Swainson's hawk is an iconic bird of the plains -- on two continents.
The birds nest on the Great Plains of North America, and they spend the winter on the Pampas of Argentina.
This is a distance of more than 7,000 miles one-way -- as the crow flies.
Hawks don't fly like crows, however. Crows take the direct route. Swainson's hawks migrate overland. That means they follow the irregular land mass that joins the two continents.
Huge numbers of Swainson's hawks pass over Panama, where Central America narrows appreciably. All of the Swainson's hawks pass through this funnel before spreading out again over northern South America.
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Scientists take advantage of this phenomenon to count Swainson's hawks. Numbers approaching in the hundreds of thousands have been noted.
Such huge numbers won't be seen in our area -- but around here, Swainson's hawks sometimes gather in pretty impressive flocks.
One September, I saw several hundred of them spread over a stubble field just west of the ridge that marks the western edge of the Red River Valley. Once, in Emmons County southeast of Bismarck, a friend and I counted 500 Swainson's hawks. One summer evening at the place Suezette and I own near Blaisdell, in northwest North Dakota, close to 50 of these birds appeared circling over our fire pit.
Those birds must have been enjoying a free ride on air thermals rising from our fire. The Swainson's hawks spread out on a Grand Forks County field were hunting on the ground. These birds take enormous numbers of grasshoppers, and the field must have been a buffet for them. They also eat small mammals and, sometimes, snakes and birds. They aren't large or strong enough to take anything much very big. Meadow mice are their staple fare
Swainson's hawks nest in the Red River Valley but not any farther east. They aren't common on the Minnesota side of the river. In fact, I can't remember seeing a Swainson's hawk there, although I've encountered them in southwest Minnesota, another area of open grasslands.
This hawk's range extends north to the Prairie Provinces of Canada and west to the Rocky Mountains and Great Basin. South, it reaches northern Mexico.
In general, the farther west you travel from Grand Forks, the more likely you are to see Swainson's hawks. They are quite readily recognized, once you learn the key field marks.
First, this is a big bird, certainly big enough to be noticed at a distance. It's also a soaring bird. Here, possible confusion arises, especially with red-tailed hawks, which are the most common of the soaring hawks here.
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Swainson's hawk is a slimmer bird, with wings that appear long in proportion to the body. A red-tailed hawk is about the same size, overall, but it appears bulkier, and its wings seem shorter in proportion to body size.
Once the bird is close enough for a good look, distinctive field marks become readily apparent. Uniquely among the hawks encountered here, Swainson's are dark on the trailing edge of the wing and light on the leading edge.
Swainson's hawks are dark on the upper chest and neck, as well, where red-tailed hawks are light. Redtails have red tails, of course, though this isn't always obvious, especially in younger birds -- the ones more commonly encountered in the fall. The Swainson's hawk has a heavily streaked tail, but it often appears quite light from below.
At rest, Swainson's hawks appear darker than red-tailed hawks, and the brick red color on the chest is distinctive.
Both birds are fond of open perches, often sitting on telephone poles, fence posts or hay bales. In general, though, a hawk on or near the ground is more likely to be a Swainson's.
September is a good time for hawk watching. Hawk populations are largest now, because they include young of the year. A casual drive down a country road should produce hawk sightings.
A bit later -- a month or six weeks from now -- the hawks will begin their migration. That's the time to be alert for big bunches of Swainson's hawks en route to their winter homes thousands of miles away.
Jacobs is publisher of the Herald. Reach him at (701) 780-1103; (800) 477-6572, ext. 1103; or send email to mjacobs@gfherald.com .
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