When Will Robins Reach the End
of the Trail?
Making Predictions Using the Plant Hardiness Zone Map
Background
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? To let
us know, and to ensure that the first robins to reach far north are properly noted
and welcomed, Journey North has set up northern observation posts where observers
will report their first robins. While we wait to hear from them, you can make your
own predictions with the help of a special map that shows climate bands. In this
lesson, students will consider climate as a factor in robin migration and use the
plant hardiness zone map to predict the FIRST robins and the robin SONG for Journey
North's 20 Northern Observation Posts.
Activity
1. Click to enlarge the righthand map below and explain that 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 students are 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.
2. Locate your community on the Plant Hardiness Zone Map
and find the minimum temberature ranges for your zone on the key. Discuss when you
see your first robins, and when you hear the first true songs of males back on territory.
3. Print out the map of the 24 northern observation posts. Locate them on the
Zone map. Explain that students will use the climate information on the Plant Hardiness
Zone map to make predictions about first robins and songs for each of the posts.
You can 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 Questions:
- Audubon officials say their annual Great Backyard Bird Count (done in February
each year) has indicated bird species that usually live year-round in Canada and
the northern U.S. are spreading south. What are some reasons why this might be happening?
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