When Will Robins Reach the End of the Trail?
Making Predictions Using the Plant Hardiness Zone Map

Short-distance migrants such as American robins are usually not winter-hardy enough to stay in northern regions during the cold winter months. Robins normally winter in the southern U.S., from Washington to California and into northern Mexico. Unlike hummingbird or oriole migration, robin migration is tightly connected to weather. When will the robins reach their northernmost breeding territories this spring?

While we wait to hear from our official Northern Observation Posts (NOPs), you can make your own predictions with the help of a special map that shows climate bands. In this lesson, you will consider climate as a factor in robin migration and use the plant hardiness zone map to predict the FIRST robins and the first robin SONG for Journey North's Northern Observation Posts.

1. Click to enlarge the righthand map below and see how Plant Hardiness Zones divide the United States and Canada into 11 areas. The divisions are based on a 10- degree Fahrenheit difference in the average annual minimum temperature. (You may want to discuss these terms to be sure everyone is clear about their meaning.) For example, the lowest average temperature in Zone 2 is -50 to -40 degrees Fahrenheit, while the minimum average temperature in zone 10 is +30 to +40 degrees Fahrenheit. The colors on the map give a picture of "climate bands" and show how cold it gets. Growers and gardeners use this information to know which seeds will grow well in their region.
NOTE: When you click to enlarge the map, the top of the new page includes a link to an enlarged map key. You will find it helpful to print out the key.

When Will the Robins Arrive?

Northern Observation Posts for Robins
Click to Enlarge)

Plant Hardiness Zones
Click to See Enlarged Map and Link to Key)

2. Locate your community on the Plant Hardiness Zone Map and find the minimum temperature ranges for your zone on the key. Discuss when you usually see your first robins and when you hear the first true songs of males back on territory.

3. Print out the map of the Northern Observation Posts. Locate them on the Zone map. Then use the climate information on the Plant Hardiness Zone map to make predictions about first robins and songs for each of the NOPs. Download reproducible recording sheets to help keep track of predictions:

4. Keep an eye on the weather maps and upcoming robin reports for news from the Northern Observation Posts to see how your predictions turn out!

Try This! Discussion or Journaling Question
  • Audubon officials say their annual Great Backyard Bird Count (done in February each year) has indicated something interesting: Bird species that usually live year-round in Canada and the northern U.S. are spreading south. What do you think are some reasons for this?

National Science Education Standards

  • Ask a question about objects, organisms, events.
  • An organism's behavior patterns are related to the nature of that organism's environment.

National Geography Standards

  • How to use maps and other geographic representations, tools, and technologies to acquire, process, and report information.