One night this week I became aware of a series of whistled “toots,” all the same pitch, coming from the adjacent woods. This far-reaching, distinctive call comes from a surprisingly small owl, the Northern Saw-whet — one of our most common owls, whose common name comes from the “skiew” call that is made when it is alarmed. This sound has a resemblance to the whetting of a saw. Although a Saw-whet only weighs about as much as a robin, you would never know it from the volume and carrying power (over 300 yards) of its call. Typically the male calls only during the mating season, in an attempt to attract a female with whom it will mate. The female then selects the nesting cavity, typically a Northern Flicker or Pileated Woodpecker hole, usually in March or April. This pint-sized raptor (weighing less than 3 ounces, and measuring 8 inches in length) feeds mainly on deer mice. Unlike most owls, it does not swallow the mouse whole, but rather tears it in half, leaving the second half for another meal.