This is bird note.

The rhythmic cries of a kill deer are familiar across most of the country in spring and summer.

It's our most often seen plover, the one with the double dark breastbands.

But what do kill deer do in the winter?

Do they migrate south or stick around through the cold months?

The answer is they do both.

Kildare that breed in the southern half of the U.S. and along the Pacific coast,

where winters are moderate, are year-round residents.

But the ones that breed in the northern U.S. and Canada, where winter conditions are more severe, migrate south to Mexico and Central America. Kildare are a clear-cut

example of what scientists call a partial migrant. Part of the species population migrates, part stays put.

Birds such as Swifts, where they all migrate, are known as complete migrants. And because the

northern kill deer fly south right over the region where other kill deer reside year-round,

they are also known as leapfrog migrants. In spring, they'll once again

leap across the resident, Kildare, en route to northern zones. For Bird Note, I'm Mary McCann.