(Aegolius acadicus)
The Willistown Conservation Trust’s Flagship Bird for the 2022 Breeding Bird Blitz is the Northern Saw-whet Owl. The short call of a Northern Saw-whet Owl sounds like someone sharpening the teeth of a saw, hence their name: saw-whet. Both male and females call to each other, but the female has a softer call. This bird has been designed for cuteness, and is no larger than a soda can. Its small size and secretive habits make it hard to see in thick woods.
The Trust, in Chester County, has been studying this migratory owl for the past 12 years as part of Project Owlnet, a continent-wide effort to study the movement of Saw-whet Owls. Most Saw-whet Owls nest in coniferous forests of the north and the females and young migrate south to winter in mixed or deciduous woods, but most males stay on their territory in the boreal forest.
Saw-whet migration had been poorly understood because of their nocturnal, reclusive behavior, but Project Owlnet, begun in the 1990s, has been gathering information on their movements via a network of over 100 owl migration banding sites, and the Trust is one of them. Now we know that Northern Saw-whet Owl migrations are cyclical (every 3 – 5 years) and tied to the influx of juveniles to the populations, as result of the prolific boreal spruce and fir cone crop, which feeds the rodents, which feeds the owls. Overall, the population of Northern Saw-whet Owls is decreasing and is considered a species of Special Conservation Need in Pennsylvania.
Landowners can help Saw-whets by allowing dead trees to remain standing to provide nest cavities. Saw-whets take readily to nest boxes, which can also be used to mitigate the loss of natural sites. The owls can’t make their own cavities, so they often rely on woodpecker cavities for nesting. They are also vulnerable to increased predation when deer and invasive species cause the loss of native understory habitat.
The Willistown Conservation Trust will use Blitz funding to remove invasive plant species and replace them with native shrubs and trees in hedge rows to improve stopover sites and food sources for songbirds and other birds like Northern Saw-whet Owls. Hedgerows are ideal food locations for Saw-whet Owls, which feed on small mammals like voles and mice. You can watch a video about the Trust’s research on Northern Saw-whet Owls at: