Identifying Bird Nests

When to Look for Nests

• Identifying nests is an activity that can be pursued at any time of year. In spring, a pair of adult songbirds may catch your attention as they fly back and forth from a nest site with twigs and small objects in their beaks. In summer, the hungry peeping of baby birds may catch your ear and draw your eyes to a nest hidden among the leaves.

  After the fall migrations, you can more easily spot unused nests among the bare branches. Occasionally, a strong wind may dislodge a nest, knocking it to the ground or to a hedge, where it may easily be accessed.

Identifying an Occupied Nest

• If you locate an occupied nest or a nest being built, the easiest way to identify it is to figure out the species of birds living there. Watch from a distance. Many North American songbird pairs stay together throughout the fledging process, so you may spot either a male or female. Once the eggs have hatched, the parents spend most of the daylight hours searching for food and bringing it back to feed the young.

  If you can see inside the nest, you may be able to identify it by the size and color of the eggs or by markings of the nestlings. The bright blue of robin eggs is an unmistakable identifying mark of what species lives there.

Four Key Features

• Four primary features can help you to identify a nest: Size, structure, composition and location. As you look at the nest, try to estimate its size. A four-inch wide nest, such as is built by the American robin, is clearly too small for a crow--just as a warbler's two-inch nest is too small for a robin.

  Note the shape and structure of the nest. Many songbirds build round cup-shaped nests in trees. The oriole builds a pendulous nest, a bag-like structure that hangs from the tips of branches, while the red-tail hawk builds a platform nest high in a tree.

  Determine the composition of the nest. Twigs, grass, leaves, lichen and mud are commonly used natural materials. Some species will also pick up human cast-offs like string, buttons, plastic bags, and scraps of fabric.

  Look at the specific location of the nest. Some species prefer to build in the middle of a tree limb, while others use the fork of two branches. Cavity-dwellers, including woodpeckers, bluebirds and chickadees, nest inside a hole in the tree trunk. City pigeons create loose assemblages of twigs on the window ledges of multi-story buildings, mimicking the cliff faces used by their ancestors.

Respect Wildlife

• Do not disturb a nest that is in use. Watch quietly from a distance. Leave the area if you sense your presence is upsetting the parents.