Option 1: Read aloud Science Warriors: The Battle Against Invasive Species by Sneed B. Collard III or Aliens from Earth by Mary Batten and Beverly Doyle, described in the Additional Resources. Invite a local scientist or resource specialist to talk to the class about invasive species in your area and what people are doing to control them.
Option 2: Have students participate in an invasive species control project. Contact your local parks or natural resources department to find out about projects in your area.
Option 3: Have students research species that are native to the United States but are considered invasive in other countries.
Option 4: Give students a math problem related to invasive species. The following example shows how these species reproduce at a geometric rate.
- Problem: You have a pair of nutrias and they breed twice a year. Each litter has four young, two females and two males. The females can begin to have young at 6 months. How many nutrias will you have in three years?
- Answer: 1,458 nutrias (problem solving is detailed below)
|After 6 Months
|After 1 Year
|After 1.5 Years
|After 2 Years
|After 2.5 Years
|After 3 Years
See Additional Resources for more ideas to enrich this activity.
Option 1: Assess students’ understanding of key terms used in this activity with the Key Vocabulary: Invasive Species student page. Refer to the Key Vocabulary: Invasive Species teacher page for the correct responses.
Option 2: Assess students’ presentations from the activity, using a rubric such as the Invasive Species Evaluation Rubric teacher page.
Option 3: Have students use the information they gleaned from the activity to list 3 reasons invasive species are harmful, 2 ways they can be controlled, and 1 type of invasive species that is found in their local area.
- Begin the activity by showing students a photograph of kudzu (or other invasive species) taking over a forest. Invite them to describe what they observe and what seems to be out of place. Ask them whether they have heard the term “invasive species,” and what they think it could mean.
- Divide students into small teams. Assign each team a different species from the Alien Invasion student pages provided, and ask students to work on the Comparing Invasive Species student page for their assigned species. Students will read about their species to determine:
- Where did it come from?
- Why or how did it get to the U.S.?
- What characteristics have helped it spread?
- How does the invasive species affect the ecosystem (including the flow of energy in the ecosystem)?
- Have teams share their species information with the class. As the class listens, ask students to complete the remaining columns of their own Comparing Invasive Species student page.
- After students have completed their chart using information provided by each group, ask teams to discuss the 3 questions at the bottom of the Comparing Invasive Species student page:
- What is the same about these species? What is different?
- What characteristics help these species spread?
- What are invasive species?
- Why are invasive species a problem?
- (Optional) Have students draw pictures of invasive species to support the discussion.
- Explain to teams that they will now research an invasive species found in your state or region (different from the ones on the student page) to learn how it affects the local ecosystems. Provide a list of invasive species in your state (see Getting Ready in the Overview) and either assign teams a species to research or have them choose one. Distribute copies of the Invasive Species in Your Community student page to help students collect the following information:
- Where the species came from (including maps).
- How it got to the local ecosystem.
- What problems it causes the local ecosystem (including how it affects the flow of energy).
- What people can do to get rid of it or keep it from spreading.
- After students learn about a local invasive species, challenge them to create a poster, video, brochure, skit, or other presentation to inform friends, family, or community groups about this species. Students can use word processing or presentation software to create their presentations.
- Allow time for teams to research and create their presentations, and to share them with the class.
An ecosystem—like all systems—is made up of many different parts working together. But what happens when that system gets out of balance?
One thing that can stress an ecosystem is adding a new species. An invasive species is any plant or animal that lives in an ecosystem where it does not occur naturally and where it causes harm. Many invasive species come to a new ecosystem because people moved them there, either on purpose or by accident. In their new locations, invasive species do not have the predators, competition, or diseases that keep them in check in their native area. Without these controls, they can take over a habitat, making it difficult for native species to thrive.
Paths to Invasion
There are many ways invasive species end up in a new location, far away from their native range. In some cases, people intentionally bring them to the new area, not realizing the damage they could cause. For example, the nutria was brought to the United States from Argentina in the 1930s to produce fur. Now there are millions of them in the wild, causing tremendous damage to crops and waterways.
In many cases, these species are “hitch-hikers” along for the ride when people move barges, boats and trailers, cars and trucks, animals, commercial goods, food, or clothing. Without realizing it, people transport these species to a new ecosystem.
Common Characteristics of Invasive Species
The more of these characteristics a species possesses, the more likely it is to be invasive:
- Tolerates a wide range of conditions.
- Produces lots of seeds or eggs.
- Has few natural controls such as predators, competition, or disease.
- Has a long growing season.
- Needs a short amount of time to reproduce.
A Worldwide Problem
Invasive species are a problem around the world as they crowd out native species and change habitats. Once they have taken hold in an ecosystem, invasive species are almost impossible to remove. Controlling invasives is very time-consuming and expensive.
Invasive species are not new, but because of more worldwide travel and shipping of goods, the number of new invasions continues to increase. In the United States alone, scientists estimate there are about 7,000 invasive species, including plants, mammals, birds, amphibians, reptiles, fish, and insects. Some have caused major environmental damage. Together, they account for about $138 billion in costs to agriculture, forestry, and other segments of the United States economy.
How to Prevent Invasive Species
The best way to manage invasive species is to prevent their spread. You can help stop the spread of harmful invaders in your community in the following ways.
- Don’t grow plants known to be invasive. If you don’t know it, don’t grow it!
- Avoid using seed mixtures, especially ones labeled “wildflowers.”
- Landscape with plants native to your area.
Boating and Fishing
- Never move water, animals, or plants from one body of water to another.
- Do not release live fish, including bait, into a new body of water.
- Wash all boating and fishing gear after use to prevent accidentally spreading invaders.
- Get any non-native pets from trustworthy dealers only.
- Don’t release any pets or aquarium fish into a native habitat or natural body of water.
- Tell others about the harm that invasive species cause.
- Volunteer to help remove invasive plants from your local park or nature reserve.
Source: Adapted from “What You Can Do to Prevent Species Invasion.” Union of Concerned Scientists.
- What is an invasive species?
- How are invasive species harmful?
- How do invasive species spread to new locations?
- What can you do to prevent the spread of invasive species?
Throughout history, people have intentionally and unintentionally moved plant and animal species to new environments. Some of these species caused no harm in their new environment, but others have invaded natural ecosystems, causing environmental, and sometimes economic, harm. In this activity, students research invasive species to determine their impact on ecosystems and what characteristics make them so challenging.
- Research an invasive species that is a problem in local ecosystems.
- Describe how invasive species impact the flow of energy in ecosystems.
- Create a method to inform the community about the problems associated with invasive species and how to prevent their spread.
- Alien Invasion and Comparing Invasive Species student pages
- Photo(s) of kudzu or other invasive species taking over a forest (or other ecosystem)
- Internet access
- Getting Ready: 10 minutes
- Doing the Activity: two 60-minute periods, plus time for research and presentations
- Evaluate: 10 minutes per student, plus time for student research
- Make copies of the Alien Invasion and Comparing Invasive Species student pages.
- Search the internet to find one or more photographs of kudzu (or other invasive species) taking over a forest ecosystem. Make copies or plan to project the images for students to see.
- Make a list of 10–20 invasive species in your state for students to research. In most states, the Department of Natural Resources, Department of Fish and Game, or other agency publishes a list of the biggest threats. To start, see the National Invasive Species Information Center and select “Browse by Geography” on the U.S. Department of Agriculture’s invasive species website.
- Decide what material from the Background page to share with students. For example, you might present some of the information in the Explain part of Doing the Activity, or use the suggested Discussion Questions to support a casual conversation on the topic.
- See Additional Resources to find other supports for teaching this activity.
You may use the Key Vocabulary: Invasive Species student page to introduce students to the following vocabulary terms or to review or assess their mastery of these terms. Note that the definitions below are geared for students, while the definitions that “pop up” within the activity text online are geared for the teacher.
|A structure or behavior that helps an organism survive in its environment.
|Suited to certain conditions in the environment.
|A community of living things interacting with their environment.
|An area that provides an organism with enough food, water, shelter, and space to live.
|A species that causes harm when it moves to a new area or habitat.
|A species that occurs naturally in an area or habitat.
|A species living in an area or habitat where it does not naturally live or grow.
|Do better than another species in getting food, space, light, or another resource.
|A group of organisms that are very similar to one another and
PLT Conceptual Framework
- 1.1. Living components of the environment interact in predictable ways with nonliving components, such as air, water, and geologic features.
- 2.2 Altering the environment affects all life forms, including humans, and the interrelationships
that link them.
- 5.3 Ecosystems change over time through patterns of growth and succession. They are also
affected by other phenomena, such as disease, insects, fire, weather, climate, and human
See Standards Connections in the Appendices for a list of standards addressed in this activity.