American
Robin Migration Update: April 13, 2004
Today's Report Includes:
Latest
Migration News: Proclaiming Territories and Nesting
Spring
is spreading as robins push steadily into Canada and points north. As the
map and data on the web show, robins—-males AND females-- are still
arriving from coast to coast. A few are singing and proclaiming territory
at least as far as 50 degrees north, even in places where it’s still
snowy and cold! Looking at the map, do you think the peak of migration has
passed for first robins seen? Please continue to report your robins to help
us track the migration all the way home! Read on to hear what’s been
happening where robins have arrived.
Claiming
a Territory: New Kids on the Block Video Clip/Viewing
Guide
Ms. Sussman from grade 4 at PJ Kennedy School in Marblehead,
MA wrote: “Observed 3 robins: appeared to be 1 adult (larger) and
2 juveniles. The 2 juveniles were bantering in the air (like a squabble)
and then separating to the ground to feed on grass seed... repeating this
behavior over and over. Or was it a mating ritual?” Good question,
and we think you’ll be able to answer it yourself after viewing
a video clip with guidance by our expert, Laura Erickson.
The first year a bird tries to find a territory, it takes a while and
a lot of exploring to find an open territory and then defend it against
other young birds. Laura Erickson watched a couple of young males when
she was in Nebraska in March. They had separated from the big migratory
and feeding flocks, and seemed to be interested in establishing a territory
for the first time. The problem was, they both picked the same place!
They were used to being with lots of robins, and now they didn’t
know what to do to make the other robin go away. See their behavior for
yourself with Laura’s video. She helps you understand what you are
seeing, and you’ll know what she means when she compares it to playing
basketball. When they’re robins, what are things like for “new
kids on the block?”
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Maid
Marion, mate of Robin Hood.
Photo Julie Brophy |
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Julie
points out one distinguishing thing about Maid Marion in her field
notes. Can you find it before you read those notes? |
Robin
Hood’s Mate Returns! Meet Maid
Marion
Last time
you met Robin Hood, an American Robin who has returned to the same territory
for the fourth spring in a row. His territory is the backyard of Journey
North’s Julie Brophy. Julie knows “who’s who”
in her backyard, and now she tells us that Maid Marion is back! What’s
Maid Marion’s story? What Robin Hood behaviors led Julie to think
his mate was back too? What questions did Julie ask herself to be sure
she was really seeing Maid Marion, and not another female robin? Julie
shares her field notes with us. Look for Julie to describe 3 differences
between male and female robins. And find out an unusual clue about Maid
Marion’s appearance!
Watch
Out for Flying Balls of Litter! Robin Watcher's Checklist
“Robins courting and checking out possible nesting sites”
was the news from Lexington, MA on April 9. And on April 3 in St-alphonse-de-granby,
PQ, our observer said, “The robin has started building the nest.”
Hooray!
Females are arriving in many places. How can you tell when nest building
begins? Watch for males and females flying with nest materials, and for
females with mud on the breast feathers. Females may begin nest building
within a day or two after arriving. For your own field checklist of other
nifty robin events to watch for, see:
The female is the main builder, but her mate helps by bringing her nest
materials. When building their nest, Mr. and Mrs. Robin can often be seen
carrying huge loads of nest material. Bird expert Roland Wauer wrote,
"One female robin at Curecanti National Recreation Area, Colorado,
was so loaded down that her package of twigs and grass doubled her head
size; she looked like a flying ball of litter."
Building a nest normally takes 4 or 6 days, but can take up to 20 days
in bad weather. What if the nest is destroyed? The female may rebuild
it in a single day. Later broods may be raised in the same remodeled nest,
or the female may build a second nearby nest in 2 or 3 days. More than
half of the second broods are raised in nests built at a new location.
No wonder nest building keeps our robins so busy!
Who decides where a nest is built? Of course, robin watchers don't get
a vote. The final decision is pretty much up to the female, and some females
have a hard time making up their minds. They may start two or more nests
before settling on a single site. Experienced females might repair an
old nest, or build a new one on the old foundation. Some bird experts
say that as many as six nests have been build on top of another.
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Nest
Building 101
Robins don't need written instructions for building their summer homes.
They follow the "nest-building blueprints" in their brains.
They instinctively know how to build the perfect structure to hold the
eggs they're about to lay. Have you ever noticed that robins' nests are
always alike? But have you ever seen a robin teaching another how to build
a nest?
Imagine you are a robin. What makes a suitable building site for your
nest? What materials will you use? How do you build a nest when you don't
have hands? Why do you, the parents, sleep on a nearby branch after the
first week, except when it rains? Why do you move out and build a new
nest after the babies leave? You'll get help with these answers along
with step-by-step instructions for building a robin's nest with this terrific
Journey North lesson:
Teacher Tip: Reading
and Writing Connections
Introduce the selection by asking students the following questions:
1. How do robins build a nest?
2. What kinds of natural materials do robins use to build their nest?
3. Where do robins build their nests? Why?
4. How big is a robin’s nest?
Create a chart to organize questions about a robin’s nest-making
process. Write the topic on chart paper: A Robin’s Nest-Making Process.
List five categories below the topic: Who? Where? When? Why? How? Use
the chart prior to reading the selection to record students’ questions
and predictions. (Activating Prior Knowledge, Making Predictions and Asking
Questions to Set a Purpose for Reading)
This tip is from Journey North’s Reading and Writing Connections.
For the complete lesson for this short nonfiction selection, click
here.
Weighty
Stuff: Challenge Question #8
As you work your way through this week’s report, you’ll learn
a lot about robins and their nesting behaviors. You’ll have the
facts to reason out the answer to this week’s Challenge Question.
Start by looking at these American robin weights:
Average
Weights in Grams |
Winter
Male |
Breeding
Male |
Winter
Female |
Breeding
Female |
American
Robin |
86.2 |
84.8 |
83.6 |
75.0 |
Challenge
Question #8:
"Which are heavier: winter robins or breeding robins? Which loses
more weight in spring: male or female robins? Why do you think this
is?"
(To respond
to this question, please follow the instructions below.)
Tracking Temps
and Robins: ComparingThis Week’s Isotherm Map
Are
you tracking the isotherm with YOUR robins? Here's a comparison between
this week and last time:
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March
27 Map |
April
10 Map |
- Has the 37-degree isotherm moved in
the past two weeks?
- Have robin movements shown a pattern
similar to the change in the 37-degree isotherm? (Compare with the migration
maps at the top of the Web report.)
- Do the changes in where the 37-degree
isotherm is correspond to where robins have been singing?
For instructions to calculate the isotherm in YOUR region, see:
News
From the Northern Observation Posts (NOPs)
Despite some recent blasts of winter, robins are appearing and even singing
in the far north. In our Northern Observation Post at Beresford, NB, Canada,
lucky Marc Landry was delighted to report April 9 that
“The spring symphony was in town!” Grade 4 teacher Linda
Miller at St. Mary of the Lake School in Widewater, AB (latitude
55.22N) said, “Two students first saw robins April 8--One in Widewater
and one in Slave Lake.” But what about in Anchorage, our official
Early Bird Contest outpost? Just see how teacher Mike Sterling
describes their winter and you’ll probably adjust your prediction
for the first robin there. (That was Challenge Question #4, and you still
have time to send your answer!) See the news from the NOPs, and continue
updating your NOP predictions/results logsheets:
That's
the Limit!
This
range map shows the northern limits of robin nesting territory. As we've
watched robins migrate many miles across North America over the past several
weeks, can you help but wonder? Journaling
Question:
"Why don't robins go even farther north? What factors influence
the northern limits of their nesting range?"
Listening
or Looking? Discussion of Challenge Question
#6
We asked, "When a robin hunting for food cocks its head, do you think
it's listening or looking?" Most of you thought the answer was BOTH.
“When a robin cocks its head, it is listening for other animals
that might be lurking. It is also probably listening for the sound of
food, like bugs or any different sounds under the earth. I also think
that it might be looking for food and predators,” said Daisy,
Grade 4, Ferrisburgh (Vermont) Central School
Iselin Middle School 7th graders agreed. Brett, Najea, Mellisa,
and Richard said he is listening and looking for predators, and
also looking for food. Shivam, Justin, Javed, Gabriel, and Eliott
said, “We think they are looking because the earthworms
are out now and they are constantly looking at the ground. They might
be listening for vibrations in the ground to detect where the earthworms
are.”
Do you wonder how robins actually DO find earthworms to eat? Read on...
Robins
Finding Earthworms: Link to Lesson and Journaling
Question
Looking, smelling, running, listening. Robins spend much of their lives
searching for one of their favorite foods: earthworms. How DO they find
them? An ornithologist named Frank Heppner wondered. He set up some experiments,
knowing he would need to investigate all the robins' senses. This is the
equipment he used: Pieces of dead earthworm, living earthworms, rotten eggs,
decaying meat, rancid butter, mercaptoacetic acid (which smells like a mix
of sewer gas, rotten cabbage, a skunk, and a stinkbug), a small drill, and
a tape recorder extremely sensitive at low frequencies.
Journaling Question:
If you had the materials Frank Heppner used, how would you design experiments
to prove which sense(s) robins use to find worms? Why do you think he
used each of these materials?
After you
write your answer, see what some savvy fourth graders thought, AND what
Dr. Heppner concluded. Find it here. (Then go tell robin-watchers what
you discovered!)
How
to Respond to Today's Challenge Questions:
IMPORTANT:
Answer only ONE question in each e-mail message.
1. Address
an e-mail message to: jn-challenge-robin@learner.org
2. In the Subject Line of your message write: Challenge
Question #8.
3. In the body of EACH message, give your answer to ONE of the questions
above.
The Next Robin Migration Update Will Be Posted on April 20* (Migration
Data Only.)
Copyright 1997-2004 Journey
North. All Rights Reserved.
Please send all questions, comments, and suggestions to our feedback form
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