- 9.4–11.8 in
- 20.9–26.8 in
- 5.6–8.5 oz
- Slightly larger than an American Kestrel; less bulky than a Rock Pigeon.
- Pigeon Hawk
- Faucon émerillon (French)
- Esmerejón (Spanish)
- Merlin pairs have been seen teaming up to hunt large flocks of waxwings: one Merlin flushes the flock by attacking from below; the other comes in moments later to take advantage of the confusion.
- Merlins don’t build their own nests. Instead, they take over the old nests of other raptors or crows. They also use magpie nests, sometimes laying eggs right on top of the nest’s dome rather than inside the cavity.
- Though it’s not much bigger than the more common American Kestrel, the Merlin is heavier and often appears considerably larger. As with most raptors, female Merlins are larger than males.
- The name “Merlin” comes from esmerillon, the old French name for the species. Merlins used to be called “pigeon hawks” because in flight they look somewhat pigeon-like. Their species name, columbarius, is also a reference to pigeons.
- Medieval European noblewomen—including Catherine the Great and Mary Queen of Scots—used Merlins for sport to hunt Skylarks. European and North American falconers continue to work with Merlins, hunting quarry that ranges from sparrow-sized to dove-sized.
- The oldest known Merlin was a male and at least 11 years, 11 months old. He was banded as an adult in New York in 1982 and recovered in New Brunswick, Canada, in 1993.
Merlins breed in open and semiopen areas across northern North America. The boreal subspecies usually nests near forested openings, in fragmented woodlots, near rivers, lakes, or bogs, and on lake islands. The Pacific Northwest subspecies seems to nest mostly in coastal areas and along rivers. The prairie subspecies nests in shrubs and trees along rivers and in small groves of deciduous trees planted as wind breaks. Merlins are increasingly breeding in towns and cities, where they often take over crow nests in conifers planted in residential areas, schoolyards, parks, and cemeteries. During migration Merlins stop in grasslands, open forests, and coastal areas. They winter in similar habitat across the western United States and southern United States, along the Pacific coast to Alaska, and along the Atlantic coast to southern New England. Their wintering range extends south through Latin America as far as Ecuador.
Merlins eat mostly birds, typically catching them in midair during high-speed attacks. They often specialize on hunting a couple of the most abundant species around; prey are generally small to medium-sized birds in the 1–2 ounce range. Common prey include Horned Lark, House Sparrow, Bohemian Waxwing, Dickcissel, Least Sandpiper, Dunlin, and other shorebirds. They don’t stoop on birds the way Peregrine Falcons do; instead they attack at high speed, horizontally or even from below, chasing the prey upwards until they tire. Other prey include large insects such as dragonflies, bats caught at cave openings, nestling birds, and small mammals. Merlin pairs have been seen teaming up to hunt large flocks of waxwings: one Merlin flushes the flock by attacking from below; the other comes in moments later to take advantage of the confusion.
- Clutch Size
- 4–5 eggs
- Number of Broods
- 1 broods
- Egg Length
- 1.5–1.7 in
- Egg Width
- 1.1–1.3 in
- Incubation Period
- 28–32 days
- Nestling Period
- 29 days
- Egg Description
- Rusty brown marked with brown or chestnut.
- Condition at Hatching
- Mostly helpless, with closed eyes. Nestlings have yellow feet and bluish bills, are covered with sparse whitish down, and weigh just under 0.5 ounces.
Merlins do not build their own nests; they reuse old crow, raven, magpie, or hawk nests, making few, if any, modifications to the original nest. They only rarely reuse a nest in subsequent years. The dimensions of the nest can vary greatly depending on which species’ nest they reuse.
Merlins lay their eggs in abandoned nests of crows and hawks, in either conifers or deciduous trees of semiopen habitats. They tend to choose nests with a good view of the surrounding area. On rare occasions they nest in tree cavities, on cliffs, or on the ground.
Like other falcons, the Merlin is a strong and maneuverable flier. A typical flight speed is 30 miles per hour, and can be faster during chases. Despite their small size, Merlins look powerful in flight; they flap their wings faster than Prairie or Peregrine falcons. During the breeding season they are highly territorial around the nest, chasing away other Merlins and potential predators. Merlins are monogamous during a breeding season, but 80 percent find new mates from year to year. When courting, Merlins (particularly males) perform spectacular flight displays, including bursts of strong, level flight while rocking side to side in the air; deep U-shaped dives; and slow, fluttering flights in a circle or figure-eight near to a perched mate. Both sexes claim their territory by soaring high in the air near their nest. Males also make a slow landing next to their mate, keeping their legs outstretched, bowing the head, and fanning the tail; he may bring food for the female. Outside of the breeding season, Merlins are usually solitary. However, they sometimes migrate in loose groups, roost communally, or spend the winter in pairs. Adults may be preyed on by Peregrine Falcons, Great Horned Owls, Cooper’s Hawks, and Red-tailed Hawks.
Merlin populations are stable and appear to have increased between 1966 and 2014, according to the North American Breeding Bird Survey. This increase reflects their recovery from widespread declines in the 1960s due to pesticide contamination. Partners in Flight estimates the global breeding population at 3 million, with 44% spending some part of the year in Canada, 23% in the U.S., and 14% wintering in Mexico. The species rates a 7 out of 20 on the Continental Concern Score. Merlin is not on the 2014 State of the Birds Watch List. Starting in the late twentieth century, breeding Merlins have been colonizing an increasing number of cities and towns, where they take advantage of abundant House Sparrows for food and old crow nests for breeding sites. They expanded into New York and northern New England starting in 1995 and now breed across Vermont, New Hampshire, and Maine. Their winter range spread into the northern Great Plains between 1960 and 1990. Their ability to colonize urban areas may be counteracting a decline from habitat loss in other parts of their breeding and wintering ranges.
- Warkentin, I.G., N.S. Sodhi, R.H.M. Espie, A.F. Poole, L.W. Oliphant and P. C. James. 2005. Merlin (Falco columbarius). In The Birds of North America Online, No. 44 (A. Poole, Ed.). Cornell Lab of Ornithology, Ithaca, New York.
- Dunne, P. 2006. Pete Dunne’s essential field guide companion. Houghton Mifflin, Boston.
- North American Bird Conservation Initiative, U.S. Committee. 2014. State of the Birds 2014 Report. U.S. Department of Interior, Washington, DC.
- Partners in Flight. 2012. Species assessment database.
- Sibley, D.A. 2000. The Sibley guide to birds. Alfred A Knopf, New York.
- USGS Patuxent Wildlife Research Center. 2015. Longevity records of North American Birds.
- USGS Patuxent Wildlife Research Center. 2014. North American Breeding Bird Survey 1966–2014 Analysis.
Resident to long-distance migrant. Dark-form Merlins of the Northwest live there year-round or move short distances southward in winter. Most of the prairie Merlins move into the southern and central U.S. and northern Mexico, although some in urban areas remain there year-round. The taiga form migrates from far northern breeding grounds to the coastal and southern U.S. and as far south as Ecuador.
Find This Bird
Merlins are widespread, particularly in migration and winter, but seeing them is unpredictable. They have two modes: scanning open areas patiently from a treetop, and cruising at top speed in pursuit of small birds. If a flock of foraging birds (particularly shorebirds) suddenly bursts into flight, a Merlin or other falcon may be the cause. Be ready to look quickly—Merlins cover a lot of ground and can be out of range in just a few seconds. Scanning treetops and low perches at forest edges, grasslands, or saltmarshes can also turn up a perched Merlin and the opportunity for a longer view. Merlins are also increasingly common around towns, where there is a steady supply of House Sparrows.