What's for Dinner: Learning about Food Webs
Lesson 12 of 17
Objective: SWBAT understand how food webs are formed to design, illustrate, and describe a food web for a given ecosystem.
Even though my students are older, they still enjoy a good read-aloud. I like to incorporate read-alouds in my class when they are appropriate. The beginning and/or end of a lesson usually provides a good time to do so, as it can be a great way to connect content to literature.
I start this lesson with a read aloud of several poems from the book, What's for Dinner? Quirky Poems from the Animal World, by Katherine Hauth.
After reading the poems, I ask students to reflect on what we have already learned about animals, and to think about what this book may have to do with today's lessons. After giving them about a minute to reflect on their own, students use sticky notes to record their responses, sticking them the whiteboard.
We read through everyone's responses and try to decide, as a class, the focus of today's lesson, based on the read-aloud. I circulate throughout the room, listening to student conversations and select a student who has correctly identified that we will discuss the feeding practices of animals. I ask them to share their ideas, confirming that today's lesson will address who, what, and how animals eat in the wild.
I pass out the Bill Nye Food Web Worksheet* and explain that we are about to watch a video on the topic. Before watching, they should try to answer as many questions as they can. Not only will this help me to gauge students' prior knowledge on the topic, but it will also prepare them for what they will learn. As we watch, it will be each student's job to complete and/or revise their answers based on what they learn from the video.
*Note: At this time, I do not pass out or have them work on the crossword puzzle page. This will serve as a review activity that will be assigned for homework, or as bell work the following day, depending on the schedule and whether or not I feel they need immediate or delayed review.
Once the video is over and students have had 5-10 minutes to complete the worksheet, we go over the questions as a class, making sure all of the information has been captured and understood. As we discuss each question, I call on random students not only to provide the correct answer, but to provide a connection to what we have learned in prior lessons. They can provide just about anything, given it has some relevance and they can explain it clearly. For example, question #2 asks students to define composers and describe what they eat. A student might make a connection to the lesson we completed on niches, and would describe the role of the niche of composers is to help put nutrients back into the soil.
I have students use their computers to access the Food Web simulation, by the Annenburg Foundation. This fascinating simulation challenges students to introduce several types of animals into an environment and identify predator-prey relationships, with the goal of maintaining and balancing each species' population.
There is also a corresponding data form on the site that requires students to record their trials, as well as any modifications made during the activity. As an additional challenge, it prompts students to consider the human impacts on the ecosystem, asking questions such as:
- How does a natural ecosystem offer suggestions toward a more economical and eco-friendly human model?
- How do humans affect the greater food web? In this model, how could humans who do not live in the ecosystem still manage to alter the flow of energy within the web?
While these are very challenging questions that are designed for older students to grapple with on their own, they do provide a great start for a class discussion!
As a final assessment of students' knowledge of food webs, I have them complete the Scholastic Food Web Creator. It is a fairly simple activity that has students connect predators to their prey in order to create a basic food web, and then has them answer questions about how different conditions, such as wildfires, would affect the web.
While it is not extremely challenging, it is a good way to determine whether or not students understand the concept of a food web and how to display relationships between the species who are a part of it. In the next lesson, Whoo Wants Leftovers, students will extend their knowledge of food webs by constructing their own web for an owl, based on the environment in which it resides.