Lesson Two: Birds Fly from Here to Where?
1
Migratory Bird Math and Science Lessons
igration occurs primarily as a means for birds to exploit the richest sources of food and it
is one of the most important aspects of their life cycle. The purpose of this lesson is for
students to become familiar with Neotropical migratory birds and the methods researchers use to
study their migration. Why do they migrate? To where do they migrate, and what are these habitats
like? Do all of the migratory birds in New England migrate to the same areas and along the same
pathways? How are researchers able to learn about the timing of migration and location of migratory
pathways? Students will explore the reason for migration, be introduced to habitat characteristics in
the tropics, sketch examples of migratory pathways, and identify the methods that researchers use to
study migration.
As a follow-up to this lesson, you may wish to devote some time to discuss some of the fascinating
means by which birds manage to y from one part of the hemisphere to the other. This process
happens with astounding accuracy and delity. Information on the mechanisms birds use for
navigation as well as adaptations for dealing with the physical demands of migration can be found in
the supplemental fact sheets written by the Smithsonian Migratory Bird Center:
Neotropical Migratory Bird Basics
Have Wings, Will Travel: Avian Adaptations to Migration
We gratefully acknowledge the Smithsonian Migratory Bird Center (SMBC) for their assistance with
this lesson. The mapping exercise included here has been modied and adapted from the SMBC
Bridging the Americas program.
Hubbard Brook Research Foundation
Migratory Bird Math and Science Lessons
Lesson: Birds Fly from Here to Where?
M
Blackpoll Warbler/Donna Dewhurst
©Hubbard Brook Research Foundation 2011
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Summary
In this three-part lesson, students will consider temperate and tropical habitats, map
migratory ranges of birds, and read a short article to become familiar with the research
methods used to study the migrations of birds.
Subject areas Life science, biology, environmental science
Skill level Basic
Objectives
• Dene what is meant by Neotropical migratory bird.
• Explain why Neotropical migratory birds migrate.
• Identify some locations that these birds migrate to, and list some characteristics of these habits.
• Describe research methods used to learn about the movement and timing of migration
patterns of birds.
NH Science Framework
Standards
S:SPS3:8:1.2, S:SPS3:11:2.8, S:SPS4:8:6.3, S:LS3:8:1.1, S:LS5:11:1.1, S:LS5:11:3.1
Time
One to two 40-minute class periods, depending on whether reading and questions are done
in class or for homework. (Part I: 15 minutes; Part II: 20 minutes; Part III: time will vary, may
be given as a homework assignment.)
Materials
Habitat-Tropical or Temperate.pdf
Erasable markers for color-coding birds’ migration ranges on whiteboard at front of
class; a different color for each bird.
Colored pencils (4 different colors for each student).
Color copies of the range maps for the four birds; copies can be shared within groups.
Maps can be found online (All About Birds) or on the following documents:
• American Redstart_All About Birds.pdf
• Bicknell’s Thrush_All About Birds.pdf
• Blackpoll Warbler_All About Birds.pdf
• Black-throated Blue Warbler_All About Birds.pdf
Student Handout - Birds y From Here to Where?
Student Reading - Cracking the Mysteries of Bird Migration
Student Handout - Cracking the Mysteries of Bird Migration
Assessment Two student handouts with answer keys are included.
Notes to Teachers page 3
Student Procedure page 5
Fact sheet on American Redstart page 6
Fact sheet on Bicknell’s Thrush page 9
Fact sheet on Blackpoll Warbler page 11
Fact sheet on Black-throated Blue Warbler page 14
Student Handout: Birds Fly from Here to Where? page 17
Student Reading: Cracking the Mysteries of Bird Migration page 20
Student Handout: Cracking the Mysteries of Bird Migration page 23
Answer Key - Part I: Birds Fly from Here to Where? page 25
Answer Key - Part II: Cracking the Mysteries of Bird Migration page 26
Table of Contents
Lesson Two: Birds Fly from Here to Where?
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Migratory Bird Math and Science Lessons
Introduce lesson to students:
This lesson should be introduced with the
following question: Why do birds migrate?
Why expend an enormous amount of energy
to make a risky journey twice each year?
Allow students to brainstorm ideas, and then
help them to realize that the reason birds
migrate is to nd optimal food. The most
nutritious, calorie-rich food is found in the
temperate zone during our summer months,
and is essential for birds while laying eggs
and raising young. In winter months food is
scarce in the temperate zone so birds must
travel to the tropics to meet their nutritional
and caloric needs.
Part I
What’s it like in the Neotropics? Students are
familiar with how the forests in New England
look in the summer, but probably less
familiar with the tropical habitats that ‘our’
migratory birds occupy during our winter.
Students will view various habitat images and
try to categorize each as either temperate or
tropical habitat.
1. Distribute copies of the Procedure and
Birds Fly from Here to Where? Student
Handout to all students.
2. The entire class will view the slideshow
“Habitat: Tropical or Temperate?” Students
will talk as a class to determine whether the
image belongs to the tropics or temperate
region of our hemisphere.
3. The slide show is designed so that after
students have made their guess the answer
will be displayed with the image.
Note to Teachers
4. As students view the slides, lead a
discussion to encourage students to think
about the signicance of the differences seen
between tropical and temperate habitats.
Possible questions to ask include: How does
vegetation relate to food sources? Do the two
habitats vary with the seasons? If so, how?
Part II
Each fall, all Neotropical migratory birds
y from their breeding habitat to their non-
breeding habitat, but do they all chose the
same route? Where, exactly do they go?
1. Project a large map of North and South
America onto a white board at front of class.
A blank copy can be found at http://www.
eduplace.com/ss/maps/pdf/americas.pdf.
2. Help students to locate and mark the
Tropic of Cancer on their maps (on their
Student Handouts). Explain the signicance
of the line: The Tropic of Cancer is a line
of latitude 23.4 degrees north of the
equator which marks the northern extent
of the tropics.
3. Discuss with students: the denition of
‘Neotropical migratory bird. ’Neotropical
migratory birds are species of birds in the
Western Hemisphere that breed north of
the Tropic of Cancer and then winter in
the tropics.
4. Divide students into four groups: each
group will focus on one of four bird species:
Bicknell’s Thrush, Blackpoll Warbler, Black-
throated Blue Warbler, or American Redstart.
5. Distribute copies of the four birds’ species
descriptions to the groups. The descriptions
come from the All About Birds website, but
©Hubbard Brook Research Foundation 2011
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www.hubbardbrookfoundation.org
PDFs of these web pages are included so
that it is not necessary for students to have
internet access tom complete the lesson. If
students do have access, teachers may wish
to have students work directly from the
bird guide search page from the All About
Birds site.
• Permission to create PDFs from the All
About Birds website has been generously
granted by the Cornell University Lab of
Ornithology, a world leader in the study,
appreciation, and conservation of birds.
The All About Birds website is an excellent,
free resource for students, teachers and
anyone wishing to know more about birds
and bird watching.
6. Students should follow the instructions
given on the Procedure handout.
Part III
How are the migratory routes of these
different bird species known? How do
scientists study bird migration?
1. Ask students this question and allow them
to brainstorm answers.
2. Assign the reading Cracking the Mysteries
of Bird Migration. After reading, students
should answer questions that accompany the
article on the Student Handout Cracking the
Mysteries of Bird Migration.
3. Recommended: After students have read
the article, trace the Godwit’s ight on a large
map to illustrate the ight as described in the
article.
Black-throated Blue Warbler/Robert Royse
Lesson Two: Birds Fly from Here to Where?
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Migratory Bird Math and Science Lessons
Student Procedure
Part I
1. View the slideshow Habitat: Tropical or Temperate? As a class, you will try to decide whether
each habitat shown is from the tropical or temperate region of the western hemisphere.
2. Complete Questions 1 and 2 on the Student Handout Birds Fly From Here to Where?
Part II
3. Use the map on your Student Handout Birds Fly From Here to Where? As a class, locate the
Tropic of Cancer and draw this line on your map in the appropriate place.
4. Your class will divide into four groups.
5. Your group will be given the name of a species of Neotropical migratory bird to research.
Obtain copies of this bird’s species description from your teacher. Alternatively, go to the Cornell
University Lab of Ornithology’s All About Birds (http://www.allaboutbirds.org/guide/search) website
and search for the species description of that bird.
6. Locate the range map that is included in the species description. Notice the location of its
summer (breeding) ground, winter (non-breeding) ground and its migratory pathway. Draw these
locations on your map with colored pencils, using a separate color for each one.
7. At the bottom of the map, create a legend to indicate what each color describes.
8. Label at least one of the countries to which your bird migrates.
9. A representative from your group should describe the range of your bird to the entire class and
use an erasable marker to mark its breeding ground, non-breeding ground, and migratory pathway
on the large map projected at the front of the room. This person should also provide the name of
one Central or South American country to which your bird migrates.
10. Listen to your classmates closely, because you will need this all of this information to answer
Questions 3–6 on the Student Handout.
Part III
11. Read the article Cracking the Mysteries of Bird Migration.
12. After reading, answer the questions on the Student Handout Cracking the Mysteries of
Bird Migration.
©Hubbard Brook Research Foundation 2011
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Search in: Website Bird Guide
American Redstart, Life History, All About Birds - Cornell Lab of Ornitholog
y
http://www.allaboutbirds.org/guide/American_Redstart/lifehistor
y
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Fact Sheet on American Redstart - page 1 of 3
http://www.allaboutbirds.org/guide/american_redstart/id
If you have internet access we recommend you view the American Redstart fact sheet online.
Lesson Two: Birds Fly from Here to Where?
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Migratory Bird Math and Science Lessons
American Redstart, Life History, All About Birds - Cornell Lab of Ornitholog
y
http://www.allaboutbirds.org/guide/American_Redstart/lifehistor
y
2 of 3 9/30/2010 11:49 A
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Fact Sheet on American Redstart - page 2 of 3
©Hubbard Brook Research Foundation 2011
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American Redstart, Life History, All About Birds - Cornell Lab of Ornitholog
y
http://www.allaboutbirds.org/guide/American_Redstart/lifehistor
y
3 of 3 9/30/2010 11:49 A
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Fact Sheet on American Redstart - page 3 of 3
Lesson Two: Birds Fly from Here to Where?
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Migratory Bird Math and Science Lessons
Search i n: Website Bird Guide
Bicknell's Thrush, Life History, All About Birds - Cornell Lab of Ornitholog
y
http://www.allaboutbirds.org/guide/Bicknells_Thrush/lifehistor
y
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Fact Sheet on Bicknell’s Thrush - page 1 of 2
http://www.allaboutbirds.org/guide/Bicknells_Thrush/id
If you have internet access we recommend you view the Bicknell’s Thrush fact sheet online.
©Hubbard Brook Research Foundation 2011
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www.hubbardbrookfoundation.org
Fact Sheet on Bicknell’s Thrush - page 2 of 2
Bicknell's Thrush, Life History, All About Birds - Cornell Lab of Ornitholog
y
http://www.allaboutbirds.org/guide/Bicknells_Thrush/lifehistor
y
2 of 3 1/24/2011 9:09 A
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Lesson Two: Birds Fly from Here to Where?
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Migratory Bird Math and Science Lessons
Fact Sheet on Blackpoll Warbler - page 1 of 3
Search in: Website Bir d Guide
Blackpoll Warbler, Life History, All About Birds - Cornell Lab of Ornitholog
y
http://www.allaboutbirds.org/guide/Blackpoll_Warbler/lifehistor
y
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http://www.allaboutbirds.org/guide/Blackpoll_Warbler/id
If you have internet access we recommend you view the Blackpoll Warbler fact sheet online.
©Hubbard Brook Research Foundation 2011
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www.hubbardbrookfoundation.org
Blackpoll Warbler, Life History, All About Birds - Cornell Lab of Ornitholog
y
http://www.allaboutbirds.org/guide/Blackpoll_Warbler/lifehistor
y
2 of 3 10/1/2010 1:21 P
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Fact Sheet on Blackpoll Warbler - page 2 of 3
Lesson Two: Birds Fly from Here to Where?
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Migratory Bird Math and Science Lessons
Blackpoll Warbler, Life History, All About Birds - Cornell Lab of Ornitholog
y
http://www.allaboutbirds.org/guide/Blackpoll_Warbler/lifehistor
y
3 of 3 10/1/2010 1:21 P
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Fact Sheet on Blackpoll Warbler - page 3 of 3
©Hubbard Brook Research Foundation 2011
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www.hubbardbrookfoundation.org
Search in: Website Bir d Guide
Black-throated Blue Warbler, Life History, All About Birds - Cornell Lab of Ornitholog
y
http://www.allaboutbirds.org/guide/Black-throated_Blue_Warbler/lifehistor
y
1 of 3 10/1/2010 1:18 P
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Fact Sheet on Black-throated Blue Warbler - page 1 of 3
http://www.allaboutbirds.org/guide/Black-throated_Blue_Warbler/id
If you have internet access we recommend you view the Black-throated Blue Warbler fact sheet online.
Lesson Two: Birds Fly from Here to Where?
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Migratory Bird Math and Science Lessons
Black-throated Blue Warbler, Life History, All About Birds - Cornell Lab of Ornitholog
y
http://www.allaboutbirds.org/guide/Black-throated_Blue_Warbler/lifehistor
y
2 of 3 10/1/2010 1:18 P
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Fact Sheet on Black-throated Blue Warbler - page 2 of 3
©Hubbard Brook Research Foundation 2011
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www.hubbardbrookfoundation.org
Black-throated Blue Warbler, Life History, All About Birds - Cornell Lab of Ornitholog
y
http://www.allaboutbirds.org/guide/Black-throated_Blue_Warbler/lifehistor
y
3 of 3 10/1/2010 1:18 P
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Fact Sheet on Black-throated Blue Warbler - page 3 of 3
Lesson Two: Birds Fly from Here to Where?
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Migratory Bird Math and Science Lessons
Part I
1. Describe or draw at least three differences, as observed from the habitat slideshow, between the
breeding and non-breeding habitats of migratory birds.
2. Why do birds migrate?
Part II
3. What is one similarity between the range of your bird and that of one of the other birds
described by your classmates? Your answer should include the names of both birds.
4. What is one difference between the range of your bird and that of one of the other birds
described by your classmates? Your answer should include the names of both birds.
Student Handout
Name __________________________________
Birds Fly From Here to Where?
©Hubbard Brook Research Foundation 2011
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www.hubbardbrookfoundation.org
5. What is a Neotropical migratory bird? (Dene the meaning of “Neotropical migratory bird.”)
6. How might deforestation in the Dominican Republic affect an American Redstart that breeds in
New Hampshire?
Lesson Two: Birds Fly from Here to Where?
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Migratory Bird Math and Science Lessons
“Americas” from the HOUGHTON MIFFLIN HARCOURT EDUCATION PLACE® web site (http://www.
eduplace.com/ss/maps/pdf/americas.pdf). Copyright © by Houghton Mifin Company. All rights reserved.
Used by permission of Houghton Mifin Harcourt Publishing Company. The map may be printed and copied
for classroom use. Any other use of the materials is strictly prohibited unless written permission is obtained
from Houghton Mifin Harcourt Publishing Company.
©Hubbard Brook Research Foundation 2011
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www.hubbardbrookfoundation.org
Cracking the Mysteries of
Bird Migration
Holmes, R. (2008, July 23). Cracking the Mysteries of
Bird Migration. New Scientist, 2666, p. 36–39.
Used and modied with permission from the New
Scientist, www.NewScientist.com.
On March 17, 2007, the Bar-tailed Godwit
known to science as E7 spread her wings and
took ight, leaving the northern shores of
New Zealand behind her. For the next eight
days and nights she ew non-stop, 10,000
kilometers (about 6,200 miles) northwards to
the coast of China’s Yellow Sea. Five weeks
later, after a brief break for refueling, E7
continued on her way. She headed east, and
then took a sharp left turn in the featureless
mid-Pacic, before arriving six days later
at her breeding ground in Alaska. By late
August, she was off again, this time on a
non-stop journey of nearly 12,000 kilometers
(about 7500 miles)—the longest continuous
bird ight on record—that ended just 13
kilometers (about 8 miles) from where she
had started.
Until recently, the idea that we
could chart a small bird’s migration
in such detail was unthinkable. Now,
however, biologists are developing tracking
technologies that are leading to a revolution
in their understanding of migration. Suddenly
they have the power to answer questions
they could barely guess at before. They
are beginning to learn not just where the
birds are going, but also the timetables of
their migratory ights and their airspeeds
and energy costs. These new techniques
are also helping to explain the biology that
underpins the uncanny navigational abilities
of migratory birds.
The new-found opportunities have biologists
brimming with anticipation. “Every
new instrument you put out is a major
breakthrough,” says Martin Wikelski from
the Max Planck Institute for Ornithology in
Radolfzell, Germany. “I think we’re entering
a new, data-rich realm of animal movement.
It’s a very exciting time.”
The old tracking techniques were crude
and not very effective. For a century or
so, biologists put numbered metal bands
on the legs of migrating birds, then waited
to see where they turned up. This helped
to sketch the outlines of migration routes,
but revealed next to nothing about where
individual birds stop to rest and refuel along
the way.
Then, in the 1960s, William Cochran
of the Illinois Natural History Survey
in Champaign, began mounting home-
made radio transmitters on birds. Using
hand-held antennas he would track their
migratory ights, chasing them by car or—
when budgets allowed—by light aircraft. The
technique is still used today because it is
quite cheap and the tiny transmitters are light
enough to mount on even relatively small
birds, but the work involved in following
them is hard and the hours punishing,
especially when tracking songbirds, which
migrate at night.
“You sit out there starting at sunset,” says
Wikelski. “You’ve lled up the gas tank.
You’ve got your food. You’ve got your
sleeping bag. You’ve cancelled all your
appointments for the next day... And you wait
for the bird to take off. Then you race with
the bird, try to catch up with it, and after 500
miles, you have to recapture it [to remove
the transmitter] and drive back again. You’re
Student Reading
1
2
3
Lesson Two: Birds Fly from Here to Where?
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Migratory Bird Math and Science Lessons
up for 35 hours—and then you have to
capture another bird, because you only have
a short season.”
The pay-off for all those sleepless nights
has been a more intimate snapshot of
migration than leg bands ever allowed. This,
for example, is how Cochran and Wikelski
discovered that Swainson’s thrushes often
y all night, but will cut their ight short if
they hit a cold front. Radio transmitters also
revealed that these thrushes are sensitive to
wind speed, and stay put on nights when it
exceeds about 10 kilometers (about 6 miles)
per hour. By adding a heart-rate sensor,
Wikelski and his colleague Melissa Bowlin
found that the birds’ hearts beat faster on
windy nights, showing they have to work
harder to go the same distance—even with
a tailwind. This may be because higher
winds cause turbulence that buffets the
small birds. Indeed, this may be the reason
most small birds choose to migrate at night,
when turbulence tends to be lower, says
Bowlin, who is now at the University of
Montana in Missoula.
Not surprisingly, the rigors of chasing birds
by car—and the many failed nights when
a bird chooses a course not well served by
roads—have meant that very few researchers
have taken on the challenge. And, of course,
such an approach will not work for birds
that migrate over water, such as Godwits. No
wonder the new tracking devices are causing
such excitement.
In-ight transmission
The Godwit study, for example,
highlights the benets of satellite
tracking. E7 was one of 24 Godwits to
have a transmitter surgically implanted in
its abdominal cavity. This sends out regular
beeps that are picked up by a satellite and
relayed to researchers on the ground. The
global coverage has made it possible to log
the Godwits’ entire migration itinerary, and
has also revealed that their travel plans are
extremely precise, with one primary site
at each of their three major stops. These
‘stopover sites’ are extremely important
because they provide migrating birds with a
place to rest and refuel. “No other stopover
sites are showing up, and that has got us
concerned,” says Robert Gill from the US
Geological Survey’s Alaska Science Center in
Anchorage, who heads the tracking program.
Although these sites are all protected,
Godwit numbers have already dwindled to
just a few thousand birds, and any damage to
any of the sites could be catastrophic to the
species, he says.
For all their ease of use, though, satellite
tags are not perfect. The transmitters draw a
lot of power and their batteries are heavy:
the smallest tags available today weigh
about 10 grams, which rules out satellite
tracking for any birds smaller than about
half a kilogram—about the size of a pigeon.
What’s more, the batteries only last a few
months—even though they are set to transmit
just a few hours a day to save power—so it’s
rare that researchers can track a single bird
through its full migratory cycle, let alone for
several years running.
Other researchers are experimenting
with ways of improving tracking
technologies. One idea is to t birds with
miniature cell phones so that they can
be tracked using the existing network of
communication towers. Another approach
that already shows promise is to t birds with
tiny, light and long-lasting devices called
geolocators that do nothing more than
sense and record the time of sunrise and
sunset each day. Once geolocators have been
recovered from their subjects and their stored
data downloaded, researchers can calculate a
position x for each day, determining latitude
from day length and longitude from the
sunrise time.
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5
6
©Hubbard Brook Research Foundation 2011
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Unlike satellite tags, geolocators can be
used on very small birds and so have
offered the rst opportunity to track the
complete migration of Sooty Shearwaters,
small seabirds that spend most of the year
roaming the Pacic away from their breeding
grounds in New Zealand. Each spring huge
ocks of Shearwaters turn up in the northern
hemisphere, proving the birds must cover
vast distances—but little else. “We knew this
migration existed, but we didn’t know if the
same birds made that migration in a single
season, which directions they chose to go, or
the routes they followed,” says Scott Shaffer
at the University of California in Santa Cruz.
“Just within the last couple of years, we’ve
really been able to answer these questions.”
It turns out that the Shearwaters make
a huge gure-eight across the Pacic,
ying eastward from New Zealand and then
north for a stopover off the coast of either
California, Alaska or Japan, before nally
heading south again. The whole journey lasts
more than six months and covers an average
of 64,000 kilometers (about 40,000 miles)—
the longest known migration of any animal.
The technologies developed in the past
decade have led to gigantic leaps in our
understanding of bird migration. Heart-
rate sensors, mini cell phones, satellite
tracking and geolocators have all contributed
important details about the journeys that
migratory birds take. Because these animals
range over very large areas, they are uniquely
sensitive to changes all around the globe.
Therefore researchers believe that it is
valuable to study migration because noticing
changes to migratory patterns could provide
an early-warning system for climate change
and other major ecological shake-ups. As
we continue to study migratory birds,
patterns of change may be revealed
that would not be obvious from a study
conducted in just one location.
American Redstart/Robert Royse
7
Lesson Two: Birds Fly from Here to Where?
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Migratory Bird Math and Science Lessons
1. In addition to learning where birds go, what else are scientists learning from new tracking
technologies?
2. Why is bird banding not an ideal technique for studying bird migration?
3. Describe the technology and methods that William Cochran used to study the movement
of birds.
Student Handout
Name __________________________________
Cracking the Mysteries of Bird Migration
The following questions are based on the article “Cracking the Mysteries of Bird Migration.”
The numbers given in the margin of the article pertain to questions 1–7 below. Use the
numbers as a guide to help you answer those questions.
©Hubbard Brook Research Foundation 2011
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www.hubbardbrookfoundation.org
4. Explain one of the things that this technology enabled him to learn about the Swainson’s
Thrush.
5. What technology has been used to map the Godwit’s migration, and what did scientists learn
from this that will help people to protect the Godwits?
6. How do geolocator tags work, and what is their advantage over satellite tags?
7. Cite one amazing fact that geolocators have enabled scientists to learn about the migration of
Sooty Shearwaters.
8. Songbirds are of interest to many people and there is widespread support for their conservation.
How can the information learned from bird migration research be used to aid in conservation
efforts?
Lesson Two: Birds Fly from Here to Where?
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Migratory Bird Math and Science Lessons
Part I
1. Describe or draw at least three differences, as observed from the habitat slideshow, between
the breeding and non-breeding habitats of migratory birds.
Answers will vary.
2. Why do birds migrate?
Birds migrate to nd the most nutritious and caloric food.
Part II
3. What is one similarity between the range of your bird and that of one of the other birds
described by your classmates? Your answer should include the names of both birds.
Answers will vary.
4. What is one difference between the range of your bird and that of one of the other birds
described by your classmates? Your answer should include the names of both birds.
Answers will vary.
5. What is a Neotropical migratory bird? (Dene the meaning of “Neotropical migratory bird.”)
Neotropical migratory birds are species of birds in the Western Hemisphere that breed north of the
Tropic of Cancer and then winter in the tropics.
6. How might deforestation in the Dominican Republic affect an American Redstart that breeds
in New Hampshire?
By this point in the lesson, students should have observed the range maps to learn that the
Dominican Republic is one of the places in which the American Redstart lives during the non-
breeding season. The alteration or destruction of its non-breeding habitat has many possible
ramications: less food, less cover from predators, less suitable habitat in general. The health of
a bird in the non-breeding season has a huge effect on the condition of the bird as it migrates
back to its breeding grounds. Even if it survives migration, it may not arrive with enough energy to
successfully reproduce (defend territories, attract mates, build nests, lay eggs, raise young, etc.)
Among avian ecologists, this concept is known as “connectivity:” conditions and habitat quality in
one part of a bird’s yearly cycle greatly affect the health of the bird during other parts of the cycle.
Birds Fly From Here to Where?
Answer Key - Part I
©Hubbard Brook Research Foundation 2011
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1. In addition to learning where birds go, what else are scientists learning from new tracking
technologies?
Airspeeds, energy costs and timetables of ight
2. Why is bird banding not an ideal technique for studying bird migration?
Answers will vary, but students should realize that the chances of recapturing the same individual
once it has migrated to another hemisphere are extremely slim.
3. Describe the technology and methods that William Cochran used to study the movement
of birds.
Radio transmitters
4. Explain one of the things that this technology enabled him to learn about the
Swainson’s Thrush.
Answers will vary: Swainson’s Thrushes y all night, will cut ight short if they encounter a cold
front, won’t y if wind speed is greater than 10 km per hour, etc.
5. What technology has been used to map the Godwit’s migration, and what did scientists learn
from this that will help people to protect the Godwits?
Satellite tracking with surgically implanted transmitters. The Godwits have only one place to rest
and refuel at each of their three stopover sites. If something happens to one of these places (e.g.,
if habitat is destroyed), the godwits most likely won’t be able to complete their migration and their
population will dwindle.
6. How do geolocator tags work, and what is their advantage over satellite tags?
Geolocator tags record light intensity. Because the sun rises at different times at different
longitudes, and because the length of day varies with latitude, these light records can be used to
gure out the approximate location of a bird tted with one of these tags. They weigh much less
than satellite tags and thus can be used on smaller, lighter birds.
7. Cite one amazing fact that geolocators have enabled scientists to learn about the migration of
Sooty Shearwaters.
Answers will vary: the Sooty Shearwater’s journey lasts over 6 months and covers 64,000 km
(about 40,000 miles); they pass quickly through the tropics and spend most of their time in the
temperate latitudes where food is abundant.
8. Songbirds are of interest to many people and there is widespread support for their
conservation. How can the information learned from bird migration research be used to aid in
conservation efforts?
Answers will vary, but should reference the technologies described in the article: i.e., if geolocators
are used to determine the migration route and stopover sites of the Bicknell’s Thrush, people can
devote efforts to be sure that these sites remain protected and suitable for this bird.
Cracking the Mysteries of Bird Migration
Answer Key - Part II
