In Ontario this endearing wee owl is most often encountered in evergreens or dense willow scrub near the shores of Lake Ontario or Lake Erie during its fall migration. Once found it often allows very close approach. During the breeding season it may be located by its call notes.
This is our smallest owl (about the length of a cowbird). It is smaller than a Boreal Owl. Young Screech Owls may depress their ear tufts and look a bit like this species in poor light.
Young Saw-whet Owls go through a plumage when they are a rather uniform dark brown colour but with conspicuous white “eyebrows” and blackish faces. This is generally lost by the time of fall migration but birds of the year can still be distinguished from adults in most cases by banders by their unworn, uniformly coloured wings while adults have two-toned worn flight feathers in the fall.
The notes uttered in the breeding season are distintive.
One kept me awake for several nights between May 14 and June 9, 1973 by its persistent rather musical whistling., on a note near high C, repeated about twice per second all night long.
Dr. J. Murray Speirs