“Rare in open spruce woods and around bogs or burned areas. Active in daylight, perching shrikelike on treetops or poles to watch for small mammals. Long pointed tail, uniformly barred underside and black frame on whitish face.” — from the Sibley Guide to Birds.
Last summer on the last hour of the final day of a birding workshop along the Rocky Mountain Front, I was piloting a vanload of participants on a bumpy road. We were motoring back to Pine Butte Guest Ranch after a week of chasing birds in this vast landscape across wetland, forest and prairie. The area we had chosen for our final day was in the 2007 Fool Creek Burn, a 60,000-acre fire that began 30 miles back in the Bob Marshall Wilderness, eventually spilling over into the Teton drainage. The workshop was led by David Sibley, and after getting our fill of the accipiters, falcons and wood warblers that had been recolonizing the burn, we began our drive home. That is, until a voice in the back of the van said, “Hey, there’s an owl over there.…”
This was when our instructor jumped out of his seat and humorously declared, “It’s a ‘mock-owl!’ ” And more than just one. We spent the next hour at close range watching a family of northern hawk owls, two adults and five young, go about the business of life. Though breeding records exist for the Polebridge area, until now, there were none known south of there. Well-traveled birders have told me that it is possible to scour the Canadian boreal forest for weeks and not find any of these creatures. Yet here they were; the five fledglings squawking to their parents in a recently burned Montana landscape, well south of their traditional breeding range. Conservation status of the species in Canada is currently “Not at Risk” on the federal level but the state of Montana considers hawk owls a “Potential Species of Concern.” In a counterintuitive twist, this bird may adapt well to climate change and the more frequently burned habitats that such changes could create.
The appearance of hawk owls (Surnia ulula) is striking, like some weird fusion of an owl head atop a strongly “hawkish” body. The wings are not nearly as broad as other owls and it sports a long, pointed tail. Their overall coloration has a dark, charcoal-ashen quality and this is no accident; its preferred habitat outside of open bogs, is burned forest. We found the owls right off the road (!) using an area of total “stand-replacement,” that is, completely torched with lots of upright snags and no living conifers. In the three years since the fire, understory forbs, grasses and shrubs had come back in a big way and apparently, so had the rodents and their attendant avian predators. While these birds can hunt day or night, they are known for their diurnal predation. So not surprisingly, hawk owls have exceptional vision. They can spot prey up to 800 meters (about ½ mile) away. However, they also possess the renowned hearing of their kind; with vertically offset ears the birds can triangulate creatures even beneath a foot of snow. The bulk of their diet is smaller mammals, especially mice and voles, but they are known to feed on birds as well.
We were unable to determine the nest site with our family of birds. Generally they will use a natural tree cavity near good hunting grounds for this purpose. The clutch size is from three to nine eggs, and incubation is done entirely by the female. Her mate will feed her while she is on the nest and fledging occurs from 25-30 days. We likely discovered the owls on the cusp of the young one’s dispersal. Because hawk owls do have a hawklike build, they are faster and more maneuverable than most of the night-hunting owls. The construction of great horned primary feathers, for example, shows a soft, comblike leading edge which breaks up the sound of air rushing past as well as that of adjacent feathers rubbing together. In contrast, hawk owls and other diurnal owls that don’t have as great a need to hunt by ear, have slightly stiffer feathers without as much capacity to muffle sound. Though you would hardly know it; our time with the birds, observing them gliding from snag to snag, left me with the impression that silence itself is the sound of a hawk owl flying.
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