|     The dashing little merlin just
barely makes it onto a list of birds that breed in the Northeast. This
falcon is at home in the northern conifer forests and prairies of Alaska
and Canada. In the East, the merlin's nesting range edges into northern
Maine. In the West, its breeding range includes the Rocky Mountains, dipping
down as far as Colorado. This falcon also occurs in the coastal rain forests
of northern California, Oregon and Washington, as well as in northern
Minnesota, Wisconsin and Michigan. Because of this wide distribution,
merlins in the U.S. occur in three distinct forms that differ in color
and size. The species is also found throughout Europe and Asia.
The compact, powerful merlin suggests a Jack Russell terrier in some ways. Both the dog and the falcon pack a lot of energy and determination into a small body. Larger than the American kestrel, the merlin lacks the contrasting white-and-black facial markings of the kestrel. The falcon trademark, a black stripe under the eye (sometimes called a mustache or malar stripe), is not boldly distinct on the merlin because the face is heavily streaked with brown. However, the merlin does clearly exhibit other falcon characteristics. Built for speed, the bird is slim and streamlined, with long, pointed wings that flick rapidly through the air. The tail is long, which gives the merlin the agility to change direction instantly. The long, thin toes, designed for grabbing, are a clue to the merlin's favorite prey. Like its larger cousin the peregrine falcon, the merlin is a bird-hunting specialist, often snatching its quarry right out of the air.
As is the case with almost all birds of prey, female merlins are larger than the males. Females have an average wingspan of 25 inches, and weigh from 6.4 to 8.3 ounces. Males have an average wingspan of 22 inches, with a weight range of 4.5 to 6.6 ounces. The size difference between the genders is not as great as it is in the peregrine falcon and the gyrfalcon. Unlike those two falcons, but in common with the American kestrel, the male and female merlin look very different once they're adults (juveniles, also called immatures, resemble the adult females). Male merlins are striking birds, gray-blue on the back, with a black tail marked with 3 gray-blue stripes. The cream-colored chest is streaked with brown. The females, by contrast, are dark brown above, with brown tails marked with 4 cream-colored stripes. The underside is heavily streaked with brown. This overall brown color camouflages the female at the nest and also serves to protect her young as she broods them.
Like other falcons, merlins don't make nests. They recycle used magpie, crow or raven stick nests. They will also nest in tree cavities or even on the ground. Merlins return to the same area year after year, although they may not use the same nest every time. There are records in Britain of generations of merlins nesting in the same area for 100 years.
By late winter or early spring the males have arrived on their home territory. Females return from migration later. Since the pair wintered apart, the pair bond must be reestablished by courtship displays. The male attempts to attract the female by spectacular flying, including dives and rolls. In May or early June 3 to 5 eggs are laid, and the male has the responsibility of hunting while the female incubates. When the young are one week old and can keep themselves warm, the female joins in the hunting chores, taking larger prey than her smaller mate can tackle. Young merlins grow up fast. At 4 weeks old they're ready to leave the nest; at 9 weeks old they're ready to leave their parents. Siblings may start migration together, often relying on large insects like dragonflies and grasshoppers for food, since their bird-hunting skills develop with time and experience.
Adult merlins are specialized hunters of small to medium birds up to the size of a pigeon (the merlin's old name was pigeon hawk, possibly because pigeons were thought to be favored prey). Species frequently preyed upon are larks, flickers, waxwings and sparrows. This falcon often seizes its quarry in flight after a rush from a concealed perch. Or it may fly low to the ground, flushing out prey as it goes. During the breeding season merlins target ground-nesting birds that can be snatched up in the open. During migration shorebirds become the principal prey. The coast of Massachusetts was the setting for an incident that clearly shows the determination and hunting skill of this falcon. An observer writes of seeing a migrating merlin speed into a group of dunlins (small sandpipers). As the terrified flock scattered, the merlin reappeared with a dunlin in each foot. For comparison, think how difficult it would be for you to catch a baseball in each hand while running at top speed. Add to that the fact that the dunlins, unlike a baseball, were alive and doing their best to escape. The merlin's impressive flying skills made it a favorite with medieval falconers. Because of its small size the merlin was considered an appropriate falcon for a lady. Noblewomen carried the little hunters about on jeweled gloves and hunted larks with them.
Residents of the Northeast are most apt to see this bold predator during the spring and fall migrations, when the merlin tends to follow the coastline south. Massachusetts residents may sight it on Nantucket, Martha's Vineyard or the outer edge of Cape Cod, where a few winter. Most merlins continue on, spending the cold months from Florida and the Gulf of Mexico down through Mexico and Central America into South America as far as Peru.
Back in the 1950s and 1960s merlin numbers dropped somewhat due to the pesticide DDT. Now the bird has recovered, and is even showing some evidence of adapting to urban environments. In at least one city (Saskatoon, in Saskatchewan, Canada) merlins are thriving, using old crow nests and feeding on house sparrows. While habitat modification, particularly to their southern wintering areas, is a potential threat, at the present time the merlin population of North America seems to be stable. Scientists estimate the total at around 8,000 pairs.