A male Northern Harrier hunts low over the marsh. Harriers have owl-shaped faces, and they hunt by sound as well as by sight.
Behind the lens.
Northern Harriers are a long-legged hawk that lives in open grasslands and meadows across most of North America, including Montana. They recently upgraded from their previously pedestrian name, "Marsh Hawk."
Harriers are one of my favorite native birds. The adults sport wingspans of 42-48" wide, but they only weigh in at 0.5 to 1.3 pounds (females are bigger than males). That's about a four-foot-wide wing weighing one pound! Such a high surface-area-to-weight ratio makes for one very manuverable and fast bird. Male Harriers have been seen overtaking Prairie Falcons in flight.
Harriers are not owls, but they do have owl-like, feathered facial discs to direct sound into their ears. So like owls, Harriers hunt by sound as well as by sight. They fly low across the meadow when hunting, in a gracefully lilting glide, watching and listening for small critters (primarily voles) hidden in the grass below. With a quick flip of their long tail, they change direction instantly and dive on their prey.
Harriers are ground nesters, and the cryptic brown female takes over and finishes construction after the male starts the nest. The light-gray male seldom comes to the nest after incubation starts. While she incubates their eggs, he handles the hunting and makes food deliveries to his mate. He flies in with a meal, calls out to her, and she flies up from the nest to make the food exchange in mid-air. About two weeks after the chicks hatch, the female starts hunting again. After the dark brown youngsters become profecient at flying, mom will make mid-air food exchanges with her young.
Harriers are occsionally polygynous (when food is plentiful), with one male mating with 1-5 females and delivering food to all of them while nesting. They'll sometimes nest in loose colonies of 10-20 individuals. Adults are not territorial, but they will aggressively defend the nest from predators (and photographers). During winter the larger females will aggressively exclude males from prime feeding areas, but then they'll roost communally on the ground at night.
The Harrier population appears to be stable in North America. A few Harriers winter in Montana, but voles are hard to hear underneath snow, and so most of Montana's Harriers are migratory. They'll head south by late November and return to Big Sky country in March or April.
My Harrier image graced the cover of the 2014 Peregrine Fund calendar.