Teacher's Guide for ODYSSEYTM Alien Invaders
"Against All Odds: Earth's Fragile Pioneers," pg. 6
"People: The Ultimate Invaders," pg. 11
- Wind, wings, and water carried life to the Hawaiian Islands over millions of
years. In modern times, humans have transported non-native species to the islands, threatening the balance of life there. One sidebar (pg. 8) defines ecological terms. A second (pg. 10) gives statistics on Hawaii's invaders.
- Vocabulary, Dynamic Equilibrium
"An Ecological Train Wreck: Protecting Hawaii's Native Birds," pg. 14
- Disruption of the established ecosystem began with the first human footsteps
on North American soil. Who were these early invaders? Where did they come from? How did they travel? How did they live? Archaeological investigations and theories seek answers to these questions.
- Historical Context, Inductive Reasoning
"Pigs Everywhere!", pg. 20
- Alien invaders - including avian malaria, non-native songbirds, mosquitoes,
pigs, and human beings - threaten Hawaii's native bird populations. Can scientific research and wildlife management save the remaining avian inhabitants? Sidebars provide more detail on mosquito control (pg. 17),
co-evolution of species (pg. 18), and Hawaii's honeycreepers (pg. 19).
- Cause and Effect, Multifactorial Reasoning
"Out of Control: The Brown Tree Snake," pg. 23
- Feral pigs are a growing concern for conservationists who watch them destroy vegetation and devour the eggs of ground-nesting birds. Management of pig populations pits trappers and hunters against animal welfare activists. ODYSSEYTM wants your ideas.
- Environmental Ethics, Problem-solving
"The Beagle Brigade," pg. 27
- Birds no longer sing on Guam, now that the population of brown tree snakes has soared to 5,000 per square kilometer. These invaders have transformed the
entire ecosystem, causing insect and spider populations to surge, while numbers of lizards and fruit bats dwindle. An interview with wildlife biologist Thomas Fritts (pg. 24) explores careers in invasive species
management. A sidebar (pg. 26) cautions travelers on their responsibilities for environmental protection.
- Cause and Effect, Interdependency
"Trouble in Paradise: Alien Plants in Our National Parks," pg. 28
- Beagles work for the Department of Agriculture as inspectors, sniffing out
potential threats to the environment.
- Awareness, Application
"Take Action Against Alien Invaders" (Activity), pg. 31
- According to the National Park Service, over seven million acres of parkland are infested with non-native plants. Park personnel must monitor invasive species and prioritize their spending in hopes of saving some of "primitive" America. A sidebar (pg. 28) explains the "Invasive Species" Executive Order.
A second (pg. 30) invites readers' reactions to NPS's mandate.
- Issues Analysis, Environmental Assessment
"Musseling In on the Ecosystem," pg. 32
- Check Web sites to discover which aliens threaten your area. Make a T-shirt
(directions included) to educate others. Send photos to ODYSSEYTM.
- Following Directions, Web Research
"The 'Eggcentric' Zookeeper" (Puzzle), pg. 35
- Zebra mussels have wreaked havoc in the Great Lakes. Attaching to any
surface, they clog waterways and disrupt the food chain. Scientists are looking for ways to combat their rapid spread.
- Cause and Effect, Interdependence
"The Purple Plague," pg. 36
- Using mathematical deduction, find answers to zookeeper Ted's animal puzzles.
- Proportional Reasoning, Problem-solving
"Wicked Weeds" (Activity), pg. 40
- Purple Loosestrife overruns wetlands, choking out native plants and depriving
birds and mammals of food, nests, and breeding grounds. Perhaps introduced beetles will prove effective biological controls in curbing the plague.
- Cause and Effect, Decision-making
"What's Up? (Planet Watch and Backyard Observations)," pg. 42
- Match the descriptions of plant invaders with their "mug shots."
- Deductive Reasoning, Following Directions
Think Tank (Discussion Starters to Use Before Reading the Magazine):
- Watch for a full Moon on April 18, named the "Full Pink Moon" and the "Full Sprouting Grass Moon" by Native Americans. Also look for Venus and Mercury in the morning sky, while Mars, Saturn, and Jupiter "shuffle" their positions after sunset. The Lyrid Meteor Shower should peak around April 21.
- Following Directions, Observation
Classroom "Syzygy": Talk, Connect, Assess
- Do dandelions threaten to take over your neighborhood? This introduced plant came to North America with the Puritan settlers, who used it for tea and medicine. What other plants or animals not native to your area do you know about? How might the introduction of a new species affect an ecosystem? List
ideas on the chalkboard. Revise the list as you read this issue of ODYSSEYTM.
- What defenses does nature use in the battle against invading species? What
weapons can scientists provide? Make lists and add to them as you read the
Pg. 6 - "Against All Odds: Earth's Fragile Pioneers"
Far Out!: Moving Beyond the Magazine
pg. 28 - "Trouble in Paradise: Alien Plants in Our National Parks"
- Talk It Over:
- How did the three Ws (wind, wings, and water) carry pioneer species to the
Hawaiian Islands? What obstacles did colonizing species have to overcome to
- Which present-day dangers exist for the native species of Hawaii? Which of
those dangers have always existed, and which have been introduced by human
- Mathematics: Use numbers from the article and sidebar to calculate the approximate age of the Hawaiian Islands. How does your answer compare with
the article's estimate for the arrival of the earliest seafaring seeds? [Answer: The number of indigenous plant species (from sidebar, page 10) equals 2,690 minus 946, or 1,744. The number of indigenous animals when the
Polynesians arrived equals 2,000. At one species per 70,000 years, the total
equals 70,000 x 3,744, or 262,080,000. That number compares favorably with
the 250-million-year estimate for the arrival of Hala seeds on the Islands.]
- Graphic Design: Draw a large map of the Hawaiian Islands. Add pictures to illustrate ecological processes and principles introduced in the article. Print pictures from the Web, scan pictures from magazines (no cutting, please!), or draw your own.
- Creative Writing: Tell the story of one of Hawaii's native insect species from the animal's point of view. Describe your journey to the Islands and the
challenges you face in your new home.
- Student Assessment:
- Write a three-paragraph essay describing the current state of Hawaii's ecosystem. After your introduction, write a paragraph about current pressures on the environment. Conclude with your predictions for the Islands' future.
- Are humans the ultimate alien invaders, or are they the last best hope for the preservation of Hawaii's plants and animals? Organize your ideas,
research supporting statistics and facts, and give a persuasive speech on your view.
- Talk It Over:
- What is the mandate of the National Park Service (NPS)? Why is that goal so important? What exceptions are made to that mandate? Why?
- In what ways do non-native plants damage ecosystems? How does the NPS use prioritizing, monitoring, and prevention in their its to preserve "primitive" America?
- Critical Thinking: Prioritizing means rank-ordering in terms of importance. For each of the following situations, list and defend your priorities.
Invent other priority-setting situations to challenge your
- You're packing for a one-month visit to Yellowstone Park in April. You
will be given food, water, and a sheltered sleeping area when you get there, but nothing else. You can take only ten items. What will they be? Why?
- You own a tract of natural forestland near Yellowstone Park. You can do anything with it you like. List your choices from best to worst. Defend your reasoning.
- Creative/Persuasive Writing: Review the sidebar "President Clinton Takes on the Invaders," pg. 28. Write the Executive Order the way you think it should have been written; then use the Web to find Clinton's actual text. How does the president's version compare to yours?
- Social Studies: What, exactly, is an Executive Order? How does it differ from
other kinds of laws? Make a poster showing the differences. Indicate when
executive orders might be better than legislation.
- Student Assessment:
- Write an essay tracing the evolution of the National Park Service from its beginnings in 1916. Make clear how the Service's goals both
complement and compete with each other today.
- Review the sidebar "Working Within the Words," pg. 30. Do you think Americans should spend millions to keep the National Parks "natural"? Debate that question in class. Send a summary of your ideas to ODYSSEYTM.
"I think that I shall never see"
Whole Class Project: Call or write your state department of agriculture or
fish and wildlife service to request maps, pictures, and descriptions of alien invaders in your area. Also research endangered species (both plants and animals) in your state. Make a display using a large state map as the
focal point. Show pictures, information, and locations of invaders, along with endangered native species.
"A poem lovely as a tree."
Individual/Class Project: Ask each student to choose a state other than your own and compile information about invading and endangered species in that
state. Write a report and make a poster conveying that information. Display
posters in the classroom or in the hall.
"In fact, if caution we let fall,"
Small-Group, Collaborative Activity: Organize five teams to research the following sources of environmental information: (1) Web sites; (2) videos and
films; (3) universities and research centers; (4) conservation organizations;
and (5) government agencies. Summarize the kinds of resources available in
each category and compile a booklet. Print copies for other classes, other schools, and local libraries.
"A tree, I'll never see at all."
Community Connection: Write and publish a class newspaper on ecological
issues in your area. Include interviews with representatives of private or
public organizations. Consider including columns such as "Looking Back" (on
endangered or extinct species); "Looking Out" (on current environmental issues); and "Looking Ahead" (on trends and predictions for the future). Distribute your newspaper to other classes, other schools, and local