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American Robin Migration Update:
May 10, 2005
Today's Report Includes:
American
Robin Migration Maps and Data
Where
are all the robins? That’s the question we began with as we asked
you to join the 2005 Winter Robin Round-up 3 months ago. And now look
at the map of your sightings! Spring's robin migration is reaching the
end of the road. All but one of our NOPs have welcomed their robins home.
First Robins
Seen |
Waves
of Robins |
First Robins Heard Singing* |
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(map)
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(map)
(data)
*Recommended for mapping |
Initiation
of "Song" is the clearest pattern we expect to see as we track
the spring robin migration. Printer-friendly format:
Instant
Replay of the Migration: Try This!
For almost 4 months you have watched the ever-changing Journey North
maps. You were challenged to think and act like scientists as you made
predictions and puzzled out the mysteries of migrations and other seasonal
changes. Now you can see an instant replay! Play this slideshow several
times and watch how the migration advanced each week through spring.
Try This! Discussion/Journaling Questions
As you viewed the slideshow, do you see changes you did not notice
before? Make a general statement to describe what happened as the
season
went
on. Try
to explain
the underlying reasons for this pattern. How did the "pace" of
spring change from one week to the next? What factors might have
influenced this?
Just
One More NOP to Go
Which of the Canadian NOPs is the only holdout still waiting to
see spring's first robin? Which places are waiting to hear
the robin’s
song? It's NOT Port Hope, Ontario, where Ute Keitsch exclaims: “We
have Spring! The Robins are going crazy.” Trees still don’t
have leaves yet, but last week brought another huge wave of robins
to Port Hope--mostly
females but also some new males. See the latest NOP News for the
fun story of the robin family on Linda Hoffman’s deck, and
to find out how spring looks for some of the NOPs who already welcomed
their
robins. A HEARTY THANK YOU to all the wonderful folks who shared
the excitement of welcoming their robins at our 20 Northern Observation
Posts!
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How
old do you think these robins are? Why
are only two hatched? When will the other(s) hatch? Photo
Dorothy Edgington |
Welcome to the World!
"Three
eggs in the nest!! It is the beginning,” exclaimed
Marielle Gauvin of St-alphonse-de-granby (45.3305 N, 72.7827
W) in the
Province of Quebec. When will these robin eggs hatch? (You
have learned from past reports how long this takes. Look back, or
see
information
on
our Robin
Resource page for this answer and more.)
Guess what? Hatching out of an egg can take an entire
day! Each chick must fight its way out of the egg.
First it
breaks a hole
in the
shell (this is called pipping) with its egg
tooth.
The egg tooth is a hard
hook on the baby’s beak, especially there for
a hatching tool. The baby pokes and stretches and struggles
from inside
the shell,
taking rest stops during the hard work. Finally it
breaks free of the shell.
Eggs usually hatch a day apart in the order they were
laid.
Baby robins grow quickly. They grow from the size of their tiny
egg to the size of their big parents in only about
two weeks! For the first
four days of a nestling's life, the parent birds regurgitate
partly digested food into the orange, yawning mouths
of the babies. By their
fifth day, the nestlings are receiving earthworms that
have been broken into small mouthfuls. As the days go by, parents give
the babies complete
worms and large insects. Fred Charles found that Illinois
robins
put in 15.5 hours a day feeding young in late May.
Each day they bring
an average of 356 pieces of food to the nest! In his
book The American Robin, Roland Wauer says this food is 50% Lepidoptera
larva (caterpillars),
29% earthworms, 7% ants, 5% flies, and 9% beetles,
centipedes,
millipedes, adult butterflies and moths.
Try This! Make a pie chart showing what baby robins eat.
Don’t
Stop Now! Robin-Watching Tips
Now that robins are nesting in many places, what kinds
of observations can you make? During summer vacation, keep a
field notebook for recording all your observations. Learn what
kinds of things to record here:
Not
all robins nest on trees! The one in this photo is nesting
on a porch light. Photo Westbrooks.
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Unbeatable
Summer Reading
If a child came to your door with a dying robin and asked what was wrong with
it, what would you do? When this happened to Jean Craighead George, the author
of many distinguished books for children, she became deeply involved in tracking
down the killer. The result was an ecological mystery that will captivate
you (Harper
Trophy edition 1992 pictured here). This
must-read book is dedicated to "sunshine,
clear water,
and sparkling skies and the kids who are cleaning up the Earth."
As he tries to figure out who really killed the town's male Robin, eighth-grader
Tony Isidoro threads his way through a maze of clues that includes trillions
of ants
in the
town park, the absence of frog songs, and strange fumes from the town dump. So
grab your copies of Jean Craighead George's wonderful mystery. Then take all
summer to enjoy some
activities
from our suggestions below!
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Baby
robin in the grass. Photo J. Brophy
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Keep Kitty Indoors
You’ve learned that robins make 2 to 4 nests a year, with 4 babies
per nest. The same two adult robins are responsible for the hatching
of children, grandchildren, great grandchildren, and more--with
the potential to produce 19.5 million descendants by the end of a ten-year
life span. In real life, this just doesn’t happen. Robins
must produce plenty of babies to keep the robin population
high enough
to replace all the robins that die.
Here’s an important reminder as generations of new birds
hatch and fledge this summer. The lives of billions of songbirds
will be
saved each year (and pet cats will be much safer) if people keep
cats indoors. The birds and cats will thank you, and so will
future generations
who will still see and hear the songbirds that beautify each
spring and summer. Remember the message and pass it on! Can you
list 10
ways you can help birds? Read more here:
You’re
the Expert: A Question for You
“While staying at a cabin in North GA we watched a female robin lay
three eggs on the edge of a deck railing. Each one of them
rolled off and broke on the deck. What would cause her to do this?” We
got this question from an observer in Helen, Georgia.
Stop
now to discuss
why this might have happened. What ideas do you have?
After your discussion, compare with what Robin expert Laura Erickson
says:
“It's hard to figure out how old she is; with females, that's only easy
when they've been banded. But my guess is that she's a young
female, and wasn't finished building a nest yet. Female birds produce one egg
a day, and when the egg is ready to come out, she needs to
lay it right
away. If the nest isn't ready, some birds lay them in another
bird's nest, but sometimes they just ‘dump’ it wherever
they can.
“With robins, this dumping is very unusual. Robins start building their
nest very quickly when they return in spring, and
their bodies are timing egg production for when the nest is finished, so I suspect
bad timing and inexperience are not the only problems this female
had. Something may have happened to the nest. For example, another
bird may have taken it over, or the nest may have been destroyed
in
bad weather.”
Disposable Diapers for Birds? Discussion of Challenge Question #11
Last time we asked you read “The
Scoop on Poop: Disposable Diapers for Birds” then "Think
of at least three advantages of parent birds eating fecal
sacs of very young babies. Why do you think they usually stop eating
them
after
the babies get older?"
Three cheers for Erin, grade 5 TAG student at South O'Brien Elementary,
who showed good thinking by naming these advantages:
1. The nest stays clean.
2. There is more room in the nest.
3. The robins are happier.
We also thought of these advantages:
- Very young babies don't digest much of their food yet, so their fecal
sacs contain a lot of nutritious food. This would be a waste
to throw away, especially when the parents are feeding their babies most
of
the food they find.
- Eating
fecal sacs on the spot saves parents the time and energy it would
take to carry them away.
- Fecal
sacs are white, which would be noticeable when parents carry
them from the nest. By eating the white fecal
sacs (evidence of babies), the parents make it harder for nest
predators
to notice where
a nest
is.
We suspect that the reason parents stop eating
fecal sacs as the babies get older is that bacteria
growing in the babies' intestines starts
making their feces germy, causing possible health
risks to the parents.
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Photo Wayne Kryduba |
Sitting
Down on the Job: Discussion of Challenge Question #12
Last time
we gave you these facts: (1) A robin egg must be incubated for 12-14
days to develop normally. (2) Except for
about a 10-minute hourly break during daylight hours, the female
robin
sits on
the eggs all day long. Next, we asked you to figure out: "If
you add up all of the time a robin egg is incubated, how
many hours do you estimate
that it takes for a robin egg to develop properly?
(Assume the egg is incubated for 13 days and that there
are 15 daylight hours. Don't
forget to subtract the time a mother robin takes for "breaks"!)
If ten minutes of every hour are spent taking a break from incubating,
that adds up to 2 hours and 30 minutes. Subtract
that break time each day, and you get 12.5 hours of sitting per day,
times 13 days
= 162.5 hours for a robin egg to develop properly.
This is one time when sitting down on the job deserves high praise.
Heads Up, Teachers! Science Standards and the Robin Study
Are you thinking ahead to science plans for the next school year?
Don’t
miss our new Standards Chart for the Journey North
Robin Study:
Year-End
Evaluation: Please Share Your Thoughts!
Please take a few minutes to share your suggestions and comments in our
Year-End Evaluation. The information readers provide is critical for planning
new initiatives and for improving Journey North. We'd appreciate your
help. THANK YOU!
This is the FINAL
Robin Migration Update for Spring 2005. It
was a delight to learn about YOUR robins this spring! Thanks to all who
shared
observations to build a picture of this spring’s robin migration,
and double high fives for everyone who will watch their robins with a
caring and attentive eye this summer!
Copyright 2005 Journey
North. All Rights Reserved.
Please send all questions, comments, and suggestions to jn-help@learner.org
 
 
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