An age-old hypothesis about robin migration says that robins arrive
in an area when the average temperature is 36°F. Is it accurate?
Why not test the hypothesis yourselves?
To test whether robins seem to travel with average temperatures of 36°F,
first find out when robins generally return to your region each spring.
Begin the study about a month before their average arrival date.
Look at the map
of average temperatures.
The lines and colored bands show places that had the same average temperatures
last week. The lines will 'migrate' across the continent as temperatures
warm in the spring. (Come back to see and print the latest map each week.)
the approximate location of your hometown. What was its average temperature
the states or regions that had a 36°F average temperature.
the states or regions you think were too cold for robins.
(Definition: The lines that connect places with the
same average temperatures are called isotherms.)
Calculate and plot your average weekly temperature.
Use our Average Weekly Temperatures data
sheet and follow the example shown in the sample
Watch for Robins!
Continue to calculate your average weekly temperature and
keep your eyes peeled! When your robins show up, how will you answer these
the robins show up . . .
your average weekly temperature reached 36°F?
average weekly temperature reached 36°F?
the average temperature was above 36°F?
Connections — Journaling and Discussion Questions
the isotherm hypothesis seem to hold true where you live? Why or why
of robins' basic needs could be affected by temperature, and how? (See
other factors might influence the date of the robins' arrival?
you see a connection between the arrival of robins and the appearance
of earthworms? What do you think causes earthworms to appear?
how robin habitat changes: Watch for the first earthworms and
note your average weekly temperatures when worms appear. When you see
the first earthworm of the season, report it to Journey North!
Predictions: Choose a faraway Journey North school and see
if you can predict the arrival of the first robins and earthworms in
their location. You can find the daily high
temperatures of most cities via these links or in the newspaper. You
can also exchange temperature data online with another class.
follow the average temperature line (isotherm) of 36°F?
Scientists believe that, by migrating north just behind the advance
of this isotherm, migrating birds will find food and open water available.
It also allows them to have as long a breeding season as that climate
1 period + occasional time over several weeks
of Average Temperatures
of last week, where was the average temperature 36°F?
For recording and calculating average weekly temperatures
of average weekly temperatures