How to Identify Birds' Nests

If you spend enough time outdoors, eventually you will come upon a bird’s nest. You may gaze at it pondering the structural architecture and exquisite craftsmanship. Then you might wonder, “Whose nest is it?” Identifying a nest that is still active is fairly straightforward if you can observe and identify the birds using it. Or, practice nest identification by examining old inactive nests from previous years. Look for nests in fall and winter, when leaves are down and nests are easy to spot.

Use these clues and a field guide to birds’ nests, or the example nest images to narrow down the possibilities and help identify the nest builder. Before monitoring active nests, please read the Code of Conduct, and get certified to monitor nests!

1. Region

Different bird species can build nearly identical nests. Knowing which bird species breed in the area will help eliminate many possibilities.

2. Habitat

Habitat is a crucial piece of information and is especially helpful for identifying birds that nest in specific or predictable habitats. Find out which birds breed in the habitat where you found the nest.

3. Height above the ground

About half of all bird species in North America nest above the ground. Others may nest low to or on the ground; others high in a canopy.

4. Nest substrate

Some bird species prefer to build nests on particular surfaces such as on grass, in a shrub, in a tree, or on a cliff.

5. Nest position

Nest placement is a telltale sign. For example, a bird may prefer to nest on a leaf, on a branch, in a fork, within a cavity, or behind a flap of bark.

6. Size

The nest’s dimensions hint at the size of the bird. For example, a nest that is 4” across, 4” high, and 2” deep is typical of a bird about the size of an American Robin.

7. Shape

Nest shape can be a diagnostic for some species. Cup nests are the most common nest type for songbirds.

8. Nest material & lining

It is important to pay attention to the material that makes up the majority of the nest. Some bird species prefer certain materials such as mud, sticks, or grass. The lining, which can be very distinctive, is typically made of softer materials like fur, feathers, hair, and cotton.

9. Eggs

Note the size, shape, and markings of eggs, if present.

10. Parents

The best way to know who owns the nest is to watch from a distance until the parent returns.