When Will Robins Reach the End of the Trail?
Predictions Using the Plant Hardiness Zone Map
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
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
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.
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:
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!
or Journaling Question
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.
- How to
use maps and other geographic representations, tools, and technologies
to acquire, process, and report information.