Today's News
A/CPB
Uriah McKinney, Macalester College
Robin Migration Update: March 18, 1997
Just a quick report today, as there are so many sightings you'll be busy marking your map. We are using a new color every 2 weeks to mark the sightings on our map, so that the migration can be visualized over time. To enlarge our map, click on the image. Robin sightings are marked in red (Before Feb. 15), blue (Feb. 15-28), and yellow (March 1-present). Please note that 26 sightings were reported after the map was created, so don't be concerned if your report does not yet show on our map.
How to REPORT:
On the left-hand side of this page you'll see a blue owl button. When you see your FIRST robin of the season, 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!
Early Bird Gets the Territory
Challenge Question # 4 asked, "Why do you think male robins return before the females? What are the advantages and disadvantages of coming early?" Almost everyone who answered this question figured the males must come first to find and defend a good territory. (Anyone who's played musical chairs knows the feeling of rushing to find a place before someone else gets it.) The male himself benefits from a good territory, and there is evidence that female birds of many species tend to chose males which hold the best territories. Although it's the male that defends the territory, the females takes responsibility for selecting the nest site and building the nest. Males do risk food shortages when they arrive early, and must withstand colder temperatures. Perhaps another reason females arrive later is to keep their energy stores high, in anticipation of egg production and laying. The migration itself requires energy, and food shortages could weaken the bird's reproductive state. Students thought of many advantages and disadvantages of this strategy as you can read below.
Try This!
- Watch for the first female robin to appear. Females usually come 1-2 weeks later than the males. The females' feathers are noticeably duller than those of the male. Compared to the males, the females look faded--like clothes that have been through the washing machine too many times.
- Count the number of days between the arrival of the first robin (presumably a male) and the arrival of the first female. Let us know what you discover by sending e-mail to: jnorth@learner.org
- Listen carefully. When male robins arrive they don't sing as frequently as they do later, when the females are in town. Once a week, go outside where you know there are robins. Sit quietly for 5 minutes and count the number of times you hear a robin sing. How does the frequency change over time? Tell us what you've found at: jnorth@learner.org
REMINDER: 1997 Early Bird Contest
Once again this spring, students at Sand Lake School in Anchorage, Alaska will officiate our annual Early Bird Contest. In this contest, we challenge you to predict when the first robins will be seen in Anchorage. To enter the contest, simply answer this question:
How to Respond to Journey North Robin Challenge Question # 6
- Address an e-mail message to: jn-challenge-robin@learner.org
- In the Subject Line of your message write: Challenge Question # 6
- 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?"
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 Update Will be Posted on March 25, 1997.