Merlin: The Fierce Little Falcon

The Merlin (Falco columbarius) is the falcon that punches far above its weight. Only a little bigger than an American Kestrel, it is nonetheless a bold, aggressive hunter of small birds, capable of running down a sparrow or a shorebird in level flight and of harassing raptors many times its size. It was long known in North America as the “pigeon hawk,” a name that says more about its hunting style than its size, and it is increasingly a bird of winter cities as well as open prairie and northern forest.

The Fierce Little Falcon

Merlins are compact and muscular, with the pointed wings and long tail typical of falcons, and they fly with rapid, determined wingbeats. Where a kestrel often hovers and drops, a Merlin almost always takes its prey through speed and pursuit — low, fast, and straight, often following a target through turns until it can close and strike. This directness is what gives the bird its reputation. A Merlin will also readily chase birds larger than itself, and it is a notorious mobbing target and mobber alike.

The species is circumpolar, breeding across the northern parts of North America, Europe, and Asia and wintering farther south. In North America, three subspecies are usually recognised: the widespread Taiga Merlin, the paler prairie Richardson’s Merlin of the Canadian and US plains, and the very dark Black Merlin of the Pacific Northwest coast. For the family as a whole, see the falcons complete guide.

Why It Was Called “Pigeon Hawk”

The old name “pigeon hawk” has nothing to do with diet — Merlins rarely take pigeons. It comes from the bird’s flight profile: fast, direct, and with a sweep that reminded early observers of a pigeon’s dash. The name persisted for decades in North American field guides before “Merlin” (borrowed from the Eurasian name) became standard. It survives in older literature and in regional usage, and it is a useful reminder that a Merlin in a hurry can look startlingly like a small, fast pigeon until the falcon shape and pointed wings register.

Identification

A Merlin is best identified by its combination of small size, dark plumage, and rapid, purposeful flight. It shows a weak dark moustache stripe and a pale collar, and it lacks the kestrel’s bold two-stripe face pattern and rufous tail.

Confusion is most likely with the American Kestrel and, in flight, with the small accipiters such as the Sharp-shinned Hawk. Size, the barred tail, and the falcon’s pointed wings versus the accipiter’s rounded wings and flap-flap-glide rhythm are the key separators.

Hunting: The Prairie Pursuit

The Merlin’s hunting method is defined by open country. On the prairies, the Richardson’s Merlin is a specialist at sprinting low over grassland and cropland, chasing larks, pipits, sparrows, and shorebirds almost to exhaustion. Rather than one decisive stoop, it often flies the prey down in a sustained tail-chase, matching every turn until it can seize the bird. It quarters the ground actively, using fence lines and hedgerows as cover, and it will stoop at prey it flushes.

During migration, Merlins in prairie and coastal regions intercept moving flocks of small birds. They are known for taking migrating wood-warblers — a group once placed in the genus Dendroica and now in Setophaga — along with vireos, kinglets, and other passerines, as these birds funnel through on migration. The timing of Merlin movements is closely tied to that of its prey, a pattern explored more widely in raptor migration explained.

Diet

Merlins eat almost entirely small birds, with an important seasonal addition of large insects.

• Small birds: larks, pipits, sparrows, finches, waxwings, and shorebirds — the core of the diet.
• Large insects: dragonflies in particular, taken in flight in summer and especially by young birds learning to hunt.
• Occasionally: small mammals such as mice and young ground squirrels, and small reptiles in southern parts of the range.

Prey is usually taken in the air, and Merlins often carry their catch to a plucking post — a favoured perch where they remove feathers or wings before eating. This habit is shared with other falcons and is one way birders confirm a Merlin’s presence in an area.

Urban Wintering and Breeding

One of the more striking changes of the past few decades is the Merlin’s move into towns and cities in winter. Urban environments offer a reliable supply of House Sparrows, Starlings, and other small birds, plus warm microclimates and abundant perches, and Merlins now winter regularly in city parks and suburbs well within and beyond the traditional wintering range. This adaptability mirrors a broader trend among falcons — the same flexibility that lets the Peregrine Falcon use skyscrapers as cliffs.

Breeding is less urban and more varied than in the kestrel. Merlins do not need a cavity and will not use a nest box. Instead they nest:

• On the ground, in tundra, moorland, and prairie, where a scrape among vegetation offers concealment.
• In trees, often taking over an old nest built by a crow or magpie.
• On cliffs or rocky ledges, less often on buildings or other structures.

Clutch size is typically three to five eggs, incubation lasts about 28–31 days, and the young fledge at roughly 25–32 days, becoming independent quickly by falcon standards. The male does most of the hunting through the nesting period, bringing food to the female and later to the young.

Frequently Asked Questions

Is a Merlin bigger than an American Kestrel?

Yes, but only slightly. The Merlin is a little longer and noticeably heavier and more muscular than the American Kestrel, and it is far darker and more streaked. Size alone is a poor separator; colour, face pattern, and flight style are usually more reliable.

Why is the Merlin called a “pigeon hawk”?

Not because it eats pigeons, but because its fast, direct, low flying style resembles a pigeon in a hurry. The name is historical, from older North American usage, and has largely been replaced by “Merlin.”

What does a Merlin eat?

Chiefly small birds — sparrows, larks, pipits, finches, shorebirds, and during migration even wood-warblers — plus large insects such as dragonflies, and occasional small mammals or reptiles.

Are Merlins found in cities?

Increasingly, yes, especially in winter. Urban Merlins hunt House Sparrows and other small city birds and have become a regular sight in some towns and cities well outside their breeding range.

How fast is a Merlin?

Fast in level flight and extremely agile, though not as fast in a dive as the much larger Peregrine Falcon or the Gyrfalcon. Its strengths are acceleration and persistence rather than record-breaking stoop speed; it flies its prey down over distance rather than in a single plunge.

Do Merlins use nest boxes?

No. Unlike the American Kestrel, the Merlin is not a cavity nester and does not take nest boxes. It nests on the ground, on cliffs, or in old nests built by other birds, especially crows and magpies.

Tell it from its smaller cousin in the American Kestrel, or explore the family in the falcons complete guide.