Be Your Own Birder

Weekly Bird: Northern Saw-Whet Owl

Owls are amazing birds, no matter what their size. The northern saw-whet owl is one of the tiniest of these nocturnal fliers, but that doesn’t make it any less amazing – how much do you know about these small-but-mighty owls?

Northern Saw-Whet Owl

Northern Saw-Whet Owl – Photo by David Mitchell

Northern Saw-Whet Owl Fun Facts
  • The northern saw-whet owl (Aegolius acadicus) got its common name because of its hoarse, rasping call that sounds like a saw against a whetstone. Other common names include the Queen Charlotte owl, saw-filer, Kirkland’s owl, wetsaw, Acadian owl, farmland owl, little nightbird, and sparrow owl.
  • These owls vocalize year-round, though they are noisiest during the mating season. They use a variety of different calls and sounds, including a tooting, hoot-like call with an even, repetitive pace, as well as raspy notes and other whistle-like or wailing calls.
  • While the plumage of male and female northern saw-whet owls looks the same, females are heavier than males. During the breeding season, they may weigh as much as 50 grams (1.75 ounces) heavier than their male partners, though in the winter, females slim down and are only about 15g (.5 oz) heavier than males.
  • These owls are skillful predators and take a variety of small prey, including mice, frogs, large insects, small birds, shrews, voles, bats, and even crustaceans. They’re such tiny birds, however, that even a mouse can be two generous meals, and they may cache leftovers to save for future meals.
  • When prey is especially abundant, northern saw-whet owls may eat only the heads of the critters they catch, as it is the most nutritious bit and easiest to digest. Brains… Zombie owl, anyone?
  • Northern saw-whet owls typically use a pouncing technique to hunt, dropping down on prey from above or only flying short distances before striking. This allows them to remain still and undetected before taking their prey by surprise.
  • These owls have irregular irruptions based on prey populations, breeding success, and weather patterns. This can bring large numbers of northern saw-whet owls into unexpected places, including suburban habitats.
  • When threatened, these owls can change their posture to disguise their body shape and look more like a branch or bump. This helps them avoid detection without leaving the safety of their roosting spot.
Adding the Northern Saw-Whet Owl to Your Life List

While these small owls can be hard to find, when you do spot one, they can seem remarkably tame and at ease, even in the daytime. They prefer coniferous forests, but may be found in deciduous habitats and even plains in autumn and winter. Habitats with nearby rivers, streams, or swamps are especially preferred. As highly nocturnal birds, it is best to take a dedicated owling trip in their habitat to try and spot northern saw-whet owls. In their breeding range, it is possible to offer nesting boxes for these owls. While they roost, northern saw-whet owls tend to stay just 10-12 feet high in coniferous trees and tuck close to the tree’s trunk for shelter and camouflage. These owls may be mobbed by protective songbirds, so birders who notice a cacophony of alarms may find a northern saw-whet owl nearby.

Learn More About the Northern Saw-Whet Owl

There’s plenty to learn about northern saw-whet owls, especially with these great resources…

  • Cornell Lab of Ornithology: Thorough overview with identification, breeding, range, etc.
  • BirdLife International: Interactive map, including breeding and non-breeding ranges
  • Project Owlnet: Detailed research project focused primarily on northern saw-whet owls
  • The Owl Pages: Profile overview with photo gallery, map, and other species details
  • Lake Placid CVB: Detailed personal journal about banding northern saw-whet owls
  • Xeno-Canto: 190+ recordings of northern saw-whet calls, songs, and noises
  • NestWatch: Details and sizes for providing nesting boxes for northern saw-whet owls
Northern Saw-Whet Owl

Northern Saw-Whet Owl – Photo by Michael Woodruff

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