Nest building happens in earnest in mid to late spring.

A nest is simply a container for eggs and to keep the young birds safe and warm. The longer the young stay in the nest, the sturdier and more elaborate the nest needs to be. Ducks and geese hatch lings leave the nest soon after all the eggs that will hatch, hatch. And ducks and geese build very simple, not very sturdy nests.

Building Takes Time

Building by many species takes quite a bit of time and energy.

It is hard to imagine building a structure with just a bill and your feet. But that is what birds do.

Most small birds will take a day or two, sometimes up to a week to build a nest. A pair of woodpecker may take up to a month to chisel out a hole in a tree.

After it is completed a nest may stay empty several days before the eggs are laid in it.

Many birds will abandon a half-started structure if it is disturbed. They will start anew at another site.

Shapes

Most of the common birds we see make cup-, saucer- or bowl-shaped nests. This includes American Robins, Mockingbirds and Cardinals.

Other birds are cavity users. These cavities are holes in trees, or the ground. These include the bluebirds, house sparrows, purple martins, wrens and some owls.

Location, Location, Location

Most songbirds build fresh nests each year. They may even build a new structure for each clutch of eggs during the season.

These cup-, saucer- or bowl shaped nests can be located in many different places. They maybe found on water such as with lake and pond dwelling birds. Or in the crotch of shrub and tree branches, such as that of Cardinals and Rose-breasted Grosbeaks. Or a structure may be located on the ground such as with Brown Thrashers. Nesting

Sometimes instead of creating a new hole, cavity users usually just build a new nest on top of an old one. Theirs or somenelse's.

Still, many birds do not build nests. They just lay their eggs on the ground. This is case with falcons and night jars.

Raw Materials

Many birds use a wide variety of materials. A good field guide will list the major materials used by each species. Most nest are cup- or bowl-shapes of grasses, twigs and leaves.

The Builder

For most songbirds the selecting of the site and building of the nest are the responsibility of the female. Sometimes males choose the nesting site and will build or help build the nest.

Helping

I put out my free nesting materials soon after spring begins. I am often surprised by a half finished nest before I realize that nest building has started. By putting the materials out early, the birds will have the free material when they are ready.

You can help with nest building by providing materials such as:

short pieces of string and yarn (four to six inches is safe) pet hair (cat or dog) brush piles of twigs and leaves

But avoid fluffy cotton fibers which can retain moisture and make nests damp.

Nest building in spring is done by many birds. The nest vary in shape, location and material used. It is a very interesting behavior to watch. Often in your own backyard.