Jim Gilbert

Robin Migration Update: March 25, 1997

Robins have swept north through most of the United States, and are now moving through Canada. There's no sign of them in Anchorage, Alaska! When do you suppose they'll arrive? Be sure to place your guess in the Sand Lake students' "Early Bird Contest". Here's a clue: There's still plenty of time to enter the contest!

Challenge Question # 6
"When do you think the first robin will be spotted in Anchorage, Alaska? Do you think it will arrive with the 36 degree isotherm?"

To respond to this Challenge Question please follow the instructions at the end of this report.

• Link to Today's Robin Migration Data.

Where in the World?
Please Note: Several teachers have said it's difficult to plot migration data because the cities are hard to find on many maps. In addition, much class time is spent using the road atlas. Teachers have asked that latitude and longitude readings be provided instead, as they feel this would be of more value to students. We need your help! Few participants are including this information with their sightings. We can't manually add lat/long information to the data ourselves. Therefore, we ask that all participants take the time to learn their own latitude and longitude.

Here are resources you can use:

• Look up your lat/long on the U.S. Geological Survey WWW Database
• Call the USGS for lat/long data: 1-800-USA-MAPS
• Calculate Your Own Latitude and Longitude Classroom Lesson: "Where in the World?"

Calling All Canadians!
More observers are now needed because robins will be moving through less populated regions. We can use your help! If you have friends and relatives in Canada, please ask them to report their first robin sightings to you. Since the volume of sightings will decrease over the next few weeks, we will now post robin migration updates every 2 weeks. Watch for our next update on April 8th. Macalester College will provide a new map as part of that report..

Worm Moon
Did you see the full moon earlier this week in your home town? Can you think of why a full moon in March might have something to do with worms?

Certain Native Americans tribes called a full moon in March a "worm moon". In March, they would look for earthworms or their castings on the ground near their tunnels, and this was a sign of spring because it showed the earth had thawed and that it would not freeze again.

Have You Seen Your First Worm of the Season Yet?

Try This!
1) With your soil thermometer, record the temperature of the soil each day.

2) Watch and listen for evidence of earthworms. Look for robins pulling worms from the ground, worms in rain puddles on the pavement and for worm castings near the openings of their burrows in the soil. Castings are small mounds of digested food left at night by worms on the soil which look like tiny mud-covered raspberries.

3) Listen for worms also, because on quite evenings you can hear them moving through grass and leaves.

4) Be sure to record the date you first see or hear evidence of worms, and when you see your FIRST worm, we hope that you will report your sighting to Journey North as a "Sign of Spring"

How to Report Worms (and Robins!)
When you see your first earthworm this year, be sure to let us know!
On the left-hand side of this page you'll see a blue owl button. Simply press the button and a FIELD DATA FORM will appear. If you have any trouble using this system, send a message to our feedback form We'd be happy to help you!

USFWS

• Males arrive and set up territories.
• Females follow a week or two later.
• Pair bonds are formed, mating, nest-building, egg-laying and incubation occur.
• Finally the first young of the year hatch.

Depending where you live, robin families in your region are at a particular point in this annual cycle. The timing of these activities varies with latitude. In fact, as a rule of thumb, it's estimated the timing varies by 10-15 days for every 5 degrees north in latitude. (Of course, this rule is intended for comparing points located at the same longitude. You couldn't use it for example, to compare timing in California and a location on the East Coast, since the seasons are so different at these places.) Here's a chance for you to use this rule of thumb:

Challenge Question # 7
"If we estimate a 2-week delay for every 5 degrees north in latitude, and we assume robins in Jackson, Mississippi, are now beginning to lay eggs, when would you expect robins in Madison, Wisconsin, to begin laying their eggs?"

How to Respond to Today's Challenge Questions:
Please do not answer both questions in one message!

How to Respond to Journey North Robin Challenge Question # 6

1. Address an e-mail message to: jn-challenge-robin@learner.org
2. In the Subject Line of your message write: Challenge Question # 6
3. In the body of the message, give your answer to this question:

Challenge Question # 6
"When do you think the first robin will be spotted in Anchorage, Alaska? Do you think it will arrive with the 36 degree isotherm?"

How to Respond to Journey North Robin Challenge Question # 7

1. Address an e-mail message to: jn-challenge-robin@learner.org
2. In the Subject Line of your message write: Challenge Question # 7
3. In the body of the message, give your answer to this question:

Challenge Question # 7
"If we estimate a 2-week delay for every 5 degrees north in latitude, and we assume robins in Jackson, Mississippi, are now beginning to lay eggs, when would you expect robins in Madison, Wisconsin, to begin laying their eggs?"

Don't Forget!
Please include the name of your school and your location so we can credit you properly for your answers.

The Next Robin Migration Update Will be Posted on April 8, 1997.