This is bird note.

The emphatic hoots of a pair of barred owls resonate in the still of February night. So-called for the stripes on their breast.

Bard owls are among the largest owls in North America.

They're also the most vocal, initiating their vocal courtship in winter.

Their signature hooting sequence has been memorably described as who cooks for you, who cooks for you all.

But this is just one of more than a dozen barred owl calls ranging from a siren call to a whale to a wonderfully

entertaining monkey call. Although the Bard Owl's calls have long been heard in eastern forests, it is a relative

newcomer to the western U.S.

During the 20th century, its breeding range has expanded into the north and the west and down as far

as northern California.

The exact reasons behind the expansion aren't certain, but new riparian forests, fire suppression, and the planting of

shelter belts in the Northern Great Plains are some of the human impacts that have

likely played a role. No matter what accounts for the Bard Owl's dramatic sweep across

the continent, the bird and its extraordinary voice seem here to stay. For Bert note, I'm Mary McCann.