Spotted a bird? Identify it instantly with the Birdby app
Open the appAbout
The Merlin is a small, powerful falcon known for its swift, agile flight and predatory prowess, primarily hunting small birds. It is found across the Northern Hemisphere, breeding in northern latitudes and migrating to more temperate regions for winter. Merlins exhibit significant sexual dimorphism in plumage and size.
Size & lifespan
- Length
- 24-33 cm (9.4-13 in)
- Wingspan
- 53-73 cm (21-29 in)
- Weight
- Males: 120-210 g (4.2-7.4 oz); Females: 160-300 g (5.6-10.6 oz)
- Lifespan
- Up to 11 years in the wild, typically 3-5 years
- Diet
- Carnivore (primarily small birds, occasionally insects, small mammals, or reptiles)
Physical characteristics
- Plumage
- Adult males (blue-backed Merlins) have a slate-blue to bluish-gray back and wings, often with faint black barring, and rufous-streaked underparts. Adult females and juveniles are browner overall, with dark brown backs and heavily streaked buffy underparts. All Merlins have a dark tail with narrow pale bands, and a faint malar stripe (mustache mark).
- Beak shape
- Short, sharply hooked, dark gray to black with a yellow cere.
- Eye color
- Dark brown
- Leg color
- Yellow
- Distinguishing features
- Small size, pointed wings, rapid wingbeats, and a distinctive flight style. Males are distinctly blue-backed. Females and juveniles are uniformly brown above. Faint malar stripe is present but not as prominent as in larger falcons. Tail has narrow pale bands.
- Juvenile appearance
- Juveniles resemble adult females, being dark brown above with heavily streaked underparts. Their plumage is generally duller than adult females, and the streaking on the underparts can be bolder. The cere and legs are typically duller yellow than adults.
- Seasonal changes
- No significant seasonal plumage changes beyond wear and tear. Plumage remains consistent between breeding and non-breeding seasons, though fresh plumage after molt may appear brighter.
- Sexual dimorphism
- Males are smaller and have a distinctive slate-blue back and wings, with rufous-streaked underparts. Females are larger and browner overall, with dark brown backs and heavily streaked underparts. This size difference is pronounced, with females being up to 25% larger and 50% heavier than males.
How to identify
- 1
Size and Shape
Small, compact falcon with pointed wings and a relatively short tail. Appears stockier than an American Kestrel.
- 2
Flight Style
Fast, direct flight with rapid, shallow wingbeats. Often flies low to the ground. Agile and relentless in pursuit of prey.
- 3
Plumage (Males)
Slate-blue to bluish-gray back and wings, with rufous-streaked underparts. Faint malar stripe.
- 4
Plumage (Females/Juveniles)
Dark brown back and wings, with heavily streaked buffy underparts. Faint malar stripe. Juveniles are duller than adult females.
- 5
Tail
Dark tail with narrow pale bands, visible from above and below.
- 6
Head
Relatively small head for a raptor, with a faint malar stripe (mustache mark) that is less prominent than in other falcons.
- 7
Vocalization
A rapid, high-pitched 'kik-kik-kik-kik' call, especially when agitated.
Habitat & range
- Biomes
- Tundra, boreal forest, temperate forests, grasslands, coastal areas, agricultural lands, urban and suburban environments during migration and winter.
- Geographic range
- Holarctic distribution. Breeds across northern North America, Europe, and Asia. Winters in southern North America, Central America, northern South America, North Africa, and southern Asia.
- Elevation range
- Sea level to approximately 3,000 meters (10,000 feet), depending on geographic location and season.
- Preferred environments
- Open country with scattered trees or shrubs for perching and nesting. Often found near water bodies, coastlines, and areas with high concentrations of small birds. During winter, they adapt to a variety of open habitats, including urban parks.
Behavior
- Activity time
- Diurnal, most active during daylight hours, particularly morning and late afternoon.
- Feeding habits
- A highly active and aggressive hunter, primarily preying on small to medium-sized birds (e.g., sparrows, sandpipers, starlings). Merlins hunt by fast, low pursuit flights, often ambushing prey. They may also catch insects in flight or occasionally take small mammals or reptiles. They are known for their relentless pursuit of prey.
- Social behavior
- Generally solitary outside of the breeding season. During breeding, they form monogamous pairs. They can be quite aggressive and territorial around their nest sites.
- Flight pattern
- Fast, direct flight with rapid, shallow wingbeats. Often flies low to the ground, using terrain for cover. Can be very agile, making sharp turns and dives during pursuit. Soars less frequently than larger falcons.
- Migration pattern
- Most populations are migratory, moving south from their northern breeding grounds to warmer wintering areas. Migration routes can be extensive, covering thousands of kilometers. Some coastal populations in milder climates may be resident.
- Territoriality
- Highly territorial during the breeding season, aggressively defending their nest site and hunting grounds from other raptors and potential predators.
Song & calls
- Song
- Merlins do not have a complex song. Their vocalizations are primarily calls.
- Call
- A rapid, high-pitched 'kik-kik-kik-kik' or 'ki-ki-ki-ki' call, often given when agitated, defending the nest, or by pairs communicating. Also a softer 'wichew' or 'tew-tew' call.
- When they vocalize
- Most vocal during the breeding season, especially around the nest, and when interacting with mates or intruders. Less vocal during migration and winter.
Breeding & reproduction
- Breeding season
- Typically May to July, varying with latitude.
- Nesting habits
- Merlins do not build their own nests. They primarily use abandoned stick nests of other raptors (e.g., crows, magpies, hawks) in trees or on cliffs. In some areas, they may nest in tree cavities, on the ground in tundra, or on ledges of buildings.
- Clutch size
- 3-6 eggs (average 4-5)
- Egg description
- 3-6 eggs, typically 4-5. Eggs are dull white to buff, heavily spotted, blotched, or speckled with reddish-brown, cinnamon, or chocolate markings, often concentrated at the larger end.
- Incubation period
- 28-32 days, primarily by the female.
- Fledging period
- 25-32 days after hatching. Young remain dependent on parents for several weeks after fledging.
- Parental care
- Both parents participate in raising the young. The female primarily incubates and broods, while the male provides most of the food during this period. Both parents hunt and feed the young after hatching.
Where to find
Coastal Areas
During migration and winter, Merlins are often found along coastlines, barrier islands, and estuaries where shorebirds and other small migrants congregate.
Open Woodlands and Forest Edges
Breeding Merlins prefer open coniferous or mixed woodlands, often near clearings or water, where they can find abandoned nests.
Grasslands and Prairies
In some parts of their range, particularly the prairies, Merlins can be found hunting over open grasslands, often perching on fence posts or utility poles.
Urban/Suburban Parks and Green Spaces
During migration and winter, Merlins can adapt to human-modified landscapes, hunting small birds in parks, cemeteries, and even backyards.
Tundra
In northern breeding grounds, they can be found nesting on the ground or in low shrubs in open tundra environments.
Field tips
- Look for fast, low flight. Merlins often fly low to the ground, using terrain to surprise prey. Scan open areas, especially near flocks of small birds.
- Watch for 'bullet-like' pursuit. Their hunting style is distinctive: a rapid, direct chase of prey, often with relentless pursuit. If you see a small bird being chased aggressively, it might be a Merlin.
- Check utility poles and snags. Merlins often perch on prominent vantage points like utility poles, dead trees (snags), or tall shrubs to scan for prey.
- Listen for calls. During the breeding season, their rapid 'kik-kik-kik' call can help locate them, especially if they are agitated by your presence near a nest.
- Observe bird alarm calls. Flocks of small birds often give alarm calls and scatter when a Merlin is in the vicinity, indicating its presence.
- Visit coastal areas during migration. Coastal migration hotspots can be excellent places to see Merlins as they hunt migrating shorebirds and passerines.
Similar species
American Kestrel
Falco sparverius
Merlins are larger, stockier, and lack the prominent facial stripes and rusty back of the American Kestrel. Kestrels often hover, a behavior rarely seen in Merlins. Male Kestrels have blue-gray wings, but their rusty back and prominent facial markings are distinct. Female Kestrels are rusty-barred on the back, unlike the uniformly brown female Merlin.
Peregrine Falcon
Falco peregrinus
Peregrine Falcons are significantly larger than Merlins, with a much more prominent, helmet-like dark cap and broad malar stripe. Peregrines have a more powerful, deeper wingbeat and often hunt from high altitudes, stooping on prey. Merlins are smaller, more agile, and typically hunt closer to the ground.
Sharp-shinned Hawk
Accipiter striatus
Sharp-shinned Hawks have rounded wings and a longer, rounded tail, unlike the pointed wings and shorter, square-tipped tail of the Merlin. Their flight pattern is characterized by a 'flap-flap-glide' motion, distinct from the Merlin's rapid, continuous wingbeats. Sharp-shinned Hawks also have a different head shape and lack the falcon's characteristic malar stripe.
Quick facts
- Primary Prey:
- Small birds
- Flight Speed:
- Very fast and agile
- Nest Type:
- Uses abandoned nests of other birds or natural cavities
- Migration:
- Mostly migratory, some resident populations
- Sexual Dimorphism:
- Males are smaller and blue-backed; females are larger and brown
Fun facts
- Merlins were historically used in falconry, particularly for hunting larks and other small birds, earning them the nickname 'lady's hawk' due to their smaller size.
- Despite their small size, Merlins are incredibly fierce and aggressive hunters, often taking prey larger than themselves.
- The Merlin's scientific name, Falco columbarius, means 'pigeon falcon,' reflecting its historical association with hunting pigeons, though small passerines are its more common prey.
- Merlins have adapted to urban environments in some areas, nesting on buildings and hunting pigeons and starlings.
- There are several recognized subspecies of Merlin, each with slight variations in plumage and geographic range, such as the 'Black Merlin' (F. c. suckleyi) of the Pacific Northwest, which is darker overall.
Scientific classification
- Kingdom
- Animalia
- Phylum
- Chordata
- Class
- Aves
- Order
- Falconiformes
- Family
- Falconidae
- Genus
- Falco
- Species
- Falco columbarius
Explore the Merlin
Identify birds anywhere
Free on iOS, Android, and Web. Photo & sound identification, full species database, and your personal life list.