American Robin Migration FINAL Update: May 13, 2003
Today's Report Includes:
- American Robins Almost at the End of the Line!
- Only One Northern Observation Post to Go!
- They Don't ALL Grow on Trees!
- Calculating Robins: Discussion of Challenge Question #12
- Year-end Evaluation: Please Share Your Thoughts!
American Robins Almost at the End of the Line!
Robins are back just about everywhere now. To the delight of robin-lovers everywhere, we hear their song drifting through the spring air, see them tugging at earthworms on lawns, and spy them building nests and incubating eggs and raising a whole new batch of little robins to bring these happy moments year after year.
|
|
|
 |
 |
 |
It may have
still looked a little like winter in New Brunswick on April 29,
when Marc Landry took these photos. |
|
Only
One Northern Observation Post to Go!
Robins have now been reported from all
but one Northern Observation Post. Of course, the first robin does
NOT always mean spring! Ken Moore spotted his first in Stirling, AB, on
March 13, but writes on May 8, "Just thought I'd update you. We've
had snow on a daily basis up until today. But the temperature is above
freezing and more snow is melting than falling. While snowflakes are drifting
to the ground the snow banks which have blemished the landscape are slowing
disappearing ... to be replaced by puddles and mud. Further north, Calgary
through Edmonton, and points west, I understand there is even more snow
around ... although I haven't been up there. By and large it's just miserable
weather about ... but it's supposed to start changing tomorrow. Sunshine,
which we haven't seen for many a day, is expected to be seen at least
on occasion tomorrow and the daytime highs are supposed to start creeping
up."
Shirley Bell, from Pinawa, Manitoba, wrote on May 3, "The robins
are finally here in flocks. I had about a score in the grass field behind
the apartment, along with a pair of killdeer fluttering around."
And Richard Darling wrote on May 2, "At last, I can report seeing
and hearing our robins in Nipawin, Saskatchewan. The weather has finally
warmed up during the days and the
grass is quickly turning green."
So which NOP was the holdout? Inuvik, Northwest Territories is the final one. When will the first robin appear there? As soon as we hear, we'll let you know!
 |
Not all robins nest on
trees! This one is nesting on a porch light. Photograph from Woodworking
for Wildlife by Carrol Henderson. |
Robins build nests in trees and on human structures, and successfully raise babies in both places. Unfortunately, robin babies in tree nests are often taken by crows, especially in towns and cities where crows are abundant. What can you do to help robins find safe places where crows won't usually hurt their babies? Look here:
Now that robins are nesting in many places, see what kinds of observations you can make. During summer vacation, keep a field notebook for recording all your observations. Learn what kinds of things to record here:
Do Robins Really Follow the 37-Degree Isotherm?
Have you been trying to learn whether robins follow the 37-degree isotherm? Here's a new map to check out. Compare the maps below.
 |
 |
Average
Temperature in United States Week of April 20-26, 2003, compared
with Week of May 4 - 10, 2003. (No map available of entire continent.) Why is there a new color this week? What color is the 37-degree isotherm? Have robin movements shown a pattern similar to the change in the 37-degree isotherm? Photo Courtesy of NOAA Climate Prediction Center. |
|
We don't have a map showing the average temperature in Canada, which makes it hard to observe changes in the 37-degree isotherm now that it's moved up so far. During this season, do you think the changes in where the 37-degree isotherm was corresponded to where robins were singing?
Calculating Robins: Discussion of Challenge Question #12
Last time we told you that William Bernard saw a lot of robins passing over. He wrote, "For at least an hour there was a steady stream of robins moving to the NNE. I did a few minute-counts and had numbers like 45, 62, and 70/minute flying overhead." We asked you to use Williams's numbers to make these three calculations:
- What was the average number of robins flying overhead per minute?
- Based on that answer, how many robins were flying overhead per hour?
- If William Bernard was counting them in an area of the sky 200 yards across, and the actual robin front was a mile wide, how many robins were flying by per hour?"
Susan, Amtul, Laura D., Adrian, Sampada, Brittney, Arslan, and Ashley from Iselin Middle School figured it out. They write:
- The average number of robins seen (45+62+70 divided by 3) is 59.
- Based on that number, there are 3540 robins flying overhead in an hour (59 X 60 minutes in an hour).
- If William Bernard was counting robins in an area of the sky 200 yards across, and the actual robin front was one mile, 31,152 robins were flying by per hour. (There are 5280 feet in a mile divided by 3 feet in a yard equals 1760 yards in a mile. 1760 divided by 200 equals 8.8 200 yards in a mile. 8.8 X 3540 birds flying over head in an hour in a 200 yard space equals 31,152 robins flying in the space of a mile every hour.)
Year-end Evaluation: Please Share Your Thoughts
Please take a few minutes to share your suggestions and comments in our Year-End Evaluation Form below. The information you provide at the end of each year is the single most important tool used to guide our planning.
|
|
Journey
North |
This is the FINAL Robin Migration Update for Spring, 2003.
Thanks for joining us as we witnessed robins making their annual Journey North. See you next spring!
Copyright 2003 Journey North. All Rights
Reserved.
Please send all questions, comments, and suggestions to our feedback form
