Invasive or Not?

Lesson Content

• Lesson Plan Template:

  General Lesson Plan

• Learning Objectives: What should students know and be able to do as a result of this lesson?

  
  
  • Explain how introduced species affect ecosystems and biodiversity.
  • Explain how new research or findings can change previously held ideas or assumptions.
  • Cite specific and relevant text evidence to support analysis of the text.
  • Use various vocabulary strategies to define academic and domain-specific words in the text.
  • Construct a written response that clearly identifies a main point(s); contains relevant textual evidence to support the main point, utilizes transitions to maintain flow, effectively uses domain-specific vocabulary, and provides an appropriate conclusion.

   

• Prior Knowledge: What prior knowledge should students have for this lesson?

  
  

  For science:

  • Students should have a general understanding of the effects of invasive species on ecosystems. This Khan Academy website provides background information on invasive species and several examples.
    • If the teacher needs more resources to help students with this topic, the U.S. Department of Agriculture has a thorough website on invasive species.
  • Students should have general knowledge about the Arctic ground squirrel. Students may refer to the Alaska Department of Fish and Game's informational page on this animal.
  • Students may benefit from reading this article from Boston University Research describing this study in more depth. It discusses the genetic analysis done on the squirrel bones and hypothesizes about the origin of the squirrels on Chirikof Island.

  For literacy:

  • Students should have prior experience utilizing various vocabulary strategies to determine the meaning of unknown words in a text. For this lesson, prior experience in using context clues to determine the meaning of words in a text would be beneficial. In addition, students should have some dictionary skills that will enable them to look up words with multiple meanings and determine the most appropriate meaning based on how a word is used in a text.
  • Students should be aware of text features that can help them locate and learn information when reading a text. The text features in the article used in this lesson include: title, subtitle, photograph, and caption.
  • Based on the rubric provided with this lesson, students should be able to respond to a writing prompt in a clear, organized manner that includes use of an introduction to establish the main point(s), a body paragraph(s) that support the main point(s) and includes relevant and specific textual evidence, and a conclusion that supports the main point(s).
  • Students should have some awareness that use of transition words or phrases can help a piece of writing flow smoothly from one point or idea to the next.

   

• Guiding Questions: What are the guiding questions for this lesson?

  
  
  • Why were Arctic ground squirrels supposedly introduced to Chirikof Island in the 1800s?
    • It was believed the Arctic ground squirrel was introduced on Chirikof Island to provide a food source for Arctic foxes being raised for their fur. It had been observed that "barrels" of squirrels were released on the island. As a result, scientists had assumed the Arctic ground squirrel was an invasive species affecting native vegetation and nesting seabirds.
  • What evidence was discovered that changed previously held assumptions about the presence of the ground squirrel onChirikof Island?
    • Archaeologists found squirrel bones in Native American middens, or dump areas.The middens dated back to Native Americans living on the island before they had western contact. The bones were carbon dated and genetically analyzed and showed that squirrels had been present on the island for at least 2000 years, and that the current squirrels were descendants of them.
  • What are the implications of the introduction of an invasive species into an ecosystem?
    • If invasive species become established in a new ecosystem, they are often able to out-compete native organisms for food and space. They have been known to decimate the native organisms or cause severe damage to them. On Chirikof Island, it had long been assumed the Arctic fox, feral cattle, and the Arctic ground squirrel were all invasive species.

   

• Teaching Phase: How will the teacher present the concept or skill to students?

  
  
  1. Begin the lesson by showing students pictures of different plants and animals. These might include the Burmese python, fire ant, and lionfish. Ask students what these images have in common with each other. Some students will know they are invasive species that have caused both economic and environmental problems in many different areas across the United States.
  2. Ask students if they know the biological definition of an invasive species. Read your students the definition of invasive species provided by the U.S. Fish and Wildlife Service: "one that is not native to an ecosystem and which causes, or is likely to cause, economic or environmental harm or harm to human health."
  3. Ask students if they know how invasive species get introduced into native ecosystems. Students might suggest that people release organisms into the ecosystems, that they were released originally as a biological control method, etc.
  4. Explain to them that invasive species are introduced into native ecosystems in a variety of ways, including human release or accidental introduction by people traveling around the world.
  5. Now show the students a picture of the Arctic ground squirrel from Chirikof Island. Inform students even though they seem harmless, the ground squirrels living on Chirikof Island off the coast of Alaska are considered detrimental to the island's ecosystem because they damage local vegetation and wildlife. Explain to students that the squirrels were historically considered an invasive species brought to the island by humans.
  6. Finally, tell students they will be reading an article from Smithsonian.com titled "The Invasive Squirrel that Wasn't" that discusses new findings on the topic.

   

• Guided Practice: What activities or exercises will the students complete with teacher guidance?

  
  

  1. Provide each student with a printed copy of the article "The Invasive Squirrel That Wasn't."

  2. Provide each student with a vocabulary note-taking guide.

  3. Have students complete this guide during or after their first reading of the article. Students can work individually, in pairs, or in small groups. Make sure to provide print or online dictionaries for students to use. Teachers should provide support and guidance as students work.

  • Note: Based on the needs and skills of students, teachers can decrease or increase the number of academic or domain-specific vocabulary students will define on the note-taking guide.

  4. For academic vocabulary, students will likely be able to use a variety of vocabulary strategies to define the meaning of the words. For domain-specific (in other words, subject-specific) vocabulary, students will typically need to draw on prior knowledge, use context clues, and/or use a dictionary to define the words.

  5. Teachers can check students' understanding by collecting their answers to the note-taking guides, checking their work, providing written feedback, and maybe grading the assignment. As another option, teachers can have students share out their responses and the teacher can provide verbal corrective feedback, allowing students to make corrections to their work during the discussion.

  6. Teachers may use the sample answer key provided with the note-taking guide to evaluate student responses.

  Common errors/misconceptions to anticipate and how to respond:

  • Students often think animals are the only invasive species. Invasive species also include plants, fungus, protists, and bacteria.
  • There is much debate about whether or not all invasive species are harmful to the environment. This National Geographic article "Opinion: It's Time to Stop Thinking all Non-Native Species are Evil" may enhance discussion of this topic.

   

• Independent Practice: What activities or exercises will students complete to reinforce the concepts and skills developed in the lesson?

  
  
  • Provide each student with a copy of the text-dependent questions to complete. Students should be reminded to continually go back and refer to the text and to use relevant and specific evidence from the text to support their answers.
  • Teachers can check students' understanding by collecting their answers to the text-dependent questions, checking their work, providing written feedback, and maybe grading the assignment. As another option, teachers can have students share out their responses and the teacher can provide verbal corrective feedback, allowing students to make corrections to their work during the discussion.
  • Teachers may use the sample answer key provided with the text-dependent questions to evaluate student responses.

  Common errors/misconceptions to anticipate and how to respond: Please see the text-dependent questions sample answer key.

   

• Closure: How will the teacher assist students in organizing the knowledge gained in the lesson?

  
  

  For literacy:

  • Before students complete the writing prompt, be sure to review their responses to the other text-dependent questions as a class, including covering the misconceptions and key points described in the sample answer key.
  • After students' written responses have been graded and returned with feedback, teachers might wish to use the provided sample response with the class. The teacher could show the sample response with an LCD projector or a document projector and discuss the following:
    • How the topic is introduced in the opening sentences of the introductory paragraph; have students identify the main point of the article. Facilitate a brainstorming session with students to identify other ways the author could have opened the article.
    • Have students examine each of the body paragraphs and explain how each supports the main points of the article.
    • Have students identify where the author effectively uses textual evidence from the article for support of points made in the article.
    • Have students identify the use of transition words or phrases that make the ideas flow.
    • Ask students to identify where domain-specific vocabulary is used accurately and effectively.
    • Have students read the final paragraph to see how the author wrapped up the article and connected final paragraph back to the main point established in the introduction of the article.
  • Teachers may have students use the rubric to provide a score for the sample written response and have them justify the score they gave, possibly providing revision suggestions for any categories they scored lower than a 4.

  For science:

  • Ask students to explain the implications of an invasive species on an ecosystem's food web in terms that a first grader could understand.
  • Play "So What?" Students answer the following prompts:
    • What takeaways from the lesson will be important to know three years from now?
    • Why will they be important?
    • Why is it important to evaluate new findings in science?

   

• Summative Assessment

  
  

  1. Students will individually respond to the writing prompt. They should be directed to respond with a multi-paragraph response, with a clear introduction, body section, and conclusion. Students will have to refer back to the text as they construct their response. 

  2. Provide students with a copy of the rubric and go over it with them so they will know how their written responses will be assessed.

  3. Go over the writing prompt with students and make sure students understand what the prompt is asking them to address. Encourage students to underline key parts of the prompt as the teacher goes over it so they will remember to answer all the required parts:

  • In the text, this quote implies the team of scientists found evidence in the midden that did not support what they previously believed: "we all thought that squirrels and foxes were a historic introduction... and we found squirrel bones in an ancient midden." How did this new information change scientists' perception of Arctic Ground Squirrels on Chirikof Island?

   

• Formative Assessment

  
  

  Specific suggestions for conducting Formative Assessment can be found in the Guided Practice and Independent Practice phases of the lesson where it says, "How will you check for student understanding?"

   

• Feedback to Students

  
  

  Specific suggestions for conducting Feedback to Students can be found in the Guided Practice and Independent Practice phases of the lesson where it says, "How will you check for student understanding?"