AEGOLIUS ACADICUS – NORTHERN SAW-WHET OWL
Among the smallest owls on the continent, the Northern
Saw-whet owl measures in at roughly 20 centimetres in length and
weighs in at only 70 to 105 grams, with females beingapproximately 20%
larger than males. Their white breast is covered in broad vertical
reddishbrown streaks, their eyes are yellow, and their tails, short.
They lack ear tufts, and have a pale face. Commonly mistaken for the
boreal owl (Aegolius funereus) which has a pale yellow beak and white
spots on the crown, the Saw-Whet has a black beak and streaks, rather
than spots, on the crown.
habitat of this small owl spreads across southern Canada, from Nova
Scotia to British Columbia, often in mature coniferous and deciduous
forests. Many Saw-whet owls remain throughout their breeding habitat
year-round and do not migrate south. These owls will often roost at
the edge of a woodlot, often near riparian areas, and will use both
dense and open areas as hunting grounds.
ambush approach is used to capture prey, by roosting close to the
ground and pouncing on prey from above. While they have been reported
to eat frogs, insects, mammals as large as squirrels, and birds as
large as northern cardinals (Cardinalis
and rock doves (Columba livia), their diet is made up primarily of deer
mice. Voles and shrews often make up the remainder of their diet.
Mice may be eaten in pieces, over the course of two meals,
and, during times when prey is abundant, the Saw-whet owl has been
known to eat only the head of the mice, leaving the rest. If they are
able, they will also catch several mice (up to six consecutively)
without consuming them, and will cache them in a safe place for
consumptionduring winter months. They will brood, or sit upon the
carcass, in order to thaw it so that it can be consumed.
These quiet birds are almost never heard outside of
breeding season (March to May), but when alarmed, they emit a “skiew”
sounding call, similar to the sound of a saw on a whetting NORTHERN
SAW-WHET OWL stone. They will often stay quiet, even after being
seen, relying on plumage and camouflage for protection. In an attempt
to blend into their surroundings when spotted, they may elongate their
body and bring their wing around in front of them, to simulate the
appearance of a tree branch or
Typically monogamous, males may take a second mate during years
when prey is abundant. They will attempt to attract females using
loud vocalizations. The male will call while circling above the female
several times, eventually landing near her and beginning a series of
shuffles and bobs, inching his way closerto her. At this time, he will
often have prey in his beak, and will give it as an offering to the
female. Once a pairing is made, they will produce a clutch of three to
seven eggs, nesting in dead trees where large holes have been created
by pileated woodpeckers (Hylatomus pileatus) or northern flickers
(Colaptes auratus). The eggs will be incubated exclusively by the
female, while the male will hunt and defend the nest. The young will
fledge at approximately four to five weeks, but will continue to be
cared for by the parents for several weeks after leaving the nest.
Pairs will only produce one brood per season, with the young reaching
sexual maturity at nine to ten months.
In captivity, the Saw-whet Owl may live up to approximately nine
years, but in the wild, mortality rates are quite high. They compete
with many species of other owls, birds, and mammals for nesting sites,
and are targeted by many predators such a martens and other larger owls
and hawks. Their population is considered to be very healthy
Author: Jeri Bell.
Jeri is a member of the
of Conservation Officers.