The arrival of the northern harrier is a sign of spring, but not one that is widely recognized.
This is no surprise.
The harrier is a common bird but not a familiar one.
There are two reasons for its relative obscurity.
One is that it is a bird of open country. Most city dwellers never encounter it, and most country people who notice it dismiss it as just another hawk.
The second reason for the harrier’s obscurity is the bird appears to be two species rather than only one, and so it provides a double challenge to those who wish to know the names of birds.
The harrier is strongly dimorphic. This is the scientific way of saying male and female harriers differ in important ways.
Of course, they are the same in important ways, as well, and for bird lovers just learning about harriers, it is the similarities that are most important. They mark this species as different from any others in our area.
These are the field marks in common:
• Medium size.
• Narrow wings edged in black.
• A white patch on the rump—that is to say the area just in front of the tail.
• A distinctive wobbling flight.
• And a vaguely—but discernible—owl-like appearance.
The last is augmented by a semicircular mark on the plumage that frames the head and sets it apart from the body.
This is a subtle mark common to both male and female harriers.
Males differ from females, however. They are ghostly gray with black wing tips, as if they were dipped in ink. Females are browner. Close up and in good light, they look rusty.
But all harriers, whether male or female, have the white rump patch. No other midsize hawk has this.
The harrier occurs across the Northern Hemisphere, a fact that justifies the adjective northern in its name. This is unique to North America, however. In Europe, the species is known as “hen harrier.”
Let us pause here to acknowledge the harrier has another name in North America, as well. This is “marsh hawk,” a reference to its preferred habitat. This name has fallen out of use, however, partly because the American has been recognized as conspecific with the European bird and partly because the name “marsh hawk” is too vague to describe the northern harrier’s place in the bird world—as a northern representative of the harrier clan.
The harrier haunts open spaces—but not any open spaces. The species requires quite dense cover, for two reasons. One is that the harrier depends on grass-loving rodents for its food supply. The other is that the harrier depends on dense grass cover for its nests.
These two dependencies limit the harrier population, of course, and the rapid conversion of grasslands to farm fields has hurt the harriers.
Still, harriers can be found throughout the Red River Valley wherever patches of grass remain.
Watch for harriers when driving through these areas.
You can recognize the birds at distances because of their peculiar tottering flight and the prominent white rump patch. These are easily the best field marks for the birds.
The harrier is a nesting species here, but many of the birds seen at this time of year are migrants that are northward bound.
They are the only midsize hawk commonly encountered in open country. The only species likely to be confused with the northern harrier is the short-eared owl, another open-country bird. The owl has its own peculiar jerky wing motion. This is quite different than the rocking, side-to-side motion of the harrier, and it should instantly separate the two species in the field. Rough-legged hawks have white rumps, like harriers do, but the rough-legged hawk is a big bird, and size distinguishes it from the harriers.
Of course, the harrier is hardly the only sign of spring. This week brought a huge movement of swans and geese, and the first of the year’s meadowlarks showed up, as well.
It’s worth remembering—at this time of year—that no single species announces the onset of spring. Rather, it is the arrival of a group of birds, western meadowlarks, dark-eyed juncos, northern harriers, snow geese and others that usher in the season.
Harriers are important—and early—in this sequence.
At the same time that migration brings bird species into the Red River Valley, it also draws other species away.
The past week saw a notable influx of snowy owls, rough-legged hawks and dark-eyed juncos. All of these are northern species that are just passing through. They’ll be back in late fall, on their way south—or if the weather is right, they may stay here in the Red River Valley.
Nesting birds also help herald the season.
Now is the time to listen for the loud, bell-like song of the blue jay and the whistling “fee-bee” call of the chickadee.
And soon, to hear the song of the western meadowlark, state bird of North Dakota.
I saw my f.o.y. meadowlark—first-of-the-year—a week ago today.
My wish for the spring and summer is a simple one: May there be many more meadowlarks.