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Build a Crow’s Nest

In this activity, students learn what a crow’s nest looks like, how it’s built and get a chance to make their own.

North American Crows do not breed until they are at least two years old, and most do not breed until they are four or more. In most populations the young help their parents raise young for a few years. Families may include up to 15 individuals and contain young from five different years.

During much of the year, individual crows leave the home territory to join large flocks foraging at dumps and agricultural fields, and to sleep in large roosts in winter. In Spring, crows build a nest for their eggs and young, starting around March or April. Both members of a breeding pair help build the nest. Young birds from the previous year sometimes help as well. 

These birds build large nests in trees, the higher the better for safety. Crows typically hide their nests in a crotch near the trunk of a tree or on a horizontal branch, generally towards the top third or quarter of the tree. They prefer to nest in evergreens, but will nest in deciduous trees when evergreens are less available. Nests can be 50cm or more wide, large than the birds are long!

Adult crows will gather all sorts of material to build their nests. Crows are very intelligent and great scavengers. They may use human-made products to their nests if they will work with their design. Commonly added materials include lint, cloth, twine, hair, or other soft materials.  It takes about two weeks to build their nests, which they leave once their young can fly.



From the ground, American Crow nests may look chaotic or messy, in fact, they are designed. There are two main sections to a crow’s nest. The majority of the nest is the outside section and is made up of large twigs woven together. Some of these twigs will stick outwards, making the nest look messy. Near the center of the nest, the sticks are tightly woven. The innermost section is made with softer materials, like moss and plant fibers. These fibers act as both cushioning and insulation for the 3-9 eggs, and young.

Objectives

  • List the survival needs of common backyard species and discover how crows build nests.

Materials

  • Per Group:
    outdoor space (preferably) with twigs spread on the ground
    pieces of twine and scrap cloth

Key Questions

  • Have you seen a nest before? Where and what was it made of?
  • How do birds find resources to construct nests? What types of materials might they use?
  • Is it easy to make a solid structure from the twigs?
  • What materials worked best? What materials did not work?

What To Do

  1. Collect materials found on the ground outside. Things to look for are small twigs, pieces of plants, moss, twine and cloth.
  2. Group students into crow families- usually this would be 10 or fewer “birds”.
  3. In “Crow Family” groups (10 or smaller), have students cooperate to weave the twigs and other pieces together in a messy nest. Aim to have it actual crow sized, not student sized.
  4. Next, have the students make a small bowl-like area in the middle of the nest where the softer materials can be placed.
  5. Have students show each other their nests. Have them discuss what materials they used and the difficulty of building a nest. Discuss what worked, and what did not.

Teacher Tip: Collect a box of potential materials beforehand and be prepared to “seed” the site for searching student “crows”, especially for younger students or on a barren school yard.

Extensions

  • What materials choices might be effected by the "tools" the crows have to work with? How is this different than human hands?
  • Play a game of capture the flag with each team having 4 or more “flags.” The “flags” are materials that you will use for building your nest. Capture all the materials for your nest to win.

Other Resources

The Cornell Lab| All About Birds | Crows