This is Bird Note.

There may be no busier bird during the nesting season than a male house wren,

because just a day or so after migrating back north from the tropics,

he claims a territory and sets to work checking out potential nest cavities.

Might be a birdhouse, a hollow pipe, an old nut hatchhole, or one of last year's Oriole nests.

And in each of these locations, the male house wren builds a starter nest.

He'll stack a couple of dozen tiny twigs here, several hundred there,

and he'll use whatever else comes to hand, or beak, too, from nails and bits of wire to paper

clips and hairpins, anything twig-like to get the job done. The male house rent stays at it

until a female pairs with him. She now picks one of the

starter nests and takes over construction, building a sturdy platform of sticks topped by a cup nest

lined with grass, hair, feathers, even snake skin. The male's leftover starter nests may

discourage other birds from nesting in those cavities.

People maintaining bluebird houses have learned to dump out these dummy nests once a female

house wren has made her choice. This helps bluebirds find a space to nest. At least until next spring,

when that male house wren gets busy again.

For Bird Note, I'm Michael Stein. Bird Note is grateful to all listeners that provide financial

support for this show. You can join them at birdnote.org.