A couple of times this winter I’ve been lucky enough to hear one of our more obscure nocturnal residents in my neighborhood. This species is relatively quiet in winter compared to our more common owls, but, if you can whistle, they can be coaxed to reveal themselves. Everything about the species in question is adorable - their tiny, compact bodies; their huge staring, yellow eyes; and their array of stuffed toy sounds. But don’t be fooled – if you are a white-footed mouse, the Northern Saw-whet Owl is a stone-cold killer.
Though Saw-whet owls are among the littlest of owls, measuring smaller than a robin and weighing less than three ounces, they are almost exclusively hunters of small mammals. Some combination of mice, voles, and shrews account for the overwhelming share of their diet. I recently saw a photo taken by a young birder in Yarmouth of a saw-whet that was unfortunately killed by a car – owls are vulnerable along roads since they often fly low when hunting. Though the little saw-whet in the photo was dead, its talons still firmly gripped the white-footed mouse it had just killed.
As cavity nesters, saw-whet owls breed in old woodpecker holes, and sometimes nest boxes, in cool coniferous forests across Canada and the northern US, as well as in mountains down to the southern Appalachians and through Central America. Cape Cod represents perhaps their southernmost breeding area along the immediate coast here in the east. Here they prefer coniferous swamps and pine barrens, and in my experience, seem especially fond of shrubby swamps for hunting, at least in winter. In Wellfleet and Truro, I‘ve had many a calling saw-whet perched no higher than my waist in dense wetland shrubs.
Like many owls, they have a variety of vocalizations beyond the best-known call. You might be familiar with the incessant tooting call of the saw-whet.
Closer to breeding season, so late winter and spring, males give this call ad nauseam at a rate of 118 calls per minute, like a truck that won’t stop backing up. It serves as their “song” – a territorial claim against other males.
In my experience owling in early winter here on the Cape, they are more likely to make one of their lesser known calls, which include short, adorable barking sounds.
As well as eerie wails more fitting of a murderous nighttime predator:
On a still night, you might get a quick response, so be ready to listen for these other calls – you may only get one quick little bark or whine. They are not as confiding as Eastern Screech-Owls, who will come sit near you and call repeatedly in response to imitations and tapes.
Recently, some folks on Nantucket won the owl lottery when they found a Boreal Owl, a vanishingly rare close cousin of the saw-whet. I’m aware of only one record of this species in Massachusetts in the last 22 years. You will never hear one, but I really like their call so wanted to include it.
Sadly, like too many birds, this owl became the victim of a window strike, but at least is now in the collection at the Mariah Mitchell Association and thus available for research.
I should mention that calling for owls should be done judiciously, and not repeatedly in the same location or when and where owls are known to be breeding. But if you can master the art of tooting, it’s a fun way to see if Northern Saw-whet Owls are around you. You might find they are more common than you realized, and that in fact, you may have an adorable killer in your neighborhood.