SCIENCE

It’s nutcracker season! As we begin December, the Clark’s nutcracker has stored up to 20,000 treasure maps in its 5-ounce birdbrain. And the maps are accurate, detailed, and instantly retrievable. (Nat Geo Phenomena blog)

How do nutcrackers navigate? Use our resources to find out.

Teachers, scroll down for a quick list of key resources in our Teachers’ Toolkit.

Discussion Ideas

• The Robert Krulwich blog says the Clark’s nutcracker can keep track of up to 20,000 mental maps. (Read more about Clark’s nutcrackers here.) What are these maps of—what information do they store?
  • They’re treasure maps! X marks the spot for 20,000 hidden caches of seeds the birds began storing six months ago, during the summer.

• Where do nutcrackers store their caches?
  • Anywhere. According to Krulwich, “Sometimes [the birds] peck little holes in the topsoil or under the leaf litter. Sometimes they leave seeds in nooks high up on trees.”

• How do the birds find the caches?
  • They triangulate! Triangulation is a method of determining distance or placement of a point by measuring angles to it from known points. Here’s a triangulation network that nicely highlights known points, unknown points, and measured angles.
    • According to Krulwich, “Nobody knows exactly how the birds manage this, but the best guess is that when a nutcracker digs its hole, it will notice two or three permanent objects at the site: an irregular rock, a bush, a tree stump. The objects, or markers, will be at different angles from the hiding place.”

TEACHERS’ TOOLKIT

Nat Geo: How a 5-Ounce Bird Stores 10,000 Maps in its Head

Nat Geo: How Do Birds Navigate?

Cornell Lab of Ornithology: Clark’s Nutcracker

Intergovernmental Committee on Surveying and Mapping: Triangulation