable as the wind. It is only in its absence that we have begun to notice what it meant.

Fun Facts

  • 👑 Designated “the Lady’s Falcon” in medieval falconry — carried on the wrists of noblewomen as a mark of rank and refinement
  • ⚡ One of the fastest birds in Britain in level flight, capable of sustained high-speed chases over open moorland
  • 🏠 Does not build its own nest — uses old crow nests, cliff ledges, or scrapes in deep heather
  • 🦅 Females are significantly larger than males — a common trait in falcons, thought to reduce competition for prey between the sexes
  • ❄️ UK winter numbers are boosted by Icelandic migrants arriving each autumn in search of milder conditions

Best Places to Spot a Merlin in the UK

  1. Sutherland and Caithness, Scotland
  2. Dartmoor, Devon
  3. The Brecon Beacons, Wales
  4. North Pennines — particularly around the Forest of Bowland
  5. Coastal marshes and estuaries in winter — the Wash, Morecambe Bay, and the Somerset Levels
  6. Yorkshire Dales National park

Recommended Viewing Tips

  • On breeding moors, scan low over the heather for fast, direct flight hugging the ground — it rarely flies high
  • The male’s blue-grey back is distinctive if you can get a clear view; females can resemble small Kestrels but lack the hovering habit
  • Listen for the loud, chattering alarm call — “kek-kek-kek” — near the nest territory
  • In winter, check coastal marshes and open farmland for birds perching on fence posts or pursuing finch flocks
  • Dawn and dusk are prime hunting times; birds are most active and visible in low light
  • Patience is key — Merlins move fast and cover large territories; watch from a high point over open ground

Conservation Notes

The Merlin suffered serious population decline through the 20th century, driven primarily by organochlorine pesticide contamination — the same chemicals that devastated Peregrine and Sparrowhawk populations — as well as the loss of heather moorland to agricultural improvement and afforestation. Numbers have partially recovered since pesticide restrictions came into force, but the Merlin remains on the Red List with a fragile UK population. Ongoing threats include the loss and degradation of upland heather moorland, disturbance at nest sites, and the wider decline of the small bird prey species it depends upon.

Merlins benefit from:

  • Protection and sympathetic management of upland heather moorland for breeding habitat
  • Continued restrictions on harmful pesticides that accumulate in raptors through the food chain
  • Maintenance of diverse upland habitats supporting healthy populations of Meadow Pipits and other prey species
  • Legal protection under Schedule 1 of the Wildlife and Countryside Act — it is an offence to disturb a Merlin at or near the nest
  • Reduced afforestation of open upland habitats, which destroys both nesting and hunting ground