This is bird note.

After dark, it's our ears that connect us to the lives of birds.

And one of our most familiar connections is with the lovely and mysterious hooting of great horned owls.

When a pair of great horned owls calls in a duet, the female usually hoots first, and the male

replies at a lower pitch.

Even though females average a third larger than males, the smaller male has a bigger voice box,

or syrinx.

Here's the female again.

Now the male.

Great horned owls may also pierce the darkness with an eerie shriek, which may signal a hungry

owllet begging for food or a female defending its nest.

Adult owls also bark in response to threats.

In fact, great horned owls have a lot to say.

Female owls sometimes call out with high-pitched trills, or hearty squawks.

And great-horned owls hiss, pop, meow, coo, and snap their bills.

So, have a listen after dark.

There may be a great- horned owl in your neighborhood.

For bird note, I'm Michael Stein.