Merlin, the other falcon
Peregrine falcons have been getting all the press here in the Fargo area for several years now. It's easy to see why. The bird is one of the prime ambassadors for reintroduction efforts after population declines a few decades ago. We've been blessed with an urban nest site that has been occupied by nesting peregrines for many years running. Plus, it features a web camera. Watching these raptors on the Internet and knowing the birds are right here in town doesn't get old. While the focus on peregrines has been ongoing, a lesser known cousin has been quietly making a move into urban areas as well--the merlin (Falco columbarius).
Merlins (known formerly as pigeon hawks) are smallish falcons (under 12 inches) not much larger than the more common American kestrel. In flight, the size and shape of a merlin strongly suggests a kestrel. But its coloration lends one to think 'immature peregrine.' Adult males display a slate-to-light gray back and head, while immatures and females are brownish. Front parts are white with variable brown streaking down the breast. The prominent "moustache" mark of peregrines and kestrels is subdued to absent in merlins.
As for reputation, merlins are the bad dudes of the falcons. Birding expert Pete Dunne calls them, "falcons with attitude." Merlins are extremely intolerant of other raptors, even those much larger than themselves. During fall migration several years ago, I stood on the shore of Lake Michigan and watched one chase and harass a pair of kestrels. For twenty minutes straight this bird pursued the pair relentlessly. Eventually I walked away with the aerial dogfight showing no signs of letting up.
In size this bird may be near to a kestrel, but in diet the merlin is light-years away. While insects and small mammals make up the lion's share of a kestrel's intake, merlins are almost exclusively bird eaters. A merlin will perch inconspicuously and surprise unsuspecting prey in a direct attack. More likely, however, this falcon tends to fly low and fast over an area in an effort to flush birds below. Several times this winter, I've gotten brief glimpses of one zipping through the back yard with birds scattering for cover.
Three races of merlin are recognized in North America with a few more in Europe and Asia. Of our three, richardsonii is the "prairie race," nesting in Canada's Prairie Provinces south to Wyoming. Dr. Paul Johnsgard points out that, for bird-dependent hawks, population densities are not high, which demands large territories. That may not necessarily be the case in target-rich environments like cities, where population dynamics are skewed.
Merlins began nesting in residential Winnipeg in 1970, a year later in Saskatoon. Twelve years later Saskatoon boasted 16 pairs, marking the highest density ever recorded for this species, including Europe. The presumed reason for such success is a high number of American crow nests (merlins build no nests themselves but take over abandoned ones of others such as crows and various raptors) and an abundance of house sparrows.
I moved back to West Fargo in 1990. It took me three years to see my first merlin locally. In Birding the Fargo-Moorhead Area, published in 2000, Bob O'Connor records these birds as "uncommon to rare winter residents." Grand Forks recorded a nest in 1998 for the first time and by 2002 there were five. Fargo finally had one about three years ago just east of the Bison Sports arena. A pair displayed courtship behavior briefly in West Fargo a year ago but apparently did not attempt a nest.
The evidence seems to point to an increase in merlin numbers as the bird becomes accustomed to nesting in urban areas. At virtually any time of year it is now possible to see one of these pugnacious little speedsters. Watch for one perched in trees, on a light pole, or even on a rooftop. It is notably tamer than a kestrel and allows a closer approach.
It may not garner the attention of the more popular peregrine falcon, but a merlin is equally thrilling to see. That is unless you're a house sparrow. Dunne writes, "Very few creatures covered with feathers and smaller than a pigeon want to be near a merlin."