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Falco columbarius

What do they look like?

Male merlins have slaty blue, purplish, or dark umber-brown upper parts, streaked with black from the crown to shoulders and back. The tail is barred by dark umber-brown or blackish bands and is tipped in white. The underparts are cream to a rich buff with heavy longitudinally streaks of dark umber-brown or black coloration, except for the throat which is an unmarked white. The sides of the head are buff with fine darker streakings. The forehead and line above the eye is white. The beak is bluish horn; the cere and feet are chromo yellow; the claws are black; and the iris is deep brown.

Females and young are similiar to males in their markings, but differ from males in coloration. The upperparts are dark brown. The neck is streaked with lighter brown and the tail is banded in yellow bars with a white tip.

Falco columbarius bendirei (Bendire's merlins): Lighter in the upper parts than Falco columbarius columbarius. The tail is black with three white bars.

Falco columbarius columbarius (American merlins): (see description of Falco columbarius). In males, the cere and feet turn reddish with age.

Falco columbarius richardsoni (Richardson's merlins): Lighter overall coloration and the tail is marked by five dark and six white bands.

Falco columbarius suckleyi (Black pigeon hawks): Darker in overall coloration than Falco columbarius columbarius. The throat of males is streaked with black markings, while the lower body parts are brownish-black with chestnut and white markings. The lower parts of young males and females are heavily marked with dusky coloration and the spotting is either faint or absent from the wings.

  • Sexual Dimorphism
  • sexes colored or patterned differently
  • Average mass
    195 g
    6.87 oz
  • Range length
    25 to 33 cm
    9.84 to 12.99 in
  • Range wingspan
    60 to 68 cm
    23.62 to 26.77 in

Where do they live?

Merlins are found throughout the Northern Hemisphere. In North America they are found from eastern Canada and Alaska, south throughout Mexico. Merlins spend the winter in the southern United States, Mexico, Central America, northern South America, and the Caribbean Islands.

What kind of habitat do they need?

Merlins favor open country, preferring grasslands, seashores, sand dunes, marshlands, steppes, and deserts. They breed in coniferous forests of the Northern Hemisphere.

How do they reproduce?

Males arrive to the breeding area before the females, usually returning to the same general area year after year. Nesting pairs don't necessarily use the same actual site each year. In open country and grassland, nests are generally scrapes located in dense vegetation. In regions of sand dunes, dune grasses may be used to create a nest. Even in wooded areas, nests may be scrapes, but empty crow nests are preferred. During the nesting period, Falco columbarius become highly aggressive towards other raptors and crows in the area. This aggressive behavior towards other predatory birds is beneficial to other woodland song and ground birds in the nesting range; since Falco columbarius hunts only in open country, thereby leaving the woodland birds relatively free from predators during the mating season. Normally the nest contains four to six eggs measuring 1.5 x 1.22 inches. The eggs are laid at two-day intervals. The coloration of the round oval eggs are variations of light buff white almost obscured by a regular pattern of rich chestnut-brown, purple and chocolate blotchings.

The eggs are laid in early April to early May in the southern ranges and in late May through June in the North. The female is the main incubator, although the male does share in the duties. The incubation period lasts 25-32 days. At the end of the incubation period, the eggs hatch in intervals.

Quills appear on the young after fourteen days, and by eighteen days the down is almost completely covered with feathers, except in the head region. Flight is achieved at 25-30 days after hatching.

Upon leaving the nest, the young remain nearby for several weeks until they are mature enough to migrate southward. Within a week's time of leaving the nest, the young are capable of distance flights, and at two weeks' time, they begin to catch insects. By six weeks the young are skilled in catching small birds, and shortly afterwards, they migrate southward from the breeding area. The success rate among the the young is exceptionally high, often three birds per nest survive to continue breeding.

Falco columbarius: Breeds throughout northern Europe, Asia and North America.

Falco columbarius bendirei: Breeds in northwestern Alaska to northern Saskatchewan and into northern California.

Falco columbarius columbarius: Breeds in eastern Canada to the eastern border of the Great Plains and southwards into Nova Scotia and northern Michigan.

Falco columbarius richardsoni: Breeding range is located in the Great Plains from southern Alberta and Saskatchewan to northern Montana and North Dakota.

Falco columbarius suckleyi: Breeding occurs only in western British Columbia and perhaps on Vancouver Island.

  • How often does reproduction occur?
    Merlins breed once yearly.
  • Breeding season
    Merlins breed from April to July, depending on the latitude.
  • Range eggs per season
    4 to 6
  • Average eggs per season
  • Range time to hatching
    25 to 32 days
  • Average time to independence
    6 weeks

How long do they live?

How do they behave?

Falco columbarius is not a social bird except in the mating season. During this period, the male and female share duties in raising the young. During incubation, the female remains on the nest while the male does the hunting. Rarely does the male visit the nest, often leaving the prey nearby for the female to retrieve. When the young are older, both male and female share hunting duties. Once the young leave for good, presumably the male and female return to their solitary life style. Flight (similiar to the flight of the swallow) is fast with steady wingbeats, often skimming in a low zigzagging pattern over the ground. Falco columbarius seldom soars. The call is a series of sharp "ki-ki-ki-ki-kee."

How do they communicate with each other?

What do they eat?

Merlins prey mainly on small birds of the ground and low vegetation, including larks (Alaudidae), sparrows (Passeridae and Emberizidae), finches (Fringillidae) and ptarmigans and grouse (Tetraoninae). Some small mammals, lizards, snakes, insects, and - in North America - dragonflies, also make up a portion of the diet. The relative proportions are about 80% birds, 5% mammals, and 15% insects.

  • Primary Diet
  • carnivore
    • eats terrestrial vertebrates
  • Animal Foods
  • birds
  • mammals
  • insects

Do they cause problems?

The diet of merlins consists mainly of small birds, including many small birds which are a benefit to agriculture and forestry. In the northern part of their breeding range merlins sometimes attack small domestic poultry, but these attacks are rare.

How do they interact with us?

Merlins occasionally prey on agricultural insect pests, such as grasshoppers and crickets. They are also widely used in falconry. Considered a lady's gaming bird, merlins are relatively easy to train for small game hunting and are usually returned to the wild after a season.

  • Ways that people benefit from these animals:
  • pet trade
  • controls pest population

Are they endangered?

Merlins are widely distributed but are not common anywhere in their range. With expanding human development, the breeding habitats and hunting grounds of these falcons are being destroyed rapidly. This species is listed as threatened in the state of Michigan.

Some more information...


Tanya Dewey (editor), Animal Diversity Web.

Graham Garett Grove (author), University of Michigan-Ann Arbor.


Brown, Leslie and Amadon, Dean, EAGLES, HAWKS AND FALCONS OF THE WORLD (vol. II), McGraw-Hill Book Company, New York, 1968.

Bruun,Bertel and Robbins, Chandler S. and Zim, Hebert S., A GUIDE TO IDENTIFICATION: BIRDS OF NORTH AMERICA, Golden Press, New York, 1983.

Burton,Maurice, NEW LAROUSSE ENCYCLOPEDIA OF ANIMAL LIFE, Bonanza, Hong Kong, 1987.

Grossman, Mary Louise and Hamlet, John, BIRDS OF PREY OF THE WORLD, Clarkson N. Potter, New York, 1964.

MacKenzie, John P.S., BIRDS OF PREY, Paper Birch Press, Ashland, WI, 1986.

May, John Bichard, THE HAWKS OF NORTH AMERICA, The National Association of Aububon Societies, New York, 1935.

Pearson, T. Gilbert, BIRDS OF AMERICA, Garden City Publishing Company, Garden City, New York, 1936.

Sprunt, Alexander Jr., NORTH AMERICAN BIRDS OF PREY, Harper and Brothers, New York, 1955.

Whitfield, Dr. Philip, MACMILLAN ILLUSTRATED ANIMAL ENCYCLOPEDIA, Macmillan, New York, 1984.

University of Michigan Museum of ZoologyNational Science Foundation

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Grove, G. 1999. "Falco columbarius" (On-line), Animal Diversity Web. Accessed May 19, 2024 at

BioKIDS is sponsored in part by the Interagency Education Research Initiative. It is a partnership of the University of Michigan School of Education, University of Michigan Museum of Zoology, and the Detroit Public Schools. This material is based upon work supported by the National Science Foundation under Grant DRL-0628151.
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