The northwest wind plays a supporting role in this week’s column, just as it did last week. The lead character this week in the northern harrier, a more appealing bird than last week’s star, the double-crested cormorant.
On a clear afternoon last week, a single harrier swept over the shelterbelt protecting my place from the wind, flew through the windless (or at least less windy) zone created by the trees, set its wings and turned its belly toward the wind.
Then, the harrier rode the wind southeastward across the fields, harvested and lying fallow now, toward some more congenial spot somewhere southeast of us.
The bird was a male. This is easily discerned among harriers because the sexes are unlike in color. Females are brownish overall, and heavily streaked. Males display various shades of gray. Some are nearly pure white, except for black on the outer edges of the wings.
“Gray ghosts” is the term David Crossley uses in his guide to birds of eastern North America.
The harrier is not confined to North America, however. It occurs across the Northern Hemisphere. In Europe, it is called “hen harrier.” Another closely related species occurs in South America. The genus, a group of closely related birds, contains 24 species, many of them in Africa.
These harriers are birds of open country. They nest on the ground, and so they require fairly heavy cover. The grasslands west of Grand Forks provide that in some abundance, and harriers are regular there, arriving quite early in the spring, often by the end of March, and leaving in October, though stragglers might be seen until snowfall makes open country hunting difficult.
The fact that harriers are dimorphic leads to some confusion, since male and female can appear to be two distinctly different birds. Two characteristics link them, however, and clinch identification of either sex as a harrier.
First, harriers have a distinctive flight pattern. They hold their wings in a dihedral, or V-shape, rather than flat. They don’t exactly soar, as other open country raptors often do, but rather glide quite close to the ground tipping from side to side. They are by no means weak fliers, however; this trick allows them to spot prey.
Harriers are also capable of maneuvers in flight, such as the one I watched last week, which involved tipping sideways, exposing more surface to the wind and gaining speed as a result.
The other identification clincher involves the birds’ plumage. Both sexes display a white rump. This feature occurs in many bird species, but in only one other raptor that is common here, the rough-legged hawk, a northern bird that pretty much replaces the harrier as the open country hunter by mid-November.
The rough-legged hawk is a larger bird. It, too, had a unique flight maneuver. Alone among large raptors, the rough-legged hawk is capable of hovering. Kestrels do this, but they are far smaller than rough-legged hawks.
Flight antics are part of harrier courtship, too. Courting harriers fly close to each other, circling and somersaulting. Males pass food items – meadow rodents of various species. The birds aren’t shy about this display; indeed, they couldn’t hide since the activity takes place in open country.
Males typically arrive in nesting habitat several days ahead of females. Their arrival alerts birders to the change in season and the approach of courtship activity. Nor do harriers limit their displays to a single partner. Although some males are monogamous, some have been found to mate with as many as five females.
During the summer, northern harriers share grasslands with short-eared owls. Numbers of each species vary; last year was a banner year for the owls while this year harriers seemed more numerous, at least in the areas I was able to visit. These were few since the pandemic kept me close to home.
Last week’s tale of birds and the wind featured the double-crested cormorant, an unpopular choice, it turns out. My fishing friends often use choice language to describe cormorants. Ornithologists have taken note. Two recent books chronicle the relationship between cormorants and humans. One is called “The Double-Crested Cormorant: Plight of a Feathered Pariah.” The author is Linda Wires, a conservation biologist. She takes the birds’ point of view. The other book is by an angler and journalist, Dennis Wild. His book is “The Double-Crested Cormorant: Symbol of Ecological Conflict.”
Jacobs is a retired publisher and editor of the Herald. Reach him at firstname.lastname@example.org.