Saturday night we had a special Northern Saw-whet Owl fall into our nets at MSRW’s owl-banding station at Historic Miller Creek Park near Cheboygan. Most owls we catch are migrants or suspected migrants. But this female had a brood patch, meaning that she is nesting, probably within a mile of the banding station. This came as a big surprise to us because we have not heard any male saw-whets responding to our audio lure. At the nets, we broadcast the saw-whet male ‘toot’ advertising call to entice owls into the area. If our nets are within a local male’s territory, he is usually vociferous in defending his area from the ‘intruder’ male. As we haven’t heard this, we assume that this female’s nest is a bit farther away and her male hasn’t found us yet.
In looking at this female’s brood patch (photo below), we see a bare featherless patch of skin which allows her to more efficiently incubate her eggs and brood the owl nestlings. Right now the patch is relatively small and is pink, the normal skin color of a saw-whet. This means that she is just beginning the nesting cycle, probably still laying eggs. As she continues into incubation, the patch will swell, become larger, and become darker red because of the rich supply of blood vessels near the skin’s surface. Then about two weeks after the nestlings hatch, feathers will start to grow back in. Male saw-whets do not incubate eggs or brood the young so they don’t develop brood patches. Instead, they are kept busy providing food, mostly mice, to both the female and the growing brood.
In addition to saw-whets, other local breeding owls include Barred and Great Horned owls. We hear Barred Owls calling most every night but haven’t found their nest. The other night, a Great Horned Owl also called nearby. These two large owl species don’t get along, so we may witness the outcome of their interactions.
Season Totals (March 15 through April 11):
Northern Saw-whet Owl: 86 (79 new, 7 recaptures)
Barred Owl: 1