Nature
Notes for October 30, 2015
“There’s
a small owl on my deck. It’s been there for a couple of hours. What is it doing
there? Do you think it’s all right?” said the worried voice on the telephone.
The
first questions I asked were to try to identify the owl species: How big is it?
Does it have ear tufts? Since it was described as quite small and without ear
tufts, my best guess was that it was a Northern Saw-whet Owl.
These
tiny owls weigh between 80 and 100 grams. As with all owls, the females are larger
than the males. Because of its small size, many people describe it as a “baby
owl”, but that’s a big as they get.
Northern
Saw-whets are one of the few owl species occurring in this area that migrate
regularly. Some other owl species irrupt south in some winters, usually due a
shortage of food at more northern latitudes. Saw-whets, however, migrate south
in winter and back north again in the spring. If the hunting is good, a few
will stay around in Northumberland County through the winter. There have been
recoveries of saw-whets, banded in Northumberland, from as far south as southern
Virginia.
These
little owls are highly nocturnal so they are seldom seen by observers. During
the day, these owls roost in dense cover, so they are difficult to detect.
There is a sub-set of bird banders that become nocturnal during the migration
period in order to capture and band saw-whets. Much of the knowledge of their
biology, including migration routes, comes from these studies.
Early
settlers gave this owl its curious name because they thought the song was like
the sound of a saw being whetted or sharpened. It has a repetitive one-note
song, which it sings in the early spring (late February to early April), around
the time the maple syrup is running.
Saw-whet
owls nest in tree cavities and will use nest boxes.
So
what was the bird doing in a Cobourg backyard in the daytime? It was probably
trying to keep as still as possible, to avoid being prey for larger birds. Even
at night, saw-whets can be at risk, since big owls will eat little owls if they
get a chance.
A
neighbouring backyard had bird feeders. Perhaps the saw-whet was waiting for an
opportunity to feed, too. They do prey on small birds. Often, the spilled seed
from bird feeders attracts small rodents which would also be the perfect size
of prey for a saw-whet owl.
A
few years, ago, our garden was visited by a saw-whet owl in the spring. In the
pre-dawn light, it tried to attack a Mourning Dove under the feeder, but was
unsuccessful. Later in the morning, our attention was drawn to its roosting
place by a flock of scolding chickadees. This bird spent half the day in the
yard and delighted several visitors.
Although
a few Northern Saw-whet Owls nest locally, most are hatched from nests in the
boreal forest. It is possible that this stop in Cobourg was the bird’s first
encounter with people. It didn’t yet know that it might be wise to be cautious
around humans.
The
Project FeederWatch season begins on November 14, 2015. For more information, go
to www.birdscanada.org/feederwatch.
