Barred Owl

Known for its distinctive “who cooks for you” call, the Barred Owl is by far the most familiar owl in New Hampshire. It can be found anywhere there’s a large enough patch of forest, and increasingly seems to be adapting to suburban landscapes. Being relatively common, it is detected with some regularly on standardized surveys, and these tend to show a slowly increasing population – albeit with lots of ups and downs. The increase likely reflects the species’ adaptability, but the fluctuations are probably more than “noise” in the data.

As is the case for many birds of prey with lengthy breeding periods, Barred Owl productivity is tied to food availability. Although they eat a wide variety of prey, small mammals consistently comprise over 50% of the diet, and local populations of mice, chipmunks, and squirrels can fluctuate widely. In good rodent years the owls will produce higher numbers of young, which in turn will need to disperse to find new homes. It is these dispersing owls we detect on our winter counts, from which we can conclude that the summers preceding the peaks were those with lots of mice and squirrels in our forests.

Weather can also influence the number of owls we see in the winter. When snow blankets the ground, small rodents can tunnel below it and be harder for owls to detect. The deeper the snow, the more difficult the hunting is, and the owls will shift toward areas with less snow (e.g., road edges) or more prey (e.g., bird feeders) making them easier to detect. An icy crust on top of snow can also make hunting more difficult since it’s not as easy for the owls to dive into the snow in search of prey they can hear beneath it.

Yes, owls can locate their prey entirely by sound. On the sides of their heads are two ear openings, and the unusual thing about owls is that one is higher – and often farther forward – than the other. As a result, a sound will reach one ear a fraction of a second before the other, allowing the owl to fine-tune its trajectory as it comes in for the kill. Aiding this process are an owl’s round facial disks, which function like a parabolic reflector to funnel sounds to their ears.