We have just begun owl migration monitoring at the Lesser Slave Lake Bird Observatory with nine Northern Saw-Whet Owls banded so far. Since the program’s inception in 2004, 2,248 of these pop can-sized owls have been banded. In 2016, our second target species, the slightly larger Boreal Owl, was added to the roster with fifteen Boreal Owls banded to date.
While the nets we use for our ongoing fall songbird migration monitoring program are entirely passive, meaning migrating birds are caught by chance as they fly through the understory each morning, these two owl species are drawn in nightly using audio lures that play their respective songs.
Northern Saw-whet Owls breed across Canada, and Slave Lake sits on the northern edge of their Albertan range. Prior to targeted banding efforts, it was difficult to know much about these owls as they move at night and prefer resting in the hidden boughs of spruce trees. Now we know that while some Saw-whets will remain in place year round, others will migrate to lower elevations or further south. One of our Saw-whets banded in 2018 was even found two and a half years later across the Rockies in California.
As one might expect of an owl their size, Saw-whets primarily hunt mice and voles. During migration, they will also hunt other small birds like warblers and sparrows. They can even eat insects.
During the breeding season, Saw-whets will nest in cavities previously excavated by large woodpeckers in dead trees. They will usually have clutches of four to seven eggs—unless you happen to be one of our owls banded in 2022, found sitting on a clutch of eight eggs the following year in a nest box near Edmonton.
Our second target species, the Boreal Owl, can also be found coast to coast in northern Canada, with a range that extends north into the territories. These secretive birds are more difficult to lure in as they do not seem to migrate regularly like Northern Saw-whet Owls, but they will leave their home range in search of food. Boreal Owls will hunt rodents and insects at night, except in the far northern reaches of their range where the sun does not set in the summer. Like Saw-whets, they will nest in tree cavities drilled out by woodpeckers, but can also take to nest boxes.
If you are interested in the chance to see an owl and to learn more about them, consider joining us for our Family Owl Nights October 4 or 5 at 8:00 PM. Space is limited. For more information and to register, contact the Boreal Centre for Bird Conservation at info@borealbirdcentre.ca or (780) 849-8240.
By Bronwyn Robinson, LSLBO Assistant Bander
