This is bird note.

In the darkness of a northern forest, the hooting of a boreal owl. This is the male owl's song. These staccato

notes can continue for more than an hour and carry for more than a mile.

Boreal owls have a large head rimmed in black,

yellow eyes, and dark plumage speckled heavily with white.

They're highly adapted to hunt in the north's long hours of winter darkness.

One ear opening in the skull is set high and the other, much lower, an asymmetry that helps pinpoint the sound of tiny rodents under the snow.

They have a pronounced disc of feathers around their faces that funneled sound to the ears.

Boreal owls can plunge their talons through inches of snow-covered ground

to capture small mammals like voles.

In most birds of prey, females are bigger than males.

Boreal owls are an extreme case, with females sometimes twice the weight of their mate.

Greater size lets females take on larger prey

than males so they don't compete as much for the same meal.

On a moonless spring night, the songs of boreal owls echo across Alaska and Canada, and from

Scandinavia to Siberia. For Bird Note, I'm Michael Stein.

This episode is sponsored by Gary and Elizabeth Kennedy Ketchison to honor the mystique

and magnificence of owls.