Biology Reference
In-Depth Information
an enormous strain on the adult pair, particularly the male, who must do all the hunting while the fe-
male is laying and incubating the eggs. Adult snowy owls consume as much as four or five lemmings a
day, and the appetites of their young grow daily, so it's been estimated that a pair of adults with a brood
of, say, eight or nine can devour more than 2,500 lemmings in a single Arctic summer!
THE SAW- WHET OWL
We tend to think of owls as large birds, but they come in all sizes, from the very large to the middle-
sized to the tiny—and one of the tiniest is the saw-whet owl
(Aegolius acadicus).
How small is tiny?
The diminutive saw-whet stands only seven or eight inches tall and weighs approximately three ounces.
It can easily fit in the palm of one's hand and somehow seems too small to be a raptor like its bigger
relatives.
Where other owls appear benign, comical, or fierce, the saw-whet, despite yellow eyes, can only
manage to look cute—an owlish version of Tom Thumb. This mien is perhaps reinforced by the fact
that the saw-whet is “earless,” with a smooth, rounded head. There is nothing cute about this diminutive
owl when it comes to predation, however. Make no mistake, those little talons are strong and needle-
sharp, and the tiny beak is perfectly capable of dissecting prey with exemplary efficiency.
Although the saw-whet eats insects and, occasionally, small birds—prey that would seem in keeping
with its size—its main diet consists of mice, voles, shrews, and even young squirrels. Consider that a
fat meadow vole approximates the weight of the saw-whet itself, and a young squirrel substantially out-
weighs it, and the rapacious nature of this little owl comes into clear focus.
The saw-whet is primarily a northern owl—resident across southern Canada and southern Alaska,
the northern portions of the United States, and south through the Rocky Mountains and along the Pacific
Coast to Mexico. Although it doesn't migrate in the true sense of the word, the population of saw-whets
does shift somewhat southward during the winter. In the eastern United States, the saw-whet often win-
ters as far south as the Carolinas; less commonly, it may even be found in winter as far south as the
Gulf Coast.
Although this tiny owl is common and wide-ranging, it's rarely seen for two reasons. First, the saw-
whet is almost entirely nocturnal and spends its days roosting mostly in dense evergreens, where its
small size and brown coloring render it nearly invisible. Perhaps that's why I've never been privileged
to see a live saw-whet. Incidentally, saw-whets are noted for their great tameness when roosting during
the day. They seem totally unconcerned by human proximity and reputedly can even be handled at such
times.
In partial recompense for never having seen a live saw-whet, I've been fortunate enough to have two
dead ones brought to me. My first sight of a saw-whet came only a couple of years after I mounted
the skunk-scented great horned owl. A lady had found the little thing in her barn, evidently dead from
natural causes. I mounted it at her request, constantly amazed that an owl could be so tiny. A second
